Subsections

Packaging

Modern packaging protects food, increasing shelf live and safety. It also makes distribution possible over long distances. Its closures are made to avoid any undesired alterations after production. This includes safety seals and other devices to show any criminal poisoning of food by blackmailer.
The best packaging is glass because of its chemical stability. Industry tries to change glass by one-way packages made of glass because of price and weight.
Glass is one hundred percent barrier against oxygen. Glass however can break. The small splinters being undetected present a great hazard to consumers. The industry spends great efforts to avoid any fragmentation.
Tin cans are widely used for packaging of pasteurized and sterilized food. They present corrosion with acid medium. Zink, iron and all other metal ions are the increased in food. Many poisoning cases were caused by the use of zinc bowls.
Metal ions were drastically reduces by internal coating the cans with layers of varnish. The wrong varnish can also create a high level of BADGE ( see this topic).
Small cracks of the varnish layer can cause black dots when chicken meat is present. The iron of the can reacts with the sulphur of the protein molecules of the resulting iron sulfide. Quality inspection of the varnish coating is therefore very important.
Packaging made of plastics present new advantages. There are rigid and flexible packages. Flexible packages may present active and barrier properties. This is used for meat packaging. At first the package acts actively to get rid of excessive moisture and works then as a barrier against oxygen.[267]

The war between glass and plastics

The war between glassworks and plastic producers fighting for increasing sales of packaging materials goes on for years. PP and PET is gaining ground because of lighter weight compared with glass and being unbreakable. These however are of minor importance when advantages of glass packagings are cited:
  1. Glass is inert. There is no migration of components of the plastics to the food. There is no danger of intake of plastic components and other chemicals and there are no alterations of taste caused by these substances.
  2. Glass is a perfect barrier to atmospheric oxygen, avoiding rancidness, changes of colour such as brown colour of Ketchup.
Plastics can also bear poisons from herbicides, insecticides and other pesticides when the bottle was wrongly used for these substances.
Reusing bottles which had been used as described before endangers the health of the consumer because of migration of the polycyclic aromatic components.
To detect and discard these bottles a complicated system called "sniffer" is being used detecting volatile compounds of pesticides which might be present in some bottles.
This system covers only a special group of substances. It does not give an ultimative solution to avoid reusing contaminated packagings.
The Fraunhofer-Institut fr Verfahrenstechnik und Verpackung (IVV) in Freising, Germany has developed a test of concerning how inert PET is.
Bringing the material in contact with a sample of four classes of chemicals (alcoholes, ester, ketones, hydrocarbons and halogenated hydrocarbons) and measuring the remigration of residues in a test filling medium PET material can be examined in relation to undesired migration of chemicals in food. As different PET plastics are produced varying from producer to producer the migration from chemicals of the packaging material itself and chemicals of poisonous fillings such as pesticides, cleaning agents,industrial chemicals and organic poisons such as aflatoxins turning the use, the reuse and even the recycling of plastics as food packaging a danger for the consumer.

PET bottles are being used increasingly for soft drinks such as cola and soft drinks, because off flavour caused by migration of plastic chemicals to food is not noticed by the consumer because of the dominance of the product flavoring.

Mineral water with carbon dioxide however shows off flavour immediately. That is why glass bottles are still used for this kind of beverage.

Unfortunately the glass bottle is being changed to PET by Gerolsteiner mineral water producer in Germany .
The PET bottle used by Gerolsteiner has acetaldehyde residues which are below taste level. Acetaldehydes are told to be responsible for apple taste in water.
Karlsberger brewery tries a new PET for its beer which is told to be a barrier against oxygen.
According to Walter Jungbauer from the Bund Natur und Umwelt (BUND) Bonn (Union for Nature and Environment the PET bottle for beer is a compound of PET-therephthalat and Nylon in order avoid changes of taste. This material can very hardly be recycled[417].
The argument of lower weight compared with Glass bottles is insignificant because of the difficult recycling.
Industry wants to force the one way bottles to get rid of recall of packagings. The Coca Cola Company sells water in one-way PET bottles, filled by BEG Badische Erfrischungsgetränke being deposit free.All other soft drinks of Coca Cola are also sold in this way.
In the early times of the use of plastics as packaging material PVC was the most common used plastic.


Multilayer-PET-bottle with EVOH barrier

EVOH barrier plastics are copolymers of ethylene and vinylalcohol and are used as gasbarrier as food packaging in order to avoid oxygen entering the packaging and to avoid modified atmosphere to leave the packaging.
Normally the EVOH film is placed between two layers of PET. This method is used for the production of bottle for beer in order to achieve same properties of glass bottles. In 6 month storage not more then 10% loss of CO$_{2}$ and a maximum of 1 ppm of oxygen are allowed for beer glas bottles. This material is also used as packaging for ketchup and mayonnaise.

\includegraphics[width=350bp,height=150bp,angle=0]{library/PVC.eps}
PVC (Polyvinylchlorid) was banned as food packages because of not entirely polymerized vinylchlorid (VC) which is carcinogenic.
PVC creates although environment problems. Being burned chloridrig acid is formed which is liberated in the atmosphere and turns out to be a part of the acid rain which is a menace to forests.
PVC is being substituted by many other polymerized products such as:
Polyethylen (PE) ,being used also as layers in other packaging materials.
\includegraphics[width=350bp,height=150bp,angle=0]{library/Polyeth.eps}
Heavy density polyethylene (HDPE) which is a higher barrier to oxygen compared to PE,HDPE is used as bottles and tubs for ketchup, mayonnaise and other products with extended self life, polypropylene (PP) which is mainly used for small vessels as packaging for fine salads, margarine and dairy products and buckets such as 10 kg mayonnaise, Ketchup and other products of fast food.
Oriented polypropylene (OPP) used as pouches,polyethylene terephthalate (PET).
Barrier resins such as ethylene vinyl alcohol (EVOH)prevent oxygen from penetrating the package, enhancing flavour, extending shelf life, avoiding rancidness.
Newcomers are metallocenes in polyolefin product which however are very expensive. The metallocene blend is based on a thee-layer coextrusion and offers strong seals at the bottom and sides of the pack with an easy-open top seal. Specially in frozen food reclosable flexible packaging is used.[267]
Flexible pouches for beverages are made of a combination of PET, aluminum and polyethylene.
Schöller ice-cream uses Tritello-Peel Pac in its 1,5 l packaging consisting of a plastic layer covered by carton. To recycle the customer is asked to separate by hand both materials and to discard them properly. Only very few people will follow these instructions.

Finish producers offer a combination of carton and three-layer polymers (High-Barrier-Layer Esobarr). The external carton is to suggest the packaging being entirely made of recycling carton. The consumer believes to help environment. He does not know that that compounds of carton and polymers are almost impossible to recycle. They are burned because a separation of the carton and the polymer layer would be to expensive. The arguments of the producer of the Carton-polymer packaging are a better protection against UV rays, a barrier of gas, flavour and humidity.
As polymers have low weight compared with other packaging materials when used as barrier-layer they represent down to 5% of total weight. This argument however fails to see the problems of recycling. The aim is therefore to find new materials which can be used as barrier-layer on biopolymer basis being recycled in nature[268].
One way packagings such as glass bottles, one way PET bottles and beverage cans made of aluminum or tinplate were in the past used only as outdoor catering.Nowaday they gain increasingly importance.
The recycling of one way packagings and recycling of PET bottles with deposit will soon be a task for the industry to avoid to burn the material because of environment problems.
Recycling is possible as long as there is no mixture of plastic types.
The following products result from recycling:[310]

  1. The resulting product has technical properties which differ from the original product.
    This is called "downcycling" PET bottles for beverages can be downcycled to packagings for non-food
  2. Recycling food packagings material for the production of industrial textile fibers can be produced.
  3. Recycled PET material may be used as internal layer of multilayer bottles
  4. PET material may be used in the steel industry in high temperature ovens instead of heavy oil
  5. Today experiments are made to recycle PET bottles to PET recycling granulate wit identical properties of the original PET using a recondensation step. The bottles obtained with this technology can be used for food.

German regulations concerning recycling of packaging:

Plastic recyclates are classified by the Plastic Commission of the BgVV in Germany as follows:


Other plastics used in nonfood articles

Common used plastics in nonfood are cited here because some of them were in headlines.
Polyurethane PUR:
The typical molecular structure is ...-NH-CO-O-... This group is repeated throughout the whole long molecule.
They are known under the names of Desmopan, Vulkollan, Elastomoll, Moltopren, Porosyn.

Linear polyurethane are thermoplastics. With increasing number of links they turn out to be elastic and later hard.
They are used as soft and hard foam and many other articles. It is on market under Desmopan, Vulkollan, Elastomoll, Moltopren, Porosyn.
Polyurethane fibres are used in textiles under trade marks like Dorlastan, Elasthan (Germany, Lycra (USA).

\includegraphics[width=350bp, height=50bp, angle=0]{library/Polyurethane.eps}

Phenoplaste PF Polycondensation of phenol or cresol with formaldehyde.
\includegraphics[width=350bp, height=150bp, angle=0]{library/Phenoplaste.eps}
It is used in all electrical articles and as glues.
Phenoplastes are on market as Bakelite, Dekorit, Haveg,Pertinax, Trolitan, Trolitax.

Aminoplaste
They are obtained by polycondensation of formaldehyde with melamine.
Important types of aminoplastes are:
Melamine resin MF
Dicyandiamid resin DD
Urea resin UF

Polyester
The typical molecular structure is ...-CO-O-... (ester group). This group is repeated throughout the whole long molecule.
It is being obtained by polycondensation of high alcohols and carboxylic acid.
Using maleic acid or fumaric acid unsaturated polyester resines UP are formed. They are known as Trevira, Diolen (Germany), Dacron (USA).

Epoxy resines EP
Reaction of polyaddition and polycondensation between epoxy (such as Epichloridrine) and a diphenol (such as diphenyl propane) originating an intermediate product which hardens together with phthalic acid anhydride or diethylentriamine as hardening agent

Polymethylmethacrylate PMMA.
It is the product of the polymerization of methacryl acid methylester

It is known as "organic glas" as security glas under the name of Plexiglas and Resartglas.

Polytetrafluorethylene PTFE
Product of polymerization of tetrafluorethene.
It is stable up to 260$^{o}$C, stable against ozone. It is used as gaskets.

Polyvinylacetate PVAC
It is a product of polymerization of vinylacetate and is used in solution as paint.

Products of cellulose
1.- Cellulose acetate CA Esterification of cellulose with acetic acid anhydride in presence of sulphuric acid.

2.- Celluloid CN
It is cellulose dinitrate with camphor as plasticiser.

Chemical fibres

Polyamide fibres PA
It is on market under Perlon(Germany) and Nylon(USA).

Polyacrylnitril fibre PAN
It is a product of polymerization of acrylnitril. Dralon, Dolan (Germany) Orlon (USA)

The Euro glass

On regard to vanishing natural resources it is important to reduce the quantity of plastics as packaging material.
Industry should look to the example of German mineral water producers: They all use the same standard bottle. This could also be done with all kind of food. The glass could have the sizes of 125 , 200 ,250,400 500 and 750 ml. For the size of 100 to 250 ml a 53 twist-off closure and 63 closure for 400 to 750 ml glass should be used.
The refund system should be used and the glasses could be cleaned in central washing factories sterilize and protecting the pallets with shrinkable foil. Food producers could order glasses from the washing factory instead from the glassworks.

The Heinz Ketchup would be found in the same bottle as Kraft Ketchup, the Thomy mayonnaise together with Hellmann mayonnaise and all fine food together with herring, mustard, coffee creamer and marmelade.

A universal glass for all products and brands is a nightmare for a marketing manager but at the same time it is a blessing for the future of his son.
Label and closure gives sufficient ground for the work of art designer to create an individual touch for every product and every brand.
Unfortunately there is a move from glass to plastic as noted by increasing number of packaging of soft drinks and soft drinks as well as traditional products such as Nestlé Coffee Mate, the coffee creamer of UK changing from glass to PET (polyethylene terephthalate) jars with a shrink-sleeve label[297].
Reuse of bottles:
Glass bottles are reused about 45 times. PET bottles are reused about 15 times.

As plastics fail to be recycled it is being burned. Precious materials are so lost. We should try to change to glass packaging.
Recycling of glass in the way which is practiced at the moment loses fossile or atom energy to melt and form glass packaging. The refund and cleaning system of a standard glass packaging would reduce energy needed to reuse glass and jars.
As recycling organizations such as The Green Dot in Germany and Spain fail to reach proper amount of recycling of plastics, government should regulate the Euro glass. This way is better as dissolving the recycling organizations leaving the responsibility in the hand of every producer to recall his own packagings.
Increasing problems with environment and vanishing resources will soon force the producers to think over their marketing strategy. The situation will also force the consumer to accept reduction of amenities which can no longer be maintained. Industry tries to change from glass to plastics because of reduced costs in handling, weight transport costs and costs of cleaning, disinfection for a reuse. Due to regulations concerning recycling of packagings in Germany there is a minimum share of 72% defined. This limit was not achieved in 1998.
It is sure that for 1999 the limit will not be achieved.
According to the regulation there will be a compulsory deposit starting from the year 2000 of 0,50 Dm for beverage packagings from 0,2 liter up to under 1,5 liter and greater packagings starting with 1,5 liter 1,00 Dm.


European regulations concerning packaging recycling

European guideline 94/62/EG from December 1994 regulates the recycling of packagings in the European Community.
According this guideline the government of the Community may regulate recycling of packaging materials in order to promote reuse of bottles but they are not allowed to create trade hindrances. Not recyclable packagings are therefore protected by this regulation.
The guideline also defines a rate of 50 to 60% of use of packaging material in any form whatsoever including heat recycling and 25 to 45% recycling the material getting new products.
These scores are ridiculous low and shows that the governments should force the introduction of standard packagings like the Euro glass.

Types of plastic packaging

The type of Packaging can interfere in the growth of bacteria[362].

Gas permeable packaging:

Aerobic bacteria can grow. Fresh meat packed in cellulose film so as used in tray packaging is threatened by Pseudomonads like Pseudomonas fluorescens and Pseudomonas fragi as dominant bacteria producing smell and slime.

Gas barrier, closed packaging:

The atmosphere in the packaging can be modified according to the food which is being packed.
Enzymes, temperature and competitive growth can produce gas like CO$_{2}$.
For some food gas packaging with modified atmosphere are used.

Vacuum packaging:

Vacuum inhibits the growth of aerobic microbes such as Pseudomonas,Bacillus, moulds. In these packagings the growth of lactobacillus is dominant. Enterobacteriaceae can grow under anaerobic conditions.

Modified Atmosphere Packaging MAP:

Nitrogen, CO$_{2}$ and in some cases O$_{2}$ are used.
Nitrogen has no activity against bacteria. It increases shelf life substuting oxygen.
CO$_{2}$ acts bacteriostatic on gram negative aerobic bacteria and bactericide because of its undissociated part of H$_{2}$CO$_{3}$ which enables CO$_{2}$ to trespass the cell membrane and act bactericide on the cells of the bacteria.
Lactobacillus is not affected by CO$_{2}$.
CO$_{2}$ can reduce growth of Listeria on meat.

Polymer used as Filling product
PVdC,EVOH,Acrylnitril Oxygen barrier  
PET/PVdc-PVC/PE multilayer foil red meat
HDPE, PVdC,PP water vapor barrier  
PA/PE-PVC/PE multilayer foil treated meat
HDPE,PP stability,suitable  
  for microwave oven  
     
PET/PVdC/PE multilayer foil poultry
Nylon high temperatures  
  resistant  
     
PET/PE/PVdC-PVC/PE multilayer foil fresh fish
CPET mechanical resistance,  
  high temperatures  
  resistant, oxygen barrier  
     
PET/PVdC/PE multilayer foil Pizza
APET mechanical resistance,  
  oxygen barrier  
     
PET/PE/PCdC multilayer foil Cheese
Polyester high temperatures  
  resistant, flexibility  
  and resistant to perforation  
     
Metallized PET/PE-metallized PA/PE multilayer foil dried products,coffee
PVC/PET mechanical stability,  
  some types  
Micropore foil-LDPE/OPP/PVCPA/PE multilayer foil fresh vegetables
     
LDPE, HDPE, EVA sealing layer  
EVA highly permeable to  
  oxygen and CO$_{2}$  



Abbreviation material
ABS Acrylbitril-Butadien-Styrol Copolymer
APET amorphous polyester
CPET crystalline polyethylenterephthalat
ECTFE Ethylen-Chlortriefluorethylen Copolymer
ETFE Ethylen-Tetrafluorethylen-copolymer
EVA ethylen-vinylacetat
EVOH ethylenvinylalcohol
FEP Tetrafluorethylen-Hexafluorpropylen
HDPE highdensity polyethylen
LDPE lowdensity polyethylen
OPP streched polypropylen
PA Polyamid (Nylon)
PC Polycarbonat
PET Polyethylenterephthalat
PE Polyethylen
l PFA Perfluor-Alkoxylalkan
PMMA Polymethyl-Methacrylat
PMP Polymethylpentene
PS Polystyrol
POM Polyoxymethylen
PP Polypropylen
PPO modified polyphenylenoxid
PTFE Poly-Tetrafluor-Ethylen
PVC Polyvinylchlorid
PVdC polyvinilidencloride
SAN Styrol-Acrylnitril-Copolymer


Multilayer foils may have PE, PVdC and PET as typical components.

Packaging as short news:[417]


Nonylphenol in food

[1375] Nonylphenol is an industrial chemical which interacts with human hormones and produces cancer. Its synonyms are p-nonylphenol,4-nonylphenol, C$_{15}$H$_{24}$O. Nonyphenoles were found in mineral waters due to migration from the plastic seal of the caps of bottles.
Another source of nonylphenol in food arethe nonylphenolethoxylate which are used in the production of plastics for wrappings and packagings of food. Nonylphenolethoxylate act as emulsifier and stabilizer in plasticizers for Packagings. Nonyphenoles are breakdown products of norylphenolethoxylate detergents usedin household and industrial cleaning products.which contaminate food. Their contact with foods leads to the contamination with nonyphenoles.
Very high amount of nonylphenoles were found in apples and in tomatoes by the Research Center in Julich.
The estimated human intake of nonylphenoles is 7.5 microgram a day. The content of nonylphenole in pesticides are now being analyzed.

Isopropilthioxantone (ITX) in baby milk:

Baby milk in Tetrapack was found in October 2005 as being contaminated with traces of Isopropilthioxantone. This chemical is being used for carton printing leaking from the carton to any fatty products like milk when it is exposed to sunlight's ultraviolet rays. Researches indicate that the migration of ITX has no known health effects. According to Tetra Pax ITX is not prohibited for use in food packaging by the EU. However EU packaging rules, as amended in 2003, require that food contact materials do not migrate into products meant for human consumption.
EU regulations: ITX is being used as curing process during ultraviolet printing processes when using UV inks. This process is also being used for packaging for water, juices, ice teas. No migration was occurring for most of those beverages, except in the case of some citrus juices such as orange and lemon, and milk. Clear juices such apple, grape and cranberry do not seem to be affected.

The European Food Safety Authority (EFSA) will undertake a risk assessment of the chemical. Health concerns about packaging chemicals, such as phthalates, have raised consumer awareness of about the risks posed by materials that may come into contact with food.

Constituents of printing inks in beverages from cartons

[1376] [1377]
According to the German BfR the occurrence of a chemical in a food does not in itself constitute a risk to health. It is the harmfulness of the substance and the degree to which the consumer comes into contact with the substance that determines the scale of possible damage and the probability that it will occur. Residues of printing inksin foods may, therefore, be safe but they may equally constitute a serious risk to health.

Talks between the Plastics Committee and representatives of the printing ink industry at BfR revealed that no technology is currently available to prevent the migration of substances from printing inks to food through a set-off effect or because of penetration of the packaging material. Nor is this situation likely to change in the short term.

Given the lack of data, a health assessment is frequently not possible at the present time. As the manufacturers bear responsibility for the safety of their products, they should do everything in their power to prevent the migration of substances of this kind to foods and put together the data needed for a health assessment.

The printing inks may contain the photo initiator isopropyl thioxanthone (ITX). Public agencies in Italy and Germany have detected residues of ITX in foods from cartons. Cartons for beverages like milk, cocoa or juice are often printed in different colours and have benn found to contain the ITX compound. Also olive oil has been found to be contaminated with ITX.

ITX is contained in UV-hardening printing inks. The cardboard used to make the packaging may be transported on rollers to the food filling plant and then moulded on site into the corresponding packaging. Constituents of the printing inks applied to the outer packaging material can, by means of spread (set-off), reach the inside that comes into contact with food.

Furthermore, there may be migration through the packaging material in the case of pre-moulded packaging unless effective barrier layers, e.g. aluminium foils, have been applied. BfR has examined the available toxicological data for the chemical isopropyl thioxanthone (ITX).

In line with the assessment scheme of the European Food Safety Authority and customary assessment practice at BfR and regarding substances used in the production of food commodities, the available data on the exclusion of genotoxicity are only sufficient to evaluate substances with a maximum migration level of 50 microgram/kg food. As, however, the ITX measurements in Germany revealed far higher levels, additional data would be needed for toxicological assessment. BfR does not have the necessary data on toxic effects, bioavailability or toxicokinetics of the substance.

Actions:
A larger manufacturer of beverage cartons has informed BfR that it switched to a new printing method for infant and baby food on30 September 2005. It no longer uses any UVhardening printing inks in orderto prevent migration of ITX from the package to the food for milk and fatty products.

The phenomenon of the migration of constituents from printing inks used on the outer packaging to foods as a consequence of both penetration of the packaging material and set-off to the inner packaging is a fundamental issue. Set-off cannot, in principle, be ruled out for any packaging material processed on rollers or in stacks. Besides the data on ITX, BfR is also aware of migration findings from packaging to food for other photo initiators used in printing inks like 2-ethylhexyl-4-dimethyl aminobenzoate and 4,4'-bis(diethylamino)-benzophenone and 4,4'-bis(dimethylamino)-benzophenone. BfR is, therefore, of the opinion that there is an urgent need to lay down requirements for the use of printing inks for food commodities on the European level.

Germany wants to phase out di-isobutylphthalate (BiBP) in food-contact paper and board

[1378]
According to the Federal Institute for Risk Assessment (BfR) concentrations of up to 5 milligram per kilogram of the chemical di-isobutylphthalate (DiBP) have been found in food such as fat-containing, powder and fine grain foods like rice, baking mixtures or breadcrumbs packaged in cartons.

In animal experiments DiBP was found to be reprotoxic and embryotoxic. It is used as a plasticiser in dispersion glues for paper and packaging and when they are recycled DiBP can be found in paper and board packaging. The BfR and the Federal Environmental Agency (UBA) advocates a voluntary undertaking by the manufacturers and processors of paper and board to no longer use DiBP-containing glues or printing inks to reduce the DiBP content in recycled paper.

The data from long-term toxicity studies are not available therefore BfR recommends a specific restriction on the migration of DiBP to foods, a so-called specific migration guidance value, of 1 milligram DiBP per kilogram food. For baby and infant formula this value should be 0.5 milligram. This was based on the Health assessment made by the European Food Safety Authority (EFSA) on di-n-butylphthalate (DnBP) which has a similar structure and effect.

DiBP is being proposed to be classified as reprotoxic substance and to be included in Annex I of the Dangerous Substances Directive 67/548/EEC) [1379]


Phthalates in medical devices

[1380]
Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer used in medical products made with polyvinyl chloride (PVC) plastic and may be toxic to humans. DEHP is lipophilic and binds noncovalently to PVC, allowing it to leach from these products. Medical devices containing DEHP are used extensively in neonatal intensive care units.

Previous research has shown that newborns treated at neonatal intensive care units may receive doses of DEHP at 2-3 times the average daily adult exposure.

Studies have linked di(2-ethylhexyl) phthalate (DEHP) with reproductive and developmental toxicity, and have demonstrated an especially pronounced effect on testicular development when administered postnatally.

The study classified low-DEHP exposure group including infants receiving primarily bottle and/or gavage feedings; the medium exposure group included infants receiving enteral feedings, intravenous hyperalimentation, and/or nasal continuous positive airway pressure; and the high exposure group included infants receiving umbilical vessel catheterization, endotracheal intubation, intravenous hyperalimentation, and indwelling gavage tube.

Ronald Green and colleagues conclude that intensive use of DEHP-containing medical devices in intensive care units results in higher exposure to DEHP as reflected by elevated urinary levels of MEHP in these infants. The use of phthalates should be reduced, if possible completely eliminated from products which come in contact with food, as well as in medical devices or other applications which come in contact with humans.
[317]
Product Modified atmosphere Remarks
Red meat 80% O$_{2}$ + 20% CO$_{2}$ CO$_{2}$ reduces growth of Pseudomonas
    aerobic bacteria which often
    spoils red meat.High concentration
    of oxygen is needed to keep red colour.
     
Porc 60% O$_{2}$ + 40% CO$_{2}$ CO$_{2}$ reduces growth of aerobic bacteria
    less O$_{2}$ is needed because of reduced red
    colour of porc compared with beef
     
Poultry 50 - 80%CO$_{2}$ + 20 - 50% N$_{2}$ A high headspace with gas is important
     
Sausages 20% CO$_{2}$ + 80% N$_{2}$  
     
Sliced heated meat 20% CO$_{2}$ + 80% N$_{2}$  
     
Fish, high-fat 60 - 70% CO$_{2}$ + 30 - 40% N$_{2}$ No oxygen should be used
    to reduce rancidity
     
Fish, low-fat 30 - 40% O$_{2}$ + 30 - 70% CO$_{2}$ Oxygen is used to keep red
  + 0 - 40% N$_{2}$ colour of low-fat fish and seafood
    It also reduces growth of anaerobic
    bacteria such as Clostridium
    and its toxins
    in case of long shelf life
     
Sliced fish,cooked 20% CO$_{2}$ + 80% N$_{2}$  
Hard Cheese 80 - 100% CO$_{2}$ + 0 - 20% N$_{2}$  
Sliced hard cheese 80 - 90% CO$_{2}$ + 10 - 20% N$_{2}$  
Soft cheese 20 - 40% CO$_{2}$ + 60 - 80% N$_{2}$  
     
Gateau 50 - 70% CO$_{2}$ + 30 - 50% N$_{2}$ Storage at +4 - +7$_{o}C$
Cake and bread 20 - 40% CO$_{2}$ + 60 - 80% N$_{2}$  
     
Pizza 30 - 60% CO$_{2}$ + 40 - 70% N$_{2}$  
Pommes frites 70 - 80% CO$_{2}$ + 20 - 30% N$_{2}$  
Salads with dressings 100% N$_{2}$  



Some special remarks concerning CA packaging (Controlled Atmosphere packaging

Spoilage of food can be caused by:
  1. The nature of bacteria and their amount.
    Bacteria can be aerobic, growing in presence of oxygen such as Pseudomonas, Acinetobacter and moraxella.Or they are anaerobic, growing in absence of oxygen such as Clostridium producing toxins and Lactobacillus producing lactic acid.
  2. Water activity a$_{w}$
  3. pH
  4. Cell breathing
  5. Composition of the food
  6. Storage temperature.
    Low temperatures reduces bacteria growth.
    Some bacteria grow even under low temperatures, the psycrophilic like Pseudomonas
  7. Hygiene during production
    Bacteria can be present in the raw material,additives and environment, such as our skin,used utensils and air.
  8. Gasatmosphere
    oxygen can cause rancidity, oxidizes vitamins, Nitrogen can replace oxygen.
    Oxygen is sometimes necessary to keep the red colour of fresh meat.
    The choice of the gas to be used during filling is therefore very important and varies from one food to another.
  9. Good Manufacturing Practice

CO$_{2}$ reacts with water forming carbonic acid which increases acidity of the product reducing bacteria growth.Nitrogen can replace CO$_{2}$
In Products such as cottage cheeseand dairy cream CA packaging with nitrogen instead of oxygen is being used. Hard cheese is packed under up to 100% CO$_{2}$ to reduce bacterial activity and stabilizes consistency of the product. Soft cheese is packed under 20 - 40% CO$_{2}$ because otherwise the packaging would shrink because the gas gets in solution with the product.In this case 30% of of CO$_{2}$ should not be exceeded.

Carbon monoxide treated meat

[318]
Different attempts have been undertaken to slow down oxidation and its effects on rancidity and browning of meat like the use of rosemary extract as ingredient, or adding the extract to the polypropylene film used to package freshly cut meat, and the use of carbon monoxide modified atmosphere packaging.
Factors which influence the colour of meat are temperature, relative humidity, oxygen partial pressure, light, and lipid oxidation.

Rosemary extract: Such natural extracts allows meat packagers to use high-oxygen atmospheres in sealed packages to maintain freshness without having to worry about browning.

Carbon monoxide modified atmosphere packaging: Meat and meat products kept under low-oxygen atmospheres with carbon monoxide look fresh for much longer time than any other artefact. The gas reacts with the meat pigment myoglobin to create carboxymyoglobin which has a pink colour.

FDA and carbon monoxide in modified atmosphere packaging
FDA had allowed carbon monoxide use as generally recognized as safe (GRAS) in meat und tuna packagings to keep it looking fresh. The GRAS regulatory category allows producers to use an additive or a procedure without public review or formal agency approval.

A petition, filed by Kalsec(R), Inc. of Kalamazoo, Michigan, in 2005, urged the FDA to withdraw its July 2004 decision and related decisions to allow the presence of carbon monoxide in meat packaging. http://www.co-meat.com/release.html and http://www.fda.gov/ohrms/dockets/dockets/05p0459/05p-0459-cp00001-toc.htm

Consumer groups such as leaded by Donna Rosenbaum of Safe Tables Our Priority, an advocacy group in Burlington, and the Consumer Federation of America wrote to the FDA in support of a ban. The groups argue that carbon monoxide may mask visual evidence of spoilage resulted from storage temperature variations. They challenge the Food and Drug Administration for allowing the practice without a formal evaluation of its impact on consumer safety.

As an alternative to a ban, consumer call for carbon-monoxide-treated meat labelling so they can decide on what they are buying.

Industry representatives say that the use of carbon monoxide is safe because other signs like odour, slime formation and a bulging package are indicators of spoilage.

The consumer groups allegate that FDA regulations under the Food, Drug and Cosmetic Act (FDCA) expressly prohibit the use of carbon monoxide in "fresh meat products", the FDA did not have legal authority to permit the use of carbon monoxide because it is an unapproved and prohibited color additive. Regulations of the U.S. Department of Agriculture's Food Safety and Inspection Service (FSIS) prohibit the introduction of ingredients in fresh meat that function to conceal damage or inferiority, or give the appearance the product is of better or greater value.[319]

European Union ban of carbon monoxide as colour stabilizer
The European Union has banned the use of carbon monoxide as a colour stabilizer in meat and fish. A December 2001 report from the European Commission's Scientific Committee on Food concluded that the presence of CO may mask visual evidence of spoilage should the meat become inadvertently warmer at some point

Modified atmosphere packaging (MAP) gases are classed as food additives under two Acts, the Directive of food additives (89/107/EEC) and the Directive of the use of food additives other than colours or sweeteners (95/2/EC). In June 2003, The European Parliament Environment Committee voted to outlaw carbon monoxide as a food additive, and thus as a MAP gas, because it could mislead the consumer as to the freshness of the meat by maintaining the red colour of the product
Japan, Canada and Singapore also ban the use of carbon monoxide in tuna.
Preservation methods: There is a growing demand for minimal processed foods without synthetic chemical preservatives. Preservation methods are being developed using high pressure systems, asseptic filling, ohmic heating, pulsed electric field, irradiation and bright light technologies.

Bioplastics

[320]
Plastics are made from ethylene, propylene, styrol, polyester such as polycaprolacton, Polyesteramide and polyesteruretane aall coming from petroleum.

Widely used plastics are: In 10 years the world demand for plastics doubled, summing 224 million tons in the year 2004. Europe consumed one fourth of the world output, whereas Germany accounted for 17,5 million tons/year, which is 8% of the world production, more than half of it, 9 million tons, were used as packaging.

In an effort to counter further growth of petrol packaging, bioplastics are being developed using renewable raw materials like starch, cellulose, sugar gelatine, chitin, polyhydroxicarbon acid ester and polyamin acid won by biotechnology technology. Their price is, however, up to four times higher as petrol originated plastics. The world production of bioplastics in 2004 summed only 250.000 tons

Other raw materials which are used to form bioplastics are
Some bioplastic articles are foamed duroplastic from starch as trays for vegetables and other foods and bottles from PLA for mineral water.

Biodegradable Packaging

The use of starch as packaging material: [327]
Different projects are running to improve water resistance of starch and starch plasticizers for the preparation of thermoplastic starch (TPS) for use in structural packaging materials for consumer products. Despite all efforts, application of TPS is still limited by its low mechanical and water resistance. Corn starch and cassava bagasse which is a by-product from cassava starch production are renewable sources for thermoplastics. [321]

Synthetic biodegradable polyesters fall into two broad categories. One is highly amorphous, imparting flexibility and clarity comparable to a conventional LDPE copolymer. A second group of semicrystalline polyesters is more rigid, with properties similar to PET, PP, or PS. [322]

Starch is an abundant, inexpensive, renewable, and fully biodegradable natural raw material. However, the hydrophilic character of starch leads to poor adhesion with the hydrophobic polymer in starch-polymer blends. In spite of its relative weakness and a about 60$^{0}$C melting point that is too low for many applications, polycaprolactone (PCL) has recently received much attention due to its flexibility and biodegradability. Additionally, similar to other aliphatic polyesters, such as polylactide (PLA) , polyglycolide (PGA), PCL and their copolymers. PCL is, however, more expensive. Hence a blend of PCL with the cheaper material starch, with a reactive functional group grafted onto PCL to improve adhesion and dispersion of the two immiscible phases, would appear to offer the best of both worlds.

Blends of regenerated cellulose and polyeteruretane are also being developed. Cellulose is built of polymerised glucose units. Thermoplasticity and biologic degradation are related to degree of derivatization (the number of hydroxil groups OH of each glucose unit which have been substituted) Every glucose unit has three OH group The average substitution degree AS value [German DS ) can vary from 0 to 3.
Derivates with AS 2.5 up to 3.0 are thermoplastic and can be extruded with available equipment. However only derivates with AS number below 1.5 are biodegradable. To overcome this problem derivates with low AS numbers and long side chain with low AS number are being tested, such as cellulosepolyhydroxihexan acid ester. [323]
Polylactic acid (PLA) may become an alternative to PET, HIPS, PVC, and cellulosics in some high-clarity packaging roles. It is synthesized from processed hybrid corn rich in amylose. Cargill has signed a joint venture partnership with Japan-based Teijin Limited to manufacture and market polylactic acid (PLA) under NatureWorks in 2007.

Recently an acrylic acid grafted polycaprolactone and starch composite (PCL-g-AA/starch) was considered to present best results for packaging material. [324][325]

Improved functionality of bioplastics and their growing market lead to more interest. Moreover, the risks created by imports and increasing costs for fossil raw materials play as much a role as climate change, whose negative effects are becoming increasingly pronounced. In consequence the plastics industry is putting more and more emphasis on the use of renewable raw materials. [326]

Calcium carbonate and binding agent as packaging The packaging material, called Calymer from Ecolean , consists of 40% calcium carbonate and polymers, which simply act as the binding agent. This material is flexible and tough with exceptional environmental properties.

Incineration transforms the binding agent of packaging waste the into water vapour and carbon dioxide and the calcium carbonate is returned to nature.

Polylactic acid (PLA) biodegradable packaging [328]
Polylactic acid (PLA), a material made from corn that can be used for food packaging under the brand Biophan.

The switch to biodegradable packaging is being driven by environmentally-conscious consumers the price of oil and recycling regulations.

Polylactic acid can be transformed within 45 days in CO$_{2}$ in a composting plant. The German Packaging Ordinance, giving preferential treatment up to 2012 to biologically degradable packaging supports this packaging material.

Innovations on the field of biodegradable plastics Amcor, together with Plantic Technologies develop a biodegradable, flexible plastic packaging for confectionery.

NatureWorks, a Cargill daughter released a polymer of corn starch, the polylactic acid (PLA) .

Danisco has produced a biodegradable plasticiser from hardened castor oil and acetic acid.

Stanelco markets a natural, biodegradable food packaging based on starch, called Starpol 2000.

BASF will launch Ecovio plastic, a biodegradable plastic made up of 45 per cent PLA from NatureWorks together with biodegradable plastic Ecoflex, which is derived from petrochemicals.

Companies which have been using PLA plastics as packaging for foods like organic milk in US is Naturally Iowa. Retailers like Delhaize in Belgium and Auchan in France have also been testing PLA for various food packaging.

Other edible films [329]
Films forming solutions composed of Amaranth (Amaranthus cruentus) flour (4.0 g/100 mL), stearic acid (5-15 g/100 g of flour), and glycerol (25-35 g/100 g of flour) were prepared by an emulsification process. The films produced under these conditions exhibited superior mechanical properties (2.5 N puncture force, 2.6 MPa tensile strength, and 148% elongation at break) in comparison to those of other protein and polysaccharide composite films,

Degradable plastics

[330]
Low density polyethylene (LDPE) film widely used in agriculture for mulching crops could become substituted by degradable plastics which do not need to be removed from field at the end of the season.

Plastics derived from petrochemicals degrade very slowly. Degradables plastics degraded rapidly by photodegradation and/or biodegradation.

Degradable plastics made from starch-based polymers are

Photodegradable Polymers
The breakdown of photodegradable plastics depends on irregularities in the polymers and photosensitive substances, called promoters, such as carbonyl groups and metal complexes, Their chemical composition varies:
  1. Carbonyl Group: Ketone Carbonyl Copolymers
    A carbonyl group, vinyl ketone comonomer, is added to the polymers of plastics such as polyethylene (PE) and polystyrene (PS). the finaldegradation requires the material to be consumed by microorganisms. This material is ideal for mulch film and products that usually end up as litter.
  2. Carbonyl Group: Carbon Monoxide Copolymers
    It is not known whether carbon monoxide products completely degrade into non-plastic products or whether they simply disintegrate into smaller pieces of plastic.Carbon monoxide copolymers.
  3. Metal Complexes
    Plastics containing metal break down in the absence of light receive enough UV light before burial they can be used in landfills and tree shelters. heavy toxic metal residues such as nickel, cobalt, and iron remain in the soil after degradation.
Biodegradable Polymers
Biodegradable plastics are polyesters, polyhydroxybutyrates, and vinyl polymers. They are degraded by microorganisms such as bacteria, fungi, and algae. Some biodegradable plastics are:

Starch-Based Polymers:
They are the most commonly used and lowest-costing ingredient of all biodegradable polymers. The starch can be derived from corn, potatoes, and rice. According the to manufacture methods there are:
  1. Surface-Modified Starch Additive·Starch is treated with a small amount of an unsaturated fat or a fatty acid oxidizing agent, such as vegetable oil.
  2. Gelatinized Starch Additive: Gelatinized starch is used in films of polyethylene coacrylic acid (EAA) and in a mixture of EAA and low density polyethylene.
  3. Thermoplastic Starch Materials: They contain 70-100 percent starch as the base for the polymer. They have great water-solubility are very easily consumed by microorganisms.They are indicated for mulch films, bags for animal feed and fertilizer, and products that will end up in water.
Other degradable plastics are:
  1. Polyesters: Polyglycolic acid (PGA): Used as a controlled drug release and as material used in cirurgy.
  2. Polylactic acid (PLA): Produced from fermenting crops and dairy products PLA is used as packaging and paper coatings, sustained release systems for pesticides and fertilizers, mulch films, and compost bags.
  3. Polycaprolactose (PCL): Its use in agriculture are as mulch, seedling containers and slow release of herbicides to control aquatic weeds.
  4. Polyhydroxybutyrate (PHB): It is produced by microorganism. It has poor resistance to solvents. Its uses are unknown.
  5. Polyhydroxyvalerate (PHBV): Its use is limited to medicine and pharmacy because of high production cost, films and paper coating.
Vinyl:
Polyvinylalcohol: Used in packaging and bagging applications. It is water soluble.
Polyvilylacetate: Uses are unknown. It is watersoluble.
Polyenlketone: Water soluble with unknown uses.

Polyhydroxyalkanoates [331]
Polyhydroxyalkanoates or PHAs are linear polyesters produced in nature by bacterial fermentation of sugar or lipids. More than 100 different monomers can be combined within this family to give materials with extremely different properties.

They can be either thermoplastic or elastomeric materials, with melting points ranging from 40 to 180$^{0}$C. The most common type of PHA is PHB (poly-beta-hydroxybutyrate). PHB has properties similar to those of PP, however it is stiffer and more brittle.

To produce PHB a culture of a micro-organism such as Alcaligenes eutrophus is placed in a suitable medium and fed appropriate nutrients so that it multiplies rapidly. Once the population has reached a substancial level, the 'diet' is changed to force the micro-organism to create PHB. Harvested amounts of PHB from the organism can be anywhere from 30% to 80% of the organisms dry weight.

A PHB copolymer called PHBV (polyhydroxybutyrate-valerate) is less stiff and tougher, and it is used as packaging material.

Antimony in PET water bottles [332]
Antimony trioxide is used as a catalyst in the manufacture of PET (polyethylene terephthalate), plastic bottles. Prof. William Shotyk, Dr. Michael Krachlerand and co-workers at the Institute of Environmental Geochemistry, University of Heidelberg found antimony to be leaching to the bottled drinking water. The antimony content of PET bottled waters increased in proportion to its storage time.

According to Shotyk and Krachlerand pristine groundwater was found to contain only two parts per trillion of Sb, with the PET bottled waters typically showing values a few hundred times greater. This is because PET material contains several hundred mg/kg of the metal whereas rocks and surface soils contain less than 1mg/kg antimony.

Japanese alternatives to antimony: An alternative to antimony as catalyst is insoluble titanium which is used in for PET bottles made in Japan.

Recommendations to the consumer: Polypropylene bottles are manufactured without antimony trioxide. Glass bottles do not leach antimony. Consumer should therefore buy water filled in glass or PPE (polypropylene) bottles.

Tin coating and bisphenol [333] Most foods contain very low concentrations of tin. Canned foods may contain higher levels because the tin coating used to protect the steel body of the can from corrosion can slowly transfer into the food.

Tin leaching present no health effect on the consumer apart stomach upsets such as nausea, vomiting, diarrhoea, abdominal cramps and bloating in some sensitive people at levels above 200 milligrams per kilogram. This is the maximum legal amount of tin that can be present in canned foods.

Limits for tin for particular categories of cans are:
Lacquered cans are used for acidic foods. This avoids tin corrosion but leads to bisphenol-A leaking. This substance is an endocrine disrupter which interacts with hormone systems, such as the female oestrogens and male androgens. No evidence of a link between harmful effects on human reproductive health and exposure to endocrine disrupters have been reported so far.

Polycarbonate bottles release bisphenol A (BPA) to water and other beverages

[334]
Bisphenol A is an endocrine disruptor that affect reproduction and brain development in animal studies. The effect on humans is not clear yet. It is being widely used as a monomer for the production of polycarbonate and epoxy resins for food and beverages plastic packaging and the resin linings of food cans.

Belcher and colleagues found in 2008 that exposure to BPA occurs mainly by consumption of contaminated foods and beverages that have contacted epoxy resins or polycarbonate plastics.

According to the authors high temperatures increases the migration of BPA to food and beverages. The authors found no difference between new and used bottles. The temperature was found to influence drastically the release of the chemical. In polycarbonate water bottles, which had not been previously submitted to heat, BPA was found to migrate at rates ranging from 0.20 ng/h to 0.79 ng/h. After a brief exposure to boiling water, rates increased to 8 to 32 nanograms per hour.

The authors concluded that BPA migration from polycarbonate drinking bottles should be included in the total Endocrine Disrupting Chemical-burden "EDC-burden". Industrial hot bottling of juices and other beverages, widely used to increase self-life may boost the release of harmful BPA.

Permeation of atmospheric oxygen through PET bottle [335]
Despite problems of materials leaching from PET (polyethylene terephthalate) bottles, they are still predicted to dominate drinks packaging markets. Growing beverage market leads to an increase of PET bottles on market. Atmospheric oxygen permeability is a problem to producers reducing self-life. Looking for test procedures for the determination of the stability and/or durability of beverages in plastic packaging. WILD developed a test procedure which simulates reality of a typical several month storage on the product quality within less than three weeks, the test being suitable for al kinds of passive barrier packaging.

Latex proteins from contact materials and food allergies

Latex proteins are used in packaging material transferred to food in some cases, according to the study by Leatherhead Food International working for FSA.

There are four major latex allergens: Hev b5 and Hev b6.02 , Hev b1 and Hev b5. No safe level oif latex are defined, but it seems that small traces can trigger an allergic reaction. Labelling of the latex content in packaging material is being proposed by some groups.

It wasn't clear from the research that allergens were being transferred from latex packaging to food. More work is required to accurately measure the levels of latex in food and the FSA is doing researche work on the matter. [336]

Latex assessment 2005 [336]
UK FSA released a report on 19 January 2005 on the assessment of latex protein transfer from contact materials into food and drink products. According to the Agency the study indicated the presence of one or more of the latex allergens in 7 out of 21 commercial packaging materials (e.g. chocolate bar and ice cream wrappers).
Low levels of latex allergens (Hev b3 or Hev b5) were found in 3 of the 7 foods tested.

This research has shown that latex allergens may be present in some food packaging materials and that there is the possibility of transfer from the material to the food. A modified ELISA method has been developed to detect and quantify latex allergens in packaging and foods. Further work is required to improve this method to make it a fully validated, quantitative, robust analytical technique. Latex allergen transfer has serious implications for some individuals.

FSA latex project 2006 [337]
Another research project of April 2006 will build on previous Agency-funded work (A03043) through development of an improved, validated enzyme linked immunosorbant assay (ELISA) that is robust and reliable. This assay will be used to determine the presence of latex allergens in food contact materials and associated foods.

Project A03043 included a review on the type and extent of latex protein containing material used industrially. Additionally, it was demonstrated that latex allergens were present and detectable in food packaging materials. When the method was applied to food matrices, overall recovery for allergens Hev b5 and Hev b6.02 was reasonable (at 68±28% and 89±18% respectively).

However, Hev b1 and Hev b3 proved difficult to extract from food matrices and measurement of these allergens in food could only be considered as semi-quantitative at best. Overall, the results indicated that further technical work was required to develop reliable and robust validated ELISAs for the quantitative recovery of latex allergens, especially Hev b1 and Hev b3. The most relevant matrices were identified as confectionery, dairy and pastry products.

The modified ELISA protocol will be re-established in the laboratory and used to measure allergen levels in representative batches of cold seal adhesive and bakery release films. The project will try to increasing the recovery of Hev b1 and Hev b3 from selected confectionery, dairy and pastry products. Validation of the new extraction and ELISA protocol will follow.

UK and Packaging waste reduction

[338] The Guide to Evolving Packaging Design published by Waste and Resources Action Programme (Wrap) is focused on retailers and manufacturers. Important companies have signed commitment to cut down on packaging going to landfill. [339]

Retailers can push their suppliers to reduce the amount of material used or moving to more recyclable, reusable and biodegradable materials.

New annual targets set by UK regulations increase manufacturers' obligations to the market to recover and recycle their packaging under international and European pressure on the UK to decrease carbon emissions.

Reducing the weight of beer bottles spares glass and transport costs. Other companies changed from glass to plastic bottles and succeeded to set it on market.

Experts should bear in mind that migration of pasticizers and other unwanted chemicals takes place from the plastic bottle to the food, which is not present when glass is used. The oxygen barrier is not as perfect as the 100% barrier of glass bottles.

Another idea was to use different containers for similar products simplifying processes.

Packaging Recovery Notes (PRNs)

[338] The regulations allow accredited waste reprocessing companies to sell Packaging Waste Recovery Notes (PRNs) for every tonne of packaging waste they recycle. Companies with 2m pounds sterling turnover or handling in excess of 50 tonnes of packaging a year meet their obligation, assessed under the scheme, by buying PRNs.

The profits are reinvested in the recycling infrastructure. This resembles the European Green Dot, where all packaging pay fees for the recycling. This system is not compulsory in UK. [340]

Estrogenic effects of food wrap packaging

[341] Estrogenicity of xenoestrogens found in food wrap packaging and phytoestrogen flavonoids. Uterotrophic and vaginal cornification assays were studied on rats by Stroheker and colleauges in 2003. Genistein, bisphenol F, and octylphenol were identified as estrogenic only in immature rats. While apigenin and kaempferol appeared to have low estrogenic activity, they potentialized the uterotrophic effect of 17 beta-estradiol in immature rats.

In this study the authors found that phytoestrogens like genistein can be as potent or even more estrogenic than compounds found in food wrap packaging. Tha authors suggest the vaginal cornification to used as a sensitive and useful test to detect weak estrogenic compounds to which humans can be exposed via food.

Introduction of biodegradable packaging in supermarkets

Searching for alternatives to petroleum-based packaging such as polyethylene terephthalate (PET) supermarket chains Sainsbury from UK and Delhaize from Belgium move its private label products to biodegradable packaging in an effort to reduce rubbish collected for landfill.

Justin King of Sainsbury called on government to ensure that every home in the UK has a compost bin. Degradable plastic is made from oil a fossil fuel with additives to enable it to break down to CO2 plus water. Compostable sugar cane trays, and the use of polylactic acid (PLA) packaging for punnets or pallets. Polylactic acid is a corn-based biodegradable polymer made by NatureWorks, a part of Cargill, are being tested.

PLA is already used in many fields:
Serviceware: disposable Dixie cups, dishware, forks, knives and spoons that are used only once, then thrown away.
Rigid Containers: precut salads, fruit, vegetables and convenience store and fast food restaurant bought fountain drink cups.
Bottles: vinegar, water, milk, juice et

Biodegradable packaging decompose in 2 years. Traditional non-biodegradable packaging takes more than 200 years to return to the earth and creates harmful greenhouse gases when burned. [342]

Polyhydroxibutirate (PHB), new biodegradable plastic from sugar [343]

PHB polyhydroxibutirate new plant operations planned to start in 2008, the new plant will produce Biocycle, a biodegradable plastic using sugar as raw material

The Pedra Sugar Mill, in Serrana, in the region of Ribeirao Preto, in the State of Sao Paulo, is Brazil produces. Polyhydroxibutirate, sugar-derived plastic under the Biocycle trademark.

The pilot plant produces 60 tons of Biocycle a year.The entire production is exported to companies in the United States, Japan and Germany PHB is biodegradable. Packing made with PHB is degraded into water and carbonic gas in six to 12 months.

According to the producer, a kilogram of the sugarcane polymer costs US$ 5, whereas a kilogram of other biodegradable plastics, made from beet or corn, for instance, costs US$ 14.

According to Jefter Fernandes do Nascimentooday the world produces 200 million tons a year of polypropylene. PHB is not indicated to replace all the uses of polypropylene, but in the next years it will take between 1% and 2% of that market.

A packaging for eucalyptus seedlings made with PHB plastic were launched. Three months after the seedling has been planted the PHB degrades into the soil. Productivity increases at paper and pulp plants farms.

A research group from the Institute of Biomedical Sciences (Instituto de Ciencias Biomedicas, ICB), of the University of Sao Paulo (Universidade de Sao Paulo, USP), led by biologist Ana Clara Schemberg, selected the bacterium - Alcaligenes eutrophus, found in sugarcane fields soil - and produced a transgenic variety that is more efficient in synthesizing PHB.

The process in stages organizes the plant's operation, which is divided into three main blocks: fermentation, in which the bacteria reproduce and synthesize the polymer; extraction, in which the polymer is taken out of the bacteria; and purification and drying, in which the organic residues - in other words, bacteria remains - are eliminated from the polymer. The selling of eucalyptus seedlings placed in PHB packaging promising cost reduction and productivity gains since the seedlings are planted directly into the soil, the elimination of handling prevents contamination, which affects 20% of the plants when conventional tubets are used.This will be extended to coffee, pupunha (known as spiny peachpalm) and papaya seedlings.

Corkiness of wine

[344] [345]
Mouldy off-flavour can be caused by 2, 4, 6 trichloranisol and is found in foods like wine raisins, ethereal oils, bottled mineral water and others.

The sources of trichloranisol are various. Aung and colleagues, for example, demonstrated that sterilized raisins formed trichloranisol under low water activity nonconducive for microbial activity. [346]

There are many sources of trichloranisol in wine.
Cork:The best known cork oak forests are located at the Mediterranean region, comprising large areas of Algeria, Tunisia, Morocco, southern Europe including Italy, Portugal, Spain and France. The cork oak develops a thick bark of cork. Trichloranisol content of the bark is relatively low, but increases in the lower part of the trees, as it nears the ground. Humidity increases near the ground triggering mould activity. That is why near the ground yellow colouration of cork an and trichloranisol content rises.

Chlorphenols: The most frequent source is the transformation of chlorphenols by several types of moulds. Chlorphenols are used in agriculture as pesticide, in packagings, in the wood industry and in cork forestry. The EU forbids therefore the use of pesticides in cork oak plantations.

Chlorine: Chlorine can come from residues in cork and wine barrels. Cork is bleached and wood barrels are treated with sodium hypochloride. Blanching of cork is now being done with hydrogen peroxide.

Pollution of the wine cellar: Trichloranisol may heavily contaminate the atmosphere of the wine cellar and migrate to the stored wine.

Crown-capped bottles: Trichloranisol has already been found in bottles with crown cape and glass plugs. in these cases the corkiness off-flavour had been originated before bottling. Wood barrels might be the reason.

Analytical quality control tries to sort out high trichloranisol charges of cork. Water steam treatment and even microwave oven were seen to remove trichloranisol, however other valuable odour and flavour components were also removed.
Mousy off-flavour of wine [347]
According to Eleanor M. Snowdon and colleagues mousy off-flavour occurs when wines are infected with either lactic acid bacteria or Dekkera/Brettanomyces. Snowdon write that 2-ethyltetrahydropyridine, 2-acetyltetrahydopyridine, and 2-acetylpyrroline are responsible for the off-flavour.

The authors say that the microbe's metabolism probably plays a key role in mousy off-flavor formation, and that oxygen may play a key role. A wine infected with Dekkera/Brettanomyces in the absence of oxygen may not become mousy unless exposed to oxygen via a processing or handling procedure
.
Epoxidised soybean oil (ESBO) as plasticizer and stabiliser in PVC gaskets
ESBO in seals for baby foods [348]
The European Food Safety Authority (EFSA) evaluated in May 2004 the dietary risk of epoxidised soybean oil (ESBO) used as plasticizer and stabiliser in polyvinyl chloride (PVC) gaskets of metal lids used to seal glass jars and bottles for baby foods packed in glass jars and bottles, and considered the formation of derivatives of ESBO such as chlorohydrins, which may occur as the PVC is heated to high temperatures.

The estimated exposure of infants aged 6-12 months to ESBO migrating into baby foods packaged in glass jars and bottles with metal lids sealed with PVC gaskets can sometimes exceed the Tolerable Daily Intake (TDI) of 1 mg/kg body weight by up to 4- to 5-fold. Since there is an inbuilt safety factor of more than 100 in the derivation of the TDI, exceeding the TDI by 4- to 5-fold does not imply that there will be adverse health effects in infants. Moreover, the Panel notes that ESBO is neither carcinogenic nor genotoxic. However, such a situation is undesirable because it could reduce on a regular basis the safety margin between exposure and adverse effects.

The Pannel recommends to develop a specific migration limit for ESBO in baby foods, derived from the TDI of 1 mg/kg body weight for infants of 6 months of age, weighing 7.5 kg, fed mainly or exclusively on processed baby foods.

The Pannel cannot give an advice on the significance for health of derivatives of ESBO in foods because of absence of toxicological data. The Pannel stresses that up to 5% of the fatty acids in ESBO in gaskets is converted into derivatives. The Pannel calls for further analytical and toxicological data on ESBO derivatives.

Adults exposure to epoxidised soybean oil (ESBO) [349]
According to EFSA 2006, ESBO is used up to 40% in PVC gaskets of metal lids of glass jars and in PVC cling film up to 10%. The overall exposure from these applications is compared to the TDI of 1 mg/kg bw for ESBO set by the SCF (SCF, 1999)
.
The plasticiser di(2-ethylhexyl)adipate (DEHA) is frequently used in combination with ESBO in cling films. Like ESBO, DEHA is practically insoluble in foods with no fat and so migrates only into fatty foods. Finally, DEHA is a much smaller molecule than ESBO and so its tendency to migrate from cling films is higher than ESBO. As a consequence of these factors, it can be concluded that consumer exposure to ESBO migration from cling films will be no greater than exposure to DEHA. The metabolite of DEHA found in urine of adults is 2-ethylhexanoic acid (2-EHA).

The Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) evaluated the risk of adults resulting from the migration of epoxidised soybean oil (ESBO) into foodstuffs such as sauces,condiments and products in oil packaged in glass jar with metal lids lined with polyvinyl chloride (PVC) containing ESBO.

ESBO can be present up to 40% of the weight of the gasket and is also used plasticised PVC cling films for wrapping foods.

Because of the high migration figures, an estimation of the exposure of adults to ESBO was necessary in order to find out if the TDI of 1 mg/kg body weight set by the Scientific Committee on Food (SCF, 1999) was exceeded. The Pannel concluded that the potential high dietary exposure of adults was estimated to be 0.25 mg/kg bw/day, and that the potential dietary exposure of adults to ESBO from foods packaged in cling films will not exceed 0.2 mg/kg bw/day, and that the potential dietary exposure of adults to ESBO from foods packaged in glass jars and in cling films is below the TDI of 1mg/kg bw as set by the SCF (SCF, 1999). The Panel considered therefore that further refinement of the exposure estimates was not necessary.

Bioplastic packaging materials [350]

Charles Onwulata 2007 looked for the use of whey, a byproduct of cheese production. He developed a way to use it in the production of candy, pasta, animal feeds and a process called reactive extrusion to supplement polyethylene with whey proteins.

Reactive extrusion involves forcing plastic material through a heating chamber, where it melts and combines with a chemical agent that strengthens it before it's molded into a new shape. Onwulata and Seiichiro Isobe combined whey protein isolate, cornstarch, glycerol, cellulose fiber, acetic acid and the milk protein casein, creating a biodegradable plastic product that can be mixed with polyethylene.

Bioplastic blends can only replace about 20 percent of the polyethylene in a product, is only partially biodegradable. However, Onwulata and his colleagues, looking for completely biodegradable bioplastics are experimenting with polylactic acid (PLA).

Polylactic acid (PLA) is a commercially available biodegradable polymer derived from lactic acid and is used in many nonfood products as an alternative to petrochemical-derived polymers. PLA substituted with starch-whey concentrates and casein blends (DPB) may enhance the properties of this polymer. Onwulata says that dairy proteins, whey and casein, may provide an advantage by lowering the molded product peak temperature of PLA allowing for more biomaterials to be used in a formulation. [351]

Onwulata 2006 evaluated the properties of several blends of extruded agricultural materials and found that the properties of extruded blends in pellet form made from milk protein, casein and whey protein isolates, starch and glycerol milk protein based (MPB) were most suitable as feed material for injection molding. Injection molded MPB cups demonstrated that agricultural materials based on dairy ingredients can be processed directly in equipment used by the plastics industry. [352]

Waste and Resources Action Programme (WRAP)

[353]
Waste and Resources Action Programme (WRAP) works in partnership to encourage and enable businesses and consumers to be more efficient in their use of materials and recycle more things more often. This helps to minimise landfill, reduce carbon emissions and improve our environment. Important issues are reducing weight of packaging material, changing to 100% recyclable carton.

Redesigning packaging current packaging can improve food protection and reduces costs, such as happened with the introduction of the light glass bottle.

Bioplastic and biopackaging applications

[355]
Bioplastics are produced from renewable raw materials which capture carbon from the atmosphere by plants. Incinerating or composting biopackaging this renewable carbon is returned to the atmosphere.

Fossil fuels is needed in the production of biopackaging, therefore it is not free of additional co2 emission. Bioplastics presents a potential to reduce the dependency on crude oil and reduce greenhouse gas emissions.

Composting could produce humus in arid-zones as an additional advantage as fertiliser and substrate in soil.

Opening up these composting systems for biopackaging, is another way of closing the loop for these innovative packaging solutions. In addition, composting systems are economically very competitive compared with incineration. The generated compost can be used to increase the carbon content in the soil and to maintain soil fertility.

Characteristics of bioplastics according to European Bioplastics:

"Degradable" PE Products:

According to European Bioplastics plastic bags and other products, e.g. agricultural mulching foils, made with polyethylene (PE) with the claim of being "degradable", or "bio-, UV- or oxo-degradable", and sometimes even "compostable"" do not fulfill this standard and were lawsuited.

The Environmental Agreement (EA) in the form of a unilateral self-commitment by industry ensures the keeping of an internationally recognised standard for the biodegradation of polymers, produced from both, renewable or fossil resources.

Properties of bioplastics

[356]
According to Bioplastics the production will tend to biobased/non-biodegradable plastics in near future, however, the barrier properties and heat resistance must be improved. Usual polylactic acid (PLA) softens at a temperature of about 60$^{0}$C and is not deployable for several applications. New PLA is being developed from D- or L-lactic acid to resist heat up to 175$^{0}$C.

Due to a low CO2-barrier carbonated beverages lose their sparkling character very soon at the moment. Furthermore, the high permeability of steam reduces the shelf-life. However, it is expected that new PLA types and barrier layers will widen the scope of applications very soon.

A new polylactic acid (PLA)-based resin from Cereplast, inc. withstands temperatures as low as -35$^{0}$C, compared to about 20$^{0}$C for standard PLA-based plastic with good structural properties. [357]

Brazil Braskem will strengthen their production of polyethylene from sugar cane, so-called "green PE".

The European Landfill Directive 1999/31/EC

[359]
The directive includes several requirements to reduce the organic component of waste. It permits explicitly the burning, the treatment in a mechanical biological facility and the mixed composting of organic waste components, but that the waste can no longer be used for soil improvement.

Like the EU parliament and the "biowaste coalition", comprising 12 European countries, the European Bioplastics supports the idea of a dedicated Organic Waste Directive that is unfortunately not yet on the agenda of the EU Commission. [356]

German government acknowledged the environment friendly potential of biopackaging with the amendment of the Packaging Ordinance by releasing bioplastic bottles from deposit obligation. The ordinance states that bottles with more than 75 percent RRM content will not be charged with a deposit fee. The privilege postpones the obligation of installing recovery systems to a point of time after market introduction. [358]

OurFood (c) 1998 - 2008 by Karl Heinz Wilm - Imprint (Impressum)