Packaged food

W. A. Jenkins and J. P. Harrington, Packaging Foods with Plastics, Technomic Publishing Co., Inc., Lancaster, Pa., 1991. 

Polystyrene (PS). Common appHcations include packaging, food containers, and disposable tableware toys furniture, appHances, television cabinets, and sports goods and audio and video cassettes. For some of these appHcations, PS is modified by blending or graft polymerization with SBR to form impact polystyrene, which is less sensitive to breakage. Expandable polystyrene is widely used in constmction for thermal insulation. 

Styrene (vinyl benzene) QH5CH=CH2 Polymers (CgHaln for audio and video cassettes, carpet backing, domestic appliances, packaging, food containers, furniture, toys, vehicle parts... 

Most packaged foods require a barrier against gases, flavors, or odors to maintain product quality and provide acceptable shelf life. Baked foods usually need moisture protection, while fresh meats and vegetables require low or controlled exposure to oxygen... 

Packaging (food, medical devices, egg cartons, dairy containers, meat and produce trays, electronic devices, tools, dinnerware, picnic dishes, drinking cups, lids, etc.)... 

The other effect of having a stretched area is a reduction in resistance to stress cracking. Crazing is a possibility in such areas such as in polystyrenes, and environmental stress cracking caused by solvent substances will occur in the stretched areas. This is a particularly important consideration in vacuum formed products used for packaging food that frequently has some solvent action on the plastics. 

At first, the program which investigated the packaging of irradiation-- processed foods, concentrated on the most advanced type of container, the tinplate can. It had performed successfully for a century as a container for thermoprocessed foods. However, as a container for the irradiation-processed foods, its physical, chemical, and protective characteristics had to be evaluated, including the effects of radiation on enamels and end-sealing compounds. This container was satisfactory for packaging foods that were irradiation sterilized while unfrozen (1, 2). 

These objective, quantitative tests have shown that nitrile containers should protect the taste and odor of packaged foods and beverages. But the primary consideration in judging overall package performance, once safety is assured, rests on the subjective evaluations of taste, odor, and appearance. It is well known that the animal senses, in many instances, are far more sensitive than the best instruments and also are capable of integrating the individual effects of the several influences on product quality. 

This paper organizes some of the how and why of flexible package-food product interactions by discussing a few specific examples of food packaging development, as well as some overall factors of packaging material application. 

LSMBSs are designed so that the types of data to be collected meet particular objectives regarding how the data will be used. For example, the number of exemplars collected in the LSMBS will depend on the use planned for the study results. Thus, if the levels of plasticizer in packaged foods will be determined to address an acute (i.e., short-term) dietary exposure and risk concern, the sample size (i.e., number of food packages to be collected) must be adequate to support the higher percentiles... 

Many polymers are used in barrier applications, either to keep contents in or contaminants out. Food packaging is an excellent example of such usage. Plastic films and containers of many types are used to package food. Blow moldedbottles often contain numerous layers, each of which provides specific benefits. Polyethylene layers are excellent water barriers, polyvinyl alcohol is a good oxygen barrier, and polyethylene terephthalate impedes the diffusion of carbon dioxide from carbonated drinks. Other barrier applications include toothpaste tubes, diaper backsheets, tarpaulins, and geomembranes, which are used to line containment ponds and landfill pits. 

Pre-packaged foods and frozen or quick-prepare dinners are increasingly available and appealing to time-stressed consumers Increase in consumption of convenience foods that are often high in fat and calories and low in nutritional value... 

METHODS OF ASSESSMENT AND QUALITY CONTROL OF PACKAGED FOODS... 

This oxygen sensor system has been successfully used by us with a number of different types of packaged foods and packaging processes, being continuously developed and optimized in these real-life conditions and applications. It was validated in several small laboratory scale and medium industrial scale trials19,30 with the following foods and processes ... 

Gestrelius H., Mattila-Sandholm T. and Ahvenainen R., Methods for non-invasive sterility control in aseptically packaging foods, Trends Food Sci. Technol. 1994 5 379-383. 

Papkovsky D.B., Papkovskaia N., Smyth A., Kerry J.P., Ogurtsov V.I., Phosphorescent sensor approach for non-destructive measurement of oxygen in packaged foods optimisation of disposable oxygen sensors and their characterization over a wide temperature range, Anal. Lett. 2000 33 1755-1777. 

---