ABSTRACT
Active food packaging has been de˜ned as a system in which the food product, the package, and the environment interact in a positive way to extend shelf life or to achieve some desirable characteristics that cannot be obtained otherwise [1,2]: it has been de˜ned as an additive to strengthen protection function of food packaging. The protection function of conventional (“passive”) frozen food packaging is related to the improved preservation of the frozen products, which inhibits or delays their quality deterioration. Even though different foods have different characteristics and sensitivity to environmental factors, as discussed in Part III of this book, and can vary in their bene˜ts attained from packaging, major protection function of the packaging is to reduce moisture loss, avoid freezer burn, and lessen oxidative deterioration during the storage of frozen foods by providing the barriers to moisture and oxygen [3,4]: low moisture permeability of packaging suppresses the moisture loss from the product and dehydration of the food surface; exclusion and ingress-prevention of oxygen help to preserve the color and pigments of frozen meats, poultry, ˜sh, fruits, and vegetables; simultaneous protection from moisture loss and oxygen permeation helps to preserve the nutritional and textural qualities; close-˜t package around the food avoids the frost formation insert the food package by preventing the moisture migration from the central part to the food surface (Figure 37.1). High gas barrier packaging also protects the foods from aroma loss and undesired ingress of volatiles. General overview on role and bene˜t of frozen food packaging can be found in Chapter 32 of this book. Active packaging technologies in frozen foods work mostly to enhance or augment these protection functions of the packaging with improved moisture and nutrient retention, deterred oxidation, and inhibited microbial spoilage up to the ˜nal consumption [2]. The positive way interactions of the active packaging comprise removal of undesired gases (such as oxygen, water vapor, etc.) from the package headspace, emission of desired gases (such as carbon dioxide, ethanol, etc.) to the package headspace, controlled release of active compounds (such as antimicrobials, antioxidants, enzymes, ›avors, nutraceuticals, etc.) to food surface, and
Introduction .................................................................................................................................... 819 Oxygen Control .............................................................................................................................. 821
Types of Oxygen Scavengers .................................................................................................... 821 Application of Oxygen Scavengers to Frozen Foods ................................................................824
