513
Chapter 40
Control by novel
Processing technologies
introduction
Many of the conventional food preservation methods used at present and discussed here have
several disadvantages. High-heat treatment given to foods for safety and long shelf life results in
loss of heat-sensitive nutrients (e.g., thiamine, riboflavin, folic acid, and vitamin C); denatures proteins and causes changes in texture, color, and flavor; and induces formation of new compounds
through covalent bonds (e.g., lysinoalanine). Low-heat processing, such as pasteurization, minimizes the disadvantages of high-heat processing of foods, but the foods have limited shelf life even
with refrigerated storage. Drying and freezing also reduce nutritional and acceptance qualities of
food, especially when stored for a long time, and moreover, not all food can be stored by drying
or freezing. Irradiated foods have not been well accepted by consumers. Many of the chemical
preservatives used are of nonfood origin and have limited efficiency.
Since the 1980s, health-conscious consumers, especially in the developed countries, have been
concerned about the possible adverse effects that “harshly produced” and “harshly preserved”
foods might have on their health and on the health of future generations. There is a concern that
the cumulative effects and interactions of different types of food preservatives on the human body
during one’s lifetime are not properly understood. The revelation about the harmful effects of
some of the additives that were once allowed to be incorporated in foods has shattered consumer
confidence. The philosophy of the consumers has changed from “How long will I live?” to “How
well will I live?” which, in turn, has shifted the desire of these consumers toward nutritious,
natural, and minimally processed foods that have not been subjected to harsh processing or harsh
preservation techniques. Because of changes in socioeconomic patterns and lifestyles, many consumers are also interested in foods that have a long shelf life and take very little time to prepare. 1
The suitability of several thermal and nonthermal processing and preservation methods are
being studied to produce such foods. The principal advantages, disadvantages, and the current
status of some of these methods are briefly described here. Major emphasis is given to their antimicrobial properties. 2–4
Chapter 40
Control by novel
Processing technologies
introduction
Many of the conventional food preservation methods used at present and discussed here have
several disadvantages. High-heat treatment given to foods for safety and long shelf life results in
loss of heat-sensitive nutrients (e.g., thiamine, riboflavin, folic acid, and vitamin C); denatures proteins and causes changes in texture, color, and flavor; and induces formation of new compounds
through covalent bonds (e.g., lysinoalanine). Low-heat processing, such as pasteurization, minimizes the disadvantages of high-heat processing of foods, but the foods have limited shelf life even
with refrigerated storage. Drying and freezing also reduce nutritional and acceptance qualities of
food, especially when stored for a long time, and moreover, not all food can be stored by drying
or freezing. Irradiated foods have not been well accepted by consumers. Many of the chemical
preservatives used are of nonfood origin and have limited efficiency.
Since the 1980s, health-conscious consumers, especially in the developed countries, have been
concerned about the possible adverse effects that “harshly produced” and “harshly preserved”
foods might have on their health and on the health of future generations. There is a concern that
the cumulative effects and interactions of different types of food preservatives on the human body
during one’s lifetime are not properly understood. The revelation about the harmful effects of
some of the additives that were once allowed to be incorporated in foods has shattered consumer
confidence. The philosophy of the consumers has changed from “How long will I live?” to “How
well will I live?” which, in turn, has shifted the desire of these consumers toward nutritious,
natural, and minimally processed foods that have not been subjected to harsh processing or harsh
preservation techniques. Because of changes in socioeconomic patterns and lifestyles, many consumers are also interested in foods that have a long shelf life and take very little time to prepare. 1
The suitability of several thermal and nonthermal processing and preservation methods are
being studied to produce such foods. The principal advantages, disadvantages, and the current
status of some of these methods are briefly described here. Major emphasis is given to their antimicrobial properties. 2–4