Nutrient deterioration

To predict nutrient deterioration, knowledge of the reaction rate as a function of temperature of storage or processing is needed. The kinetics of ascorbic acid destruction have been examined most extensively in model systems, with particular attention being given to intermediate moisture foods (17, 71,78,79). Most of the data available for vitamin C losses in actual food systems are insuflBcient to calculate the kinetic parameters needed to predict losses during heat treatment or storage. 

From the legal point of view, antioxidants are substances which prolong the shelf-life of foodstuffs by protecting them against deterioration caused by oxidation, such as fat rancidity, colour changes and loss of nutrient value. Hundreds of compounds, both natural and synthesised, have been reported to possess antioxidant properties. Their use in food, however, is limited by certain obvious requirements, not the least of which is adequate proof of safety. 

Downstream water quality deterioration (altered nutrient composition, oxygen-depleted deep-water with reduced components)... 

Eutrophication is caused by the growth in the ecosystem of chemical nutrients, with nitrogen and phosphorus being typical representatives. In general, eutrophication is followed by intensive growth of algae and intensive decomposition, which leads to prevalence of weeds and deterioration of the quality of water. In principle,... 

At a certain moment my health deteriorated very quickly and I broke down. Doctors still had no clue but they did see that I was very ill. The only way out was a treatment in the Environmental Health Center in Dallas with Dr. Rea. There they were able to ascertain serious damage to my immune and nervous systems. Tests also confirmed that I react strongly to various everyday chemical substances, numerous nutrients, molds, pollen, medicines, et cetera. Staying in the clinic was tough. There wasn t a single food item that I could endure without side effects. Many chemicals incited strong reactions and I often became unconscious. Many times I was hooked up to oxygen and an IV. 

As mentioned in the introduction, fermentation has been used since ancient times to conserve and alter food. Also today, it is still applied on a very large scale for this purpose. A few typical examples are described in this chapter. The principle is similar in most cases. Lactic acid produced by bacteria protects the food from deterioration by inhibiting the growth of mold and other microorganisms. Most vitamins and nutrients of the food are preserved during fermentation. Three examples are discussed in more detail below The production of sauerkraut, soy sauce, and milk products (Table 9.3). 

Refrigeration sloiw down the chemical and biological processes in foods, and the accompanying deterioration and loss of quality and nutrients. Sweet com, for example, may lose half of its initial sugar content in one day at 21 C, but only 5 percent of it at 0°C. Fresh asparagus may lose 50 percent of its vitamin C content in one day at 20 C, but in 12 days... 

The temperature of frozen storage is critical for optimal nutrient retention. The International Institute of Refrigeration (107) recommends that for good retention of nutrients and quality of foods the maximum freezing storage temperature should be — 18°C (0°F). At this temperature there is a slow but acceptable deterioration of food quality (35). 

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