Nutrition processing conditions

The cited observations suggest that it is possible to identify potato cultivars with low or high phenolic acid content for human use and to select processing conditions that minimize losses of phenolic compounds. In summary, the methods we developed and used to determine the content and distribution of phenolic compounds in potato plant flowers, leaves, and tubers, in the peel and flesh parts of potato tubers, and in freeze-dried and processed commercial potatoes merit application in numerous studies designed to assess the role of potato phenolic compounds in host-plant resistance, plant breeding, plant molecular biology, food chemistry, nutrition, and medicine. The described wide distribution of phenolic compounds in different commercial... 

Bioavailability can be influenced directly or indirectly by many physiological, pathological, chemical, nutritional, and processing conditions. Discussion in this chapter will be limited to unit food processing effects upon the bioavailability of nutrients from plant protein foods. The bioavailability of amino acids, carbohydrates, lipids, vitamins and minerals from processed foods will be selectively reviewed. Amino Acids... 

Mustakas et al. (46) evaluated the effects of extruder-processing on nutritional quality, flavor, and stability of the product in an attempt to describe extruder conditions which would be acceptable in all three respects. Urease activity was used as an estimation of trypsin inhibitor activity thus the area between the two urease curves in Figure 2 indicates processing conditions which strike a balance between too much and too little heat treatment, showing optimal nutritional quality. Using the flavor and peroxide value isograms, processing conditions may be chosen such that acceptable flavor and stability may also be achieved. 

Under proper processing conditions minimal alterations in the structure and bioavailability of food lipids take place. However, excessive heat and/or improper storage conditions can result in a number of degradative changes in lipids. These chemical changes have a much greater effect upon palatability than upon nutritive value. 

Nutrient composition. The nutritional quality of dried citrus pulp may be affected by processing conditions, particularly dehydration temperatures. Pulp dried with dryer exit-stack gas temperatures greater than 143°C shows caramelization or browning. Ammerman et al. (6J and Chapman et al. ( 7) have shown that a... 

In another study by Tsen et al (14), a substantial PER difference was observed between diets with bread crust (0.36) and bread crumb (1.35). Palamidis and Markakis (12) also found that the PERs of their bread and its crumb were 0.46 and 0.91, respectively, while the crust showed a negative PER, -0.23. Hansen, et al.(18) reported that bread crumb and crust had respective PERs of"T.36 and 0.62. The difference in PERs for bread crumb or crust reported by the three groups of investigators is largely due to different raw materials and processing conditions for the breads. Nevertheless, the marked difference in PER between bread crumb and crust indicates clearly that the browning reaction can reduce the nutritive value of bread (Table IV). 

Deodorizer distillate is the material collected from the steam distillation of oils. It is a mixture of free fatty acids (especially during physical refining) tocopherols, phytosterols and their esters, hydrocarbons, and hpid oxidation products. The quality and composition of deodorizer distillate depends on the feedstock oil composition and processing conditions. Tocopherols and sterols are the most valuable components that can be recovered from the distillate, and they are used in the nutrition supplement and pharmaceutical industries (201). Typical soybean deodorizer distillate contains about 33% unsaponifiable matters, of which 11% is tocopherol and 18% sterol (202). 

The polyphenols are an important class of minor constituents linked both to the flavour of virgin olive oil and to its keeping ability. Many publications deal not only with the nutrition effects of polyphenols, but also with the agronomic factors that influence their presence in olives and in olive oil, the mechanisms that contribute to a longer shelf life, and the importance of the processing conditions. 

Of all the efforts to reduce LAL formation, careful control of processing conditions is the most satisfactory approach at this time. Careful control of pH, temperature, air incorporation, and ingredient quality will allow manufacture of products with minimum LAL content. The safety and nutritional quality of pro-... 

For edible purposes, TAG have the greatest nutritional importance (see Chapter 10). Therefore, the processing conditions are selected in such a way as to obtain TAG in high yield and high purity (Section 11.5.5). 

Treatments used in food processing may modify the native structure of proteins independently of or in concomitance with chemical/enzymatic modification of the amino acids in their primary structure. In most cases, such structural changes are a highly desirable result of processing, and process conditions are chosen that result in extensive (but controlled) protein denaturation and in the exposure of reactive functional groups. In many other cases, however, protein denaturation represents a major drawback, in that it may alter the nutritional and functional properties of the processed material. 

The acacia trees produce gum arable only under adverse conditions, lack of moisture, poor nutrition, and hot temperatures. Gum arable is produced at wounded surfaces of the acacia trees. The wounds are generally produced deUberately in cultivated trees by stripping bark during the dry season. The gum is collected by hand over a period of several weeks with average yields of 250 grams per tree per year. Cmde exudates are hand sorted and exported before processing and milling to various specifications. 

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