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Dietetic bread is mainly produced for diabetics. Gluten accounts 80% of the protein of whole wheat flour. Forty per cent wheat gluten are incorporated in the dough to increase the protein content and decrease the starch in the final product. Gluten-rich foods are still of low cost as compared to others such as skim milk, soya and fish flour.

The different nutritional ingredients of the Egyptian varieties of rice (Giza 171, Giza 172, and Giza 180) were determined. 1. The nutritive values decreased in polished varieties more than in the hulled ones. 2. A wide variation in the protein content in the different varieties was recognized. 3. Giza 180 could be considered as the best Egyptian variety from the nutritional aspects.

The amino acid analysis revealed that wheat grains, white and dark flour, baladi bread prepared from white or dark flour, bread prepared from formulae enriched with gluten and biscuits are poor in lysine with chemical scores ranging between 20 and 49. The assessment of the protein quality of wheat and related products was done by slope ratio bioassay. Results based on slopes relative to those of reference casein + methionine ranked bread prepared from dark flour and cooked wheat (belila) as the highest in their protein quality, followed by their parent; wheat (RNV = 44). Dietetic bread with gluten had RNV = 20-24; owing to its high protein content (38%), its utilizable protein approached that of good proteins (8%). Very high significant correlation existed between the two measures of response; gain in weight and net increase in body water as response of nitrogen intake.

Degradation of sunflower oil, rapeseed oil, and lard during the frying operation was investigated by studying the loss of essential fatty acids compared to the accumulation of decomposition products. Linoleic and/or linolenic acid concentration was measured by GLC, and for detecting decomposition products determination of polymer content by GPC was chosen. Twelve laboratory experiments with different heating or frying conditions were run aimed at modelling practice and studying the effects of certain factors. The results indicated that loss of essential fatty acids being a parallel process to the accumulation of breakdown products is suitable both for detecting the decrease in nutritive value and for quality assessment of used frying fats. It was also found that the rate of deterioration is considerably affected by the nature of fat and the frying parameters. Study of the relationship between polymer content and the decrease in essential fatty acid concentration (using data from 110 samples) showed that high, linear correlation depending on the nature of fat can be found. Correlation coefficients and equations of regression lines were calculated.

Chemical and biological evaluation of both the edible and nonedible portion of banana fruit was carried out. The possibility of using the nonedible portion (peel) as animal feed was also explored. The results showed a remarkable difference concerning the chemical composition of both the edible and nonedible portions. The amino acid contents were proved to vastly deficient with regard to the indispensable amino acids with exception of phenylalanine which was found in good amounts in the edible portion (pulp). The biological results demonstrated that neither the pulp nor the peel portions yielded good P.E.R. values when used at 6% protein level. The P.E.R values showed negative values which amounted to -1.75, -5.85 and -4.67 for the pulp and peel diets respectively. Incorporation of the stock diet to the peel diet resulted in a slight increase which amounted to 6% in both male and female rat groups.

The protein quality of biscuits (Mary's Bisuit), a product largely consumed by infant and children in this country proved to be of very inferior quality, with very low lysine content, which is obviously completely destroyed during the baking process. Rats fed biscuits as protein source lost weight during the experimentation period and their food consumption was too low. Rats fed this diet showed also very slight increase in body water (1.9 g), in comparison to a value of 16.0 g in rats fed casein at the same dietary protein level.

Changes in the nutritive value of meat under the influence of an interaction between oxidized fats and proteins were studied in model experiments. Parameters were the digestibility of protein, sensitivity of tissue against thermohydrolysis, changes in the content of essential amino acids and in the RNV coefficient of the protein. Muscle gel and tissue served as meat substrates, methyl ester of linoleic acid and its oxidation products were used as fat substrates. It has been found that reactions of the oxidation products of methyl linoleate with meat proteins lead to a crosslinking of proteins. Hexanal and hydroperoxide of the oxidized methyl linoleate influence the decrease in digestibility of muscle protein and the thermohydrolysis of the collagen. Proteins of pasteurized gels showed losses in essential amino acids, which corresponded to a lower nutritive value (determined in the RNV coefficient).