Nitrogen retention of adult human subjects fed a high protein rice

Protein quality in cereals and pulses. 1. Application of microbiological and other in vitro methods in the evaluation of rice (Oryza sativa L.), sorghum (Sorghum vulgare Pers.), barley and field beans (Vicia faba L.)

1. The Streptococcus zymogenes assay procedure was modified and used in the estimation of available methionine and relative nutritional value in rice (Oryza sativa L.), sorghum (Sorghum vulgare Pers.), barley and field beans (Vicia faba L.). The results were assessed in relation to the content of tannins and 'dye-binding lysine', and to published information on the nutritional quality of some of the test samples. 2. In grain of ten varieties of sorghum, for which other workers had reported a correlation (r -0.82; P less than 0.01) between tannin content and amino acid digestibility in chicks, the available methionine content ranged from 6.3 to 17.7 g/kg protein (nitrogen x 6.25) and was highly correlated with tannin content (r -0.97; P less than 0.001). The content of total methionine and dye-binding lysine varied little between varieties and was not related to tannin content. 3. In nine samples of rice the availability of methionine was uniformly high, in accordance with literature values for true digestibility of the N. 4. In field beans the presence of tammins in the seed coat was associated with a significant (P less than 0.001) reduction in the availability of methionine. In eleven tannin-free varieties the coefficient of availability averaged 0.791, compared with 0.685 in eleven tannin-containing varieties. The standard deviation associated with both values was 0.04. There was no such difference between the corresponding dye-binding lysine values. 5. Thirty-three samples of barley were examined, representing fourteen varieties, four of which had been grown at several widely different latitudes in England and Sweden. There was little difference in methionine content between samples. The average availability coefficient for eighteen samples grown in England was 0.995+/-0.044, and for fifteen varieties grown in Sweden it was 0.851+/-0.042. The difference was not associated with any difference in tannin content, which was uniformly low. The findings contradict published evidence for marked increase in tannin content with increase in geographical latitude of cultivation, associated with decrease in digestibility of N.

The nutritional and physiological impact of cereal products in human nutrition

There is a need for reeducation of the population, especially in developed countries, as to the value of cereals in the diet. Cereals provide calories and important nutrients to the diet. Refined cereal products and unrefined cereals have certain advantages and disadvantages. With refinement, some nutrients and fiber are removed, but the body is better able to make use of certain nutrients. Essential nutrients are being replaced through fortification to compensate for losses in processing. The high fiber content of unrefined cereal products is believed to aid in the prevention of certain diseases. Special dietary bakery products have been introduced for the treatment of conditions generally exacerbated by standard food items. The increased consumption of cereal products appears warranted as a means of decreasing the saturated fat and cholesterol consumption. Cereals and cereal products have been mentioned in connection with allergies, celiac disease, schizophrenia, obesity, dental caries, cancer, atherosclerosis, goiter, and diverticulosis. This review discusses the possible role of cereals in the prevention or cause of these health problems.