Study on digestibility and energy availability of daily food intake in Japanese (Part 3. Cereals).

Four male Japanese were fed a semisynthetic diet including egg and soy powder as protein source for seven days (Basal-diet period), and in the following seven days 200 g of polished rice, wheat flour and buckwheat flour added at the expense of part of the corn starch and sugar in the basal diets (Test-diet period). Urine and feces were collected throughout both periods and the contents of nitrogen, fat and energy in these excreta were determined. Digestibility of protein (N), fat and carbohydrate (by difference) was calculated. The protein digestibilities of the polished rice (in the form of cooked grains), wheat flour (in the form of cooked powder) and buckwheat flour were 89.6 +/- 5.0%, 93.4 +/- 2.9% and 85.1 +/- 2.5%, respectively. The fat digestibilities of the polished rice, wheat flour and buckwheat flour were 93.6 +/- 1.8%, 70.8 +/- 13.5% and 103.1 +/- 8.4%, respectively showing relatively large variation (This results may be caused by an errors in measurement). The carbohydrate digestibility was close to 100%. The net energy availabilities of the polished rice, wheat flour and buckwheat flour were 100.6 +/- 1.4%, 96.5 +/- 1.1% and 96.0 +/- 1.1%, respectively.