Minimum nitrogen requirement from glandless cottonseed protein for nitrogen balance in college women.

Seven women, 18 to 23 years of age, were fed cooked cottonseed products for 42 days in order to determine the minimum nitrogen requirements for glandless cottonseen flour after baking. The women consumed from 81 to 213 mg N/kg body weight from cottonseed protein. Nitrogen intake from each experimental period was calculated from the average nitrogen content of the cottonseed products consumed each day of the experiment period. Nitrogen excretion was determined from the measurement of nitrogen in a total collection of urine and feces for each experimental period plus an obligatory loss of 5 mg/kg body weight. Fasting blood samples were taken prior to the study and at the end of each 7-day experimental period thereafter. The minimum requirement for cottonseed protein to maintain a positive nitrogen balance was 106 mg N/kg body weight. For the "reference woman," weighing 58 kg, at least 6.1 g of cottonseed flour nitrogen would be required to maintain nitrogen equilibrium. Plasma amino acid values of threonine, proline, valine, isoleucine, leucine, tyrosine, and lysine decreased significantly from day 0 to day 7 of the study. There were no significant differences in these plasma amino acids thereafter. Cottonseed flour incorporated into baked products maintained nitrogen balance in college women with no change in their nutritional status.