Availability of the Essential Amino Acids in Cottonseed Meal

Abstract

The availability of the essential amino acids in cottonseed meal samples which were processed in various ways was determined by a rat feeding method. Marked variation in individual amino acid availability was characteristic of commercial hydraulic cottonseed meal. Lysine and methionine were particularly low, with values of 64 and 67%, respectively. Lysine availability values as high as 85% were obtained with special solvent and gland-free meals. The binding of gossypol as a result of heating cottonseed meal in the presence of either gossypol or pigment glands did not reduce amino acid availabilities appreciably unless cottonseed oil was also present. Heat treatment as severe as autoclaving for one hour at 15 lb. pressure did not reduce the availability of the essential amino acids in cottonseed meal of low oil content. Lysine was more sensitive to heat destruction than the other essential amino acids. About a 10% reduction in lysine content was observed when solvent-processed cottonseed meal was autoclaved at 15 lb. pressure for 60 minutes.