Cereal Chem 45:304 - 318.  |  VIEW ARTICLE
Heat-Processing of Wheat Germ Meal and Its Effect on Utilization and Protein Quality for the Growing Chick: Toasting and Autoclaving.

E. T. Moran, Jr., J. D. Summers, and E. J. Bass. Copyright 1968 by the American Association of Cereal Chemists, Inc. 

Raw wheat germ meal was autoclaved for 20, 45, and 90 min. at 121 C., or toasted. Hemagglutination and antitrypsin activities were both very high for the raw and negligible for the toasted and autoclaved meals. The respective meals were used as sole sources of dietary protein (15 or 20%) in semipurified rations calculated to be isonitrogenous and isocaloric. Net protein utilization (NPU) values were obtained for the chick (7 to 21 days of age) with the 15% protein level. Toasting significantly improved NPU; the 20-min. autoclave treatment was without apparent effect. Further autoclaving progressively reduced NPU. Growth experiments employing the 20% protein level showed that cystine was the only amino acid limiting for the chick when the meals were raw, toasted, or autoclaved for 20 min. Pressure processing beyond 20 min. resulted in destruction of lysine, systine, and arginine to the point where in the 90-min. autoclaved meal they became first through third limiting, respectively, and seriously impaired chick growth and feed utilization. Both energy (corn oil) and further amino acid supplementation of the 90-min. autoclaved meal were ineffective in improving chick growth and feed utilization comparably to those observed with the lesser processed meals.