Cereal Chem 59:132 - 136.  |  VIEW ARTICLE
Semiautomated in Vitro Analysis of Sorghum Protein Availability via Pronase Hydrolysis.

D. H. Hahn, J. M. Faubion, S. H. Ring, C. A. Doherty, and L. W. Rooney. Copyright 1982 by the American Association of Cereal Chemists, Inc. 

Sorghum varieties with varying kernel structures were analyzed for availability of protein. Small (100-mg) samples of ground grain were digested with a protease enzyme, pronase, and optimum pH, time, and temperature. The hydrolysate was assayed for alpha-amino groups by monitoring absorbance at 570 nm following reaction with ninhydrin. Pronase digestibility was determined for 196 sorghum samples, including those without a testa (b1b1b2b2ss), with a testa (B1-B2-ss), with a testa and a spreader gene (B1-B2-S-), and with waxy (wxwxwx) and nonwaxy (WxWxWx) endosperm types. Sorghums with a testa showed significantly lower in vitro digestibility than sorghums without a testa. Sorghums with waxy endosperm had slightly higher digestibility than did nonwaxy sorghums. Pronase digestibilities of 11 sorghum samples were compared with those obtained by a multienzmye in vitro digestibility method, which grouped sorghums together in a narrow range of digestibilities. The pronase method was more sensitive, separating sorghums into groups according to observable characteristics.