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Nutritional Quality of Great Northern Bean Proteins Processed at Varying pH
Author(s) -
EICHER N. J.,
SAITERLEE L. D.
Publication year - 1988
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1988.tb13548.x
Subject(s) - chemistry , cystine , food science , protein quality , isoelectric point , trypsin inhibitor , soya bean , slurry , trypsin , cysteine , biochemistry , enzyme , materials science , composite material
Heating whole dry beans at pH well above or below their average protein isoelectric point of 6.3, results in significant increases in protein digestibility, as measured by the rat NPR assay. Yet the nutritional quality of these pH‐adjusted beans was lower than that for conventionally cooked dry beans due to the loss of cysteine/cystine (Cys) from the beans during the long pH adjustment step as well as the increased sensitivity of Cys to heat at alkaline pHs. In contrast pH adjusted bean flour slurries, after rapidly drying (40 set) on a double drum drier, yielded products having a high protein digestibility (>80%), low trypsin inhibitor content (< 10mg TI/g protein) and showing little or no loss of Cys.