EFFECT OF FERMENTATION SUBSTRATES ON ENZYME PRODUCTION AND DEGRADATION OF OLIGOSACCHARIDES IN PINTO BEAN FLOUR AS AFFECTED BY PARTICLE SIZE DANFENG SONG 1,2 , SAM K.C. CHANG 1,3 and SALAM A. IBRAHIM 2 1 Cereal and Food Science Department North Dakota State University Fargo, ND 58105 2 Family and Consumer Science Department North Carolina A&T State University Greensboro, NC 27411 Accepted for Publication July 12, 2008 ABSTRACT Different substrate combinations and different fungal species were screened for the production of a-galactosidases. Particle sizes of pinto bean flour, activities of enzyme solution and incubation times of enzyme treatment were tested to get the optimum processing conditions to eliminate raffinose oligosaccharides in pinto bean flour. Okara and tofu whey at 2:1 (w/v) and wheat bran and tofu whey at 1:1 (w/v) were used as the substrates for enzyme production. Aspergillus awamori NRRL 4869 was used to produce enzyme. Pinto bean flour (passed through 60 mesh screen) incubated with enzyme solution (60 Gal U/mL) most effectively eliminated the raffinose oligosaccharides. A. awamori NRRL 4869, wheat bran and tofu whey substrates at 1:1 (w/v), particle size 60 mesh and enzyme activity 60 Gal U/mL were the best conditions for enzymatic degradation of oligosaccharides in pinto bean flours. PRACTICAL APPLICATIONS Dry edible beans are highly nutritious and healthy foods. One of the obstacles for the utilization of dry beans is the presence of flatulence factors, especially the raffinose oligosaccharides, which are well known to produce flatulence in man and animals. The flatulence causes some social problems in adults and may cause discomfort in infants and young children. The elimina- 3 Corresponding author. TEL: +701-306-7485; FAX: +701-231-6536; EMAIL: kow.chang@ndsu.edu Journal of Food Processing and Preservation 33 (2009) 527–546. DOI: 10.1111/j.1745-4549.2008.00304.x 527 © 2009 The Author(s) Journal compilation © 2009 Wiley Periodicals, Inc.