EFFECT OF ARABINOXYLANS CONCENTRATION ON WHEY PROTEINS ACID GELS PRODUCED BY FERMENTATION OF PROBIOTIC BACTERIA

LOYEAU, PAULA A.; SANCHEZ CARNERO, AGOSTINA; FIORAMONTI, SILVANA A.; VINDEROLA, GABRIEL; CARRARA, CARLOS R.; SPOTTI, MARÍA JULIA

Raileigh, North Carolina

Conferencia; 15th Conference of Food Engineering (COFE); 2022

Society of Food Engineering

Acid gels produced by fermentation, using probiotic bacteria as starters and whey proteins, constitute an alternative for the design of functional foods. The aim of this study was to evaluate the effect of glucose and arabinoxylans concentration on the properties of acid gels of whey protein isolate (WPI) produced by the fermentation of Bifidobacterium animalis subsp. lactis INL1. For obtaining the gels, WPI solution (3%) was thermally treated to promote protein denaturalization. Different concentrations of glucose (0.1, 0.5, 1, and 2%), and arabinoxylans (1 and 2%) were used as a carbon source for bacterial fermentation. The solutions were inoculated with the bacterial suspension (108 CFU/g) and incubated (42 ° C-5h), to promote the acidification and gelation of the systems. The gels were measured in their texture profile analysis (TPA), uniaxial compression, water retention capacity (CRA), glucose consumption, syneresis, and weekly cell counts for 4 weeks after storage at 4 ° C. In gels containing no arabinoxylans, the acidification and, therefore, the gel formation was faster for those systems with higher glucose content. Gels with 0.1% glucose had a final pH close to 6, showed a soft texture (not self-supporting gel) and the consumed glucose was close to 0.09%. Gels with 0.25, 0.5 and 1% of glucose had a final pH around 5, stiffer texture (no differences in TPA and compression tests between these samples) and the consumed glucose was around 0.2%. Gels with lower glucose concentration had higher syneresis after storage for 4 weeks. The pH of the gels did not change upon storage. The cell counts at the end of the storage time were higher than 106 CFU/ml. The presence of arabinoxylans prevented the acidification in gels with 0.1 and 0.25% glucose (the pH did not change after incubation up to 6 h) but increased the cell counts.