Physicochemical properties and biological activities of ovine caseinate hydrolysates

DANIEL J. DAROIT; ANA PAULA F. CORRêA; MANUEL M. CANALES; JULISE G. COELHO; MARIA E. HIDALGO; DEISE M. TICHOTA; PATRICIA H. RISSO; ADRIANO BRANDELLI

DAIRY SCIENCE & TECHNOLOGY

EDP SCIENCES S A

Lugar: Paris; Año: 2012

1958-5586

A Bacillus sp. P45 protease preparation was employed in the hydrolysis of ovine sodium caseinate (NaCAS) for up to 7 h. Absorbance and intrinsic fluorescence spectra suggested that NaCAS proteolysis exposed aromatic amino acids to the aqueous media. Following a slight decrease on the surface hydrophobicity (S0) observed up to 2 h of hydrolysis, S0 increased from 3 to 7-h hydrolysates, indicating the exposure of hydrophobic groups in the surface of the generated peptides. Antioxidant and antimicrobial activities of the hydrolysates, and their gelation ability through acid aggregation induced by glucono-ä-lactone (GDL), were investigated. The antioxidant properties, evaluated by the 2,2?-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) method, showed an increasing trend following hydrolysis up to 4 h. One-hour hydrolysates inhibited the growth of Salmonella Enteritidis, Escherichia coli, Corynebacterium fimi, Listeria monocytogenes, showing also antifungal activity. Hydrolysates maintained the ability to aggregate upon GDL-induced acidification. Although aggregation occurred at slower rates than that of non-hydrolyzed samples, compactness of aggregates formed from 1 and 2-h hydrolysates was comparable to that of non-hydrolysed NaCAS. The final state of aggregates formed from NaCAS:hydrolysates mixtures (4:1) was not altered. Thus, these functional hydrolysates might be potentially added to dairy products manufactured through acid-induced aggregation, without significant texture modifications.