Lermen AM, Clerici NJ, Borchartt Maciel D, Daroit DJ. Characterization and application of a crude bacterial protease to produce antioxidant hydrolysates from whey protein.
Prep Biochem Biotechnol 2022;
53:12-21. [PMID:
35156901 DOI:
10.1080/10826068.2022.2033997]
[Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bacillus sp. CL14 crude protease was partially characterized and applied to obtain antioxidant whey protein isolate (WPI) hydrolysates. Optimal activity occurred at pH 9.0 and 60 °C. Ca2+, Mg2+, and Mn2+ (5 mM) enhanced activity (12-26%), whereas Co2+, Cu2+, Fe2+, and Zn2+ inhibited it (50-94%). At 1% (v/v), Tween 20 and Triton X-100 enhanced activities (21-27%), β-mercaptoethanol decreased it (15%), and dimethyl sulfoxide (DMSO) had no effect. Sodium dodecyl sulfate (SDS; 0.1%, w/v) increased activity by 36%. Complete inhibition by phenylmethylsulfonyl fluoride (PMSF), and 85% inhibition by ethylenediaminotetraacetic acid, indicates its serine protease character and the importance of cations for activity/stability. With 5 mM Ca2+, protease was optimally active at 65 °C and completely stable after 20 min at 40-55 °C. Crude protease preferentially hydrolyzed WPI and soy protein, followed by casein. WPI hydrolysis was then performed (55 °C, pH 9.0, 5 mM Ca2+) for 0-180 min. Contents of trichloroacetic acid (TCA)-soluble proteins in WPI hydrolysates (HWPI) increased from 29% (0 min) to 50-52% (60-180 min), accompanied by enhanced radical scavenging activity (14%, 0 min; ∼34%, 60-180 min) and Fe2+-chelating ability (56%, 0 min; ∼74%, 45-180 min). CL14 protease might represent an alternative biocatalyst to obtain antioxidant hydrolysates from WPI and, potentially, from other food proteins.
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