Improvement of thermal, microwave and ultrasonication pretreatment on the production of antioxidant peptides from sweet potato protein via in vitro gastrointestinal digestion

Abstract

Summary Effects of thermal (boiling, steaming and autoclaving), microwave and ultrasonication pretreatments on the production of sweet potato protein hydrolysates (SPPH) through in vitro gastrointestinal digestion (GID) were investigated. All pretreatments significantly increased the degree of hydrolysis (DH), antioxidant activities and molecular weight (MW) <3 kDa peptide fractions contents of SPPH in the order of autoclaving > microwave, steaming > boiling > ultrasonication (P < 0.05). Correlation analysis between peptides content and antioxidant activity suggested that antioxidant activity of SPPH mainly attributed to MW <3 kDa peptides. Diverse peptides ranged from 487.24 to 1477.74 Da with 7–13 amino acids were identified in the MW <3 kDa peptides fraction with autoclaving pretreatment and matched sporamins A, A precursor and B sequences from LC–QTOF–MS/MS analysis. Conformational structures of nine peptides were predicted with well‐known antioxidant amino acids. There is a high potential for SPPH used as a functional supplement in food system.

Extraction of bioactive compounds fromAraucaria angustifoliabracts by microwave‐assisted extraction

“…About proteins (9.44 g and 100 g –1 ), pre‐treatment with microwave may be helpful in gastrointestinal digestion and enzymatic hydrolysis of food proteins, as well as significantly enhanced antioxidant capacity of peptides produced (Zhang, Huang, & Mu, 2019).…”

Production and characterisation of antioxidant peptides from sweet potato protein by enzymatic hydrolysis with radio frequency pretreatment

“…Among WB and RF pretreatments, RF80 and RF90 showed the best enhancement on antioxidant activities of MW < 3 kDa peptides with · OH‐scavenging activities of 64.72% and 68.12%, Fe 2+ ‐chelating capacities of 97.12% and 97.30%, and ORAC values of 125.49 and 129.78 μg TE mL −1 , respectively, but without significant differences between these two treatments ( P > 0.05, Table ). Low MW peptide fractions could react more readily with free radicals, which normally presented higher antioxidant activities than high MW peptides (Zhang et al , ).…”

“…Sweet potato (cultivar Shang Shu 19) was supplied by Shangqiu Academy of Agriculture and Forestry Sciences (Henan, China). SPP powder was produced according to the method by Zhang et al () with a purity of 85.79% (w/w). Alcalase (ALC) with the activity of 2.4 Au g −1 was provided by Novozymes (Bagsvaerd, Denmark).…”

“…ORAC was determined using the microplate reader (Infinite ® M1000 Pro; Tecan, Gröedig, Austria) described by Zhang et al () and expressed as μg Trolox equivalent per mL of SPPH (μg TE mL −1 ).…”

“…Sweet potato is not only a cheap source for starch production worldwide, but also an alternative source of protein that can be exploited from the starch wastewater with environmental and economic benefits (Zhao et al , ). Sweet potato protein (SPP) presents excellent physicochemical and functional characteristics (Zhao et al , ), and SPP hydrolysates (SPPH) exhibited certain antioxidant activity, which was significantly improved by thermal, microwave and ultrasonication pretreatment (Zhang et al , ). However, research on production and characterisation of antioxidant peptides from SPPH by enzymatic hydrolysis with RF pretreatment as compared to traditional water bath (WB) heating pretreatment is lacking.…”