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Identification and synthesis of multifunctional peptides from wheat germ hydrolysate fractions obtained by proteinase K digestion
Author(s) -
Karami Zohreh,
Peighambardoust Seyed Hadi,
Hesari Javad,
AkbariAdergani Behrouz,
Andreu David
Publication year - 2019
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/jfbc.12800
Subject(s) - hydrolysate , wheat germ , digestion (alchemy) , chemistry , identification (biology) , germ , biochemistry , peptide , chromatography , biology , hydrolysis , botany , microbiology and biotechnology
Wheat germ protein hydrolysate (WGPH) was obtained by proteinase K digestion, in order to produce bioactive antioxidant and antihypertensive peptides. Response surface methodology (RSM) was used to optimize hydrolysis conditions (enzyme‐to‐substrate ratio, time, and temperature) for antioxidant activity of hydrolysates. The crude WGPH produced in this way significantly inhibited angiotensin‐I converting enzyme (ACE) in a concentration‐dependent manner. It was next fractionated by reversed‐phase semi‐preparative High Performance Liquid Chromatography (HPLC) into 12 fractions that were examined for antioxidant and antihypertensive activities. Fractions with antioxidant and ACE‐inhibitory activities were then submitted to further analysis by nano‐LC‐ESI‐MS‐MS. Among the various peptides identified, MDATALHYENQK (IC 50 : 293.3 ± 6.5 µg/ml) and SGGSYADELVSTAK (IC 50 : 265.5 ± 8.3 µg/ml) displayed antioxidant activity and VALTGDNGHSDHVVHF (IC 50 : 189.3 ± 4.05 µg/ml), VDSLLTAAK (IC 50 : 159.7 ± 0.33 µg/ml), MDATALHYENQK (IC 50 : 303.6 ± 2.47 µg/ml), IGGIGTVPVGR (IC 50 : 125.7 ± 2.3 µg/ml) and SGGSYADELVSTAK (IC 50 : 128.2 ± 1.17 µg/ml) showed good ACE‐inhibitory activity. Practical applications Wheat milling industries produce massive amounts of wheat germ as by‐product that can be converted into valuable compounds. The present research indicates that proteinase K is useful to hydrolyze wheat germ proteins in a search for bioactive peptides with antioxidant and ACE‐inhibitory properties. The identified peptides can be regarded as functional food additives, or nutraceuticals to improve human health.