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α‐Glucosidase inhibiting activity and antioxidant properties of grape pomace extracts (134.5)
Author(s) -
Kadouh Hoda,
Sun Shi,
Zhou Kequan
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.134.5
Subject(s) - pomace , chemistry , food science , gallic acid , dpph , trolox , antioxidant , polyphenol , wine grape , wine , antioxidant capacity , biochemistry
While grape pomace contains considerable amounts of polyphenols, dietary antioxidants have been associated with a reduced risk of type 2 diabetes. We have previously reported strong α‐glucosidase inhibition exhibited by red wine grape pomace extracts, implying a potential role in diabetes management. In the current study, we aim to understand the relationships between this activity and antioxidant capacity of these extracts. Chambourcin, Merlot, Norton, Petit Verdot, Syrah and Tinta Cão red wine grape pomaces extracted with 50% acetone were evaluated for antioxidant properties via common antioxidant assays. At 2 mg/ml, Merlot, Syrah and Tinta Cão appeared to have the highest respective total phenolic content expressed as 0.29, 0.28 and 0.26 mg gallic acid equivalents/ mg extract. At 5 mg/ml, Chambourcin, Merlot and Tinta Cão exhibited the highest DPPH radical scavenging capacity, at 58%, 51% and 49%, respectively. At 0.1 mg/ml, Tinta Cão exceeded all other varieties in oxygen radical (AAPH) absorbing capacity, at 4878 uM trolox equivalents/ g extract. A strong positive correlation was observed between these results and our previous findings of 95%, 88% and 85% α‐glucosidase inhibition exhibited by Tinta Cão, Syrah and Merlot pomace extracts, respectively. Results were significant, suggesting that the α‐glucosidase inhibiting potency of grape pomace extracts may be related to their richness in antioxidants. Grant Funding Source : Supported by the United States Department of Agriculture