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Ability of English and black walnut phenolics to inhibit cupric‐ion induced LDL oxidation in vitro and following human nut consumption
Author(s) -
Wilson Ted,
Freeman Michelle R,
Olson Rachel M,
Rorabaugh Jacki M,
Singh Ajay P,
Vorsa Nicholi,
Maher Margaret A,
Fitschen Peter
Publication year - 2009
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.23.1_supplement.901.3
Subject(s) - tbars , chemistry , antioxidant , polyphenol , acetone , food science , flavonoid , antioxidant capacity , ethanol , low density lipoprotein , biochemistry , lipid peroxidation , cholesterol
Walnut consumption may reduce the risk of cardiovascular disease, possibly by improving the plasma lipid profile or providing antioxidant protection to low density lipoproteins (LDL). This study sought to compare the phenolic profile and antioxidant activity of English walnut (EW) to its less well known relative, the black walnut (BW). EW and BW samples were extracted in ethanol, methanol, or acetone, prior to analysis using LC‐MS‐MS. EW contained more phenolic compounds (ug/g wet weight) than BW. In vitro studies of LDL oxidation (5uM Cupric ions) demonstrated that EW phenolics extended lag‐time (A234) and reduced TBARS formation, providing significantly better antioxidant protection than BW at 1.0 ug/ml. Furthermore, acetone extracts (1.0 ug/ml) of either EW or BW provided greater antioxidant capacity than paired ethanol extracts. When EW or BW (30 g nuts/day) was administered to humans for 28 days, LDL antioxidant capacity (A234 or TBARS) did not change significantly between groups or within groups between day 0 and 28. This study suggests that EW polyphenolic profile and in vitro antioxidant capacity is better than BW, but that LDL resistance to oxidation does not improve following nut consumption.