Premium
Effects of Water‐Soluble Natural Antioxidants on Photosensitized Oxidation of Conjugated Linoleic Acid in an Oil‐in‐Water Emulsion System
Author(s) -
Liu T.T.,
Yang T.S.
Publication year - 2008
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2008.00717.x
Subject(s) - antioxidant , chemistry , ascorbic acid , polyphenol , emulsion , food science , linoleic acid , conjugated linoleic acid , green tea extract , biochemistry , green tea , fatty acid
The effect of photosensitized oxidation of conjugated linoleic acid in an oil‐in‐water (o/w) emulsion system was studied. Water‐soluble natural antioxidants, including apple polyphenols from apple extract, green tea extract, 4‐hydroxy‐2(or 5)‐ethyl‐5(or2)‐methyl‐3(2H)‐furanone(HEMF), 4‐hydroxy‐2,5‐dimethyl‐3(2H)‐furanone (HDMF), and ascorbic acid, were tested for antioxidant activity in this system. The green tea extract showed the highest antioxidant activity followed by ascorbic acid. Apple polyphenols did not give significant antioxidant activity. HEMF and HDMF exhibited a prooxidant effect. The antioxidant activity of tea catechins was also investigated. Of them, EGCG and ECG exhibited antioxidant activity at 50 ppm, but the antioxidant activity between them was not significantly different ( P < 0.05). Comparatively, EC, EGC, and GCG showed no significant antioxidative effect at 50 ppm. When the concentration increased to 100 ppm, the antioxidant activity of ECG and EGCG significantly increased compared with that at 50 ppm, and EGCG had higher antioxidant activity than ECG. GCG also showed significant antioxidant activity at 100 ppm. EGCG exhibited the highest antioxidant activity among the tea catechins in the emulsion system at 100 ppm.