Effect of Lipids and Thermal Processing on Antioxidant Activities of Tested Antioxidants and Tom-Kha Paste Extract

摘要

The effect of lipids on antioxidant activities of tested antioxidants and Tom-Kha paste extract was determined in the food system. 2,2’-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) scavenging activity, peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and p-anisidine value (AV) were methods for determining. The result showed that heating at 121°C for 15 min caused decreasing on DPPH scavenging activity of lauric acid but didn’t affect ABTS scavenging activity of both lauric acid and virgin coconut oil. DPPH scavenging activity of all mixtures was significantly decreased (p p-hydroxycinnamic acid and Tom-Kha paste extract in both lauric acid and virgin coconut oil systems increased after thermal processing. In food systems of lauric acid, PV of almost mixtures except lauric acid-Tom-Kha paste extract 2:1 and lauric acid-Trolox 15:1 was increased after heating. TBARS value of the mixtures was not significantly different (p?≥ 0.05) after thermal processing. AV of only lauric acid-gallic was enhanced after heating. PV of virgin coconut oil added with all tested antioxidant was not changed after heating. TBARS of virgin coconut oil added with antioxidant samples seemed to slightly increase after heating. AV of virgin coconut oil with added gallic acid and Tom-Kha paste extract were not changed by heat treatment while AV of virgin coconut oil with added p-hydroxycinnamic acid and Trolox seemed to decrease after heating.