Effect of alkyl‐chain unsaturation on the antioxidant potential of chlorogenic acid derivatives in food and biological systems

Summary Chlorogenic acid (CGA) was modified using acyl chlorides with different levels of unsaturation (C18:0–C18:3) to enhance the lipophilicity and promote its application. The antioxidant activity of CGA derivatives in food and biological models was evaluated. All CGA derivatives had significantly greater antioxidative activity than CGA in fish oil and β‐carotene/linoleic acid emulsions ( P < 0.05), but there was no linear relationship between antioxidative activity and unsaturation. The effectiveness of CGA‐C18:0 was significantly greater than that of CGA in scavenging H 2 O 2 and reducing copper‐induced human low‐density lipoprotein (LDL) oxidation ( P < 0.05). Furthermore, the H 2 O 2 scavenging activity, inhibitions of copper‐induced human LDL oxidation and hydroxyl or peroxyl radical‐induced DNA oxidation were all linearly related to the unsaturation of the alkyl chains, mainly with the free radical chain reactions of the unsaturated bonds. Our findings showed that CGA derivatives could potentially be used as antioxidants in food and biological systems.