Polyphenol antioxidants from cocoa pods: Extraction optimization, effect of the optimized extract, and storage time on the stability of palm olein during thermoxidation

Abstract

This study was conducted in order to optimize the extraction process of phenolic antioxidants in cocoa pods and to evaluate the effect of optimized extract and storage time on the oxidative stability of palm olein heated at 180 °C using response surface methodology (RSM). The optimization of the extraction process of cocoa pods antioxidants was done and the results showed that the total polyphenols of 153.51 mg GAE/g and scavenging activity of 100% were obtained under optimal conditions. Vanillic acid was the phenolic antioxidant detected in the optimized extract using HPLC-DAD (diode array detector). Rancimat test showed this extract was efficient in delaying palm olein oxidation. To preserve quality of palm olein during heating at 180 °C, RSM concerning iodine value and thiobarbituric acid value proposes to supplement the oil with 2,000 ppm of cocoa pods extract during 1–7 days (03 hr heating cycle per day) of treatments. Practical applications To improve the oxidative stability and shelf-life of vegetable oils, only few natural sources who are supposed to be safer than synthetic antioxidants have been authorized for industrial purpose (case of rosemary). Therefore, there is a strong rational to continue the search of new natural sources of antioxidants by screening plant materials. This study can be useful for the development of industrial extraction process of cocoa pods and its application as an ingredient to delay lipid oxidation in oils.