Different Extraction Solvents and Sample Preparation Methods Affect the Antioxidant Activities and Total Phenol Contents of Theobroma Cacao Powder (P01-016-19)

Cacao(Theobroma cacao) has been widely consumed since more than 4000 years ago which was regarded as sacred food. Cacao has been considered as a strong antioxidant due to its abundant phenolic and especially flavonoid contents. In this experiment, different extraction solvents and methods were used to analyze whether these factors affect the antioxidant activities and phytochemical compounds of cacao powder extracts. Four different cacao extract samples were examined to identify their anti-oxidative activities; raw cacao powder extracted in 70% methanol solution(RM), raw cacao powder extracted in 80% ethanol solution(RE), freeze dried cacao powder extracted in 70% methanol solution(FM), freeze dried cacao powder extracted in 80% ethanol solution(FE). Total phenolic compound content was calculated based on gallic acid standard curve and total flavonoid content was calculated based on the standard curve of quercetin. ABTS scavenging activity was experimented with ABTS reagent diluted by PBS(pH7.4) to make the O.D. value 0.7 ± 0.02 at 734 nm before using 2.5 mM ABTS. The DPPH radical scavenging activity was assessed by 1 mM DPPH methanol solution. The contents of total phenol compounds were 45.4 mg GAE/g(RM), 37.3 mg GAE/g(RE), 50.6 mg GAE/g(FM), and 52.7 mg GAE/g(FE). The contents of total flavonoid compounds were 34.3 mg QE/g(RM), 29.7 mg QE/g(RE), 85.1 mg QE/g(FM), and 89.7 mg QE/g(FE). FM group showed the highest ABTS radical scavenging activity which is a marker of antioxidant activity but the other sample groups represented almost as high ABTS radical scavenging activity as FM group. RM group showed the highest DPPH radical scavenging activity which is also a marker of antioxidant activity. The results show that different extract solvents and sample preparation methods affect DPPH radical scavenging activity, total phenol and flavonoid contents of cacao powder extracts. Therefore, appropriate methods should be applied according to the purpose of the study. Department of Food and Nutrition, Sookmyung Women's University, Republic of Korea.