Phytochemical component, and antioxidant and vasculo-protective activities of Taiwan cocoa polyphenols by different processing methods

Abstract

Cocoa tree (Theobroma cacao L.) is a recently planted crop in Taiwan, a country located in East Asia. Taiwanese cocoa beans are appreciated globally because of their distinctive flavor and aroma. The effects of the water extracts of unfermented Taiwan cocoa beans (WUFCB) and fermented and roasted Taiwan cocoa beans (WFRCB) on the anti-oxidation, vascular protection, and variation in phytochemical components were investigated. Variations in the catechins components of WUFCB and WFRCB were examined by high performance liquid chromatography. The values of catechin compounds in WUFCB (epicatechin [EC]: 52.32 ± 0.56 mg/g, and catechin (C): 15.14 ± 0.26 mg/g) were approximately two times higher than those found in WFRCB (EC: 26.22 ± 0.48 mg/g, and C: 4.56 ± 0.10 mg/g), indicating that the fermentation and roasting steps caused decline in catechins compounds of WFRCB. In the range of 50–300 µg mL-1, both WUFCB and WFRCB depict noncytotoxicity in endothelial cells; they protect cells from H2O2-induced cytotoxicity as established by MTT assay. Meanwhile, nitric oxide (NO) levels in endothelial cells were elevated by WUFCB. In addition, WUFCB displayed radical scavenging in the acellular model and inhibited increase in reactive oxygen species (ROS) noted in endothelial cell induced by H2O2. Overall, the significant vascular protection of WUFCB is associated with increased NO formation. The decreased ROS generation against oxidative damage was attributed to abundant catechin compounds. This study establishes Taiwan cocoa polyphenol as an effective and complementary tool for preventing endothelial dysfunction and cardiovascular disease.