Optimal SC-CO2 fractionation condition of cocoa flavanol

• Main Author: 王曉涓
• Other Authors: 王璧娟
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/a4z484

碩士 === 國立嘉義大學 === 食品科學系研究所 === 106 === Fresh cocoa beans contain many health benefits polyphenolic compounds. The 50% ethanol extract (E) of cocoa was fractioned into R, F1, and F2 fractions by supercritical CO2 based on density and solubility according to Box-Behnken factorial experiment design: temperatures (40, 50, 60℃), pressures (15, 20, 25 MPa) and flow rate of cocoa 50% ethanol extract (2, 3, 4 mL/min). The physiochemical properties, bioactive compounds contents, and antioxidant capabilities of fractions were determined. Moreover, the distributions of the active ingredients were calculated. The regression analysis and response surface method (RSM) were used to simulate the trend and predict the optimal conditions. The result showed the pH values of all fractions lower than the pH values of cocoa extract (E), especially R fraction. The soluble solids were mainly distributed in R, while and soluble solids of fraction F (F1, F2) were extremely low. Compared to the extract (E), R exhibited significant high L* value and low a* and b* values, while F fractions possessed lower L* value and a* and b* values. From appearance of view, fraction R was dark brown, fraction F1 was light green or light brown, and fraction F2 was closer to colorless. The bioactive omponents including cocoa flavanols, total phenols, total flavonoids and total proanthocyanidins mainly concentrated in R, particularly operated at 20 MPa. Simulation of response surface method (RSM) showed that the higher distribution was conducted at low temperature and high pressure. Antioxidant capacity including DPPH free radical scavenging ability, FRAP assay and total antioxidant capacity, showed R exhibited the strongest antioxidant capacities. All antioxidant capacities tested were significantly correlated with each bioactive ingredients (p <0.01). In conclusion, the results confirmed that the supercritical carbon dioxide fractionation can effectively enhanced the concentration of the active ingredients and antioxidant capability of R fraction.