Abstract

Five extraction conditions (AE, autoclave extraction; OE, oven extraction; HWSE, hot water and sonication extraction; HWASE, hot water acidified with 0.5% (v/v) acetic acid and sonication extraction; and BE, boiling extraction) were examined to compare the effects of different hot water extraction methods on the antioxidant properties of blueberries. The extraction yields of the AE, OE, HWSE, HWASE, and BE were 7.94%, 8.35%, 8.55% 9.15%, and 8.50%, respectively. The polyphenol and flavonoid contents of AE were 3.47 mg GAE/g and 1.59 mg RE/g, respectively, which were highest centents among others. Those of OE were ranked second to the highest. The total anthocyanin content of HWSE (5.29 mg/g) was significantly higher than that of others whereas that of AE showed the lowest content (0.96 mg/g). The order of ABTS radical and alkyl radical scavenging activities was as follows: AE › BE › OE › HWSE › HWASE. The antioxidant properties were considerably correspondent with the total polyphenol and flavonoid content. DPPH radical scavenging activity was quite high in HWSE, AE, and BE extraction, however, there were no significant differences among the five extraction methods in the aspect of Fe2+ ion chelating activities. Moreover, AE showed the highest SOD activity, and protected the dermal fibroblast the best against H2O2-induced cytotoxicity. In conclusion, it was suggested that the autoclave extraction (AE) would be the most effective method for preparing blueberry hot water extracts with relatively high antioxidant activities.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call