SCIENCE ASIA

Volume 46, No. 1S, Month MARCH, Year 2020, Pages 12 - 18

Conventional and microwave-assisted extraction for bioactive compounds from dried coffee cherry peel by-products and antioxidant activity of the aqueous extracts

Somruedee Thaiphanit, Warintorn Wedprasert, Aristha Srabua

Abstract Download PDF

The purposes of this research are to measure the chemical composition, bioactive compounds and antioxidant activities in dried coffee cherry peel by products from the mature fruits of Arabica and Robusta coffee beans and to determine the effects of conventional and microwave-assisted extraction techniques on the quantities of those compounds and antioxidant activities in aqueous extracts. Bioactive compounds from the by-products were extracted with water using either conventional or microwave-assisted extraction equipment at temperatures of 80, 90 and 100 °C or at microwave power settings of 450, 630 and 900 W, respectively, for various time period (1-5 min). The results showed that Arabica coffee cherry peel extracts exhibited significantly higher levels of bioactive compounds (except total carotenoids) and antioxidant activities than the Robusta coffee cherry peel extracts. The highest quantities of bioactive compounds in the aqueous extracts were found with conventional extraction. However, microwave-assisted extraction was far more efficient for compounds with antioxidant activity. The optimum extraction process for caffeine and carotenoids was a conventional extraction at 100 °C with a 5 min holding time using either Robusta or Arabica coffee cherry peels.

Keywords

coffee cherry peel, caffeine, bioactive compounds, conventional extraction, microwave-assisted extraction

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