Location: Plant Polymer Research
Title: Microwave-assisted Extraction of Phenolics from Bean (Phaseolus vulgaris L.) Authors
Submitted to: Food Research International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 17, 2009
Publication Date: October 15, 2009
Citation: Sutivisedsak, N., Cheng, H.N., Willett, J.L., Tangsrud, R., Lesch, W.C., Biswas, A. 2009. Effect of Microwave Extraction on Phenolic Content of Beans. Food Research International. Available online at: http://dx.doi.org/10.1016/j.foodres.2009.09.014. Interpretive Summary: In this work, we discovered that microwave irradiation is an effective method of extracting phenolic phytochemicals from beans. Phenolics phytochemicals are associated with many health benefits. Eight beans were chosen that are important for North Dakota and Minnesota. In all cases, microwave extraction was superior, producing 2-3 times more phenolics than conventional heat extraction. This discovery will benefit bean growers from North Dakota and Minnesota who funded this research.
Technical Abstract: The phenolic phytochemicals are associated with many health benefits, and it is useful to develop improved methods for its extraction from beans. In this work, we showed that extraction with microwave irradiation is an effective method for the determination of extractable phenolic content in beans. Eight beans were chosen that are important for the Northarvest region of North America, including North Dakota and Minnesota. For this study, four temperatures (25ºC, 50ºC, 100ºC, 150ºC) and three solvents (water, 50% ethanol in water, and 100% ethanol) were used. As expected, the more colored beans gave higher phenolic extractables, and the phenolic level in hull was much higher than in meat. Furthermore, higher temperatures provided higher levels of extractable phenolics. The most effective extraction was achieved at a temperature of 150ºC with 50% ethanol in water as the extracting solvent. A comparison was made with conventional methods of extraction at 100ºC. In all cases, microwave extraction was superior, producing 2-3 times more phenolics than conventional heat extraction.