การสกัดสารสำคัญจากข้าวสังข์หยดงอกโดยวิธีสกัดด้วยตัวทำละลาย

Abstract

Sangyod rice is a native rice species with high nutritional value. Currently, the cultivation of Sangyod rice is decreased because the average selling price and yield per acre lower than other types of rice. This research aimed to produce rice extract by Sangyod rice germination and solvent extraction. In extraction process, ethanol with concentrations of 0%, 50% and 95% were used. Various extraction times of 0.5, 1, 2 and 4 h, rice-to-solvent ratio of 1:10, 1:15, 1:20 and 1:25 (g/mL), grinding of rice at 40 and 70 mesh size sieves and solvent recovery were studied. The results showed that the extract from germinated Sangyod rice has higher contents of active ingredient and antioxidant activity than non-germinated Sangyod rice and Riceberry rice. The results of 40 mesh size sieves with using 50% ethanol, extraction time of 0.5 h and rice-to-solvent ratio of 1:15 (g/mL) were optimum condition for the germinated Sangyod rice extraction. The extraction yield, TPC, TFC, GABA and DPPH antioxidant assay were found at 6.56%, 1,627.00 ± 53.08 mg GAE/100 g rice, 559.50 ± 17.06 mg QE/100 g rice, 9.97 ± 0.17 mg GABA/100 g rice and 0.16 ± 0.01 mg/mL, respectively. The ethanol can effectively be recovered from extraction with 86.33-87.33%. After make-up the used solvent by 50% ethanol, the solvent density was found at 0.940 g/cm3 closely to the initial solvent for extracting. The extract yield and active ingredient content by using the used solvent were almost as same as the using of initial solvent. These will effect to low cost and economically performing for rice extraction by ethanol in industrial scale. The results of this study can provide new opportunities to promote Sangyod rice growers and value added to the rice product in the form of face serum formulated with antioxidants.