The processed drinks produced from grass of three varieties of rice (Jasmine, Sukhothai 1 and Sukhothai 2) and one each from wheat and barley grasses were analyzed for chlorophyll and total phenolic contents, and antioxidant activities [ABTS radical cation decolorisation assay and ferric reducing/antioxidative power (FRAP) assay]. The consumer acceptance of all the drinks was also evaluated. One serving size (200 mL) of these contained 82-958 μg of chlorophyll, 5.60-26.14 mg Gallic acid equivalent for total phenolic content and their antioxidant activities, ABTS and FRAP values were 17.88-35.18 mg Vitamin C equivalent and 5.66-23.70 mg FeSO4 equivalent, respectively. The overall consumer acceptability of drinks was significantly correlated to their aroma intensity and consumer preference on aroma and flavor. Jasmine and Sukhothai 1 rice grass drinks were most preferred, however, one subgroup preferred grass drink from Sukhothai 1 rice, while the second subgroup preferred the drinks from Sukhothai 2 rice and Jasmine rice. Wheat and barley grass drinks were not preferred by both subgroups.
Keywords: Antioxidant activities; Chlorophyll; Cluster analysis; Grass drinks; Internal preference map; Total phenolic content.