Quality characteristics and antioxidant activities of Korean traditional rice and quinoa-based wine "Makgeolli"

Background and ObjectivesMakgeolli is a traditional Korean rice wine that is brewed by fermenting a mixture of steamed rice and Nuruk. Quinoa products contain polyphenols, including phenolic acids, flavonoids, and tannins, which make up bioactive secondary plant metabolites that contribute to diverse physiological properties, such as antimicrobial, antioxidant, and antitumor activities. The preparation of rice-based Makgeolli (RM) and quinoa-added Makgeolli (QM) were obtained by combining rice and quinoa in ratios 1:1 (RM; control: without supplement). This study sought to assess the physicochemical, microbiological, antioxidant, and taste tests of RM and QM during a 6-day fermentation period. FindingThe alcohol content increased steadily until Day 6 (10.7%-10.3%). From the start of fermentation to Day 2 of fermentation, the number of lactic acid bacteria (LAB) in RM and QM increased rapidly (p < .05), with no significant increase thereafter (p > .05). 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities were significantly (p < .05) higher in QM (DPPH: 81.01%, ABTS: 91.46%) than in RM (DPPH: 43.65%, ABTS: 53.85%). The average result of iron(II) chelating activity for RM was 39.81%, while for QM was 47.09%. Moreover, superoxide dismutase scavenging activity of both RM and QM were 41.07% and 56.23%, respectively. There were no significant differences in color, smell, appearance, and overall acceptability between RM and QM (p > .05). However, taste values were significantly higher (p < .05) in QM than in RM (5.9 vs. 4.3). ConclusionMakgeolli supplemented with quinoa owing to its good physicochemical and microbiological characteristics, including high antioxidant properties and good consumer acceptance.