Production, iron analysis and consumer perception of functional Thai Sinlek iron rice (Oryza sativa) drink

Abstract

SummaryWe produced the iron rice (IR) drink, determined the relevant chemical composition and antioxidant activity and tested the consumers’ degree of satisfaction. IR grains were digested with α‐amylase and analysed chemical composition and antioxidant activity, while the hydrolysate (pH 4.0) and flavouring agents were added for final preparation of the IR drink. The IR hydrolysate contained a total iron content of 13.9 mg g−1, a total phenolic content of 1.33 ± 0.07 mg gallic acid equivalent g−1 and γ‐oryzanol of 70.12 ± 2.7 mg kg−1 rice grain, all of which inhibited the generation of free radicals in a concentration‐dependent manner. The IR drink was composed of flavonoids and phenolic acids for which kaempferol was predominant. The members of all three groups of elderly subjects who consumed the low‐dose IR (1.47 mg iron/100 mL), high‐dose IR (2.74 mg iron/100 mL) and white rice (WR; 0.5 mg iron/100 mL) drinks expressed satisfaction and interest with the beverages at 91.2%, 100% and 88.9%, respectively. In terms of sensory evaluation, the low‐dose IR drink revealed a higher acceptance rating than high‐dose IR and WR (P < 0.05). Notably, the Sinlek rice drink was abundant with iron, anti‐oxidative phenolics and γ‐oryzanol, for which consumers expressed an overall degree of acceptance (8.1 ± 1.1).