Effect of germination on nutritional and bioactive properties of red rice grains and its application in cupcake production

Abstract

Rice flour is a promising ingredient for the development of gluten-free products due to its natural characteristics such as hypoallergenic nature, mild flavor, gel stability while freezing or thawing, and resistance to acidic ingredients. The aim of this study was to evaluate the effect of germination time on nutritional and bioactive properties of red rice and its application in the production of cupcakes. Red rice grains that were germinated for 8, 16, 24, 32, and 40 h, were evaluated along with a sample of non-germinated grains. The increase in germination time promoted a reduction in ash content, moisture, and pH, without changes in the other constituents of the basic composition. Regarding the content of phenolic acids and individual flavonoids in the free fraction, there was an increase in caffeic, coumaric, and ferulic acids, and myricetin after 16 h of germination. The content of GABA (gamma-aminobutyric acid) in the flour also increased over time, reaching 1.86 mg 100/g in 40 h, which further increased to 3.66 mg 100/g after baking the cupcakes. Concurrently, the cupcake acceptability index of 89.65% indicated that the product was accepted sensorially by the consumer. The germination of red rice results in the release of/increase in the content of some compounds, which makes it a suitable alternative for application in food products.