Quality Characteristics and Antioxidant Activity of Germinated Black Rice Porridge Based on the Amount of Astragalus membranaceus (Fisch.) Bunge and Fermented A. membranaceus (Fisch.) Bunge Added

Abstract

In this study, germinated black rice porridge was produced using Astragalus membranaceus (AM) and fermented A. membranaceus (FAM), and an attempt was made to compare their quality characteristics and antioxidant activities which are properties useful for the development of elderly-friendly food materials. As in previous studies, the black rice variety with the highest gamma-aminobutyric acid (GABA) content was germinated for three days, and the AM and FAM were extracted with distilled water and then freeze-dried and used for analysis. A porridge was prepared with the addition of extracts at different concentrations and the quality characteristics such as pH, acidity, and reducing sugar levels were investigated. The analysis showed that the content of free amino acids tended to increase with an increase in the amount of the AM and FAM added and the content increased by about 2.6 and 4.2 fold, respectively, compared with the control. In particular, the GABA content was 187.74 mg/kg in germinated black rice porridge with the addition of 5% FAM, which was about a 3.4-fold increase compared to the control. Therefore, this study suggests that while preparing germinated black rice porridge the addition of AM and FAM can increase the content and antioxidant activities of physiologically active substances and enhance its utility as an age-friendly food or functional material.