Characteristics and Antioxidative Activity of Fermented Mixed Grain Beverages Produced by Different Microbial Species

잡곡발효물의 제조와 항산화 활성 비교

The purpose of this study was to evaluate the functional characteristics of fermented mixed grain beverages obtained using different microbial species and to evaluate their suitability for consumption. Various fermented mixed grain beverages were prepared through fermentation with Aspergillus (A.) oryzae CF1003 (A), A. acidus KACC46420 (B), Rhizopus (R.) delemar KACC46149 (C), R. oryzae KACC45714 (D), R. oryzae KACC46148 (E), A-E mixed strains (F), A. oryzae CF1001 (G), A. acidus CF1005 (H) and A+H mixed strains (I). The visual appearance, flavor, taste, and the antioxidant capacity of each fermented beverage were then assessed. The chromaticity and aesthetic quality of the fermented beverage was measured and all fermented beverages appeared yellow. The C-, G-, H- and I-fermented beverages received scores of 3.319, 3.206, 3.170 and 3.025 points, respectively, following a sensory evaluation, while the others received less than 3 points. The polyphenol content of the different beverages were similar, while the flavonoid content significantly differed. In particular, the flavonoid content of the C- and E-fermented beverages was significantly higher than other beverages. Although the electron donating ability and reducing power of the fermented beverages was very low, the superoxide dismutase (SOD)-like activity of all beverages (except the E-fermented beverage) increased in a concentration-dependent manner. Specifically, the SOD-like activity from the F-fermented beverage at 10,000 ppm was more than 50%. Interestingly, the antioxidant activities of the beverages were unrelated to their polyphenol or flavonoid levels. This study also found that the aesthetic qualities of G- and H-fermented beverages were the highest and that this was completely independent of their antioxidant capacity. Therefore, our results suggest that further studies are required to develop mixed grain-derived fermented beverages that can also fulfill a useful functional purpose.

다양한 발효 균주를 이용한 잡곡발효음료 개발의 가능성을 확인하고자 7종의 균주와 2가지의 혼합균주를 이용하여 잡곡발효물을 제조하여 분석한 결과, 색도가 비교적 밝으며 붉은색보다는 노란색이 더 많이 측정되었다. 관능검사 결과, 종합적으로 C와 G, H가 상대적으로 높은 평가를 받았으며, 제조된 잡곡발효물의 세포독성은 10,000 ppm까지 관찰되지 않았다. 총 폴리페놀과 플라보노이드 함량에서 총 폴리페놀은 7.51~7.94 mg/g으로 모든 잡곡발효물에서 유사한 함량을 나타냈으나, 플라보노이드 함량은 C 샘플에서 15.62 mg/g으로 가장 많은 것으로 나타났다. 또한 잡곡발효물의 항산화 활성을 조사한 결과, 전자공여능에서는 C 샘플에서 4.48%로, 환원력에서는 G샘플이 0.247로 가장 높았으며, SOD 유사활성 측정에서는 E를 제외한 모든 샘플에서 농도 비례적으로 활성이 증가하였고, F 샘플 10,000 ppm에서 55.15%로 가장 높은 활성을 나타내었다. 이와 같이 다양한 균주를 이용한 발효물의 관능적 특성과 기능성을 검토함으로써 잡곡을 이용한 기능성 발효식품의 개발가능성을 제시하였다.