This study was conducted to investigate the effect of manufacturing temperature on curcuminoid contents and the antioxidant activity of turmeric (Curcuma aromatica Salab.) powder-enhanced nurungji. Two different processes employed turmeric powder (2%): AR (added after rice cooked) and BR (added before rice cooked). AR and BR nurungji samples were prepared by heating cooked rice at 180oC, 200oC, and 220oC for 3 minutes. As a result of the HPLC analysis, the contents of curcumin, demethoxycurcumin, and bisdemethoxycurcumin decreased as the heating temperature increased. Moreover, AR samples showed higher curcuminoids than BR samples. The total polyphenol contents, DPPH, and ABTS radical scavenging ability proportionally increased with the increase of the manufacturing temperature. On the other hand, flavonoid contents were decreased with increasing temperature. These results suggest that the preparation of turmeric powder-enhanced nurungji by AR process at 200oC is preferable to preserving curcuminoid contents and antioxidative activity.

This study was performed to evaluate the quality characteristics and antioxidant activity of Nurungji by varying the purple sweet potato powder addition time (AR: added after rice cooking, BR: added before rice cooking) and powder ratio (0, 2, 4, 6, 8%) on the prepared rice during Nurungji’s manufacturing. In both AR and BR samples, water binding capacity, soluble solid content, reducing sugar, and hardness increased with an increasing proportion of purple sweet potato powder; however, the pH and moisture content decreased. The L value and b value decreased and increased with the influence of anthocyanin in purple sweet potato powder. The total polyphenol, flavonoid, anthocyanin contents, DPPH, and ABTS radical scavenging activity were highest in Nurungji with 8% of purple sweet potato powder. Moreover, AR samples showed higher antioxidant activity than BR samples. Based on the study results above, the preparation of Nurungji with 8% purple sweet potato powder by AR process was more favorable based on the content of antioxidants and antioxidant activity.

This study was carried out to compare the quality characteristics and antioxidant activity by varying the barley sprout powder addition time, production temperature, and powder addition ratio (0, 2, 4, 6, 8%) on the prepared rice during the manufacturing process of Nurungji. When we manufactured for 2 min at 200oC, the total polyphenol and flavonoid contents were the highest in Nurungji with 4% of barley sprout powder. In this way, we measured the weight, water content, water binding capacity, soluble solids content, reducing sugar, color, hardness, sensory evaluation experiments by varying the powder content. The weight, water binding capacity, soluble solids content, reducing sugar, and hardness increased with an increasing proportion of barley sprout powder, however the water content decreased. The L value and b value decreased and the a value increased with the influence of chlorophyll pigments in barley sprout. Sensory evaluation showed that Nurungji with 4% sprout barley powder was the highest. Therefore, we judged that it is desirable to add 4% of the powder when manufacture the barley sprout powder Nurungji.