Chemical Composition of Smilax china Leaves and Quality Characteristics of Rice Cakes Prepared with Its Water Extract

The chemical composition of Smilax china leaves and the quality characteristics of seolgitteok (rice cake) prepared with a water extract of these leaves were evaluated. Sucrose, glucose, maltose, and fructose were found as free sugars in the leaves, while the main fatty acids were stearic and palmitic acids. Glutamic acid and potassium were found at the highest levels among the analyzed amino acids and minerals in the leaves, respectively. On a fresh weight basis, the content of total phenolics and condensed tannin was 1.26 and 0.74%, respectively. As the amount of S. china leaf extract increased, the lightness of seolgitteok significantly decreased (p<0.001) in the rice cake, while redness and yellowness of the cake increased. Texture evaluation showed that springiness, strength, and cohesiveness were higher in rice cakes prepared with 2% S. china leaf extract compared to rice cakes made with 1% extract. At the beginning of the storage period ($20^{\circ}C$), there were no significant differences in viable aerobic cell and mold counts among rice cakes, but after four days in storage, a significant reduction in microorganisms was observed in rice cakes prepared with increasing amounts of leaf extract. On sensory evaluation, rice cakes made with 1% water extract from S. china leaves scored the highest on flavor, taste, texture, and overall acceptability.