Jeung-Pyun is one of the Korean traditional rice cake with the fermentation process. It is made by adding Makgeolli, rice wine, residue to the rice flour and steaming after fermentation. Dutch coffee is also called cold-brew, meaning brewing for a long time at low temperature. It has been gaining popularity recently due to distinctive scent and mild taste, which is possible to store in refrigerator. Therefore, this study was conducted to investigate the effects of Dutch coffee extracts on the quality characteristics of Jeung-Pyun in order to diversify colors and tastes of Jeung-Pyun for revitalization of traditional food, and increase in the consumption of rice.
Optimal Dutch coffee extraction condition using the RSM were: a extraction time of 3 h and a temperature of 20°C. The moisture content of Jeung-Pyun was 51.47~52.08%. The pH of Jeung-Pyun batters gradually decreased to 5.44~5.55 as the fermentation was progressed, but increased again to 5.49~5.77 after steaming. L-value (lightness) of Jeung-Pyun was significantly higher in the 5% group, but the a (redness) and b-value (yellowness) significantly increased as the coffee addition ratio increased. Moreover, L-value of the upper surface of Jeung-Pyun was lower than in the side surface, whereas the reverse was true for a- and b-values. In the texture profile analysis, the 9% group resulted in the highest hardness, cohesiveness and springiness. On the other hand, gumminess and brittleness were the lowest in the control group and significantly increased as the coffee addition ratio increased. For the sensory test, overall desirability was the highest in the 5% group, but the lowest in the 3% group. Therefore, based on above results, the Jeung-Pyun with 5% Dutch coffee is concluded to be the best.