Physico-Chemical and Sensory Properties of Commercial Korean Traditional Soy Sauce of Mass-Produced vs. Small Scale Farm Produced in the Gyeonggi Area
The core ingredient of traditional Korean style soy sauce is soy bean without any wheat or rice incorporated. National brands as well as regional micro-brewed companies constitute the soy sauce market in Korea. The present study investigated the physico-chemical and sensory properties of soy sauces produced by small-scale or mass-production. Additionally, the key physico-chemical parameters sufficiently representing the critical sensory characteristics have been identified. Ten types of soy sauce brewed by the Korean traditional method were selected for the study. Among these samples, seven types were brewed in small-scales in the Gyeonggi-do region whereas the other 3 types were mass-production products of major national brands. The total solid, reducing sugar, salinity, sugar content, amino nitrogen, CIELAB, acidity, and pH of soy sauce samples were measured for the physico-chemical analysis. A generic descriptive analysis was conducted to analyze the sensory characteristics of the samples using six trained panelists. The descriptive panel developed 21 sensory attributes. The data were statistically analyzed using ANOVA, PCA and PLSR. Overall, the micro-brewed products showed significantly higher value of salinity and acidity but lower content of reducing sugar than the mass-production products. The micro-brewed soy sauces elicited stronger fermented flavor, sourness, and bitterness whereas the national brand products elicited stronger alcoholic odor, sweetness and umami taste. Sugar content, acidity, and amino nitrogen showed strong relationships with fish sauce flavor, umami taste, and rich flavor. Salinity was closely related to the overall flavor intensity.