Study On The Production Technology And Characteristics Of Fermented Rice Sauce

Rice sauce is a kind of semi-solid traditional condiments by cleaning, cooking,inoculating, fermentating. The mode of traditional manual workshop production is stillpopular, which is lack scientific guidance, technical support, quality control and so on. Atpresent, using the broken rice for making rice sauce has not been reported. Quality evaluation,the fermentation process and the characteristics of the product were studied in this paper. TheChanges of key indicators and the characteristics of flavor substances, antioxidant propertiesof the basic technology to make rice sauce and the Koji making process to fermentate wereanalyzed. The main conclusions can be summarized as follows:1. Sensory evaluation was used to evaluaterice sauce which were made from April1atthe natural conditions. The koji which was made the sauce had the highest fuzzy qualityevaluation value was selected from18groups.2. The response surface (RSM) analysis was used in screening the rice sauce yeast anduse amylase activity as the judgment standard to seach the growth condition. It’s obvious thatadded1.3times of water to steam rice to make sure the moisture content at55%～65%, andthen inoculation proportion at2%, the cultural temperatuer at31℃, natural pH is good forkoji-making.3. A large number of amylase was secreted during the procedure to culture koji for32～48h. The first crest value appeared when kojicultured for48h, and then much of protease wasproducted. During koji culturing, two peak formed at72h,96h. The koji which produced bynatural fermentation for72h is beneficial to obtain the greater enzyme activity koji.4. In the process of fermentation, the pH decreased rapidly at the first1～4d, at the sametime, total acid increased steadily and after30d remained stable. In the first10days, aminoacid nitrogen content and the reducing sugar content accumulated steadily, and then remainedstable. In fermentation for30days,each index of rice sauce become stable.5. In the later process of rice saucemash to fermentate,8%ethanol and5%salt wasadded to making rice sauce. In this method, we could obtain the sugar content to be20.73%,total acid content to be2.32g/L of rice sauce. 6. The L*values gradually decline, the a*value in general is on the rise and the b*values decrease after rising first during fermenting for1month. When fermentated for1month later the ingredient keep stable. Taking1～3months for fermentation, the flavor of ricesauce become rich, and then along with the extension of fermentation time, flavor componentsof rice sauce lose its original rich flavor.Timely stop the fermentation to insure high qualityproduct is needed. At the same time, in the wake of the rice sauce mash fermentation, totalphenolic content and its DPPH scavenging ability increased gradually.