Effects Of Pretreatment With Dimethyl Dicarbonate On The Quality Characteristics Of Fermented Huyou Juice And Storage Stability

Huyou (Citrus grandis (L.) Changshan-huyou) from ChangShan in Zhejiang, China, is one of the most popular fruits cultivated and consumed worldwide. However, there are no reports on improvement of the edible value through fermentation processing using lactic acid bacteria (LAB). In this study, effects of pretreatment of Huyou juice with dimethyl dicarbonate (DMDC) on quality attributes of the product fermented by Lactobacillus plantarum L1 and Lactobacillus fermentum L2 were investigated using a pasteurized Huyou juice as a control group. The results showed that the application of DMDC to a Huyou juice preparation can ensure the microbiological safety, sensory, and nutritional properties of the products. Furthermore, the flavor of Huyou juice was improved, and the total phenolic and total flavonoid contents (TPC and TFC) increased after the fermentation processing. Compared with the fermented pasteurized Huyou juice, the fermented DMDC-sterilized Huyou juice had better color, which was closer to that of the fresh Huyou juice (p > .05). Moreover, the fermented DMDC-sterilized Huyou juice had a better odor and overall acceptability in the sensory evaluation. Various physicochemical parameters, including the viable cell count, pH, L* value, b* value, vitamin C, TPC, and TFC, of the fermented product treated with DMDC were determined during storage at 4 degrees C. The a* and Delta E* values slowly increased. The viability counts of LAB in both fermented pasteurized and DMDC-sterilized Huyou juices were maintained at 7.0 log CFU/ml after 4 weeks of storage at 4 degrees C. These results indicate that DMDC can be a good alternative for pasteurization at the prefermentation stage of Huyou juice.Practical applications This study compared the effects of pasteurization and dimethyl dicarbonate (DMDC) sterilization on the quality and flavor of Huyou juice and the storage quality of fermented Huyou juice. DMDC could be an ideal alternative for pasteurization for the prefermentation stage of Huyou juice and played a positive role in improving the flavor and quality of fermented Huyou juice. At the same time, it also laid a theoretical foundation for the upgrade and transformation of Huyou (Citrus changshanensis) products.