Optimization of the Sterilization Process of Slightly Acidic Electrolyzed Water and Its Effect on the Storage Quality of Yunnan Fresh Rice Noodles

To investigate the optimization of the sterilization process of fresh rice noodles by slightly acidic electrolyzed water(SAEW)and to find out the regularity of quality changes during the storage process of rice noodles. The conditions of SAEW sterilization on fresh rice noodles were optimized by response surface methodology using slightly acidic electrolytic water processing temperature,processing time and ratio of material to liquid as independent values respectively and the order of magnitude of death microorganism as response value. The fresh rice noodles were investigated with the best processing parameters and stored in a 27 ℃ incubator. Periodically determine the total surface colonies,moisture content,total acidity,pH value and color value of the fresh rice noodles during the storage process,and discuss the SAEW treatment. Sterile water treatment was used as control. The optimal processing conditions for SAEW were as follows: Processing temperature of 21 ℃,processing time of 15 min,and material-liquid ratio of 1∶16 (m∶V).Under this technological condition,the theoretical value of the death order of the total number of colonies was 3.09 lg CFU/g. Three verification experiments were carried out and the actual average colony death magnitude was (3.01±0.09) lg CFU/g. Under this condition,SAEW treatment could effectively control the number of microorganisms on the surface of the sample,at the same time delayed browning and increased in total acidity,reduced the loss of moisture content,and had no significant effect on pH.After the storage of fresh rice noodles after treatment,the total number of surface colonies was 7.46 lg CFU/g,and the total acidity was 0.392 g/100 g,which was lower than 8.73 lg CFU/g and 0.49 g/100 g of the control group,respectively. Color value was 39.73 and the water content was 0.69,which was higher than the control group’s 35.57 and 0.65.The pH was 4.64.The results show that the treatment of wild bacteria by SAEW can not only control the growth of microorganisms on the surface,but also slow down the deterioration of storage quality. The results can provide a theoretical basis for studying the application of slightly acidic electrolyzed water in the processing of fresh and wet rice noodles.