Abstract: The effects of mixed culture fermentation with yeast, Lactobacillus bulgaricus and Streptococcus thermophilus on the quality of non-fried instant noodles were studied by rehydration test, texture analysis, electronic nose analysis and scanning electron microscopic (SEM) observation. The results showed that yeast largely affected the rehydration property and texture, while L. bulgaricus and S. thermophilus were mainly responsible for improving the flavor of non-fried instant noodles. The primary fermentation process was conducive to maintaining the cooking tolerance of non-fried instant noodles, while the secondary fermentation process was beneficial to improve the rehydration property and flavor, reducing the rehydration time to 4.0 min; the R(2) and R(7) responses of the rehydrated sample were 2.8 and 2.9, respectively. The SEM results showed that the samples had a uniform pore distribution after the secondary fermentation. Taken collectively, the optimal starter culture for the primary and secondary fermentation was 1.5% yeast + 0.075% L. bulgaricus + 0.075% S. thermophilus.

Key words: mixed starter culture; fermentation; non-fried instant noodles; rehydration; flavor