Recently, the research team of Fengzhong Wang, an innovation team for food nutrition and functional food, revealing the effects of different starter on quality, microbial composition and flavor of fresh fermented rice noodles. The relevant research results were published in the journal Food Research International (IF: 7.425).

The traditional fermentation process of fresh fermented rice noodles mainly relies on the bacteria coming from the surrounding environment and the rice material. Poor flavor even safety risks could be resulted from the pathogens which from surrounding environment or the rice. Four starter cultures that consist of Limosilactobacillus fermentum, Lactoplantibacillus plantarum and Saccharomyces cerevisiae were used to produce fresh fermented rice noodles. The cooking qualities and texture profiles of fresh fermented rice noodles, the dynamics of microbial diversities and volatile compounds at different fermentation stages were explored.

Fig. 1. Changes of fresh fermented rice noodles bacterial composition. (A) Relative abundance of bacterial community at the phyla level; (B) Relative abundance of bacterial community at the genus level; (C) Relative abundance of fungal community at the phyla level; (D) Relative abundance of fungal community at the genus level.

Fig. 2. Topographic plots (A, B and C), top view of the topographic plots (D, E and F) and the qualitative analysis topographic plots (G, H and I) of HS-GC-IMS about fresh fermented rice noodles.

Results showed that the fermentation time of the adding starter culture groups required 12 h, while that the natural fermentation group required 36 h. Significant improvement were observed in the texture profiles and cooking qualities of these five groups FFRNs (P ＜ 0.05). In addition, compared with natural fermentation group, the microbial diversity of four adding starter culture groups was significantly lower, which meant that the edible safety of fresh fermented rice noodles could be enhanced. Meanwhile, a total of 115 volatile compounds were detected by Gas chromatography-ion Mobility Spectrometry and Gas chromatography-mass spectrometry, the aldehydes, alcohols, acids and esters were increased while aldehydes were decreased in fresh fermented rice noodles during fermentation. Among these, the relative odor activity value of 50 volatile compounds was greater than 0.1, contributing unique flavors to fresh fermented rice noodles. The results of this study could provide theoretical basis for large-scale and industrial production of fresh rice flour.

Master student Aixia Wang is the first author of this work, while Prof. Fengzhong Wang and Prof. Li-Tao Tong are co-corresponding authors. This research was supported by the National Natural Science Foundation of China (31972005) and the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences (31401505).

Link to the paper: https://doi.org/10.1016/j.foodres.2022.111184