Pellicle formation, microbial succession and lactic acid utilisation during the aerobic deteriorating process of Sichuan pickle

Abstract

The pellicles formation, microbial changes and lactic acid utilisation during the aerobic deterioration of Sichuan pickle were discussed in this study. By plate counting, chemical detection and HPLC analysis, the aerobic deterioration of Sichuan pickle was featured by microbial growth, pellicle formation, lactic acid decrease and pH elevation. Bacteria dominated in pellicles and the pellicles present morphological change from smooth to wrinkly along with the aerobic deteriorating process. Nine species of bacteria were identified and responsible for the pellicle formation. Combined with Lactobacillus plantarum, eight pellicle‐forming bacteria were the dominant lactic acid consuming organisms in deteriorating Sichuan pickle. Especially under the harsh acid condition of the early deteriorating period, Lb. plantarum, pellicle‐forming bacteria Bacillus amyloliquefaciens, B. subtilis and Citrobacter freundii participated in the pellicles, utilised lactic acid and increased the brine pH effectively. Sequence analysis of 16S rDNA libraries suggested that the resulting pH of 4.8–5.0 initiated the growth of more undesirable organisms, and the pellicle bacterial diversity changed greatly compared with that in the early deteriorating period. The study indicated the important role of pellicles in the initiation of Sichuan pickle's aerobic deterioration and enhanced our ability to understand and potentially control the aerobic deterioration.

Influence of oxygen exposure on fermentation process and sensory qualities of Sichuan pickle (paocai)

“…S2C † ). 7,9 The fungi presented in COJ might play a vital role in the production of plant cell-wall degrading enzyme and coincide with significant texture collapse in Sichuan pickle ( Fig. 6 ).…”

“…It has been reported that Lactobacillus could participate in the conversion of lactic acid to acetic acid and initiate the aerobic deterioration of fermented vegetables. 7 The relative abundance of Lactobacillus (16 AE 9%) in CCJ still ranked no. 1 but was quite lower than that in COJ (Fig.…”

“…The degradation of lactic acid and the increase of acetic acid in COJ from the 32 nd day might be related to the premature pellicle formation in COJ ( Table 2 ), which was considered as an indicator of lactate utilization and aerobic deterioration. 7 The resulting pH elevation ( Fig. 1A ) from the 32 nd day provided alleviation in acid stress and initiated the rapid growth of undesirable organisms such as fungi (Fig.…”

“…3,5 Oxygen exposure is an inevitable environmental factor during vegetable fermentation. 6,7 During industrial production, the fermentation of Sichuan pickle may be exposed to different oxygen conditions. In most cases, the Sichuan pickle fermentation containers are sealed with water or plastic lm.…”

Microbiota Succession and Chemical Composition Involved in the Radish Fermentation Process in Different Containers

“…Fermented pickle is a typical food type representative of traditional Chinese fermented food, which dates back to 3,000 years ago (Xiong et al, 2012). It is always served as a side dish accompanying an entree or alone as an appetizer (Rao et al, 2018). The fermented vegetable has attracted increasing attention in recent years due to the pleasant taste, nutritional value, and health benefits .…”