Characterization and comparison of the bacterial community on environmental surfaces through a fresh-cut vegetables processing line in China

Jing-Guo Xu; Xiao-Ning Huang; Jiao Meng; Jing-Yu Chen; Bei-Zhong Han

doi:10.1016/j.foodres.2022.111075

Characterization and comparison of the bacterial community on environmental surfaces through a fresh-cut vegetables processing line in China

Food Res Int. 2022 May:155:111075. doi: 10.1016/j.foodres.2022.111075. Epub 2022 Feb 28.

Authors

Jing-Guo Xu¹, Xiao-Ning Huang¹, Jiao Meng¹, Jing-Yu Chen², Bei-Zhong Han¹

Affiliations

¹ Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
² Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: chenjy@cau.edu.cn.

PMID: 35400453
DOI: 10.1016/j.foodres.2022.111075

Abstract

Zoning is typically adopted by food manufacturers and classified into three different zones including Zone 1 (food contact surface), Zone 2 (proximity to food and food contact surfaces) and Zone 3 (remote surfaces from processing). In this study, environmental surfaces belonging to these three zones were sampled during food processing in a fresh-cut vegetables (FVs) processing facility located in Beijing, China. Bacterial loads in terms of aerobic plate count and coliform count were evaluated by culture-dependent techniques. The profile and diversity of bacterial community in these three zones were investigated by high-throughput sequencing. Zone 1 showed similar microbiota and predominated by Pseudomonas and Acinetobacter, while the predominant genera on Zone 2 or 3 were quite varied among different processing steps. The SourceTracker analysis showed that most of the bacteria (above 80%) on surfaces were from unknown sources, while sorting and disinfection & cleaning steps contributed equally to the bacterial community of cutting areas. Microbial association network analysis revealed strong positive interactions of Comamonas and Janthinobacterium with Myroides and Serratia, respectively, whereas Pseudomonas showed no significant correlation with other genera. The function of microbial communities was predicted based on BugBase 16S rRNA database, and the results indicated that the proportions of potential biofilm-forming bacteria were above 70% in all samples, and species of Pseudomonas, Comamonas, Chryseobacterium and Janthinobacterium were opportunistic pathogens or spoilage bacteria. This study evaluated the bacteria risks including bacterial load, composition, as well as potential bacterial interaction, function and microbial transfer on food processing surfaces, which will facilitate our better understanding on the cross-contaminations and preventions of harmful microorganism in FVs processing industry.

Keywords: Bacterial community; Environmental surface; Fresh-cut vegetables; High-throughput sequencing; Pseudomonas.

MeSH terms

Bacteria / genetics
Food Microbiology
Microbiota*
Pseudomonas
RNA, Ribosomal, 16S / genetics
Vegetables* / microbiology

Substances

RNA, Ribosomal, 16S