Ademola O M, Adeyemi T E, Ezeokoli O T, Ayeni K I, Obadina A O, Somorin Y M, Omemu A M, Adeleke R A, Nwangburuka C C, Oluwafemi F, Oyewole O B, Ezekiel C N
Department of Food Science and Technology, Federal University of Agriculture, Abeokuta, Nigeria.
Department of Microbiology, Federal University of Agriculture, Abeokuta, Nigeria.
Lett Appl Microbiol. 2018 Oct;67(4):354-362. doi: 10.1111/lam.13040. Epub 2018 Aug 22.
Analysis of the bacterial community dynamics during the production of traditional fermented condiments is important for food safety assessment, quality control and development of starter culture technology. In this study, bacteria isolated during the processing of iru and ogiri, two commonly consumed condiments in Nigeria, were characterized based on phylogenetic analyses of the bacterial 16S rRNA gene. A total of 227 isolates were obtained and clustered into 12 operational taxonomic units (OTUs) based on 97% 16S rRNA gene similarity. The OTUs spanned three phyla (Firmicutes, Actinobacteria and Proteobacteria), and nine genera: Acinetobacter, Aerococcus, Bacillus, Enterococcus, Enterobacter, Lysinibacillus, Micrococcus, Proteus and Staphylococcus. OTUs closely related to species of Bacillus dominated the processing stages of both condiments. Although no single OTU occurred throughout iru processing stages, an OTU (mostly related to B. safensis) dominated the ogiri processing stages indicating potentials for the development of starter culture. However, other isolates such as those of Enterococcus spp. and Lysinibacillus spp. may be potential starters for iru fermentation. Presumptive food-borne pathogens were also detected at some stages of the condiments' processing, possibly due to poor hygienic practices.
Iru and ogiri are important condiments used for flavour enhancement in foods and serve as protein substitutes in diets among rural populations across West Africa. Consumption of these condiments is growing, reinforcing the need to scale up their production. Production of these condiments includes spontaneous fermentation, which often leads to inconsistent product quality and unguaranteed safety. This study has demonstrated the bacterial succession in iru and ogiri processing and highlights species that could be selected and exploited for starter culture development. This study provides a starting point to produce quality and microbiologically safe iru and ogiri condiments.
分析传统发酵调味品生产过程中的细菌群落动态对于食品安全评估、质量控制和发酵剂培养技术的发展至关重要。在本研究中，基于对细菌16S rRNA基因的系统发育分析，对尼日利亚两种常见食用调味品iru和ogiri加工过程中分离出的细菌进行了表征。共获得227株分离株，并根据97%的16S rRNA基因相似性聚类为12个操作分类单元（OTU）。这些OTU跨越三个门（厚壁菌门、放线菌门和变形菌门）和九个属：不动杆菌属、气球菌属、芽孢杆菌属、肠球菌属、肠杆菌属、赖氨酸芽孢杆菌属、微球菌属、变形杆菌属和葡萄球菌属。与芽孢杆菌属物种密切相关的OTU在两种调味品的加工阶段中占主导地位。虽然在整个iru加工阶段没有单一的OTU出现，但一个OTU（主要与安全芽孢杆菌相关）在ogiri加工阶段占主导地位，表明有开发发酵剂培养物的潜力。然而，其他分离株，如肠球菌属和赖氨酸芽孢杆菌属的分离株，可能是iru发酵的潜在发酵剂。在调味品加工的某些阶段也检测到了推定的食源性病原体，这可能是由于卫生习惯不良所致。
Iru和ogiri是用于增强食品风味的重要调味品，也是西非农村人口饮食中的蛋白质替代品。这些调味品的消费量正在增加，这加强了扩大其生产规模的必要性。这些调味品的生产包括自然发酵，这往往导致产品质量不一致和安全性无保障。本研究展示了iru和ogiri加工过程中的细菌演替，并突出了可用于开发发酵剂培养物的物种。本研究为生产高质量和微生物安全的iru和ogiri调味品提供了一个起点。
