Prospects for Food Fermentation in South-East Asia, Topics From the Tropical Fermentation and Biotechnology Network at the End of the AsiFood Erasmus+Project

Physicochemical, Nutritional, and Antioxidant Properties of Traditionally Fermented Thai Vegetables: A Promising Functional Plant-Based Food

Fermented plant-based products were gathered from various regions in Thailand and categorized into 10 types of traditional commercial vegetables. Different vegetable materials and natural fermentation methods influence the diverse physical, chemical, nutritional, and functional attributes of the products. All the traditionally fermented Thai vegetable samples collected showed physicochemical properties associated with the fermentation process, contributing to the nutritional and functional quality of the final products. Achieving consistent research results is challenging due to the intricate nature of food matrices and biochemical processes during fermentation. The roles of microorganisms, especially probiotics, are crucial in delivering health benefits through fermented foods. Traditionally fermented Thai vegetable foods contain high levels of total soluble solids, titratable acidity, and salinity in pickled shallot and ginger as a result of the natural fermentation process and the ingredients used. The research findings were confirmed using a hierarchical cluster analysis (HCA)-derived dendrogram pattern. The nutritional compositions, total phenolic contents, and antioxidant activities varied among the different types of vegetables. The correlations among lipid, protein, fiber, total soluble solid (TSSs), total titratable acidity (TTA), and salinity as potential biomarkers in fermented vegetable products were examined. The results suggest that traditionally fermented Thai vegetable products significantly impacted food research by enhancing the quality and preserving the authenticity of traditionally fermented Thai vegetables.

Fermented fish products in South and Southeast Asian cuisine: indigenous technology processes, nutrient composition, and cultural significance

The cleaner production of biomass into value-added products via microbial processes adds uniqueness in terms of food quality. The microbe-mediated traditional process for transforming biomass into food is a sustainable practice in Asian food industries. The 18 fermented fish products derived through this process as well as the associated micro-flora and nutritional composition have been focused. This review aims to update the process of green conversion biomass into value-added food products for a more sustainable future. Fish products are classified based on the substrate and source of the enzymes used in fermentation, which includes the three types of technology processing discussed. According to the findings, these fermented fish contain a plethora of beneficial microbiota, making them a valuable source of probiotics that may confer nutritional and health benefits.Bacillus(12 products),Lactobacillus(12 products),Micrococcus(9 products), andStaphylococcus(9 products) were the most common bacterial genera found in 18 fermented fish products. Consuming fermented fish products is beneficial to human health due to their high levels of carbohydrate, protein, fat, and lactic acid. However, biogenic amines, which are produced by certain bacteria as a by-product of their catabolic activity, are a significant potential hazard in traditionally fermented fish.

Evolution of Food Fermentation Processes and the Use of Multi-Omics in Deciphering the Roles of the Microbiota

Food fermentation has been practised since ancient times to improve sensory properties and food preservation. This review discusses the process of fermentation, which has undergone remarkable improvement over the years, from relying on natural microbes and spontaneous fermentation to back-slopping and the use of starter cultures. Modern biotechnological approaches, including genome editing using CRISPR/Cas9, have been investigated and hold promise for improving the fermentation process. The invention of next-generation sequencing techniques and the rise of meta-omics tools have advanced our knowledge on the characterisation of microbiomes involved in food fermentation and their functional roles. The contribution and potential advantages of meta-omics technologies in understanding the process of fermentation and examples of recent studies utilising multi-omics approaches for studying food-fermentation microbiomes are reviewed. Recent technological advances in studying food fermentation have provided insights into the ancient wisdom in the practice of food fermentation, such as the choice of substrates and fermentation conditions leading to desirable properties. This review aims to stimulate research on the process of fermentation and the associated microbiomes to produce fermented food efficiently and sustainably. Prospects and the usefulness of recent advances in molecular tools and integrated multi-omics approaches are highlighted.

Fermented fish products in South and Southeast Asian cuisine: indigenous technology processes, nutrient composition, and cultural significance

The cleaner production of biomass into value-added products via microbial processes adds uniqueness in terms of food quality. The microbe-mediated traditional process for transforming biomass into food is a sustainable practice in Asian food industries. The 18 fermented fish products derived through this process as well as the associated micro-flora and nutritional composition have been focused. This review aims to update the process of green conversion biomass into value-added food products for a more sustainable future. Fish products are classified based on the substrate and source of the enzymes used in fermentation, which includes the three types of technology processing discussed. According to the findings, these fermented fish contain a plethora of beneficial microbiota, making them a valuable source of probiotics that may confer nutritional and health benefits. Bacillus (12 products), Lactobacillus (12 products), Micrococcus (9 products), and Staphylococcus (9 products) were the most common bacterial genera found in 18 fermented fish products. Consuming fermented fish products is beneficial to human health due to their high levels of carbohydrate, protein, fat, and lactic acid. However, biogenic amines, which are produced by certain bacteria as a by-product of their catabolic activity, are a significant potential hazard in traditionally fermented fish.

Biogenic Amine Contents and Microbial Characteristics of Cambodian Fermented Foods

Naturally fermented foods are an important part of the typical diet in Cambodia. However, the food safety status of these products has not been widely studied. The aim of this study was, therefore, to provide an overview of the quality of these foods in relation to microbiology and biogenic amines. Additionally, the obtained results were compared to the habits and practices of Cambodians in handling this type of food. A total of 57 fermented foods (42 fishery and 15 vegetable products) were collected from different retail markets in the capital of Cambodia. Pathogenic Salmonella spp., Listeria spp., and Listeria monocytogenes were not detected in 25 g samples. Generally, less than 102 cfu/g of Staphylococcus aureus, Escherichia coli, Pseudomonas spp., Enterobacteriaceae, and molds were present in the fermented foods. Bacillus cereus group members (<102 to 2.3 × 104 cfu/g), lactic acid bacteria (<102 to 1.1 × 107 cfu/g), halophilic and halotolerant bacteria (<102 to 8.9 × 106 cfu/g), sulfite-reducing Clostridium spp. (<102 to 3.5 × 106 cfu/g), and yeasts (<102 to 1.1 × 106 cfu/g) were detected in this study. Still, the presence of pathogenic and spoilage microorganisms in these fermented foods was within the acceptable ranges. Putrescine, cadaverine, tyramine, and histamine were detected in 100%, 89%, 81%, and 75% of the tested products, respectively. The concentrations of histamine (>500 ppm) and tyramine (>600 ppm) were higher than the recommended maximum levels in respectively four and one of 57 fermented foods, which represents a potential health risk. The results suggest that the production process, distribution, and domestic handling of fermented foods should be re-evaluated. Further research is needed for the establishment of applicable preservation techniques in Cambodia.

Fermented foods in a global age: East meets West

Fermented foods and alcoholic beverages have long been an important part of the human diet in nearly every culture on every continent. These foods are often well-preserved and serve as stable and significant sources of proteins, vitamins, minerals, and other nutrients. Despite these common features, however, many differences exist with respect to substrates and products and the types of microbes involved in the manufacture of fermented foods and beverages produced globally. In this review, we describe these differences and consider the influence of geography and industrialization on fermented foods manufacture. Whereas fermented foods produced in Europe, North America, Australia, and New Zealand usually depend on defined starter cultures, those made in Asia and Africa often rely on spontaneous fermentation. Likewise, in developing countries, fermented foods are not often commercially produced on an industrial scale. Although many fermented products rely on autochthonous microbes present in the raw material, for other products, the introduction of starter culture technology has led to greater consistency, safety, and quality. The diversity and function of microbes present in a wide range of fermented foods can now be examined in detail using molecular and other omic approaches. The nutritional value of fermented foods is now well-appreciated, especially in resource-poor regions where yoghurt and other fermented foods can improve public health and provide opportunities for economic development. Manufacturers of fermented foods, whether small or large, should follow Good Manufacturing Practices and have sustainable development goals. Ultimately, preferences for fermented foods and beverages depend on dietary habits of consumers, as well as regional agricultural conditions and availability of resources.

Unraveling the Contribution of High Temperature Stage to Jiang-Flavor Daqu, a Liquor Starter for Production of Chinese Jiang-Flavor Baijiu, With Special Reference to Metatranscriptomics

Jiang-flavor (JF) daqu is a liquor starter used for production of JF baijiu, a well-known distilled liquor in China. Although a high temperature stage (70°C) is necessary for qualifying JF daqu, little is known regarding its active microbial community and functional enzymes, along with its role in generating flavor precursors for JF baijiu aroma. In this investigation, based on metatranscriptomics, fungi, such as Aspergillus and Penicillium, were identified as the most active microbial members and 230 carbohydrate-active enzymes were identified as potential saccharifying enzymes at 70°C of JF daqu. Notably, most of enzymes in identified carbohydrate and energy pathways showed lower expression levels at 70°C of JF daqu than those at the high temperature stage (62°C) of Nong-flavor (NF) daqu, indicating lowering capacities of saccharification and fermentation by high temperature stage. Moreover, many enzymes, especially those related to the degradation of aromatic compounds, were only detected with low expression levels at 70°C of JF daqu albeit not at 62°C of NF daqu, indicating enhancing capacities of generating special trace aroma compounds in JF daqu by high temperature stage. Additionally, most of enzymes related to those capacities were highly expressed at 70°C by fungal genus of Aspergillus, Coccidioides, Paracoccidioides, Penicillium, and Rasamsonia. Therefore, this study not only sheds light on the crucial functions of high temperature stage but also paves the way to improve the quality of JF baijiu and provide active community and functional enzymes for other fermentation industries.