Fermented foods in a global age: East meets West.

Microbial sulfur metabolism plays crucial roles in various food and alcoholic beverage fermentations. 3-(Methylthio)-1-propanol and dimethyl disulfide are important sulfur compounds in fermented foods and alcoholic beverages. Here, we studied the dynamics of these two compounds during spontaneous Chinese liquor fermentation. The two compounds reached the maximum concentration at day 10 and the maximum production rate at day 3. Metatranscriptomic analysis at days 3 and 10 revealed a total of 354 metabolically active microorganisms. Saccharomyces and Lactobacillus were identified as core microbiota critical for sulfur compound production based on both the transcript abundances of the principal genes and the distribution frequencies of 31 enzymes involved in sulfur metabolism. Saccharomyces transcribed genes encoding 23 enzymes related to the generation of 3-(methylthio)-1-propanol and dimethyl disulfide, and Lactobacillus was active in the methyl cycle, which recycles methionine, the precursor of the two sulfur compounds. Furthermore, the sulfur metabolism-related characteristics of two representative species were studied in coculture during a simulated fermentation. Saccharomyces cerevisiae JZ109 produced 158.4 μg/liter 3-(methylthio)-1-propanol and 58.5 μg/liter dimethyl disulfide in monoculture, whereas Lactobacillus buchneri JZ-JN-2017 could not produce these two compounds in monoculture. Their coculture significantly enhanced the generation of 3-(methylthio)-1-propanol (350.0 μg/liter) and dimethyl disulfide (123.8 μg/liter). In addition, coculture significantly enhanced the gene transcriptions (fold change, 1.5 to ∼55.0) that convert methionine to these two compounds in S. cerevisiae and in the methyl cycle of L. buchneri This study reveals a novel synergistic effect between members of the core microbiota in the production of sulfur compounds via methionine recycling in spontaneous Chinese liquor fermentation.IMPORTANCE Sulfur compounds play a crucial role in the aroma quality of various fermented foods and alcoholic beverages. However, it is unclear how these compounds are produced by microbes during their spontaneous fermentations. Here, we identified the core microbiota (Saccharomyces and Lactobacillus) associated with sulfur metabolism by determining both transcript abundance and distribution frequency of each genus in spontaneous Chinese liquor fermentation. This study provides a system-level analysis of sulfur metabolism by the metatranscriptomic analysis and culture-dependent methods. It sheds new light on how the metabolic behavior of the microbiota contributes to the liquor aroma quality. Furthermore, this work reveals a novel synergistic effect between Saccharomyces and Lactobacillus in the production of sulfur compounds, in which Lactobacillus regenerates the precursor methionine for sulfur compound production by Saccharomyces Our findings can contribute to the enhancement of aroma characteristics in Chinese liquor and open new avenues for improving various food and alcoholic beverage fermentation processes.

A study on indigenous fermented foods and beverages of Kokrajhar, Assam, India

The concept of "ethno-microbiology" is to understand the indigenous knowledge of the Indian people for production of culturally and organoleptically acceptable fermented foods by natural fermentation. About 1000 types of common, uncommon, rare, exotic and artisan fermented foods and beverages are prepared and consumed in different geographical regions by multi-ethnic communities in India. Indian fermented foods are mostly acidic and some are alkaline, along with various types of alcoholic beverages. A colossal diversity of microorganisms comprising bacteria mostly belongs to phylum Firmicutes, filamentous moulds and enzyme- and alcohol-producing yeasts under phyla Ascomycota and Mucoromycota, and few bacteriophages and archaea have been reported from Indian fermented foods. Some microorganisms associated with fermented foods have functionalities and health promoting benefits. "Ethno-microbiology" of ethnic Indian people has exhibited the proper utilisation of substrates either singly or in combination such as fermented cereal-legume mixture (idli, dosa and dhokla) in South and West India, sticky fermented soybean food (kinema and related foods), fermented perishable leafy vegetable (gundruk and related foods), fermented bamboo shoots (soibum and related foods) and fermented fish (ngari and others) in North East India, and fermented meat and sausage-like products in the Indian Himalayas, fermented coconut beverage (toddy) in coastal regions, and various types of naturally fermented milk products (dahi and related products) in different regions of India. This review has also highlighted the "ethno-microbiology" knowledge of the people involving the consortia of essential microorganisms in traditionally prepared amylolytic starters for production of cereal-based alcoholic beverages. The novelty of this review is the interpretation of ethno-microbiological knowledge innovated by ethnic Indian people on the use of beneficial microorganisms for food fermentation to obtain the desired fermented food products for consumption.

Chhattisgarh is known as “rice bowl of India” due to enormous production of rice. Rice is the major ingredient of the ethnic fermented food and beverages of Chhattisgarh. Apart from rice, traditional dishes are also made from wheat, barley, and different lentils. Fermentation process has an impact on food’s aroma, flavor, texture, and nutritional content besides preservation. The ethnic food of Chhattisgarh serves a wide range of mouthwatering dishes that are enriched with flavor and exceptional taste. With nutritional values, different fermented foods are lays an important ethic place in tribal people’s life. Beverages play an important role in the life of tribal people of Chhattisgarh state. Fermented beverages are consumed in festivals, marriages, funeral feast, and other ceremonies cerebrated by tribal peoples. Fermented beverages and foods have several health benefits. Main ethnic beverage of Chhattisgarh is handia, salfi, and mahua. Handia is made up of cooked rice, mahua is made up of mahua flowers, and salfi is obtained from trunk sap of salfi. Some important fermented foods of Chhattisgarh are boree basi, bara, dehori, aeersa, pidiya, bafaur, bijori, rakhiya bari, etc. Most of the dishes are made up mainly from rice or rice flour and consumed during the festivals, marriage ceremony, and special occasions. Fermented food and their recipes give a real treat to the taste buds of people. These ethnic fermented Chhattisgarh beverages and dishes are healthy, cheap, and easy to digest.

Ethyl carbamate, a genotoxic chemical contaminant present in fermented alcoholic beverages and foods, is formed from naturally occurring substances in these beverages and foods. Studies have shown that the content of ethyl carbamate can increase significantly during product storage and maturation, especially if favorable conditions are present. Higher levels of ethyl carbamate have been associated with distilled alcoholic beverages, mainly obtained from stone fruits. Ethyl carbamate content is lower in fermented foods, such as bread, yogurt, and fermented sauces. EC formation occurs through several different pathways in food systems. A primary pathway involves select compounds reacting with ethanol (EtOH); therefore, the majority of the research has focused on the occurrence of EC in alcoholic beverages Due to health risks, some countries have imposed legal limits on carbamate content in alcoholic beverages.

More than 48 types of major and minor ethnic fermented foods and alcoholic beverages are produced using indigenous knowledge of food fermentation in Sikkim and Darjeeling hills. There are eight different categories of ethnic fermented foods and beverages based on substrates which are prepared and consumed in these regions: fermented vegetable products, fermented legumes, fermented cereals, fermented dairy products, traditionally preserved fish products, traditionally preserved meat products, amylolytic starter cultures and alcoholic beverages. Almost all categories of fermented foods are prepared by natural fermentation without starter cultures, except in alcoholic fermentation which is traditionally prepared by ‘back-sloping’ dry amylolytic starters. Among the ethnicity, the Gorkha is the largest stakeholder as well as consumers of 80% of the fermented foods and beverages of Darjeeling hills and Sikkim. Functional microorganisms play important roles in the traditional fermentation processes by their functionality and impart health-promoting benefits. Extensive researches have been carried on almost all ethnic fermented foods and beverages of Sikkim and Darjeeling hills by Tamang and team for the last 33 years documenting and profiling microbial community, functionality, nutritional aspects and some health benefits. Our finding proves that microbial diversity in ethnic fermented foods contributes significant genetic resources due to diverse food cultures of the multi-ethnic groups of people in Sikkim and Darjeeling hills.

Diversity of yeasts in Indian fermented foods and alcoholic beverages.

Melatonin has recently been detected in fermented beverages and foods, in which microorganism metabolism is highly important. The existing literature knowledge discusses the direction for future studies in this review. Evidence shows that many species of microorganisms could synthesize melatonin. However, the actual concentrations of melatonin in fermented foods and beverages range from picograms per milliliter to nanograms per milliliter. Different types of microorganisms, different raw materials, different culture environments, the presence or absence of precursors, high or low alcohol content, and different detection methods are all possible reasons for the huge difference of melatonin levels. Thus far, there have been relatively few studies on the melatonin synthesis pathway microorganisms. Thus, referring to the synthetic pathway of plants and animals, the putative melatonin biosynthesis pathway of microorganisms is presented. It will be significant to discuss whether all species of microorganisms have the capacity to synthesize melatonin and what the biological functions of melatonin are in microorganisms. Melatonin plays a lot of important roles in microorganisms, particularly in enhancing the tolerance of environment stress. Also, the loss of melatonin concentration in commercially available fermented foods and beverages is a ubiquitous trend, and how to solve this problem is a new field to be further explored.

Himachal Pradesh is situated in the lap of the Western Himalayas with a diverse culture and cuisine. Mostly preparation and usage of fermented foods and alcoholic beverages are associated with tribal areas of the region. Some ethnic fermented foods, commonly prepared in Himachal Pradesh, are bhaturu, manna, marchu, siddu, dosha, chilra (lwar), bedvin roti, gulgule, seera, pinni/bagpinni, pakk, thuktal, borhe, sepubari, bari, churpa, and aska. Mostly these fermented foods are prepared from cereals, viz., wheat, barley, and buckwheat, but some are prepared from legumes and milk too. Traditional fermented alcoholic beverages of Himachal Pradesh include sura, chhang/lugri, angoori/kinnauri, daru/chakti, chulli, behmi, and arak/ara which are prepared from cereals (rice/barley), fruits (apple/wild apricot/grapes), jaggery, and millets. These ethnic fermented foods and alcoholic beverages are especially used during the local festivals, religious ceremonies, and marriage functions in the rural and urban areas of the state and are an important part of the day-to-day life of people of Himachal Pradesh.

As one of the origin centers of domesticated plants in the world, Ethiopia is rich in diversified fermented foods and beverages, in which yeasts are usually among the essential functional microorganisms. This study aims to investigate yeast species diversity and distribution in indigenous fermented products in Ethiopia using conventional isolation and molecular identification methods. Yeast cell counts in 221 samples of various Ethiopian traditional fermented products, including fermented staple foods, alcoholic beverages, dairy products, and condiments, were compared using the typical dilution plating method. A total of 475 yeast isolates were recovered from these samples and 41 yeast species belonging to 25 genera were identified from yeast isolates using the sequence analysis of the D1/D2 domain of the large subunit of rRNA gene. Candida humilis, Wickerhamomyces anomalus, Meyerozyma guilliermondii, Pichia kudriavzevii, and Saccharomyces cerevisiae were the most dominant species that were widely distributed among the majority of the fermented products analyzed in the current study. Significant variations were encountered both in yeast cell counts, diversity, and distribution of yeast species among different types of fermented products and even among different samples of the same types of fermented products. It calls for a more extensive and systematic microbiological study of Ethiopian indigenous fermented foods, beverages and other related products that can be helpful for standardization and large-scale production of these foods in Ethiopia. © 2020 Society of Chemical Industry.

Fermentation has been a significant food processing and storage method in human dietary culture since ancient times. Nowadays, an increasing number of research studies are intensely focusing on the health advantages that fermented beverages and foods have. Type 2 diabetes mellitus, known as the metabolic disorder with high blood glucose level, is prevailing in modern society and seriously harms publics’ well-being. However, several studies showcased the benefits of fermented food in the potential treatment and prevention of type 2 diabetes. Effect of animal-based fermented food, such as yogurt, on type 2 diabetes has been greatly explored, but insufficient studies specifically explored the relationship between plant-based fermented food and type 2 diabetes. This article investigated the health benefits of plant-based fermented beverage and food, including vegetables, tea, fruits, legumes, and grains, on type 2 diabetes. In conclusion, the fermentation process enhanced the nutritional value of the raw material. Fermented food and beverage are potentially diabetes-friendly and desirable, but they must be consumed in moderation.

The tradition of making fermented foods and beverages in Iraq dates back to 7500 BC. These fermented foods and beverages are represented by meat-, milk-, vegetable-, and fruit-based products reflecting diversity of agricultural production in ancient Iraq (Mesopotamia). Although the recipes for some fermented foods and beverages were lost throughout history, those remaining foods and beverages occupy a noticeable position in modern Iraqi cuisine. In this review, knowledge and techniques for preparation of 5 traditional fermented foods, i.e. Basturma, Smoked Liban,Aushari cheese, Turshi, and Sour Khobz, and 3 fermented beverages, i.e. Shanina, Sharbet Zbeeb, and Erk Sous in Iraq, are documented. Traditional fermented foods and beverages have multiple health benefits because of high content of probiotics and bioactive compounds. Traditional fermented foods and beverages are made using the back-slopping technique which ensures safety of production and maintains organoleptic properties. The review highlights the potential of fermented foods and beverages for their large-scale commercialization.

Biogenic amines (BAs) are potential amine hazards that are detected in fermented foods and alcoholic beverages. Excessive intake of BAs may lead to allergic symptoms such as difficulty in breathing, nausea, and vomiting. Degradation of BAs by multicopper oxidase (MCO) is a promising method as it has little effect on the fermentation process, food nutrition, and flavor. However, the application of MCO in food industry was restricted due to its poor catalytic properties and low productivity. In this work, food-grade expression of the Bacillus amyloliquefaciens MCO (MCOB) and its three mutants were successfully constructed in Lactococcus lactis NZ3900. The expression level of MCOB in L. lactis NZ3900 was dramatically enhanced by optimizing the cultivation conditions, and the highest expression level reached 4488.1 U/L. This was the highest expression level of food-graded MCO reported so far, to our knowledge. Interestingly, the optimal reaction pH of MCOB expressed in L. lactis NZ3900 switched to 4.5, it would be more suitable for degrading BAs in food as the pH value of most fermented foods was found to be 4.5. Moreover, MCOB expressed in L. lactis NZ3900 was quite stable (with more than 80% residual activity) in the pH range of 4.0–5.5, the catalytic rate constant (kcat) and specific activity of MCOBLS were all dramatically increased compared with that of MCOB expressed in Escherichia coli. Using histamine as the substrate, the degradation of BAs within 24 h by MCOB expressed in L. lactis NZ3900 was 69.7% higher than that expressed in E. coli. The results demonstrated the potential applications of MCOB in food industry for reduction of biogenic amines.

As Korea represents longer than 5000 years of history, various foods and beverages have been developed and settled as daily foods during this long period of history. Also, foods and beverages contribute to be settled down to the unique diet as traditional foods. Based on agricultural, livestock, and marine products produced in the Korean Peninsula, many types of traditional foods are introduced and transmitted from generation to generation. In addition, a specific culture of dishes that garnishes dishes with boiled rice, which is the staple food influenced by grain-based dietary habits, has settled. Vegetables and fishes have been used as major side dishes, and various fermentation techniques depending upon raw materials were applied to create new varieties of unique foods. By these fermentation skills, there were various fermented foods that appeared and led to establish the basis of unique tastes and flavors to all kinds of foods. The fermented traditional foods have very unique flavors and tastes that are not present in their original raw materials. They produce not only those flavors but also various components which have a wide range of bioactive functions, such as anticancer, anti-hypertension, anti-diabetes, and anti-obesity. In this chapter, fermented soybean products, lactic acid-fermented vegetable products, Kimchi, fermented fishes for condiments, and fermented alcoholic beverages, mainly Makgeolli that represent Korean ethnic fermented beverage, are presented with their functionalities.

ABSTRACTThe occurrence of ethyl carbamate was investigated in fermented foods and alcoholic beverages of the Korean total diet study. The concentrations of ethyl carbamate ranged from not detected to 166.5 μg kg−1. Dietary exposure to ethyl carbamate was estimated by the probabilistic method. Estimated intakes of ethyl carbamate from foods and alcoholic beverages were 4.12 ng kg−1 body weight (bw) per day for average consumers and 12.37 ng kg−1 bw/day for 95th percentile high consumers. The major foods contributing to ethyl carbamate exposure were soy sauce (63%), followed by maesilju (plum liqueur, 30%), whisky (5%), and bokbunjaju (black raspberry wine, 2%). On the basis of the benchmark dose lower confidence limit 10% (BMDL10) of 0.3 mg kg−1 bw/day, margins of exposure were 128,000 for mean exposure and 40,000 for 95th percentile exposure. This indicates that the exposure of the Korean general population for ethyl carbamate is of low concern. However, careful vigilance should be continued for high consumers of fermented foods and alcoholic beverages.