Fermented foods, feeds and beverages

There has been a proliferation of books and papers dealing with the indigenous fermented foods/beverages of the world. It is anticipated that these foods/beverages will play an ever-increasingly important role in feeding both the developing and the developed world as population increases from approximately 4.5 billion to 6 billion by the year 2000 and to 8 to 12 billion people in the 21st century. The indigenous fermented foods consist of microbial protein grown on edible substrates. Microbial or single cell protein (SCP) per se continues to receive research and development attention. It is likely to play an important role in feeding animals in the future when it becomes competitive with soy protein. It may play a direct role in feeding humans in the future after its safety for feeding animals has been adequately demonstrated and it has been shown that it can be processed into foods acceptable to humans. At the present time, mushrooms, a form of microbial protein highly acceptable to humans, which can be grown readily on ligno-cellulosic and other agricultural and food processing wastes, offer considerable opportunity for expanding man's food supply.     

Preventive and therapeutic aspects of fermented foods

In recent times, the status of some fermented foods which are considered as functional foods that confer health benefits in certain disease conditions has grown rapidly. The health benefits of fermented foods are due to the presence of probiotic microbes and the bioactive compounds formed during fermentation. Microbes involved and metabolites produced by them are highly species specific and contribute to the authenticity of the fermented foods. Several studies pertaining to the effect of fermented foods on various disease conditions have been conducted in recent years using both animal models and clinical trials on humans. This review focuses on the impact of fermented foods on conditions such as diabetes, cardiovascular disease, obesity, gastrointestinal disorder, cancer and neurodegenerative disorders.     

传统大豆发酵食品在心脑血管疾病防治上的研究现状

人类生活水平的提高以及生活压力的增加,使心脑血管疾病的发生频率显著增加,并日趋成为威胁人类健康的重要原因。传统大豆发酵食品中的各种生理活性物质通过降血压和调节体内脂质、糖类代谢等多种作用来有效地防治心脑血管疾病;与传统药物相比,有效果显著与无毒副作用等优点,因此传统大豆发酵食品有广阔的发展应用前景。     

A microbiological study of Hussuwa: a traditional Sudanese fermented food from germinated Sorghum bicolor c.v. feterita

Hussuwa is a traditional Sudanese fermented food. Hussuwa made from Sorghum bicolor variety feterita exists in northern, central and eastern Sudan. The microbiological study indicated that the fermentation was primarily a lactic acid fermentation. The changes in microbial population, acetic acid bacteria, lactic acid bacteria and yeasts during all stages of hussuwa preparation and ripening were studied. The identification of fermented hussuwa microorganisms revealed that the main microorganisms were Lactobacillus saccharolyticum, Gluconobacter oxydans, Acetobacter xylinum and Saccharomyces cerevisiae. The metabolic products were studied in all stages of preparation and the period of ripening of hussuwa. The values of pH decreased as fermentation proceeded, and titratable acidity and volatile fatty acids increased.     

Occurrence and function of yeasts in Asian indigenous fermented foods

In the Asian region, indigenous fermented foods are important in daily life. In many of these foods, yeasts are predominant and functional during the fermentation. The diversity of foods in which yeasts predominate ranges from leavened bread-like products such as nan and idli, to alcoholic beverages such as rice and palm wines, and condiments such as papads and soy sauce. Although several products are obtained by natural fermentation, the use of traditional starter cultures is widespread. This minireview focuses on the diversity and functionality of yeasts in these products, and on opportunities for research and development.     

Evaluating the palatability of fermented foods

ABSTRACT

The present review deal with the novel studies which present possibility of generating a novel sensory evaluation instrument for describing comprehensive food palatability. These studies suggest the palatability can be dissected into its componential subdomains and the subdomains in turn reconstitute comprehensive palatability with evaluation of the quantitative contribution of each subdomain. The studies suggest the novel instrument is useful for comprehensive evaluation of palatability of multifarious fermented foods.     

Occurrence and taxonomic characteristics of strains of Saccharomyces cerevisiae predominant in African indigenous fermented foods and beverages

Indigenous fermented foods and beverages play a major role in the diet of African people. The predominant yeast species seen is Saccharomyces cerevisiae, involved in basically three groups of indigenous fermented products: non-alcoholic starchy foods, alcoholic beverages and fermented milk. These products are to a great extent made by spontaneous fermentation and consequently S. cerevisiae often coexists with other microorganisms even though a microbiological succession usually takes place both between and within species. The functions of S. cerevisiae are mainly related to formation of alcohols and other aroma compounds, but stimulation of e.g. lactic acid bacteria, improvement of nutritional value, probiotic effects, inhibition of undesired microorganisms and production of tissue-degrading enzymes may also be observed. Several different isolates of S. cerevisiae have been shown to be involved in the fermentations and some of the isolates show pheno- and genotypic characteristics that deviate from those normally recognised for S. cerevisiae.     

Koji glycosylceramide commonly contained in Japanese traditional fermented foods alters cholesterol metabolism in obese mice

ABSTRACT

Koji, which is manufactured by proliferating non-pathogenic fungus Aspergillus oryzae on steamed rice, is the base for Japanese traditional fermented foods. We have revealed that koji and related Japanese fermented foods and drinks such as amazake, shio-koji, unfiltered sake and miso contain abundant glycosylceramide. Here, we report that feeding of koji glycosylceramide to obese mice alters the cholesterol metabolism . Liver cholesterol was significantly decreased in obese mice fed with koji glycosylceramide. We hypothesized that their liver cholesterol was decreased because it was converted to bile acids. Consistent with the hypothesis, many bile acids were increased in the cecum and feces of obese mice fed with koji glycosylceramide. Expressions of CYP7A1 and ABCG8 involved in the metabolism of cholesterol were significantly increased in the liver of mice fed with koji glycosylceramide. Therefore, it was considered that koji glycosylceramide affects the cholesterol metabolism in obese mice.     

营养相互作用对传统发酵食品微生物群落构建的推动作用研究进展

传统发酵食品是由自然接种的多微生物组成的混菌体系,了解微生物群落自发式构建的机制是认识发酵机理和调控发酵的关键。尽管大量的测序数据已经对传统发酵食品中微生物群落的结构和功能有了较为清晰的认识,但是仍然不清楚微生物群落自发式构建的机制。本文提出微生物群落是分布式的代谢系统,微生物之间的营养相互作用推动了传统发酵食品微生物群落的自发式构建。本文主要阐述了营养相互作用的概念、发生的机理以及研究方法体系,整理了传统发酵食品中微生物之间营养相互作用的研究进展,并提出了未来的研究方向。通过营养相互作用推动的传统发酵食品微生物群落的自发式构建有助于定向控制发酵过程中的微生物种类、提高生产效率和改善发酵质量。     

中国传统发酵食品微生物组研究进展

传统发酵食品风味独特、营养丰富,多采用自然接种方式进行生产,部分类型的生产技艺已具有数千年的历史。近年来应用新技术手段对传统发酵食品发酵过程进行的研究表明,传统发酵食品微生物组具有丰富的科学内涵和重要的应用价值。本文就我国传统发酵食品微生物组的基本特征、研究进展和发展方向进行了简要的评述。     

“Ethno-microbiology” of ethnic Indian fermented foods and alcoholic beverages

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.     

The price of ultra-processed foods and beverages and adult body weight: Evidence from U.S. veterans

The consumption of ultra-processed foods in the U.S. and globally has increased and is associated with lower diet quality, higher energy intake, higher body weight, and poorer health outcomes. This study drew on individual-level data on measured height and weight from U.S. Department of Veterans Affairs medical records for adults aged 20 to 64 from 2009 through 2014 linked to food and beverage price data from the Council for Community and Economic Research to examine the association between the price of ultra-processed foods and beverages and adult body mass index (BMI). We estimated geographic fixed effects models to control for unobserved heterogeneity of prices. We estimated separate models for men and women and we assessed differences in price sensitivity across subpopulations by socioeconomic status (SES). The results showed that a one-dollar increase in the price of ultra-processed foods and beverages was associated with 0.08 lower BMI units for men (p ≤ 0.05) (price elasticity of BMI of −0.01) and 0.14 lower BMI units for women (p ≤ 0.10) (price elasticity of BMI of -0.02). Higher prices of ultra-processed foods and beverages were associated with lower BMI among low-SES men (price elasticity of BMI of −0.02) and low-SES women (price elasticity of BMI of −0.07) but no statistically significant associations were found for middle- or high-SES men or women. Robustness checks based on the estimation of an individual-level fixed effects model found a consistent but smaller association between the price of ultra-processed foods and beverages and BMI among women (price elasticity of BMI of −0.01) with a relatively larger association for low-SES women (price elasticity of BMI of −0.04) but revealed no association for men highlighting the importance of accounting for individual-level unobserved heterogeneity.     

传统大豆发酵食品中大豆低聚糖的生理功能研究

大豆低聚糖是大豆中可溶性碳水化合物的总称,在大豆和传统大豆发酵食品中含量丰富。近年研究发现大豆低聚糖在改善肠胃道功能、抗肿瘤、调节血脂等方面具有着重要的生理活性,因此引起了国内外研究人员的广泛关注。大豆低聚糖的研究,不仅能为功能性大豆制品的开发提供理论基础,也能为人们合理的膳食提供参考。本文综述了近年来国内外对大豆低聚糖生理保健机能的研究进展。     

Isolation and identification of killer yeasts from Agave sap (aguamiel) and pulque

Wild killer yeasts have been identified as inhibitory to strains used as starters in the production of alcoholic beverages such as beer and wine; therefore, killer or killer-resistant strains have been sought for use in alcoholic fermentations. In the current paper a total of 16 strains belonging to six species were isolated. From two samples of Agave sap (aguamiel) the following yeast strains were isolated: Candida lusitaneae (1), Kluyveromyces marxianus var. bulgaricus (2), and Saccharomyces cerevisiae (capensis) (1). Additionally, in seven samples of pulque (the fermented product), the species C. valida (six strains), S. cerevisiae (chevalieri) (4), S. cerevisiae (capensis) (1), and K. marxianus var. lactis (1) were found. The killer strains were C. valida and K. marxianus var. lactis from pulque and K. marxianus var. bulgaricus from aguamiel. One strain of S. cerevisiae (chevalieri) isolated from pulque which did not show killer activity was, on the other hand, resistant to other killer strains and it had a remarkable ethanol tolerance, suggesting that this strain could be used for alcohol production.     

新疆传统发酵乳品中乳酸菌与酵母菌的益生特性

目的 观察新疆传统发酵乳品中分离的14种菌株的生长特点及产酸能力,筛选出具有较强耐胆盐能力,并能在人工胃肠液中存活的菌株。方法 对10株乳酸菌和4株酵母菌进行生长曲线、pH、耐胆盐能力和耐人工胃肠液检测。结果 10株乳酸菌和4株酵母菌具有良好的生长曲线和产酸能力;马乳酒样乳杆菌具有较强的耐胆盐能力;希氏乳杆菌、马乳酒样乳杆菌、乙醇假丝酵母和东方伊萨酵母具有较强的耐人工胃液能力;乳酸乳球菌、哈尔滨乳杆菌、瑞士乳杆菌、马乳酒样乳杆菌、乙醇假丝酵母和东方伊萨酵母具有较强的耐人工肠液能力。结论 10株乳酸菌和4株酵母菌具有优良的益生特性,有望成为益生菌制剂的备用菌株。     

Molecular characterization, technological properties and safety aspects of enterococci from 'Hussuwa', an African fermented sorghum product

AIMS: To identify enterococci from Hussuwa, a Sudanese fermented sorghum product, and determine their technological properties and safety for possible inclusion in a starter culture preparation. METHODS AND RESULTS: Twenty-two Enterococcus isolates from Hussuwa were identified as Enterococcus faecium by using phenotypic and genotypic tests such as 16S rDNA gene sequencing, RAPD-PCR and restriction fragment length polymorphism of the 16S/23S intergenic spacer region fingerprinting. Genotyping revealed that strains were not clonally related and exhibited a considerable degree of genomic diversity. Some strains possessed useful technological properties such as production of bacteriocins and H2O2 or utilization of raffinose and stachyose. None produced alpha-amylase or tannase. A safety investigation revealed that all strains were susceptible to the antibiotics ampicillin, gentamicin, chloramphenicol, tetracycline and streptomycin, but some were resistant to ciprofloxacin, erythromycin, penicillin and vancomycin. Production of biogenic amines or presence of genes encoding virulence determinants occurred in some strains. CONCLUSIONS: Enterococcus faecium strains are associated with fermentation of Sudanese Hussuwa. Some strains exhibited useful technological properties such as production of antimicrobial agents and fermentation of indigestible sugars, which may aid in stabilizing and improving the digestibility of the product respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: Enterococci were shown to play a role in the fermentation of African foods. While beneficial properties of these bacteria are indicated, their presence in this food may also imply a hygienic risk as a result of antimicrobial resistances or presence of virulence determinants.     

Evaluation of the concentration and enantiomeric purity of selected free amino acids in fermented malt beverages (beers)

Even though amino acids are important trace components in the brewing of beers, they have not been extensively evaluated in these beverages. Studies involving the enantiomeric composition of these amino acids are even less prevalent. A brief summary of the brewing process for malt beverages is given. The total concentration and enantiomeric composition of three amino acids (leucine, phenylalanine, and proline) were determined in 25 different beers. Proline tended to have the highest average absolute concentration and the lowest percentage of the D -enantiomer in most samples. In some cases the relative amounts of D -phenylalanine and D -leucine exceeded 10% of the individual amino acids. The enantiomeric composition of the amino acids in different beer samples did not vary as extensively as the absolute concentrations. The reason for the concentration differences between proline and the other amino acids is discussed. A knowledge of amino acid concentrations and enantiomeric compositions appears to be useful in characterizing specific beers and brewing processes. © 1996 Wiley-Liss, Inc.