scholarly journals Yeast Fermentation at Low Temperatures: Adaptation to Changing Environmental Conditions and Formation of Volatile Compounds

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1035
Author(s):  
Wiktoria Liszkowska ◽  
Joanna Berlowska

Yeast plays a key role in the production of fermented foods and beverages, such as bread, wine, and other alcoholic beverages. They are able to produce and release from the fermentation environment large numbers of volatile organic compounds (VOCs). This is the reason for the great interest in the possibility of adapting these microorganisms to fermentation at reduced temperatures. By doing this, it would be possible to obtain better sensory profiles of the final products. It can reduce the addition of artificial flavors and enhancements to food products and influence other important factors of fermented food production. Here, we reviewed the genetic and physiological mechanisms by which yeasts adapt to low temperatures. Next, we discussed the importance of VOCs for the food industry, their biosynthesis, and the most common volatiles in fermented foods and described the beneficial impact of decreased temperature as a factor that contributes to improving the composition of the sensory profiles of fermented foods.

2020 ◽  
Vol 8 (8) ◽  
pp. 1142
Author(s):  
Sergi Maicas

In recent years, vessels have been discovered that contain the remains of wine with an age close to 7000 years. It is unclear whether, in ancient times, humans accidentally stumbled across fermented beverages like wine or beer, or was it a product intended as such. What is a fact is that since then, alcoholic beverages have been part of the diet and culture of many of the civilizations that have preceded us. The typical examples of beer and wine are an example of many other drinks resulting from the action of yeasts. In addition to these two beverages, various companies have developed other types of fermented foods and non-alcoholic beverages prepared in a traditional or commercial manner. The climatic conditions, the availability of raw material and the preferences of each region have conditioned and favored the maintenance of some of these products. In addition to the aforementioned traditional alcoholic beverages produced from fruits, berries, or grains, humans use yeast in the production of chemical precursors, global food processing such as coffee and chocolate, or even wastewater processing. Yeast fermentation is not only useful in food manufacturing. Its uses extend to other products of high interest such as the generation of fuel from vegetable sources.


2021 ◽  
Vol 7 (7) ◽  
pp. 569
Author(s):  
Hideyuki Yamashita

Koji is made by culturing koji mold on grains. Koji has wide-ranging applications, for example, in alcoholic beverages and seasonings. The word ‘mold’ generally has a bad image, but in Japan, koji mold is valued for its usefulness, and over the years, efforts have been made to make safe, stable, and delicious food products from it. Koji mold spores, essential when making koji, are called koji starter in the industry. From the many available strains, those suitable for the production of each fermented food are chosen based on indicators such as growth rate and enzyme production capacity. In manufacturing using microorganisms, purity and yield are prioritized. However, the production of fermented foods using koji is more complex, with focus not only on the degree of decomposition of raw materials but also on factors influencing overall product design, including palatability, color, smell, and texture. Production can be facilitated by the variety of koji brought about by the diversity of koji mold combined with the solid culture method which increases the amount of enzyme production. In this report, we introduce the history of koji starter in Japan, the characteristics of koji mold in practice, and various fermented foods made from it. In addition, the factors affecting the quality of koji in solid culture are described.


Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 289
Author(s):  
Berenice Negrete-Romero ◽  
Claudia Valencia-Olivares ◽  
Gloria Andrea Baños-Dossetti ◽  
Beatriz Pérez-Armendáriz ◽  
Gabriel Abraham Cardoso-Ugarte

The growing interest in the consumption and study of traditionally fermented food worldwide has led to the development of numerous scientific investigations that have focused on analyzing the microbial and nutritional composition and the health effects derived from the consumption of these foods. Traditionally fermented foods and beverages are a significant source of nutrients, including proteins, essential fatty acids, soluble fiber, minerals, vitamins, and some essential amino acids. Additionally, fermented foods have been considered functional due to their prebiotic content, and the presence of specific lactic acid bacterial strains (LAB), which have shown positive effects on the balance of the intestinal microbiota, providing a beneficial impact in the treatment of diseases. This review presents a bibliographic compilation of scientific studies assessing the effect of the nutritional content and LAB profile of traditional fermented foods on different conditions such as obesity, diabetes, and gastrointestinal disorders.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1619
Author(s):  
Hiroyuki Fukami ◽  
Yuki Higa ◽  
Tomohiro Hisano ◽  
Koichi Asano ◽  
Tetsuya Hirata ◽  
...  

Red yeast rice has been used to produce alcoholic beverages and various fermented foods in China and Korea since ancient times; it has also been used to produce tofuyo (Okinawan-style fermented tofu) in Japan since the 18th century. Recently, monacolin K (lovastatin) which has cholesterol-lowering effects, was found in some strains of Monascus fungi. Since statins have been used world-wide as a cholesterol-lowering agent, processed foods containing natural statins are drawing attention as materials for primary prevention of life-style related diseases. In recent years, large-scale commercial production of red yeast rice using traditional solid-state fermentation has become possible, and various useful materials, including a variety of monascus pigments (polyketides) that spread as natural pigments, in addition to statins, are produced in the fermentation process. Red yeast rice has a lot of potential as a medicinal food. In this paper, we describe the history of red yeast rice as food, especially in Japan and East Asia, its production methods, use, and the ingredients with pharmacological activity. We then review evidence of the beneficial effects of red yeast rice in improving lipid metabolism and the circulatory system and its safety as a functional food.


2019 ◽  
Vol 15 (7) ◽  
pp. 707-711
Author(s):  
Vipasha Sharma ◽  
Sampan Attri ◽  
Rishi Mahajan ◽  
Gunjan Goel

Background: Traditional fermented food preparation uses customary processing methods passed on from generation to generation under natural conditions. These fermented foods use native flora without being aware of the significant role of microbes involved in the fermentation process. Therefore, the present study aimed to determine the bacterial composition of traditional starters used in different fermented food preparations in Himachal Pradesh region India. Methods: The study investigated the bacterial DGGE (Denaturating Gradient Gel Electrophoresis) profile targeting V3 region of 16S rRNA of two traditional starters known as Malera and Phab. The starters are used in the preparation of fermented cereals product known as bhaturoo and alcoholic beverages. The Shannon diversity and richness were calculated from DGGE profile. The 16S rRNA gene sequences of identified bacterial species were deposited in NCBI database. Results: The DGGE profile identified eleven and seven different bacterial strains in Malera and Phab, respectively. The Shannon diversity index of 1.07 and 0.94 was obtained for Malera and Phab, respectively. The bacterial population was dominated by different strains of Bifidobacterium sp. in both the starters along with the presence of non lactic enterobacteriacae members such as Klebsiella sp. and a pathogenic strain of Dickeya chrysanthemi. Conclusion: The study is the first report on microbial profiling of microflora of starters. A careful examination of individual components and method of preparation of the starters should be taken to avoid contamination by pathogens.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrienn Gréta Tóth ◽  
István Csabai ◽  
Gergely Maróti ◽  
Ákos Jerzsele ◽  
Attila Dubecz ◽  
...  

AbstractAntimicrobial resistance (AMR) is a global threat gaining more and more practical significance every year. The main determinants of AMR are the antimicrobial resistance genes (ARGs). Since bacteria can share genetic components via horizontal gene transfer, even non-pathogenic bacteria may provide ARG to any pathogens which they become physically close to (e.g. in the human gut). In addition, fermented food naturally contains bacteria in high amounts. In this study, we examined the diversity of ARG content in various kefir and yoghurt samples (products, grains, bacterial strains) using a unified metagenomic approach. We found numerous ARGs of commonly used fermenting bacteria. Even with the strictest filter restrictions, we identified ARGs undermining the efficacy of aminocoumarins, aminoglycosides, carbapenems, cephalosporins, cephamycins, diaminopyrimidines, elfamycins, fluoroquinolones, fosfomycins, glycylcyclines, lincosamides, macrolides, monobactams, nitrofurans, nitroimidazoles, penams, penems, peptides, phenicols, rifamycins, tetracyclines and triclosan. In the case of gene lmrD, we detected genetic environment providing mobility of this ARG. Our findings support the theory that during the fermentation process, the ARG content of foods can grow due to bacterial multiplication. The results presented suggest that the starting culture strains of fermented foods should be monitored and selected in order to decrease the intake of ARGs via foods.


1990 ◽  
Vol 6 (1) ◽  
pp. 71-108 ◽  
Author(s):  
Rene E. Sotomayor ◽  
Thomas F.X. Collins

Urethane, a known animal carcinogen, has been the subject of intensive research efforts spanning 40 years. Recent concerns have focused on the presence of urethane in a variety of fermented foods and alcoholic beverages, although no epidemiological studies or human case reports have been published. Much information is available about the mutagenesis, metabolism, and DNA interactions of urethane in experimental systems. Urethane is generally not mutagenic in bacteria although in some instances it acts as a weak mutagen. Urethane is not mutagenic in Neurospora but is weakly mutagenic in Saccharomyces. Drosophila appear to be the only organisms that consistently give positive mutagenic results with urethane, but its mutagenicity is weak and in many cases shows no clear dose dependence. Urethane is a good clastogen in mammalian somatic cells in vivo, but it shows variable results with cells in vitro. It efficiently induces sister chromatid exchanges in a variety of cells. Mammalian spermatogenic cells are insensitive to the induction of specific locus and dominant lethal mutations by urethane. Mutational synergism has been reported to occur between ethyl methanesulfonate and urethane when administered two generations apart, and some investigators have suggested possible synergism for cancer-causing mutations in mice exposed to X-rays and urethane one generation apart. These studies are controversial and have not been confirmed. Studies on the induction of cancer-causing dominant mutations by urethane are at variance with results from extensive studies with the specific locus test in mice. Urethane studies with the unscheduled DNA synthesis assay in mouse spermatogenic cells and with the sperm abnormality test have given negative results. Urethane is rapidly and evenly distributed in the body. The rate of elimination of urethane from plasma is a saturable process and varies according to the strain and age of the animal. Recent studies have concentrated on the effect of ethanol on urethane metabolism. At concentrations similar to those in wine, ethanol inhibits the tissue distribution of urethane in mice. These results are important because they suggest a lower carcinogenic/mutagenic risk than expected from exposure to urethane in alcoholic beverages. Although research on the metabolic activation of urethane has been extensive, no conclusive results have been obtained about its active metabolite, at one time thought to be N-hydroxyurethane. More recently, it has been postulated that urethane is actived to vinyl carbamate and that this metabolite is capable of reacting with DNA. Vinyl carbamate is more carcinogenic and more mutagenic than the parental compound, but despite intensive efforts it has not been identified as a metabolite in animals treated with urethane. Urethane binding to DNA appears to correlate well with tissue susceptibility to cancer. Various studies have attempted to elucidate the molecular nature of the bound molecule and the binding site. Some results have indicated the formation of a single DNA adduct, 7-(2-oxoethyl)guanine. This adduct may isomerize to O6,7-(1'-hydroxyethano)guanine, which might be more mutagenic than the 2-oxoethyl adduct; however, this possibility seems unlikely. Despite extensive research, urethane's metabolism and molecular mechanisms of mutation are still not clearly understood.


2021 ◽  
Vol 924 (1) ◽  
pp. 012077
Author(s):  
M Nurcholis ◽  
A Setiawan ◽  
J Kusnadi ◽  
J M Maligan

Abstract Bioethanol is a liquid chemical produced from sugar-, starch-or lignocellulosic-based biomass through fermentation by ethanol-producing microbes. Ethanol-producing yeast generally has limited tolerance to ethanol and has limitation to high temperatures above 40°C. High-temperature tolerant yeast is required because it potentially reduces the risk of contamination and it also reduces the cost of the cooling process. This study aims to determine ethanol-producing yeasts that have tolerance to ethanol and high temperatures from local fermented food products. This study uses a descriptive method conducted in three stages. Isolation and selection of yeast were performed from 18 local fermented foods in Indonesia. Temperature and ethanol tolerance of selected yeast were performed by using a spot test method. The ethanol content was tested using Gas Chromatography (GC). The results exhibited that isolate F08b had the highest tolerance to ethanol and temperature. The isolate was able to grow up to a temperature of 50°C and a concentration of 18% ethanol. Meanwhile, isolate F10 was able to produce the highest ethanol concentration at 3.37% (v/v) in 48th-hour fermentation.


2021 ◽  
Vol 7 (6) ◽  
pp. 6303-6316
Author(s):  
Weixi Gao ◽  
Yan Zhuang

in the detection of chloramphenicol residues in fermented food, there are often problems of slow detection speed. Using UPLC-DAD method, a rapid detection method of chloramphenicol residues in fermented food based on UPLC-DAD method is designed. According to the characteristics of chloramphenicol, set up the detection reagent, select the detection equipment, and form the detection laboratory. It is usingUPLC-DAD method to design the test paper, using the set test reagent to deal with the sample to be tested, according to the design results of the test process, combining the reagent with the sample, to determine its specificity. Chloramphenicol residue was detected by test paper. So far, the rapid detection method of chloramphenicol residues in fermented food based on UPLC-DAD method has been designed. Compared with the original detection method, the detection speed of the detection method designed in this paper is significantly higher than the original method. In conclusion, the rapid detection method of chloramphenicol residues in fermented food based on UPLC-DAD method is effective.


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