The Role of Yeasts in Fermentation Processes

Abstract

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.

An Overview onSaccharomyces cerevisiaeIndigenous Strains Selection Methods

“…Further research developments, achieved through microbiology, ecology, biochemistry and recently, molecular biology, have elucidated the metabolisms and in particular the biochemical process of alcoholic fermentation (Figure 1), as well as the interactions among microbial communities involved in winemaking, the phylogenetic and taxonomy. Based on this knowledge, the key role of yeasts in determining the quality of wine is now universally accepted [1,[11][12][13].…”

“…These scientific achievements have made it possible to supply oenological products and starter cultures appropriate for the industry. In fact, beginning from the mid-1960, the production and use of S. cerevisiae strains in form active dry yeasts (ADY) has expanded from California (United States) to the rest of the world [11][12][13][14]. In the major wine producing countries France, Italy, Spain, USA, Australia and Sud-Africa the use of ADY has almost fully replaced the spontaneous fermentation, especially in large-scale productions [3,11,13].…”

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

“…The enzymatic activity of yeast now plays an essential role in the production of a wide range of fermented food products ( Figure 1 ). Under anaerobic or oxygen-rich conditions, it is possible to obtain ethanol, carbon dioxide, and various organic compounds through fermentation, all of which have applications in food processing [ 5 ]. Alcoholic beverages can be produced with high percentages of ethanol.…”

In Vitro Activity of Selected Phenolic Compounds against Planktonic and Biofilm Cells of Food-Contaminating Yeasts

“…Microbiological food spoilage is a major concern nowadays due to the economic losses caused [ 2 ]. Yeasts are renowned as great fermenters of alcoholic and non-alcoholic beverages, have a key role in bread making, and are producers of products of high interest, such as volatile aroma compounds or biofuels [ 3 ]. Despite the positive application of yeasts in food production, spoilage yeasts may lead to food deterioration and loss, which is a common problem in the food industry [ 4 , 5 ].…”