The Importance of Yeasts on Fermentation Quality and Human Health-Promoting Compounds

Alice Vilela

doi:10.3390/fermentation5020046

Abstract

Non-Saccharomyces are important during wine fermentation once they influence wine composition. In the early stages of wine fermentation, and together with indigenous or commercial strains of Saccharomyces cerevisiae, non-Saccharomyces are able to transform grape-must sugars into ethanol, CO2, and other important secondary metabolites. A better understanding of yeast biochemistry will allow the selection of yeast strains that have defined specific influences on fermentation efficiency, wine quality, and the production of human health-promoting compounds. Yeast metabolism produces compounds derived from tryptophan, melatonin, and serotonin, which are found in fermented beverages, such as wine and beer. Melatonin is a neurohormone secreted from the pineal gland and has a wide-ranging regulatory and neuroprotective role, while serotonin, as well as being a precursor of melatonin synthesis, is also a neurotransmitter. This review summarizes the importance of some conventional and nonconventional yeast strains’ alcoholic fermentations, especially in the production of metabolites that promote human health and thus, attract consumers attention towards fermented beverages. A brief reference is also made on fermented beverages containing probiotics, namely kombucha, also known as kombucha tea, and its interesting microorganism’s symbiotic relationships named SCOBY.

Highlights

The term “fermentation” comes from the Latin word “fermentum”
GSH is involved in nutrient metabolism and regulation of cellular metabolic functions ranging from DNA and protein synthesis to signal transduction, cell proliferation, and apoptosis [12,13,14]
Yeast metabolism produces compounds derived from tryptophan, which are found in fermented beverages, such as wine and beer

Summary

Introduction

The term “fermentation” comes from the Latin word “fermentum” (meaning, to ferment). The science of fermentation is called “zymology” and the first zymologist was Louis Pasteur who was able to identify and apply yeast in fermentation [1]. In the 16th century, the beginning of industrialization initiated technological interventions in food and beverage production [2]. Beer, distilled beverages, and yogurt are developed by submerged fermentation Both methods of fermentation are influenced by numerous factors, including temperature, pH, nature, and composition of the medium, dissolved O2 , dissolved CO2 , operational system, and feeding with precursors, among others. Variation in these factors may affect the rate of fermentation, the product spectrum and yield, the sensory properties of the product (appearances, taste, smell, texture), physic-chemical properties, nutritional quality, and the production of metabolites that promote human health attracting consumers attention towards fermented products, namely beverages

Alcoholic Beverages Consumption and Health-Promoting Compounds

Mechanisms of Microbial

Melatonin and Other Tryptophan Metabolites

Fusel Alcohols Formed Via the Ehrlich Pathway

Fermented

Final Remarks