The influence of local microbiota on the quality, authenticity and organoleptic characteristics of wine

Abstract

Microbial diversity, also known as “microbial terroir”, is an important component of the character, specificity and authenticity of wine. This concept was introduced to the field of oenology a few years ago, thanks to the development of NGS techniques, which allow the identification of microbial ecology in different wine regions. The purpose of experimental study consisted to study the number of microorganisms present in grapes from the AOC Ștefan Vodă area (Cimișlia center), Republic of Moldova. Under laboratory conditions at the Oenological Research Center/Department of Oenology and Chemistry/UTM. Two strains of non-Saccharomyces yeasts were used in wine production by the bio-protection method. The production of experimental wines included the application of the classical winemaking method with the obtaining of 2 batches with indigenous microbiota selected from the Cimișlia viticulture center and 1 batch of control wine fermented with industrial active dry yeasts. The wines obtained by using indigenous yeast starter (IYS) and the control sample were studied in the dynamics during technological process regarding the physico-chemical, microbiological and organoleptic parameters. The experimental results described that during the alcoholic fermentation process, several non-Saccharomyces yeasts such as H. uvarum and Metschikowia were involved. The S. cerevisiae species represented less than 50%, which contributed to the perceived defects in the MT group samples. In dynamics, the Metschikowia species participated in the fermentation, gradually decreasing, while the Lanchancea microbial population increased towards the end of the process. As the alcohol level increased, the Lanchancea and Saccharomices species continued to play a flavor impact. Both Lanchancea and Metschikowia are considered to improve the fruity aroma of the experimental wines.