Yeast Multi-Enzymatic Systems for Improving Colour Extraction, Technological Parameters and Antioxidant Activity of Wine

LONGHI, SARA JAQUELINA; MARTÍN, MARÍA CAROLINA; MERÍN, MARÍA GABRIELA; MORATA DE AMBROSINI, VILMA INÉS

FOOD TECHNOLOGY AND BIOTECHNOLOGY

FACULTY FOOD TECHNOLOGY BIOTECHNOLOGY

Lugar: Zagreb; Año: 2022 vol. 60 p. 556 - 570

1330-9862

Research background. Wine yeasts are a heterogeneous microbial group with high enzymatic potential that makes them a useful tool in winemaking. With a better understanding of their oenological properties, selection procedures can be optimised to obtain moreefficient strains. The present study aims to isolate and select yeasts from wine grape surface by studying their production of enzymes that hydrolyse plant cell wall polymers andby linking them to different technological parameters and antioxidant activity of wines.Experimental approach. Yeasts that are able to produce carbohydrolases and relatedenzymes of oenological importance were firstly selected on plates and subsequently identified. Then, a secondary selection of yeasts was carried out according to technologicaleffects of their extracellular enzyme extracts on short macerations. In this way, the colourextraction, total polyphenol content, clarification, filterability and antioxidant activitywere studied. This approach makes it possible to correlate the microorganism capacity toproduce cell wall-depolymerizing enzymes with their technological effects.Results and conclusions. From 366 isolates, 96 strains (26.2 %) showed at least one ofthe polysaccharidase activities and 55 strains (57.3 %) of them exhibited activities of multiple enzymes that degrade plant cell wall polymers. Sixteen strains were selected andidentified as Aureobasidium, Candida, Debaryomyces, Hanseniaspora, Metschnikowia, Pichia,Saccharomyces and Torulaspora. Pectinolytic enzymes had the highest hydrolytic activity.Aureobasidium pullulans had a broader enzyme blend and higher activity, dominated bypectinases and followed by xylanases and cellulases. Moreover, the Torulaspora delbrueckii m7-2 strain produced high amounts of polysaccharidase and this was strain-dependent.Strains that produced enzyme extracts with a wide range of activities that were also thehighest, also had the best chromatic and technological properties. Cluster analysis confirmed that A. pullulans R-22, m11-2, m86-1 and m86-2 and T. delbrueckii m7-2 could becorrelated with a better effect on filterability, clarification and extraction of bioactive compounds, encouraging future studies regarding their application in winemaking.Novelty and scientific contribution. The study of yeast multi-enzymatic systems impacting the grape maceration process enables a proper selection criterion for wine yeasts toimprove colour extraction, technological parameters and antioxidant activity of Malbecwine. This work shows that A. pullulans and T. delbruekii have a high enzymatic potentialfor oenological purposes.