Study of the ultrasound effects on yeast lees lysis in winemaking

Abstract

This work focused on the study of ultrasound (US) treatment effects on wine lees, in order to verify the possibility of accelerating the protective colloids (i.e., polysaccharides) release. Moreover, these effects were compared with the usual practices of aging wine over lees and with the enzyme treatment of lees by means of betaglucanases able to demolish the glucans and facilitate the release of intracellular components. This work was performed considering the possibility of setting up a technology applicable in a cellar. Ultrasound treatment on wine lees resulted in an increase in total colloids, proteins, and polysaccharides in the medium with a reduction in the colloids particle diameter. These results were mainly correlated with treatment duration rather than its intensity. Treatment at 90 % amplitude for 3 min provided good enough results in terms of colloids release, and therefore, it was used for the comparative study with natural lysis and enzyme treatment. The parameters evaluated showed that the ultrasound treatment resulted in an increased release of colloids from yeast (polysaccharides and glycoproteins); therefore, a significant effect on the extraction of cellular components compared to the long stay on the lees was detected, indicating the interesting advantage that this new technological application can bring to the winemaking process

Evidence of the Possible Interaction between Ultrasound and Thiol Precursors

“…Sonication is already employed in many food applications such as emulsifying, homogenizing, sterilizing, extracting, degassing, crystallizing or inactivating microorganisms and enzymes [14]. In winemaking, US technology has already been studied in different stages of the process, namely: Yeast lysis and accelerated aging of wines [15,16], color evolution [17], vessels sanitation [18], prevention of wine spoilage by microorganisms [19], and the release of compounds located in the skin [20,21], with encouraging results, however research on this topic is still ongoing and needs to be developed.…”

Non-Thermal Ultrasonic Extraction of Polyphenolic Compounds from Red Wine Lees

“…Moreover, these technologies have been reported to be relatively friendly to the environment [69,70]. The efficiency of ultrasound-assisted extraction of polyphenolic compounds depends on various factors such as frequency, rated output power, amplitude, probe geometry, treatment time, temperature, dry matter content, sample particle size and type of solvent used [71][72][73].…”

“…Moreover, these technologies have been reported to be relatively friendly to the environment [69,70]. The efficiency of ultrasound-assisted extraction of polyphenolic compounds depends on various factors such as frequency, rated output power, amplitude, probe geometry, treatment time, temperature, dry matter content, sample particle size and type of solvent used [71][72][73].Recently, natural deep eutectic solvents (NADESs) such as choline chloride:malic acid (ChMa), choline chloride:oxalicacid (ChOa), and choline chloride:citric acid (ChCit) have been recognized as a novel class of sustainable solvents to replace common organic solvents. Combination of ultrasound-assisted extraction and natural deep eutectic solvents (NADESs) of wine lees anthocyanins to result higher efficiency of extraction have also been previously explored [74].Despite numerous potential applications, large quantities of lees generated as a by-product during the production of red wines are discarded [45,73,[75][76][77].…”

Preliminary study of the effects of ultrasound on red wine polyphenols

“…Ultrasound could also be used to accelerate the release of protective colloids from lees and stabilize wines in a very short time (Cacciola, Ferran Batllό, Ferraretto, Vincenzi, & Celotti, 2013;García Martín, Guillemet, Feng, & Sun, 2013). The ultrasound cavitation would be able to facilitate the release of these compounds, causing disruption of cell walls and membranes.…”