Protective agents used to reverse the metabolic changes induced in wine yeasts by concomitant osmotic and thermal stress.
OBJECTIVE
The reversion of the metabolic changes induced in wine yeasts by stressors.


METHODS
Six strains of Saccharomyces were inoculated in grape must containing over 400 g l-1 of sugar and incubated at 35 degrees C, both with and without the addition of 100 mg l-1 of catechin, inositol or SO2.


RESULTS
Significant correlations between addition of the stress-protectants and change in the metabolic behaviour of the wine yeasts were observed. Depending on strain and protectant, and expressing data as a percentage of increase or decrease compared to the control, fermentation vigour after 3 d increased by up to 10%, titratable acidity of the wines increased by up to 7%, ethanol content increased by up to 20%, unitary acetic acid production decreased by up to 35%, and unitary glycerol production decreased by up to 20%. IMPACT OF STUDY: By using protective agents it is possible to minimize the abnormal fermentation performance that wine yeasts exhibit under thermal and osmotic stress.
Caridi
A
A
Department of Agro-Forestry and Environmental Technology and Sciences, Mediterranean University of Reggio Calabria, Gallina (RC), Italy. acaridi@unirc.it
D019342:Acetic Acid / Q000032:analysis / Q000378:metabolism; D002392:Catechin / Q000378:metabolism; D018929:Cell Culture Techniques; D005285:Fermentation; D005990:Glycerol / Q000032:analysis / Q000378:metabolism; D006358:Hot Temperature; D007294:Inositol / Q000378:metabolism; D009997:Osmotic Pressure; D020011:Protective Agents / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000145:classification / Q000378:metabolism*; D013644:Tartrates / Q000032:analysis / Q000378:metabolism; D014920:Wine / Q000382:microbiology*; D015003:Yeasts / Q000145:classification / Q000378:metabolism
D020011:Protective Agents; D013644:Tartrates; D007294:Inositol; D002392:Catechin; D005990:Glycerol; D019342:Acetic Acid; C029768:tartaric acid