28 research outputs found
Impact of yeast starter formulations on the production of volatile compounds during wine fermentation
Genetic improvement ofSaccharomyces cerevisiaewine strains for enhancing cell viability after desiccation stress
In Vitro Study of Probiotic, Antioxidant and Anti-Inflammatory Activities among Indigenous Saccharomyces cerevisiae Strains
Nowadays, the interest toward products containing probiotics is growing due to their
potential health benefits to the host and the research is focusing on search of new probiotic microorganisms.
The present work was focused on the characterization of indigenous Saccharomyces
cerevisiae strains, isolated from different food matrixes, with the goal to select strains with probiotic
or health-beneficial potential. A preliminary screening performed on fifty S. cerevisiae indigenous
strains, in comparison to a commercial probiotic strain, allowed to individuate the most suitable
ones for potential probiotic aptitude. Fourteen selected strains were tested for survival ability in the
gastrointestinal tract and finally, the strains characterized for the most important probiotic features
were analyzed for health-beneficial traits, such as the content of glucan, antioxidant and potential
anti-inflammatory activities. Three strains, 4LBI-3, LL-1, TA4-10, showing better attributes compared
to the commercial probiotic S. cerevisiae var. boulardii strain, were characterized by interesting healthbeneficial
traits, such as high content of glucan, high antioxidant and potential anti-inflammatory
activities. Our results suggest that some of the tested S. cerevisiae strains have potential as probiotics
and candidate for different applications, such as dietary supplements, and starter for the production
of functional foods or as probiotic to be used therapeutically
Assessment of competition in wine fermentation among wild Saccharomyces cerevisiae strains isolated from Sangiovese grapes in Tuscany region
Chemical Methods for Microbiological Control of Winemaking: An Overview of Current and Future Applications
Preservation technologies for winemaking have relied mainly on the addition of sulfur dioxide (SO2), in consequence of the large spectrum of action of this compound, linked to the control of undesirable microorganisms and the prevention of oxidative phenomena. However, its potential negative effects on consumer health have addressed the interest of the international research on alternative treatments to substitute or minimize the SO2 content in grape must and wine. This review is aimed at analyzing chemical methods, both traditional and innovative, useful for the microbiological stabilization of wine. After a preliminary description of the antimicrobial and technological properties of SO2, the additive traditionally used during wine production, the effects of the addition (in must and wine) of other compounds officially permitted in winemaking, such as sorbic acid, dimethyl dicarbonate (DMDC), lysozyme and chitosan, are discussed and evaluated. Furthermore, other substances showing antimicrobial properties, for which the use for wine microbiological stabilization is not yet permitted in EU, are investigated. Even if these treatments exhibit a good efficacy, a single compound able to completely replace SO2 is not currently available, but a combination of different procedures might be useful to reduce the sulfite content in wine. Among the strategies proposed, particular interest is directed towards the use of insect-based chitosan as a reliable alternative to SO2, mainly due to its low environmental impact. The production of wines containing low sulfite levels by using pro-environmental practices can meet both the consumers’ expectations, who are even more interested in the healthy traits of foods, and wine-producers’ needs, who are interested in the use of sustainable practices to promote the profile of their brand
Indigenous yeast population from Georgian aged wines produced by traditional “Kakhetian” method
Experimental approach for target selection of wild wine yeasts from spontaneous fermentation of "Inzolia" grapes
The aim of this research was the study of indigenous
yeasts isolated from spontaneous fermentation of Inzolia
grapes, one of the most widespread native white grapes
in Sicily (Italy). The use of selective medium for the isolation
and the screening for sulphur dioxide tolerance were useful
for the first selection among 640 isolates. The yeasts characterized
by high SO2 tolerance were identified at species
level by restriction analysis of ITS region; although the
majority of isolates were identified as S. cerevisiae, some
non-Saccharomyces yeasts were found. Forty-seven selected
yeasts, both S. cerevisiae and non-Saccharomyces yeasts,
were characterized for genetic and technological diversity.
The genetic polymorphism was evaluated by RAPD-PCR
analysis, whereas the technological diversity was analyzed
by determining the main secondary compounds in the
experimental wines obtained by inoculating these yeasts.
Both the molecular and metabolic profiles of selected yeasts
were able to clearly discriminate S. cerevisiae from non-
Saccharomyces yeasts. This research was useful for the
constitution of a collection of selected indigenous yeast
strains, including S. cerevisiae and non-Saccharomyces
species possessing interesting enological traits. This collection
represents a source of wild yeasts, among of which it is
possible to select indigenous starters able to maintain the
specific organoleptic characteristics of Inzolia wine
Saccharomyces cerevisiae and Hanseniaspora uvarum mixed starter cultures: influence of microbial/physical interactions on wine characteristics
The growing trend in the wine industry is the revaluation of the role of non-Saccharomyces yeasts, promoting the use of these yeasts in association with Saccharomyces cerevisiae. Non-Saccharomyces yeasts contribute to improve wine complexity and organoleptic composition. However, the use of mixed starters needs to better understand the effect of the interaction between these species during alcoholic fermentation. The aim of this study is to evaluate the influence of mixed starter cultures, composed by combination of different S. cerevisiae and Hanseniaspora uvarum strains, on wine characteristics and to investigate the role of cell-to-cell contact on the metabolites produced during alcoholic fermentation. In the first step, three H. uvarum and two S. cerevisiae strains, previously selected, were tested during mixed fermentations in natural red grape must in order to evaluate yeast population dynamics during inoculated fermentation and influence of mixed starter cultures on wine quality. One selected mixed starter was tested in a double-compartment fermentor in order to compare mixed inoculations of S. cerevisiae/H. uvarum with and without physical separation. Our results revealed that physical contact between S. cerevisiae and H. uvarum affected the viability of H. uvarum strain, influencing also the metabolic behaviour of the strains. Although different researches are available on the role of cell-to-cell contact-mediated interactions on cell viability of the strains included in the mixed starter, to our knowledge, very few studies have evaluated the influence of cell-to-cell contact on the chemical characteristics of wine