Search results for "Volatile"
showing 10 items of 606 documents
Diversity and technological potential of lactic acid bacteria of wheat flours
2013
Abstract Lactic acid bacteria (LAB) were analysed from wheat flours used in traditional bread making throughout Sicily (southern Italy). Plate counts, carried out in three different media commonly used to detect food and sourdough LAB, revealed a maximal LAB concentration of approximately 4.75 Log CFU g−1. Colonies representing various morphological appearances were isolated and differentiated based on phenotypic characteristics and genetic analysis by randomly amplified polymorphic DNA (RAPD)-PCR. Fifty unique strains were identified. Analysis by 16S rRNA gene sequencing grouped the strains into 11 LAB species, which belonged to six genera: Enterococcus, Lactobacillus, Lactococcus, Leucono…
Sensory and chemical drivers of wine minerality aroma: An application to Chablis wines
2017
The goal of this work was to evaluate the effect of vineyard position on the minerality of wines and to establish relationships between minerality scores, sensory descriptors and chemical composition. Sensory analyses included minerality rating and free description performed by wine professionals under two conditions: orthonasal olfaction alone and global tasting. Chemical characterization included analysis of major and minor volatile compounds, volatile sulphur compounds, mercaptans, metals, anions and cations. Results showed a significant effect of the river bank on wine minerality scores only in the orthonasal olfaction condition, samples from the left being more mineral than those from …
Effects of different yeast strains, nutrients and glutathione-rich inactivated yeast addition on the aroma characteristics of Catarratto wines
2021
Catarratto is one of the most common non-aromatic white grape varieties cultivated in Sicily (Southern Italy). In order to improve the aromatic expression of Catarratto wines a trial was undertaken to investigate the effect of yeast strain, nutrition and reduced glutathione. Variables included two Saccharomyces cerevisiae strains, an oenological strain (GR1) and one isolated from honey by-products (SPF52), three different nutrition regimes (Stimula Sauvignon Blanc™ (SS), Stimula Chardonnay™ (SC) and classic nutrition practice), and a specific inactivated yeast rich in reduced glutathione to prevent oxidative processes [Glutastar™ (GIY)] ensuing in ten treatments (T1-T10). Microbiological an…
The Chardonnay wine olfactory concept revisited: A stable core of volatile compounds, and fuzzy boundaries
2011
Abstract An earlier study by the same team showed that Chardonnay wines have common olfactory properties by which wine experts can recognize them. The specific Chardonnay olfactory space was also tentatively linked to the relative concentrations of 29 volatile compounds, regarded as possible aroma-impact compounds. The question now is whether or not those initial results hold independently of the sample under consideration, that is, whether these sensory and chemical spaces are vintage-specific. A series of investigations was conducted on a new set of 46 wines (23 Chardonnay wines and 23 non Chardonnay wines) using the same sensory (wine typicality level) and physico-chemical (Gas Chromatog…
Transfer of volatile phenols at oak wood/wine interface in a model system
2006
Abstract In order to assess the influence of wood on the concentration of aroma compounds during ageing of wine, the transfer of volatile phenols including 4-ethylphenol, eugenol and a homologous series of guaiacols from wine to oak wood were studied in a model system at 10°C. At equilibrium most of the volatile phenols adsorbed in the wood. The results display that the amounts adsorbed depend on the nature of the volatile phenols and the botanical origin of oak wood.
Amino acids and volatile compounds in wines from Cabernet Sauvignon and Tempranillo varieties subjected to malolactic fermentation in barrels
2012
The aim of the present paper is to compare the behaviour of industrial lactic bacteria and indigenous bacteria of the cellar when malolactic fermentation was carried out in barrels. The effects of these bacteria on the concentration of metabolised amino acids during malolactic fermentation and on the composition of volatile compounds both before and after malolactic fermentation are studied. The experiment was performed with wines of the Tempranillo and Cabernet Sauvignon varieties. An analysis has been made of the easily extractable volatile compounds of the wood and the compounds from the grapes, and the action of the yeasts during the alcoholic fermentation. Acetoin and diacetyl decreas…
Intraspecific biodiversity and 'spoilage potential' of Brettanomyces bruxellensis in Apulian wines
2015
Abstract The yeast Brettanomyces bruxellensis, generally considered the main oenological spoilage microbe, is able to survive during the winemaking process and it confers off-odors to wine, in reason of its ability to produce considerable amounts of volatile phenols. Forty-eight isolates of B. bruxellensis, obtained from several wines collected in Apulia (Southern Italy), were genetically characterized using an integrated approach, including a strain biodiversity analysis by Sau-PCR. Furthermore, the production of volatile phenols was assessed in wine and in synthetic medium, confirming the oenological spoilage potential of the analysed strains. Our findings indicate a remarkable genetic va…
Application of high Power ultrasounds during red wine vinification
2017
[EN] Wine colour is one of the main organoleptic characteristics influencing its quality. It is of special interest in red vinifications due to the economic resources that wineries have to invest for the extraction of the phenolic compounds responsible for wine colour, compounds that are mainly located inside the skin cell vacuoles, where the volatile compounds are also found. The transfer of phenolic compounds from grapes to must during vinification is closely related to the type of grapes and the winemaking technique. During traditional winemaking, grapes are crushed and skin macerated for several days, with pumps overs to facilitate the colour extraction. To increase this extraction, som…
Development and characterization of essential oil component-based polymer films: a potential approach to reduce bacterial biofilm
2013
The development of new polymeric materials aimed to control the bacterial biofilm appears to be an important practical approach. The goal of the present study was to prepare and characterize poly(ethylene-co-vinyl acetate) copolymer (EVA) films containing citronellol, eugenol, and linalool and evaluate their efficiency on growth and biofilm formation of Listeria monocytogenes, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa in monospecies and dual species. The results showed that the addition of oil components influenced the elastic modulus (15 % decrease), the tensile stress (30 % decrease), the elongation at break (10 % increase), and the co…
Comparative efficacy of Zataria multiflora Boiss., Origanum compactum and Eugenia caryophyllus essential oils against E. coli O157:H7, feline caliciv…
2013
Abstract Ready-to-eat salads using baby-leaf and multi-leaf mixes are one of the most promising developments in the fresh-cut food industry. There is great interest in developing novel decontamination treatments, which are both safe for consumers and more efficient against foodborne pathogens. In this study, emulsions of essential oils (EOs) from Origanum compactum (oregano), Eugenia caryophyllus (clove), and Zataria multiflora Boiss (zataria) were applied by spray (0.8 ml) after the sanitizing washing step. The aim was to investigate their ability to control the growth of potentially cross-contaminating pathogens and endogenous microbiota in commercial baby leaves, processed in a fresh-cut…