Search results for " grape"
showing 10 items of 104 documents
Assessment of Postharvest Dehydration Kinetics and Skin Mechanical Properties of “Muscat of Alexandria” Grapes by Response Surface Methodology
2016
The dipping of berries in a dilute solution of sodium hydroxide during a short time was evaluated as pretreatment undertaken prior to convective dehydration of wine grapes. The impact of the sodium hydroxide content and dipping time on weight loss (WL) at different dehydration times was thoroughly assessed using central composite design (CCD) and response surface methodology (RSM). Furthermore, the effects of these two variables were also investigated on the skin mechanical properties of dehydrated grapes. The effect of these two pretreatment factors on the dehydration kinetics and skin hardness was satisfactorily fitted to regression models. The berry pretreatment with low sodium hydroxide…
Effect of the natural winemaking process applied at industrial level on the microbiological and chemical characteristics of wine.
2013
The composition of yeast and lactic acid bacteria (LAB) communities and the chemical evolution of the large-scale commercial vinification of Catarratto IGT Sicilia, carried out under the biological regime, was followed from grape harvest until bottling. Simultaneously to the maximum growth of yeasts, LAB counts reached high level of concentration (6-7 log CFU mL(-1)) during the first steps of the alcoholic fermentation. Yeast identification was determined applying different molecular methods. The highest species biodiversity was observed on grape and must samples taken soon after pressing. Saccharomyces cerevisiae was detected at dominant concentrations during the entire winemaking process.…
Computational annotation of genes differentially expressed along olive fruit development
2009
Abstract Background Olea europaea L. is a traditional tree crop of the Mediterranean basin with a worldwide economical high impact. Differently from other fruit tree species, little is known about the physiological and molecular basis of the olive fruit development and a few sequences of genes and gene products are available for olive in public databases. This study deals with the identification of large sets of differentially expressed genes in developing olive fruits and the subsequent computational annotation by means of different software. Results mRNA from fruits of the cv. Leccino sampled at three different stages [i.e., initial fruit set (stage 1), completed pit hardening (stage 2) a…
First report of Neofusiccoccum vitifusiforme and presence of other Botryosphaeriaceae species associated with Botryosphaeria dieback of grapevine in …
2013
Summary. Since 2007, when a grapevine decline caused by Lasiodiplodia theobromae was reported for the first time in Sicily, vines showing similar declining symptoms have been also found in other grape-growing areas of western and central Sicily. We report the result of a study on fungi associated with grapevine decline in Sicily, with particular regard to those belonging to the Botryosphaeriaceae. Four species were found to be associated with declining vines, namely Diplodia seriata, Lasiodiplodia sp., Neofusicoccum parvum and Neofusicoccum vitifusiforme, the latter species reported for the first time on Vitis vinifera in Italy.
Climatic Characterization and Phenology of Local Peach Genotypes in the Udzungwa Uplands of Tanzania
2014
The phenology of two local peach genotypes was studied to verify whether peaches can be produced in the Tanzanian uplands. Observations were conducted on trees of one early- and one late-ripening peach genotype in 2010 and 2011. Temperature trends were reconstructed and three chilling estimation models were tested. The two peach genotypes differed for timing of flower and leaf bud-break. Common symptoms of insufficient chilling (presence of numerous stages at a specific date and about 20% of undeveloped flower buds) were observed in the late genotype. Both Utah and Dynamic models indicated low chilling accumulation, lower than the Mean Temperature model in most cases. This is inconsistent w…
Indigenous yeast communities in the environment of ‘‘Rovello bianco’’ grape variety and their use in commercial white wine fermentation
2009
The indigenous yeast communities associated with several vineyard habitats were analysed. Wild yeasts were isolated, differentiated at strain level and identified. A phylogenetic tree based on partial 26S rRNA genes was constructed. The strains were characterized and the indigenous Saccharomyces cerevisiae GR1 was then used to carry out a vinification process and compared with a commercial yeast. Wines obtained were subjected to chemical and sensory analysis. The comparison between the two products highlighted differences due to the fer- menting strains employed. The vineyard environment was found to strongly influence the composition of yeast communities, thus, confirming the theory of ‘te…
Antifungal peptides produced by Bacillus amyloliquefaciens AG1 active against grapevine fungal pathogens
2012
Abstract Antifungal metabolites produced by Bacillus amyloliquefaciens AG1, previously isolated from wood of grapevine with “esca syndrome”, were studied. The crude protein extract (CPE) obtained from culture supernatant fluid by precipitation with ammonium sulfate was assayed against many grapevine fungal pathogens. B. amyloliquefaciens strain AG1 showed a broad spectrum of antifungal activity, inhibiting mycelial growth in vitro of all tested fungal microorganisms. The metabolites contained in CPE were heat stable and remained active over a wide pH range (2–10). Their activity was not affected by proteolytic or glycolytic enzymes. Tricine- SDS-polyacrylamide gel electrophoresis revealed a…
The yeast Starmerella bacillaris (synonym Candida zemplinina) shows high genetic diversity in winemaking environments.
2015
International audience; The yeast Candida zemplinina (Starmerella bacillaris) is frequently isolated from grape and wine environments. Its enological use in mixed fermentation with Saccharomyces cerevisiae has been extensively investigated these last few years, and several interesting features including low ethanol production, fructophily, glycerol and other metabolites production, have been described. In addition, molecular tools allowing the characterization of yeast populations have been developed, both at the inter- and intraspecific levels. However, most of these fingerprinting methods are not compatible with population genetics or ecological studies. In this work, we developed 10 micr…
Comparison of SWAP and FAO Agro-Hydrological Models to Schedule Irrigation of Wine Grapes
2012
This paper compares two agro-hydrological models that are used to schedule irrigation of a typical Mediterranean crop. In particular, a comparison between the Food and Agriculture Organization (FAO) model, which uses a black box approach, and the soil-water-atmosphere-plant (SWAP) model, which is based on the numerical analysis of Richards' equation, are shown for wine grape. The comparison was carried out for the 2005 and 2006 irrigation seasons and focused on hydrological balance components and on soil water contents. Next, the ordinary scheduling parameters were identified so that the performance of the two models, which aimed to evaluate the seasonal water requirements and the irrigatio…
Ecology and technological capability of lactic acid bacteria isolated during Grillo grape vinification in the Marsala production area
2011
Grapes of the “Grillo” variety, used to produce Marsala wine, were harvested from five vineyards with different climatic and agronomic parameters, in order to obtain a first mapping of lactic acid bacteria (LAB) inhabiting the production area. Marsala base wine production was followed at a large-scale, and also two experimental vinifications, with different lysozyme and SO2 concentrations and in combination, were carried out at pilot-plant scale. LAB communities and conventional chemical parameters were periodically analysed. LAB were found on grapes at an average concentration of about 102 CFU g−1 which decreased during the transformation process. A total of 146 colonies were collected, bu…