Search results for "VOLATILE COMPOUND"

Non-

2017

Nitrogen sources in the must are important for yeast metabolism, growth, and performance, and wine volatile compounds profile. Yeast assimilable nitrogen (YAN) deficiencies in grape must are one of the main causes of stuck and sluggish fermentation. The nitrogen requirement of Saccharomyces cerevisiae metabolism has been described in detail. However, the YAN preferences of non-Saccharomyces yeasts remain unknown despite their increasingly widespread use in winemaking. Furthermore, the impact of nitrogen consumption by non-Saccharomyces yeasts on YAN availability, alcoholic performance and volatile compounds production by S. cerevisiae in sequential fermentation has been little studied. With…

Volatile Compounds in Red Wines Processed on an Industrial Scale by Short Pre-fermentative Cold Maceration

2012

Nero d’Avola and Shiraz grapes were subjected to pre-fermentative cold maceration at 4°C for about 24 h in industrial winemaking, in order to evaluate the effects of the pre-treatment on aroma profile. The volatile compounds were identified by gas chromatography-mass spectrometry and grouped into 14 chemical families 4 and 9 months after bottling. Principal components analysis (PCA) plots of the volatile compounds showed clear separation among wines from the Shiraz and Nero d’Avola varieties. For instance, Shiraz wines were characterized along the PC1 axe by esters of organic acids, norisoprenoids and C6 alcohols, while Nero d’Avola wines were characterized by acetates and monoterpenic oxid…

The Effect of Plant Water Status on the Chemical Composition of Pistachio Nuts (Pistacia vera L. Cultivar Bianca)

2020

Pistachio nuts are worldwide appreciated for their chemical and organoleptic profiles. There are several studies on the influence of irrigation on pistachio productivity, whereas there are little available data on the influence on nut quality. In this study we characterized some qualitative traits of pistachio nuts cultivar Bianca in Mediterranean environment and how plant water status affected them. Water status had a positive and significant influence on the chlorophylls content, nuts from less stressed trees showed higher values of chlorophyll a (14.7 mg/100 g) and b (21.1 mg/100 g) compared than more stressed trees (9.3 and 11.5 mg/100 g for a and b, respectively). Solid phase microextr…

Partition of volatile compounds in pea globulin–maltodextrin aqueous two-phase system

2014

International audience; This study is based on the assumption that the off-flavour of pea proteins might be decreased using the retention of volatile compounds by a mixture with another biopolymer. The partition of volatile compounds in an aqueous system containing pea protein and maltodextrins was followed under thermodynamic incompatibility conditions. Firstly, the phase diagram of the system was established. Then, the partition of aroma compounds between the phase rich in protein and the phase rich in maltodextrin was measured by SPME–GC–MS. There was a transfer of volatile compounds during phase separation. Variations of pH were also used to vary the retention of volatile compounds by p…

I fattori di variabilità genetici, ambientali e colturali della composizione dell'olio d'oliva

2009

The compositon of olive oil results from a multivariate interaction in which genotype, environment, and agronomic-dependent factors are involved. The genotype controls genetic traits accounting for the rate pattern of fruit growth, oil accumulation in mesocarp cells and fruit ripening, while the genotype x environment interaction changes the rate of fruit growth, oil accumulation and fruit ripening pattern. The latter accounts for large changes in oil composition and sensorial features. The influence of genotype is linked to differences in the fruit growth and ripening patterns, though all those factors that may have an influence on fruit size, flesh/pit ratio and relative growth rate have …

Modifications over years of volatile compounds and agronomic features in a Sicilian Clary sage biotype.

2006

Clary sage is a biennial native to Mediterranean area, spontaneous and often ubiquitous in many environments of inner Sicily. The large white-pinkish flowers are used, besides for ornamental purposes, for extracting a strongly-scented essential oil largely used by perfume industries. This work has been carried out with the aim to observe over several years the behaviour of a Sicilian Clary sage biotype, grown on experimental plots laid out in Sparacia (Cammarata - AG - Sicily). For this purpose seeds of Clary sage collected from a wild population growing in Pietraperzia (EN) were sown in experimental plots each year for seven consecutive years (from 1998 to 2005). Since Clary sage is a bien…

Drying kinetics and physico-chemical quality of mango slices

2019

Mango (Mangifera indica L.) is an important tropical fruit consumed worldwide and grown in Italy only in Sicily, where the areas of the Tyrrhenian coast have proved to be suitable to produce valuable fruits. Mango fruit has a pleasant aroma and taste, which are important qualities for consumer’s sensorial acceptance. However, they are highly perishable, prone to progressive undesired changes if stored untreated, resulting in around 25% postharvest losses, which is further increased during storage and transportation. An alternative for reducing the above-mentioned undesired changes is the dehydration of the cut fruit, which reduce the fruit water activity, thereby avoiding the deteriorative …

Impact of Genetic and Cultural Factors on Extra-Virgin Olive Oil Composition

Low Tree Vigor, Free Palmette Training Form, and High Planting Density Increase Olive and Oil Yield Efficiency in Dry, Sloping Areas of Mediterranean…

2022

Exploiting biodiversity must be considered today an effective strategy to improve the sustainability of olive production systems. The evaluation of local cultivars, based on their vegetative and fruiting traits, along with an analysis of product quality, may contribute significantly to the development and diffusion of new olive-growing systems. The aim of this study was to evaluate growth, productivity, and olive oil quality of three Sicilian cultivars with different vigor/growth habit grown in four different combinations of training form and planting density. ‘Abunara’, ‘Calatina’, and ‘Nocellara del Belice’ olive trees were planted in four different int…

Vinificazione in bianco in presenza di chips di quercia di origine e livello di tostatura diversi

2011

Some musts from Grillo grapes, a cultivar autochthonous of western Sicily, fermented with medium toasted American oak chips or with non toasted French oak chips (Classic Line – HTS enology) have been vinified. the wines were significantly different as regards the contents in volatile and non volatile compounds extracted from American and French oak chips. a slight increase in alcoholic fermentation rate and in some cases a higher content of ethyl esters and medium chain fatty acids, were observed in musts charged with chips, independently of their origin. In wines obtained from musts charged with french medium toasted oak chips, the content in furans was higher (5-methylfurfural, trans-meth…