Evaluation of Aglianico grape skin and seed polyphenols astringency by SDS-PAGE electrophoresis of salivary proteins after the binding reaction

SDS–PAGE electrophoresis and densitometry analysis were carried out to evaluate the reactivity of Aglianico red grape skin and seed polyphenols with human salivary proteins in order to find a method able to assess their astringency. Analysis of the supernatant obtained after a tannin/human salivary protein binding assay and sensorial analysis showed that four proteins, lactoferrin, PRPbg1, PRPbg2 and a-amylase, were the proteins best able to distinguish tannin solutions characterised by different levels of astringency. A correlation between densitometric data and tannin concentration was plotted in order to give an indirect measure of astringency. The two sources of Aglianico grape polyphenols differed from each other in astringency power; the seed extract solution was about two-fold more tannic than the skin one. The difference in astringency was also perceived by sensorial analysis. The results from this study show that SDS–PAGE electrophoresis of human salivary proteins after the binding reaction with grape polyphenol extracts, coupled with densitometric analysis and the use of a calibration curve, looks extremely promising as a new approach to evaluate polyphenol astringency

trans-Resveratrol, Quercetin, (+)-Catechin, and (-)-Epicatechin Content in South Italian Monovarietal Wines: Relantionship with Maceration Time and Marc Pressing during Winemaking

The concentrations of trans-resveratrol, (+)-catechin, (-)-epicatechin, and quercetin were evaluated by means of high-performance liquid chromatography-diode array detection in red wines obtained from Aglianico, Piedirosso, and Nerello Mascalese grapes. The trans-resveratrol and epicatechin concentrations did not differ significantly between experimental wines. The concentration of quercetin in Nerello Mascalese wines was more than twice that observed in Aglianico and Piedirosso wines. Nerello Mascalese wines also significantly differed from other wines in the (+)-catechin content, which was significantly higher than those found in the other two wines. During maceration, the maximum extraction of trans-resveratrol was reached after 12 days for Aglianico and Piedirosso, after which a decline was observed. On the contrary, in the case of Nerello Mascalese, the concentration of trans-resveratrol increased steadily throughout the whole maceration process. After 2 days of maceration, the maximum concentration of quercetin was observed in Aglianico must, whereas the maximum quercetin extraction was reached after 12 days for Piedirosso and 17 days for Nerello Mascalese. The maximum levels of (+)-catechin and (-)-epicatechin were generally observed after 12 days of maceration for all wines, although a decline of (-)-epicatechin occurred after maximum extraction in Aglianico and Piedirosso wines. Following marc pressing, a significant increase in the concentration of trans-resveratrol for Aglianico, (+)-catechin and (-)-epicatechin for Piedirosso, and (-)-epicatechin for Nerello Mascalese was observed

Biochemical features of native red wines and genetic diversity of the corresponding grape varieties from Campania Region

Campania region has always been considered one of the most appreciated Italian districts for wine production. Wine distinctiveness arises from their native grapevines. To better define the chemical profile of Campania autochthonous red grape varieties, we analysed the phenolic composition of Aglianico di Taurasi, Aglianico del Vulture, Aglianico del Taburno, Piedirosso wines, and a minor native variety, Lingua di Femmina in comparison with Merlot and Cabernet Sauvignon, as reference cultivars. A genetic profiling was also carried out using microsatellite molecular markers with high polymorphic and unambiguous profiles. Principal component analysis applied to 72 wines based on the 18 biochemical parameters, explained 77.6% of the total variance and highlighted important biological entities providing insightful patterns. Moreover, comparison of SSR-based data with phenylpropanoid molecules exhibited a statistically significant correlation. Our approach might be reasonably adopted for future characterisations and traceability of grapevines and corresponding wines

Influence of yeast strain on odor-active compounds in fiano wine

The type of yeast strain used for wine alcoholic fermentation dramatically affects its final volatile composition and, therefore, its sensory properties. In this study, the influence of four oenological Saccharomyces strains (three S. cerevisiae and one S. bayanus) on wine volatile composition was determined on the Fiano variety, a typical cultivar from the Campania region (Italy), fermented in oak barrique. Fiano wines were analyzed by means of gas chromatography/mass spectrometry (GC/MS) and gas chromatography/olfactometry (GC/O). The results showed that the four selected yeast strains had a significant impact on the majority of volatile compounds as shown by the concentration of volatile compounds and based on the Aroma Extract Dilution Analysis (AEDA) values for many of the odor volatile compounds. This resulted in a dramatic change of the odor impact of the wines, such as the “fruity” attribute, which was higher compared to the control, and caused some changes of other odor attributes, particularly “floral”, “phenolic” and “honey”. This research demonstrates the potential of using these selected yeast strains and this technological approach of oak fermentation for this typical white wine grape variety

Alternative fining of Sangiovese wine: effect on phenolic substances and sensory characteristics

Background and Aims: In recent years, alternative fining practices have increasingly been adopted by the wine industry.The use of plant proteins, as alternatives to traditional fining agents of animal origin for clarification, meets the expectationsof a safe product. The effect of alternative fining practices was studied in Sangiovese wine.Methods and Results: Four wines of variable phenolic composition were fined with a protein of vegetable origin (patatin)and one of animal origin (gelatin) at 5 and10 g/hL, and the influence on phenolic substances (colour parameters, CIElabcoordinates, polymeric pigments, anthocyanins, flavans reactive to vanillin, tannins reactive to bovine serum albumin andsaliva) and sensory characteristics (astringency, bitterness, astringency subqualities, odour, and aroma) compared. Colourshowed that the efficiency of fining depends on: dose for high tannin wine and protein type for wines with a low concentra-tion of anthocyanins. Astringency decreased in high tannin wine and bitterness in low anthocyanin wine following fining.Fined wines resulted in improved astringency subqualities and aroma descriptors.Conclusions: The efficacy of traditional and alternative fining practices is influenced by the composition of wine phenolicsubstances.Significance of the Study: Due to the potential allergenicity of animal proteins, plant proteins represent a safe and healthyalternative to the traditional fining of Sangiovese win

Measurement of Tissue Oxygen Saturation During Ovariohysterectomy in Domestic Felines With Near-Infrared Spectroscopy (NIRS)

Near-infrared spectroscopy (NIRS) is a noninvasive and continuous technique, easily and quickly to apply, that gives information in real-time of regional tissue oxygen saturation at microcirculation level. NIRS technique has proven to be an early indicator of organ ischaemia and oxygenation changes, when compared to other methods such as pulse oximetry, lactate and mental status. The objective of this study is to determine the NIRS range values in the caudal portion of the sartorius muscle in domestic female cats, during ovariohysterectomy. It will also be studied if NIRS is able to detect noxious stimulation, and to determine if NIRS values correlate to the physiological variables recorded during the surgical procedures in the same group of cats. This preliminary study evaluated NIRS technique using the O3™ Regional Oximetry device on sartorius muscle of six female cats, under general anesthesia and submitted to elective ovariohysterectomy. The haemodynamic and ventilatory data was recorded using the Mindray BeneView T8 monitor (Mindray Medical International Co., Ltd., Shenzhen, China). Pearson´s correlation analysis was used to compare NIRS regional oxygen saturation (rSO2) values with the physiologic variable recorded. NIRS (rSO2) values were also compared at each surgical moment using Kruskal- Wallis analysis of variance. Statistical significance was defined when p-value<0.05. Data are mean±SD. Statistical analysis was performed using SPSS version 25 software. The tissue oxygen saturation values obtained were 71.84±4.85% (65% to 83%), with cut-off 62%. Tissue hypoperfusion should be considered when sartorius NIRS values drop below 62% (two standard deviations below NIRS mean) during general anaesthesia in cats. Statistical significance was observed with a positive correlation between NIRS and minimum alveolar concentration, heart rate, and systolic blood pressure, reflecting the influence of the haemodynamic variables in the sartorius NIRS monitoring values. On the other hand, the negative correlation observed between NIRS and body temperature is interesting because, the haemodynamic changes induced by decreasing temperature values, also reflect a decrease in the metabolic state of the tissue. Which allows us to hypothesize that NIRS technology may have the potential of addressing the tissues’ metabolic state. NIRS was not able to detect noxious stimulation in this study

Interactions between polyphenols and volatile compounds in wine: A literature review on physicochemical and sensory insights

Wine polyphenols (PPhs) and volatile organic compounds (VOCs) are responsible for two of the main sensory characteristics in defining the complexity and quality of red wines: astringency and aroma. Wine VOCs’ volatility and solubility are strongly influenced by the matrix composition, including the interactions with PPhs. To date, these interactions have not been deeply studied, although the topic is of great interest in oenology. This article reviews the available knowledge on the main physicochemical and sensory effects of polyphenols on the release and perception of wine aromas in orthonasal and retronasal conditions. It describes the molecular insights and the phenomena that can modify VOCs behavior, according to the different chemical classes. It in-troduces the possible impact of saliva on aroma release and perception through the modulation of polyphenols–aroma compounds interactions. Limitations and possible gaps to overcome are presented together with updated approaches used to investigate those interactions and their effects, as well as future perspectives on the subject

Ocorrência de Megastigmus sp. (Hymenoptera: Torymidae) parasitoide da vespa da galha Leptocybe invasa (Hymenoptera: Eulophidae) no Brasil.

Resumo

Desempenho do parasitoide Trichospilus diatreae (Hymenoptera: Eulophidae) utilizando como hospedeiro Spodoptera frugiperda (Lepdoptera: Noctuidae), sob diferentes tempos de exposição.

Resumo

Extraction of phenolic compounds from 'Aglianico' and 'Uva di Troia' grape skins and seeds in model solutions: Influence of ethanol and maceration time

The effect of increasing concentration of ethanol (0, 4, 7.5 and 13 %) and contact time (respectively 1, 4, 7 and 10 days) on the extraction of phenolics from berry skins and seeds of the grape, Vitis vinifera 'Aglianico' and 'Uva di Troia', were examined. Two assays of post-fermentative maceration in two hydroalcoholic solutions at 11 and 13 % ethanol, were also performed. Chromatic properties and phenolics of medium were analyzed by HPLC and spectrophotometric methods. The extraction of total phenolics, anthocyanins, proanthocyanidins, and vanilline reactive flavans (VRF) from berry skins reached the maximum on the 4th day of maceration. Quercetin and gallic acid were gradually extracted from grape skins. The maximum release of flavan-3-ols from the skins was achieved on the first day of maceration. Total phenolics, tannins and VRF were gradually extracted from seeds. During the postfermentative maceration, higher the content of ethanol, higher the extraction of total polyphenols and tannins from 'Uva di Troia' skins and the extraction of total polyphenols and tannins from 'Aglianico' seeds. These results clearly indicate that the grape cultivar mainly influences the release of phenolic compounds from the solid parts of berry to the must especially during postfermentative maceration.