Optimization of SPME-Arrow-GC/MS Method for Determination of Free and Bound Volatile Organic Compounds from Grape Skins

(1) Background: Solid phase microextraction (SPME)-Arrow is a new extraction technology recently employed in the analysis of volatiles in food materials. Grape volatile organic compounds (VOC) have a crucial role in the winemaking industry due to their sensory characteristics of wine.; (2) Methods: Box–Behnken experimental design and response surface methodology were used to optimise SPME-Arrow conditions (extraction temperature, incubation time, exposure time, desorption time). Analyzed VOCs were free VOCs directly from grape skins and bound VOCs released from grape skins by acid hydrolysis.; (3) Results: The most significant factors were extraction temperature and exposure time for both free and bound VOCs. For both factors, an increase in their values positively affected the extraction efficiency for almost all classes of VOCs. For free VOCs, the optimum extraction conditions are: extraction temperature 60 °C, incubation time 20 min, exposure time 49 min, and desorption time 7 min, while for the bound VOCs are: extraction temperature 60 °C, incubation time 20 min, exposure time 60 min, desorption time 7 min.; (4) Conclusions: Application of the optimized method provides a powerful tool in the analysis of major classes of volatile organic compounds from grape skins, which can be applied to a large number of samples.

Combining Grape Byproducts to Maximise Biological Activity of Polyphenols in Chickens

Grape seeds (GS) and grape skins (GK) are natural sources of polyphenols with antioxidant capacity. An experiment was conducted to investigate in chickens the effect of including GS and GK (40 g/kg), individually or combined in different proportions (20 g/kg GS–20 g/kg GK; 30 g/kg GS–10 g/kg GK; 10 g/kg GS–30 g/kg GK), in a corn-soybean diet on growth performance, ileal and excreta contents of total extractable polyphenols (TEP) and tannins, ileal digestibility of protein, plasma and meat α-tocopherol concentration and lipid oxidation (assessed by measuring the thiobarbituric acid reactive substances, TBARS) of stored thigh meat. Neither growth performance parameters nor ileal digestibility of protein were affected by dietary treatments. As compared with control birds, chickens fed the grape byproduct diets showed higher ileal (p < 0.001) and excreta (p < 0.001) TEP and tannins contents. Dietary inclusion of grape byproducts increased α-tocopherol concentration both in plasma (p < 0.001) and in thigh meat (p < 0.01 at 1 d; p < 0.001 at 7 d), as compared with the control group. The highest plasma α-tocopherol concentrations were reached with the 30 g/kg GS–10 g/kg GK and 20 g/kg GS–20 g/kg GK combinations. On day 1 of meat storage, no differences on meat α-tocopherol concentration were found among the grape byproducts treatments but on day 7 of storage, the 20 g/kg GS–20 g/kg GK and 10 g/kg GS–30 g/kg GK combinations led to the highest α-tocopherol concentrations in chicken thigh meat. After seven days of refrigerated storage of meat, the TBARS value was lower in chickens fed the grape byproducts diets than in control birds (1.27 vs. 2.49 mg MDA/kg, p < 0.001). Moreover, among the different grape byproduct treatments, the lowest MDA values were reached with the diets containing GK at rates from 20 to 40 g/kg. In conclusion, dietary incorporation of 40 g/kg of GS and GK added separately or combined increased the plasma and meat α-tocopherol content. Furthermore, the combinations of GS and GK with a proportion of GK of at least 50% optimised α-tocopherol concentration both in plasma and in thigh meat and mitigated lipid oxidation in 7-day stored meat.

Phenolic profile of grapevine cv. Tempranillo skins is affected by timing and severity of early defoliation

Aim of study: To investigate the effects of three early leaf removal treatments on the phenolic compounds of cv. ‘Tempranillo’ (Vitis vinifera L.) grape skins. Area of study: The experiment was conducted in a vineyard located in Requena, Valencia (South-eastern Spain) over two consecutive seasons. Materials and methods: Four treatments were investigated over two seasons in drip-irrigated vines: Control (C), non-defoliated and three defoliation treatment, applied at different phenological stages and intensities where all leaves from the first 6 nodes were eliminated just before flowering (ED) and at fruitset (LD). The fourth defoliation treatment was performed at the same time of ED but only the leaves facing east of the eight first nodes were removed (EED). At harvest, thirty-eight phenolic compounds were quantified by HPLC in the grape skins, including anthocyanins, flavanols, flavonols, hydroxycinnamic acids and their tartaric derivatives. Main results: A general increase of the skin phenolic compounds concentration was found in response to the defoliation treatments. The largest and more significant effects were observed for LD in 2009 with relative increases with respect to the un-defoliated vines of 14.8, 86.0, 119.0, and 75.9% for anthocyanins, flavanols, flavonols and hydroxycinnamates, respectively. On the other hand, EED did not clearly modify any polyphenolic compound. In addition, the response of phenolic families analyzed to defoliation treatments was different. Malvidine derivatives were not altered by any of the treatments, while the contents of quercetin and kaempferol derivatives and ferulic and coumaric acids, increased in both years when LD was applied. Research highlights: The defoliation effects on specific phenolic substances were dependent on timing, severity, and the season. Skin phenolic compounds increase in response to defoliation treatments and flavonols and hydroxycinnamates were the most affected families.

Contribution of Grape Skins and Yeast Choice on the Aroma Profiles of Wines Produced from Pinot Noir and Synthetic Grape Musts

The aroma profile is a key component of Pinot noir wine quality, and this is influenced by the diversity, quantity, and typicity of volatile compounds present. Volatile concentrations are largely determined by the grape itself and by microbial communities that produce volatiles during fermentation, either from grape-derived precursors or as byproducts of secondary metabolism. The relative degree of aroma production from grape skins compared to the juice itself, and the impact on different yeasts on this production, has not been investigated for Pinot noir. The influence of fermentation media (Pinot noir juice or synthetic grape must (SGM), with and without inclusion of grape skins) and yeast choice (commercial Saccharomyces cerevisiae EC1118, a single vineyard mixed community (MSPC), or uninoculated) on aroma chemistry was determined by measuring 39 volatiles in finished wines using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC-MS). Fermentation medium clearly differentiated the volatile profile of wines with and without yeast, while differences between EC1118 and MSPC wines were only distinct for Pinot noir juice without skins. SGM with skins produced a similar aroma profile to Pinot noir with skins, suggesting that grape skins, and not the pulp, largely determine the aroma of Pinot noir wines.

Ohmic heating for polyphenol extraction from grape berries: an innovative prefermentary process

High energy consumption is often required to increase the extraction of phenolic compounds from grapes during alcoholic fermentation. Processes such as thermovinification require significant temperature changes over a long period of time to ensure the diffusion of phenolic compounds from the grape skin layer to the must. In this study, the capability of the ohmic heating (OH) process (E = 55 V/cm, t = 60–90 s, T = 72 °C) to improve the extractability of valuable intracellular compounds from grape skins of Aglianico and Barbera grape matrices before the alcoholic fermentation stepAs similarly reported by Donsì et al. (2010), any tissue damage to grape skins occurring after the application of either conventional or ohmic heating was not found to influence the rate of fermentation. was investigated and compared with both untreated and conventional thermally (CH) treated (T = 72 °C, t = 90 s) samples. Total phenolics and antioxidant capacity were monitored during fermentation (10 days). In comparison to the conventional thermal treatment, the results showed that the phenolic compound content of musts was twice as high immediately after OH treatment. This process could drastically improve the classic prefermentary maceration (thermovinifications, cold macerations, etc.) time. In finished wines produced from the treated musts, the total polyphenolic content of OH wines was up to 17 % higher than that of CH wines, and 30 % higher than that of untreated wines. No differences in concentrations of total tannins and anthocyanins were observed between conventional and ohmic heated musts. However, an increase of 30 to 200 % for some aromatic esters was observed in wines from ohmic heated musts. Overall, the outcomes of this work proved that, in addition to the thermal effect, the moderate electric field (MEF) applied during ohmic heating has the potential to induce an instantaneous release of polyphenolic compounds due to the electroporation phenomenon of cell membranes, thus saving energy and reducing processing time.

Peranan Resveratrol terhadap Progresivitas Uterine Fibroid

Uterine fibroids or leiomyomas are benign neoplasms that occur in the uterus and still become a health problem among women of reproductive age. Predominantly, uterine fibroids are found at productive age but some cases are found after menopause. Based on previous studies, there were 145 cases of uterine fibroids in 2014 and 69.7% were found in women over 40 years. Patients with uterine fibroids show a decreased quality of life with symptoms such as heavy uterine bleeding, pelvic pain, and loss of pregnancy. The pathogenesis of uterine fibroids is still unknown, but genetic factors, cytokines, growth factors, and steroid hormones are weak and play an important role in the development of uterine fibroids. Several studies have shown the effect of resveratrol that can be obtained from grape skins. Resveratrol can reduce extracellular matrix deposition and uterine fibroid cell proliferation. Looking at the induced events then resveratrol is effective in preventing the progression of uterine fibroids.

Quality Evaluation of Winery By-Products from Ionian Islands Grape Varieties in the Concept of Circular Bioeconomy

The aim of this work was the study and evaluation of winery by-products in the framework of the circular bioeconomy. Grape seeds and grape skins from Greek Ionian Islands varieties were analyzed in an attempt to provide the appropriate basis for model development of their sustainable exploitation at a local or regional level. The by-products were collected directly from the wineries immediately after the vinification process and were analyzed by chromatographic and spectroscopic techniques. In addition, annual production and yields were estimated. Grape seed oil quality was evaluated based on fatty acid methyl ester (FAME) composition. The grape skins’ phenolic fraction was extracted by an eco-friendly, nontoxic water-glycerol solvent system and was detected qualitatively. In addition, total phenolic content (TPC) and antioxidant activity (ABTS, DPPH) were measured. Based on estimated yields, our results demonstrate that winery by-products have the potential to promote the cyclical bioeconomy in a modern economic growth model that will reduce by-products and environmental costs as they can be reused as whole material in foods, dietary supplements, cosmetic ingredients, food colorants, and preservatives.