Influence of flash heating and aspergillopepsin I supplementation on must and wine attributes of aromatic varieties.

The protein instability with haze formation represents one of the main faults occurring in white and rosé wines. Among the various solutions industrially proposed, aspergillopepsin I (AP-I) supplementation coupled with must heating (60-75 °C) has been recently approved by OIV and the European Commission for ensuring protein stability of wines. This study investigates the impact of AP-I either applied independently or in combination with flash pasteurization on the chemical composition of grape must and wines derived from Sauvignon Blanc and Gewürztraminer. The efficacy on protein stability of a complete treatment combining heat (70 °C) and AP-I (HP) was confirmed through heat test and bentonite requirement, although no differences were observed between must heating and HP treatments. However, high-performance liquid chromatography analysis of unstable pathogenesis-related proteins revealed that AP-I supplementation reduced chitinases and thaumatin-like proteins compared to the non-enzymed samples, with and without must heating. Amino acid increase was reported only in HP musts, particularly in Sauvignon Blanc. The concentration of yeast-derived aroma compounds in Gewürztraminer wines was increased by must heating; compared to controls, flash pasteurization rose the overall acetate esters content of 85 % and HP of 43 %, mostly due to isoamyl acetate. However, heat treatments -with or without AP-I- reduced terpenes up to 68 %. Despite the different aroma profiles, no differences were observed for any descriptor for both varieties in wine tasting, and only a slight decrease trend was observed for the floral intensity and the typicality descriptors in heated wines.

Improved Sustainability in Wine Industry Byproducts: A Scale-up and Economical Feasibility Study for High-Value Compounds Extraction Using Modified SC-CO2.

The objective of the present work was to optimize the operating conditions (P, T cosolvent %) and to study the scale-up and the feasibility of the supercritical fluid extraction (SFE) process for polyphenols from grape pomace, the main solid byproduct of the wine industry. Pilot-scale equipment (1 L extraction vessel) was used to study the scale-up prediction for extraction vessels of 50, 100, 500, and 1000 L capacity. The adopted scale-up criteria consisted of maintaining and keeping constant the solvent mass-to-feed mass ratio and the bed geometry dimension. The results indicated an excellent predictive level obtained by Sovová's model and success of the adopted scale-up criteria. At industrial scale, yields were close to 2.3 gGAE/100 gDM, a value obtained using the pilot-scale equipment. High concentrations of high-added-value phenols such as cis-resveratrol glucoside, cis-coutaric acid, trans-p-coumaric acid, quercetin, and proanthocyanidins were found in the extract. An economic evaluation of the process indicated the feasibility of an industrial SFE plant with a capacity of 500 L for producing in 60 min an extract with an expected phenolics' concentration of approximately 133 gGAE/kg extract at an estimated 67€ /kgextract cost of manufacturing. Notably, all values are better than those currently reported in the literature.

Comparison of a Rapid Light-Induced and Forced Test to Study the Oxidative Stability of White Wines.

The oxidation processes of white wines can occur during storage and commercialization due to several factors, and these can negatively affect the color, aroma, and quality of the wine. Wineries should have faster and simpler methods that provide valuable information on oxidation stability of wines and allow fast decision-making procedures, able to trigger suitable technological interventions. Using a portable prototype instrument for light irradiations at different wavelengths and times was considered and evaluated on sensorial, spectrophotometric, and colorimetric parameters of white wines. The sensorial analysis revealed that white and light blue were the most significant, after only 1 h of irradiation. The experimental results showed that hydrogen peroxide could enhance the effect of light treatment, allowing a contemporary evaluation of the oxidation stability of wine against light and chemical stresses. As expected, a good correlation (R2 > 0.89) between optical density at 420 nm and b* parameter was highlighted. The synergic effect of light and H2O2 was also studied on the hydrolyzable and condensed tannins' additions to white wine. The proposed methodology could be used to evaluate the oxidative stability of white wines, but also to evaluate the effect of some oenological adjuvants on wine stability.

High Power Ultrasound Treatments of Red Young Wines: Effect on Anthocyanins and Phenolic Stability Indices.

Polyphenols, especially anthocyanins, play an important role on red wine sensory qualities and their evolution during storage. High Power Ultrasound (HPU) has been recognized as one of the most promising technologies which can be applied in winemaking processes for several purposes, and it is recently officially approved for crushed grapes treatments. The effect of ultrasound amplitude (41 and 81%) and treatment time (1, 3, and 5 min) has been studied on anthocyanins, flavan-3-ols, tannins, polymerized pigments, HCl index, and the color intensity of two finished red young wines. Anthocyanins and phenols compounds were not degraded with an increase in amplitude and sonication time, and the chromatic properties of the selected wines were preserved. Amplitude and ultrasound time were also evaluated considering their effect on evolution of anthocyanin content and phenolic stability indices during the first thirty days of storage. The higher level of amplitude (81%) induced a higher percentage decrease in tannins, 15% and 40% after 15 and 30 days of storage, respectively, compared to untreated wine which did not show a significant change during storage. HPU shows a possible chemical effect on the evolution of some analytical indices during bottling maturation, but their effectiveness could be strictly linked with the initial phenolic profile and ratios between polyphenol classes.

Extraction kinetic modelling of total polyphenols and total anthocyanins from saffron floral bio-residues: Comparison of extraction methods.

Analysis of the extraction kinetic modelling for natural compounds is essential for industrial application. The second order rate model was applied to estimate the extraction kinetics of conventional solid-liquid extraction (CSLE), ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) of total polyphenols (TPC) from saffron floral bio-residues at different solid-to-liquid ratios (RS/L)(1:10, 1:20, 1:30, 1:50 g ml-1), ethanol 59% as solvent and 66 °C temperature. The optimum solid-to-liquid ratios for TPC kinetics were 1:20 for CLSE, 1:30 for UAE and 1:50 for MAE. The kinetics of total anthocyanins (TA) and antioxidant activity (AA) were investigated for the optimum RS/L for each method. The results showed a good prediction of the model for extraction kinetics in all experiments (R2 > 0.99; NRMS 0.65-3.35%). The kinetic parameters were calculated and discussed. UAE, compared with the other methods, had the greater efficiency for TPC, TA and AA.

Potential oil yield, fatty acid composition, and oxidation stability of the hempseed oil from four Cannabis sativa L. cultivars.

The cultivation of four industrial hemp cultivars (Felina 32, Chamaeleon, Uso31, and Finola) was investigated for oil production in the north-east of Italy along two years. The oils of all cultivars resulted in rich amount of linoleic acid (ω-6) and α-linolenic acid (ω-3). Felina 32 and Chamaeleon oils exhibited the highest amount of linoleic acid (59%) and α-linolenic acid (18%). Finola and Uso31 oils resulted in the richest of γ-linolenic acid (5-6%). All hempseed oils presented high oxidation stability and an acceptable initial quality. It is suggested that these oils can be used to produce EFA dietary supplements high in ω-6 and ω-3 of vegetal origin.