Detailed phenolic composition of Vidal grape pomace by ultrahigh-performance liquid chromatography–tandem mass spectrometry

UHPLC-MS/MS analysis and protective effects on neurodegenerative diseases of phenolic compounds in different parts of Diospyros kaki L. cv. Mopan

Persimmon (Diospyros kaki L. cv. Mopan.), an important commercial crop belonging to the genus of Diospyros in the Ebenaceae family, is rich in bioactive phenolic compounds. In this study, the phenolic compounds from fruits, leaves, and calyces of persimmon were qualitatively and quantitatively determined by UPLC-Q-Exactive-Orbitrap/MS and UPLC-QqQ-MS/MS, respectively. Furthermore, the role of phenolic extract from different parts of persimmon on neuroprotective activity in vitro, through against oxidative stress and anti-neuroinflammation effect was firstly evaluated. The results showed that 75 phenolic compounds, and 3 other kinds of compounds were identified, among which 44 of phenolic compounds were quantified from different parts of persimmon. It is the first time that epicatechin-epigallocatechin, catechin-epigallocatechin, catechin-epigallocatechin (A-type), and glycoside derivatives of laricitrin were identified in persimmon extract. The dominated phenolic compounds in three parts of persimmon were significantly different. All phenolic extracts from each part of persimmon showed strong neuroprotective activities against H2O2-induced oxidative stress in PC-12 cells and LPS-induced BV2 cells. The fruit extract presented the strongest activity, followed by calyx and leaf extract. The systematic knowledge on the phytochemical composition along with activity evaluation of different parts of persimmon could contribute to their targeted selection and development.

Quality Characteristics and Antioxidant Activities of Six Types of Korean White Wine

The cultivation of European grape cultivars suitable for winemaking in Korea presents challenges due to factors such as climate, soil conditions, precipitation, and sunlight. Consequently, Korea has traditionally resorted to adding sugar to its wine production to counteract the low sugar content in Korean grapes, yielding lower-quality wines. However, recent success in the cultivation of five European grape cultivars and the development of the domestic grape cultivar Cheongsoo have increased the possibility of achieving high-quality Korean wines. This study aimed to explore the potential of European grape cultivars and Cheongsoo as wine grapes in Korea. This study also conducted sensory evaluation and analyzed the physicochemical properties of the grapes and wines, including antioxidant capacity and color. Despite originating from the same vineyard, the composition of grapes and wines, including volatile aromatic compounds, significantly differed among the grape cultivars. In particular, Vidal wine exhibited superior antioxidant capacity compared with other wines. Moreover, Cheongsoo wine showed higher levels of essential volatile aromatic compounds, such as monoterpenes, than other wines. Sensory evaluation of these two wines also revealed excellent results. In conclusion, these findings hold promise for enhancing the diversity of Korean white wine and fostering growth in the wine industry.

White Grape Pomace Valorization for Remediating Purposes

The present investigation focuses on a possible alternative to reduce grape pomace’s negative impact on the environment by exploiting its capacities for wastewater remediation. Therefore, three directions are followed: (1) the characterization of white grape byproducts’ antioxidant and antiradical properties; (2) the determination of organophosphorus compound concentration that might be present in the samples; and (3) the evaluation of the possible use for wastewater remediation. The grape pomace was used for obtaining different extracts considering different extraction conditions. The hydroalcoholic extracts have an increased amount of total phenolic content. The lyophilized hydroalcoholic extract showed high total phenolic content (159.52 mg/100 g) and low organophosphorus content (0.257 ± 0.015 nmol). The lowest DPPH antiradical-scavenging activities were obtained for the extracts in ethanol obtained from refrigerated pomace (0.055) and for dried pomace (0.045).

Effect of Issatchenkia terricola WJL-G4 on Deacidification Characteristics and Antioxidant Activities of Red Raspberry Wine Processing

Our previous study isolated a novel Issatchenkia terricola WJL-G4, which exhibited a potent capability of reducing citric acid. In the current study, I. terricola WJL-G4 was applied to decrease the content of citric acid in red raspberry juice, followed by the red raspberry wine preparation by Saccharomyces cerevisiae fermentation, aiming to investigate the influence of I. terricola WJL-G4 on the physicochemical properties, organic acids, phenolic compounds and antioxidant activities during red raspberry wine processing. The results showed that after being treated with I. terricola WJL-G4, the citric acid contents in red raspberry juice decreased from 19.14 ± 0.09 to 6.62 ± 0.14 g/L, which was further declined to 5.59 ± 0.22 g/L after S. cerevisiae fermentation. Parameters related to CIELab color space, including L*, a*, b*, h°, and ∆E* exhibited the highest levels in samples after I. terricola WJL-G4 fermentation. Compared to the red raspberry wine pretreated without deacidification (RJO-SC), wine pretreated by I. terricola WJL-G4 (RJIT-SC) exhibited significantly decreased contents of gallic acid, cryptochlorogenic acid, and arbutin, while significantly increased contents of caffeic acid, sinapic acid, raspberry ketone, quercitrin, quercetin, baicalein, and rutin. Furthermore, the antioxidant activities including DPPH· and ABTS+· radical scavenging were enhanced in RJIT-SC group as compared to RJO-SC. This work revealed that I. terricola WJL-G4 had a great potential in red raspberry wine fermentation.

Effects of Simultaneous Co-Fermentation of Five Indigenous Non-Saccharomyces Strains with S. cerevisiae on Vidal Icewine Aroma Quality

In this study, Vidal grape must was fermented using commercial Saccharomyces cerevisiae F33 in pure culture as a control and in mixed culture with five indigenous non-Saccharomyces yeast strains (Hanseniaspora uvarum QTX22, Saccharomycopsis crataegensis YC30, Pichia kluyveri HSP14, Metschnikowia pulcherrima YC12, and Rhodosporidiobolus lusitaniae QTX15) through simultaneous fermentation in a 1:1 ratio. Simultaneous fermentation inhibited the growth of S. cerevisiae F33 and delayed the time to reach the maximum biomass. Compared with pure fermentation, the contents of polyphenols, acetic esters, ethyl esters, other esters, and terpenes were increased by R. lusitaniae QTX15, S. crataegensis YC30, and P. kluyveri HSP14 through simultaneous fermentation. S. crataegensis YC30 produced the highest total aroma activity and the most abundant aroma substances of all the wine samples. The odor activity values of 1 C13-norisoprenoid, 3 terpenes, 6 acetic esters, and 10 ethyl esters improved significantly, and three lactones (δ-decalactone, γ-nonalactone, and γ-decalactone) related to coconut and creamy flavor were only found in this wine. Moreover, this sample showed obvious “floral” and “fruity” note odor due to having the highest amount of ethyl ester aromatic substances and cinnamene, linalool, citronellol, β-damascenone, isoamyl ethanoate, benzylcarbinyl acetate, isobutyl acetate, etc. We suggest that simultaneous fermentation of S. crataegensis YC30 with S. cerevisiae might represent a novel strategy for the future production of Vidal icewine.

Qualitative and quantitative analysis of phenolic compounds in blueberries and protective effects on hydrogen peroxide-induced cell injury

This work was conducted to optimize an accelerated solvent extraction for ultra high performance liquid chromatography-mass spectrometry/mass spectrometry analysis of blueberry phenolic compounds. The conditions for accelerated solvent extraction were verified using response surface methodology to obtain the following optimized conditions: ethanol concentration (pH = 3), 48%; temperature, 50℃, and static cycle times, 3. Further, ultra high performance liquid chromatography with quadrupole Exactive Orbitrap mass spectrometry and ultra high performance liquid chromatography with triple-quadrupole tandem mass methods for determination of the detailed phenolic composition were developed and validated. Total of 81 phenolic compounds were identified by ultra high performance liquid chromatography with quadrupole Exactive Orbitrap mass spectrometry including 23 anthocyanins, 32 flavonols, 11 proanthocyanidins, 2 other flavonoids, and 13 phenolic acids. Fifty-one of these compounds have been simultaneously quantified by ultra high performance liquid chromatography with triple-quadrupole tandem mass including 31 anthocyanins, 8 flavonols, 6 proanthocyanidins, 2 other flavonoids, and 8 phenolic acids. Malvidin-dinhexoside has, for the first time, been detected in wild. Moreover, by verifying the protection on PC12 cells against oxidative damage, it was showed that the phenolic extracts (500 µg/mL) can improve significantly the viability (9.26-24.78%) of hydrogen peroxide-induced PC12 cells, activities of superoxide dismutase (34.59-37.90 U/mg) and glutathione peroxidase (6.87-14.42 mU/mg) and decrease the content of malonic dialdehyde (13.27-24.62 nmol/mg). Correlation analysis suggested that anthocyanins might contribute most to these activities.

Development of a rapid and accurate UHPLC-PDA-FL method for the quantification of phenolic compounds in grapes

Grapes are a great source of phenolic compounds, which have excellent antioxidant properties. Efficient analytical methods are necessary to selectively and precisely determine these compounds content in grapes. In this study, a reverse-phase ultra-high performance liquid chromatography (UHPLC) method with fluorescence and photodiode array detection has been developed to determine and quantify 27 of the main phenolic compounds present in grapes. An ACQUITY UPLC® BEH C18 (50 mm × 2.1 mm i.d., 1.7 mm particle size) column was employed. A gradient method was developed and column temperature (25-55 °C), as well as flow rate (0.6-0.75 mL min^-1), were optimized. The optimum conditions allowed the separation of all the compounds in less than 9 min. The method was validated and demonstrated excellent detection and quantification limits, precision, and selectivity. Finally, several grape varieties were studied in order to demonstrate the applicability of the method to the analysis of real matrix samples.

Valorisation of Grape Stems as a Source of Phenolic Antioxidants by Using a Sustainable Extraction Methodology

Pressurized liquid extraction with ethanol:water mixtures was proposed for obtaining phenolic antioxidants from grape stems. The optimal extraction conditions were elucidated by using a central composite rotatable design (solvent (X₁, 0–100% ethanol:water v/v), temperature (X₂, 40–120 °C) and time (X₃, 1–11 min)). Response surface methodology determined 30% ethanol:water, 120 °C and 10 min as the optimal extraction conditions regarding total phenolic content (TPC) (185.3 ± 2.9 mg gallic acid/g of extract) and antioxidant activity (3.55 ± 0.21 mmol Trolox/g, 1.22 ± 0.06 mmol Trolox/g and 1.48 ± 0.17 mmol Trolox/g of extract in ABTS, DPPH and ORAC methodologies, respectively). The antioxidant activity was attributed to total polymer procyanidins and flavan-3-ol monomers and oligomers, although other phenolic compound contributions should not be ruled out. Forty-two phenolic compounds were identified in the optimal extract, mainly polymer procyanidins and, to a lesser extent, monomers and oligomers of flavan-3-ols, quercetin-3-O-glucuronide, ε-viniferin, gallic and caftaric acid. Ethyl gallate, ellagic acid, protocatechuic aldehyde, delphinidin-7-O-glucoside and cyanidin-3-O-glucoside were reported for the first time in grape stem extracts. In conclusion, this study highlights the use of this winery side stream as a source of antioxidants within a sustainable food system.

Investigation of the chemical composition and biological activity of edible grapevine (Vitis vinifera L.) leaf varieties

Chemical composition and bioactivity of eight edible Vitis vinifera L. leaf varieties originating from Fruška Gora, Serbia, including two autochthonous varieties, were evaluated. The LC-MS/MS analysis confirmed the presence of 28 natural products in leaf samples, among which most abundant were glycosylated flavonoids, ellagic and chlorogenic acids. The highest amounts of most of the tested compounds were detected in leaves of autochthonous variety Sila. Bioactivity was assessed by a set of in vitro antioxidant, neuroprotective and cytotoxic assays. Leaves of all examined varieties exhibited average bioactivity, with leaves of autochthonous variety Župljanka standing out as the most promising sample. To conclude, investigated grapevine leaves proved to be a rich source of nutraceuticals, primarily antioxidants, and their further employment as medicinal food in human diet and beneficial raw material for food, pharmaceutical and cosmetic industries should be supported.

Chemical and sensory characterisation of sweet wines obtained by different techniques

Little is known about the chemical and sensory characteristics of natural sweet wines obtained by different grape dehydration processes. The main aim of this work is to characterise several natural sweet wines, in order to understand the influence of grape dehydration on the chemical and sensory profile of those wines. First, conventional oenological parameters and low molecular weight phenolic compounds have been determined. Next, sensory descriptive analysis was performed on individual samples based on citation frequencies for aroma attributes and conventional intensity scores for taste and mouth-feel properties. Low molecular weight phenolic compounds and acidity were found in a lower concentration in most wines from off-vine dried grapes. Late harvest wine presented higher amounts of phenolics. White wines showed higher sensory and chemical acidity. Most wines obtained from off-vine and on-vine grape dehydration presented common notes of dry fruits and raisins as aroma properties. Chemical and sensory analyses performed in this study were able to define sweet wines. No significant differences have been found in chemical and sensory profiles of sweet wines according to dehydration processes of the grapes. Late harvest wine and white wines were differentiated from other wines through chemical and sensory analysis.