Grape pomace enzymatic extract restores vascular dysfunction evoked by endothelin-1 and DETCA via NADPH oxidase downregulation and SOD activation

Grape pomace enzymatic extract (GP-EE) exhibits a potent antioxidant and vasodilator activity, although the mechanisms underlying this action are not completely understood. Our aim was to evaluate its vasoactive mechanisms, focusing on vascular NADPH oxidase and superoxide dismutase (SOD)-dependent pathways. GP-EE effectively restored vascular impairment induced by the NADPH oxidase activator endothelin-1 through downregulation of its Nox-1 and p47^phox subunits. GP-EE partially prevented endothelial dysfunction elicited by the SOD inhibitor, DETCA, preserving EC-SOD and Mn-SOD isoenzymes protein expression. Although many of these vasoactive effects could be attributed to the presence of catechin, GP-EE was able to exert additional protection against the vascular deleterious effects evoked by NADPHox activation and SOD inhibition. This additional vasoprotection could be related to the enzymatic extraction process, providing polyphenols from winemaking residue with a potent activity against vascular dysfunction by preventing NADPHox activation and maintaining SOD defense, making GP-EE as an ideal nutritional supplement.     

Changes in polyphenol and polysaccharide content of grape seed extract and grape pomace after enzymatic treatment

Grape seed extract and grape pomace are rich sources of polyphenols. The aim of this study was to evaluate the release of polyphenols, the solubilisation of carbohydrate, and the antioxidant capacity of these grape by-products after enzymatic reaction with carbohydrases (cellulolytic and pectinolytic activities) and tannase for 24 h. The use of tannase in these by-products, and pectinase in grape pomace changed the galloylated form of catechin to its free form, releasing gallic acid and increasing the antioxidant activity. In grape pomace, cellulase treatment was not efficient for phenolic release and antioxidant activity improvement. The addition of carbohydrases to grape pomace, either alone or in combination, degraded the cell wall polysaccharides, increasing the content of monosaccharides. These results provide relevant data about the potential of pectinase, tannase and combinations of enzymes on the release of polyphenols and monosaccharides from grape by-products, improving the antioxidant capacity and the nutritional value.     

诺丽果渣成分分析及抗氧化性研究

目的分析诺丽果渣成分及抗氧化活性,为诺丽加工副产物诺丽果渣的开发利用提供理论依据。方法通过分光光度法测定诺丽果渣中的总黄酮、黄酮甙、多糖、皂甙和果胶,采用过氧化氢体系、超氧阴离子体系、羟基自由基体系和Oyaizu法,分别对诺丽果渣水提取物(waterextract,WE)、石油醚提取物(petroleum ether extract, PEE)、乙酸乙酯提取物(ethyl acetate extract, EAE)、氯仿提取物(chloroform extract, CE)和正丁醇提取物(n-butanol extract, BE)的抗氧化活性进行测定和比较。结果诺丽果渣含有总黄酮、黄酮甙、多糖、皂甙和果胶等功能成分,诺丽果渣的5种提取物在过氧化氢体系中,对H_2O_2的清除能力强弱顺序依次为VCCEEAEBEPEEWE;在超氧阴离子体系中,对O_2~-·抗氧化活性强弱顺序依次为VCEAEWEBEPEECE,在羟基自由基氧化体系中,对?OH抗氧化活性强弱,依次为VCBEWEEAEPEECE;还原能力强弱,依次为EAEBECEWEPEE。结论诺丽果渣5种提取物都有抗氧化性,随浓度增大抗氧化能力增强,在不同的自由基体系中,自由基清除能力不同, EAE抗氧化活性较好。     

Antioxidant Effects of Grape Pomace on the Quality of Silver Carp (Hypophthalmichthys molitrix) Fillets During Refrigerated Storage

This study aimed to determine the phenolic content and antioxidant effect of grape pomace extract on silver carp fillets during refrigerated storage. Total phenolic content of grape pomace extract was quantified by colorimetric methods. Silver carp samples were treated with 0, 2, and 4% of grape pomace extract (g extract/100 g flesh) and stored 15 days in a refrigerator (4°C). Changes in pH, peroxide value, thiobarbituric acid, and heme iron at 0, 3, 6, 9, 12, and 15 days of storage were investigated. Results showed that the values of pH, peroxide value, and thiobarbituric acid increased and iron levels decreased in all treatments during storage (p < 0.05). The phenolic contents were generally much more influenced by the quality parameters treated compared to the control. The addition of grape pomace extract delayed lipid oxidation in silver carp fillet considerably during refrigerated storage. These results suggested that grape pomace extract has the potential to be used as a natural antioxidant.     

橄榄渣提取物对马肉饼的抗氧化作用

为研究橄榄渣提取物对马肉饼的抗氧化作用,以橄榄渣提取物为研究对象,分别测定其总酚含量,DPPH自由基清除能力以及ABTS⁺·清除能力;将不同浓度(0.2%、0.4%、0.6%)橄榄渣提取物添加到马肉饼中,测定其在9 d冷藏(4℃)过程中色差、高铁肌红蛋白含量、过氧化值、硫代巴比妥酸(TBARs)值和羰基含量的变化。结果表明:橄榄渣提取物的总酚含量为(70.82±7.34)mg GAE/g DW。随着橄榄渣提取物浓度的升高,橄榄渣提取物的DPPH、ABTS⁺自由基清除率逐渐升高。与对照组相比,橄榄渣提取物的添加使马肉饼中高铁肌红蛋白的含量降低、红度(a^*)值升高,过氧化值、TBARs值和羰基含量显著降低(p<0.05)。并且提取物的添加量越高,上述作用越明显。因此,橄榄渣提取物有助于改善马肉饼贮藏过程中颜色的褪变,并延缓脂质和蛋白氧化,可以作为马肉饼贮藏过程中的潜在天然抗氧化剂。     

不同水解方法对刺梨渣多酚含量及活性的影响

该研究以刺梨渣为原料,分别经酸水解、碱水解以及酶水解得到刺梨渣提取液,测定提取液中多酚含量组成及体外抗氧化能力,并比较酚类物质与抗氧化能力之间的相关性。结果表明,刺梨渣提取液中游离多酚、游离黄酮含量最高（分别为84.44 mg RE/g和136.67 mg RE/g）;碱水解得到的结合酚、结合黄酮含量最高（2.04 mg RE/g和5.89 mg RE/g）。抗氧化分析结果表明,游离酚抗氧化能力最强,对DPPH·、ABTS+·清除能力、还原铁离子和铜离子的能力分别达到854.87 μmol TE/g、995.35 μmol TE/g、336.24 μmol TE/g、1 212.08 μmol TE/g。皮尔逊相关性分析结果表明,多酚含量与抗氧化活性呈较强的正相关（P＜0.05）。综上可知,刺梨渣富含酚类物质,且碱水解处理刺梨渣能释放更多的结合酚,具有较强的抗氧化活性。     

红枣果汁果渣与果酒果渣中色素抗氧化活性的比较

为比较红枣果汁果渣与果酒果渣中色素抗氧化活性的差异,以红枣果汁及果酒果渣为原料,碱法提取红枣色素,运用比色法测定红枣果汁果渣、果酒果渣色素中抗氧化活性成分含量,测定DPPH·、ABTS⁺·、·OH、O₂^-·清除能力和还原力,比较红枣果汁果渣与果酒果渣色素的抗氧化活性,采用SPSS软件分析抗氧化活性成分含量与抗氧化活性之间的相关性。结果表明:红枣果汁果渣与果酒果渣色素抗氧化活性成分含量间存在显著差异(P<0.05),且随着发酵时间延长,色素抗氧化活性成分含量逐渐降低;红枣果汁果渣与果酒果渣色素清除DPPH·、ABTS⁺·、·OH、O₂^-·能力和还原力差异显著(P<0.05),随着发酵时间延长,色素抗氧化活性逐渐降低;相关性研究显示,果汁果渣色素抗氧化活性成分含量与抗氧化活性相关性较强,果酒果渣色素总黄酮含量与抗氧化活性相关性相对较弱,表明红枣果汁果渣色素抗氧化活性显著高于果酒果渣(P<0.05)。     

蓝莓果渣花色苷提取工艺优化及抗氧化活性比较研究

以蓝莓干果渣为原料,酸化乙醇为溶剂,应用超声辅助法提取花色苷,利用pH示差法测定花色苷含量,通过单因素实验和响应面试验优化得出蓝莓干果渣花色苷提取工艺条件,比较相同干重的蓝莓干果渣、湿果渣采用超声辅助提取和无超声辅助工艺得到的提取液的总多酚、花色苷含量及抗氧化活性。结果表明,蓝莓干果渣最佳提取工艺为液料比(31:1)mL/g,乙醇浓度63%,pH2.6,超声功率500 W,提取时间20 min,在此条件下蓝莓果渣提取液中花色苷含量为498.84 mg/100 g。相同原料,超声辅助提取工艺提取液较无超声辅助提取工艺提取液的总多酚和花色苷含量多;相同工艺条件下,相同干重的湿果渣总多酚和花色苷含量较干果渣低,但却拥有更高的抗氧化活性。     

水浴和超声法制备苹果渣可溶性膳食纤维及其性能的研究

以苹果渣为原料,研究水浴法和超声法制备苹果渣可溶性膳食纤维及其性能。结果表明水浴法制备苹果渣可溶膳食纤维的适合工艺条件为:水浴温度80℃,水浴pH5,水浴料液比1∶20g/mL和水浴时间90min,在此条件下苹果渣SDF得率为12.76%;超声法制备苹果渣可溶膳食纤维的适合工艺条件为:超声温度60℃,超声pH5,超声料液比1∶20g/mL,超声时间45min和超声功率225W,在此条件下苹果渣SDF得率为14.14%。与水浴法相比超声法能加快苹果渣组织水解,扫描电镜分析表明超声对苹果渣纤维表面的微结构有破坏作用。在相同浓度下,苹果渣SDF抗氧化活性比苹果渣抗氧化活性高很多,但都远低于商业合成抗氧化BHA。      

Chemical characterization and antioxidant evaluation of muscadine grape pomace extract

Concentrated muscadine pomace extract was chromatographically analyzed for its individual phenolic, flavonoid, and anthocyanidin compounds. This extract was also characterized regarding its total phenolic content (TPC), total flavonoid content (TFC), antioxidative activities in terms of scavenging DPPH free radicals, reducing ferric, and chelating Fe²⁺. The TPC of this product was 34.1 ± 1.8 mg of gallic acid equivalents(GAE)/g of extract, and TFC was 3.0 ± 0.3 mg of quercetin equivalents/g of extract. Some phenolic compounds including ellagic acid, gallic acid, (−)-epicatechin, (−)-epigallocatechin, catechin, myricetin, quercetin, and kaempferol were identified. Some anthocyanidins including delphinidin, cyanidin, petunidin, peonidin, and malvidin were also identified in the extract by using a combination of retention and spectral properties on a reverse-phase HPLC–PDA. In addition, 3,3′,4,4′5,5′-hexahydroxystilbene-a resveratrol analogue present in the extract was identified for the first time by LC–MS. The results from this study demonstrate that the muscadine pomace extract is rich of natural antioxidants such as phenolics, flavonoids and anthocyanins, and possesses strong antioxidant properties. Besides, the developed methods can be used for routine quality control of the muscadine products for manufacturing efficiency and consistency.     

ANTIOXIDANT ACTIVITY COMPARISON OF THOMPSON GRAPE POMACE EXTRACT, ROSEMARY AND TOCOPHEROLS IN SOYBEAN OIL

The effect of natural antioxidants was tested by oxidative stability index (OSI) in refined soybean oil (RSO) using Rancimat method. Phenolic compounds of Thompson grape pomace were extracted with 95:5 (v : v) ethanol : water. The antioxidant activity of grape pomace extract (GPE) obtained was compared with those of rosemary extract (RE), and tocopherols mix (TM) known as covi-ox T-70. The synergistic effect of citric acid was also evaluated. Results showed a total phenols content of 17.39 mg ( + )-catechin equivalents per g of GPE. Thompson GPE at 0.3 and 0.5% (w/w) exhibited greater antioxidant activity than TM. RSO containing GPE or RE at 0.5% (w/w) showed an OSI higher than 48 h at 110C. Citric acid did not show synergistic effect with GPE. However, a synergistic effect for TM at 0.02% (w/w) with citric acid at 1.0% (w/w) was observed. Citric acid at 2.0% (w/w) with RE at all concentrations tested also displayed synergism.

PRACTICAL APPLICATIONS

Synthetic antioxidants are widely used in the food industry to delay fat oxidation; however, their utilization has been questioned due to toxicology concerns. Researchers have recognized the need to identify new natural antioxidants to use as additives. In this study, we measured total phenolics content of Thompson grape pomace extract (GPE) and found that the antioxidant activity of this extract was stronger than tocopherols from soybean oil. We propose that GPE can have applications as a food antioxidant.     

腰果梨渣多酚提取及抗氧化性研究

为提高腰果梨加工的附加价值,采用响应面分析法优化腰果梨渣多酚提取的工艺条件,并以DPPH 法和ABTS+ 法对其多酚提取物的抗氧化性进行研究。结果表明：以体积分数40% 乙醇溶液为提取剂,以经过烘干的黄色腰果梨渣为样品,液料比为35:1,在95℃水浴中回流提取150min,得到多酚提取得率最高为1.54%;腰果梨渣的抗氧化能力较强,其中红色腰果梨渣对DPPH 自由基的清除能力强于黄色腰果梨渣,其EC50 为1.35mg/mL,而黄色腰果梨渣对ABTS+ 的清除作用又强于红色腰果梨渣,其EC50 为0.057mg/mL。     

Effect of pectinase treatment on extraction of antioxidant phenols from pomace,for the production of puree-enriched cloudy apple juices

Effects of pomace maceration on yield, turbidity, cloud stability, composition of phenolics, antioxidant activity and colour properties were studied, to evaluate the potential applicability of enzyme preparations in puree-enriched cloudy apple juice production. The yield of mixed juice and puree from pomace obtained in the enzymatic processing of apple ranged from 92.3% to 95.3%, significantly higher than the yield from the control without enzymatic pomace treatment (81.8%). Higher turbidity was obtained upon pomace treatment with Pectinex XXL and Pectinex Ultra SPL enzymes. The total content of phenolic compounds in apple pomace was higher than in raw juices (1520 mg/kg and 441 mg/L, respectively). The total polyphenol yields were higher in juices treated with Pectinex AFP L-4, Pectinex Yield Mash and Pectinex XXL, as compared to the control treatment. During 6 months of storage, a significant change was observed in the content of polyphenols, especially in procyanidin fractions.     

Changes in polyphenolic content and antioxidant activity after thermal treatments of grape seed extract and grape pomace

This study was undertaken to investigate the effect of heat treatment on polyphenolic content and antioxidant activity in grape pomace (GP) and grape seed extract (GSE). GP and GSE were heat treated in a furnace or autoclaved at 100 °C for 15, 30 and 60 min. Structural modifications of the polyphenols during thermal processes were determined by HPLC–MS, and the antioxidant activity was determined by ABTS, DPPH and photochemiluminescence methods. In general, furnace thermal treatment of GSE and GP did not affect the total extractable polyphenols content, tannin content, procyanidin components and the antioxidant activity. Autoclave treatment caused an extensive hydrolysis of gallocatechin (70%), catechin (61%), epicatechin (65%), procyanidin B1 (75%) and procyanidin B2 (73%) in GSE, and an increase in gallic acid (71%), gallocatechin (100%) and epicatechin gallate (129%) in GP. Autoclave treatment did not affect the antioxidant activity of GSE or GP. It can be concluded that the effect of autoclave was more severe than furnace heat treatment modifying the phenolic profile in a different manner depending on the grape seed product used. These modifications were not related with changes in antioxidant activity.     

甘薯渣多酚粗提液的抗氧化活性研究

多酚具有抗氧化特性。以从甘薯渣中提取的多酚类物质为材料,对其抗氧化性能进行了体外实验,分别测定了甘薯渣多酚粗提液对超氧阴离子自由基(O2-·)、H2O2、羟自由基(·OH)的清除能力及还原能力。结果表明,甘薯渣多酚提取物粗提液具有较强的综合抗氧化能力,是一种有开发价值的天然抗氧化剂。     

Characterisation of hydrogels and aerogels as carriers for sea buckthorn pomace extract

In this study, aerogels were prepared from kognac glucomannan (KG) or whey proteins loaded with bioactive sea buckthorn pomace extract. KG was diacetylated with Na₂CO₃ (0.1; 0.2; 0.3; 0.4 m ) resulting hydrogel formation that were further freeze-dried to obtain an aerogel structure. Whey protein aerogels were prepared by removing pore fluid from alcogels using supercritical CO₂ drying. Produced aerogels evaluated for microstructure, porosity, specific surface area, absorption capacity, encapsulation efficiency and antioxidant capacity of the extract. It was found that higher concentration of alkali induced higher hardness, resilience and elastic modulus values. It was also obtained that pores in the konjac glucomannan aerogels were irregular in shape and a decrease in total pore volume (0.026 to 0.019 cc/g) and surface area (12.39 to 11.40 m²/g) after increasing the carbonate concentration was observed. These aerogels were found to have better encapsulation efficiency properties for sea buckthorn pomace extract (17 to 20%) in comparison to whey protein aerogels (0.05 to 0.36%). Overall, the KG aerogels show potential for applications in the food industry as a carrier of bioactive sea buckthorn pomace extract, while whey proteins must be used in combination with other biopolymers to enhance their bioactive compound loading capacity.     

Kinetics of ultrasonic extraction of polyphenols,anthocyanins and tannins from five different New Zealand grape pomaces

Polyphenols were extracted from five kinds of New Zealand grape pomace (Sauvignon Blanc, Pinot Gris, Gerwurztraminer, Merlot and Pinot Noir) at 30, 50 and 70 °C in an ultrasonic generator. The extraction kinetics for total phenol, anthocyanin and tannin were determined. The results of dynamics study showed that the extraction of total polyphenols, anthocyanin and tannin followed first-order reaction kinetics during the extraction at 30, 50 and 70 °C. The total phenolic content, anthocyanin conten, and tannin content of water–ethanol extracts from grape pomaces were compared, and the parameters in the extraction kinetics equations were determined. The extraction results showed that the Pinot Noir pomace extract had the highest total phenolic content of 59.95 mg GAE g⁻¹ pomace and tannin content of 79.93 mg EE g⁻¹ pomace. The anthocyanin content in Merlot pomace extract was the highest, which was 4.50 CE g⁻¹ pomace. The results might be of great significance for the development of grape pomace or its polyphenol and/or anthocyanin components as an antioxidant source with natural and inexpensive benefits.     

Phenolic profiles,antioxidant activity and in vitro antiviral properties of apple pomace

Methanolic and acetonic extracts of apple pomace were evaluated for phenolic profiles, antioxidant properties and antiviral effect against herpes simplex virus type 1 (HSV-1) and 2 (HSV-2). Acetone extraction yielded the higher amounts of phenolic compounds. The extraction method influenced the phenolic composition although antioxidant activity correlated weakly with phenols concentration. Among the polyphenols analysed, quercetin glycosides were the most important family, followed by dihydrochalcones. Apple pomace extracts were able to inhibit both HSV-1 and HSV-2 replication in Vero cells by more than 50%, at non-cytotoxic concentrations. Selectivity indexes (SI) ranged from 9.5 to 12.2.     

Optimization of a process for enzyme-assisted pigment extraction from grape (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.) pomace

A process for enzyme-assisted extraction of polyphenols from grape pomace was developed on laboratory and pilot-plant scale. After resuspending grape pomace in water, the skins were ground and the resulting mash was pasteurized to inactivate the deteriorative enzymes responsible for polyphenol degradation, and then pre-extracted with hot water. Subsequently, cell wall polysaccharides were hydrolyzed. The extract was separated from the solid residue by pressing, and finally spray dried. Before scaling-up, enzymatic hydrolysis was optimized on laboratory scale using a D-optimal design and analyzed by response surface methodology. A mixture of pectinolytic and cellulolytic enzyme preparations (ratio 2:1) yielded the highest amounts of phenolic compounds after 2 h of treatment, applying a dosage of 4,500 mg/kg (based on dry matter) at T = 40 °C and pH 4.0. Aqueous pre-extraction of the pomace followed by enzymatic treatment resulted in significantly improved extraction yields reaching 91.9, 92.4, and 63.6% for phenolic acids, non-anthocyanin flavonoids and anthocyanins, respectively. As the yields obtained were comparable to those from sulfite-assisted extraction, this process can be considered a suitable alternative to the application of sulfite.     

苹果渣粗多糖对发酵乳品质及抗氧化活性的影响

为提高苹果渣的开发利用价值,将提取的苹果渣粗多糖添加到发酵乳中,研究其对发酵乳的乳酸菌活菌数、滴定酸度、pH、持水力、色泽、质构、存储模量和损失模量、抗氧化活性及感官评定等指标的影响。结果表明：质量分数为0.06%～0.14%的苹果渣粗多糖可显著增加发酵乳的活菌数和酸度（P<0.05）;对持水力具有显著提高效果（P<0.05）;当苹果渣粗多糖添加量为0.10%时,其硬度、咀嚼性最高,此时也具有最高的感官评分（90.8分）;苹果渣粗多糖的添加有助于改善酸奶的凝胶特性,增加其存储模量G’和损耗模量G’’;同时显著提高了发酵乳的体外抗氧化活性（P<0.05）,且抗氧化活性与添加量呈正相关性。本研究为苹果渣的再利用和功能性发酵乳的开发提供理论依据。