Screening grape seeds recovered from winemaking by‐products as sources of reducing agents and mammalian α‐glucosidase and α‐amylase inhibitors

Grape seeds collected from vinification of various grape varieties were extracted by supercritical CO₂ for oil recovery. The defatted residues thus obtained were considered as a re‐utilisable co‐product and assessed for phenolic content, reducing capacity and inhibitory activities against mammalian α‐amylase and α‐glucosidase enzymes. Supercritical CO₂ treatment led to higher recovery of anthocyanins. Reducing capacity of phenolic extracts reached up to ~2200 mmolFe(II) kg^?1, much higher than that of various natural phenolic sources. The anthocyanin‐rich extracts showed the highest inhibitory effectiveness towards α‐glucosidase (I₅₀ value equal to ~40 μg gallic acid equivalents (GAE)/mL ~ half than acarbose). Inhibitory effectiveness towards α‐amylase activity was similar among grape varieties, with I₅₀ values comparable to that of acarbose and correlated with proanthocyanidin contents. These results could pave the way for an efficient processing of grapes, including cascade processes, namely: winemaking, oil extraction from recovered grape seeds and phenolic extraction from defatted grape seeds as potential cost‐effective nutraceuticals.     

Optimisation of supercritical CO2 extraction of grape seed oil using response surface methodology

The aim of this study was to use waste from the wine production process with special accent on grape seeds and new green technology. Supercritical CO₂ was considered as a green solvent in extraction of grape seed oil. The effects of different extraction process parameters on oil yield and antioxidant activity were investigated. Extraction optimisation was conducted using response surface methodology (RSM). Extraction pressure has proven to be the most significant factor influencing oil yield and antioxidant activity (P < 0.0001). The optimal conditions for obtaining the highest oil yield and antioxidant activity within the experimental range of the variables studied were at extraction pressure of 400 bar and temperature of 41 °C. Under these optimal conditions, the predicted extraction oil yield was 14.49% and DPPH 37.07%. Applying this green extraction method, the oil from grape seeds was totally extracted. The produced oil was of satisfactory quality, and the content of α‐tocopherol in obtained grape seed oil at optimal extraction conditions was 36.05 mg kg^?1.     

超临界CO_2萃取葡萄籽油的研究

提出了超临界CO2 萃取葡萄籽油的方法 ,研究了不同萃取压力、温度、流量、颗粒细度和萃取时间对葡萄籽出油率及油品质的影响。     

不同方法提取的葡萄籽油品质研究

以酿酒后同一批次葡萄籽为原料,采用索氏法、微波辅助法、超声波辅助法、超临界CO2萃取4种方法提取葡萄籽油。分别从提取率、油品理化性质、脂肪酸组分及含量方面对4种提取方法进行比较。结果表明,不同提取方法对葡萄籽油各脂肪酸组分、含量及提取率均有不同程度的影响,采用微波辅助提取率最高,达16.85%;采用超临界CO2萃取的葡萄籽油理化指标均优于其它方法;其中超临界CO2萃取的葡萄籽油亚油酸含量最高,达70.54%。     

葡萄籽提取物抑菌活性及葡萄籽油化学成分对比研究

研究了葡萄籽提取物的抑菌活性,并测定了两种葡萄籽油的化学成分。以宁夏贺兰山东麓产区两种酿酒葡萄的葡萄籽为原料,通过微生物抑菌圈实验,测定了葡萄籽不同极性有机溶剂提取物、两种葡萄籽油对三种细菌的抑菌活性;同时,采用气相色谱联合质谱法(chromatography-mass spectrometry,GC-MS)测定了葡萄籽油的化学成分。结果表明,葡萄籽提取物的抑菌活性由强到弱排列如下:正丁醇萃取物(N-butanol part of 95% ethanol total extracts,TEN)>95%乙醇总浸提物(95% ethanol total extracts,TE)>石油醚萃取物(Petroleum ether part of 95% ethanol total extracts,TEP)>乙酸乙酯萃取物(Ethyl acetate part of 95% ethanol total extracts,TEE)>两种葡萄籽油(Oil-1、Oil-2);TEN样品在0.20 g/mL浓度时对金黄色葡萄球菌、大肠杆菌显示出强抑菌效果,对枯草芽孢杆菌也显示出较强抑菌效果。此外,两种酿酒葡萄的葡萄籽油化学成分种类相似,Oil-1、Oil-2中分别鉴定出11个和10个化合物,主要组成成分为脂肪酸和酯类,但各成分含量差异较大,Oil-1、Oil-2的亚油酸含量分别为55.36%、43.97%,除亚油酸外Oil-1中其余相同成分的含量均低于Oil-2。本实验提示葡萄籽正丁醇萃取物可以应用于食品的保鲜防腐,为葡萄籽的药用食用开发利用提供基础理论支持。     

EXTRACTION OF VICTORIA AND RED GLOBE GRAPE SEED OILS USING SUPERCRITICAL CARBON DIOXIDE WITH AND WITHOUT ETHANOL

SFE of the oils of two varieties of grape seeds (Victoria and Red Globe) was performed in a flow apparatus at 40C and 250 bar. The effect of the solvent on the extraction yield was studied using CO₂ and CO₂ modified with ethanol, and the yield of extraction was compared with conventional extraction methods (Bligh and Dyer and Soxhlet using hexane). SC CO₂  +  ethanol extracted higher lipid amounts from both varieties, compared with SC CO₂ extraction. The comparison between SFE and conventional extraction methods showed that the highest extraction yield was obtained with SC CO₂  +  ethanol (10%, w/w) (14.7 and 11.8% for Red Globe and Victoria grape seeds, respectively), while pure SC CO₂ afforded the lowest lipid yields. The fatty acid compositions of the oils obtained by SFE were analyzed. Fractions containing higher proportions of PUFAs were obtained at lower solvent/dry grape seed ratios, while fractions richer in SFAs and MUFAs were obtained at higher solvent/dry grape seed ratios.

PRACTICAL APPLICATIONS

SFE could fractionate grape seed oil and afford various grades of oil containing different proportions of fatty acids. The highest grape seed lipid yield obtained was with SC CO₂ + ethanol, making this solvent a promising and powerful one for grape seed oil extraction, showing a great advantage compared with conventional extraction methods.     

Residues of grape (Vitis vinifera L.) seed oil production as a valuable source of phenolic antioxidants

Phenolic compounds of seven grape seed samples originating from mechanical seed oil extraction were identified and quantified by HPLC–DAD before (intact seeds) and after (press residue) the oil recovery process. Total amounts of all identified compounds ranged from 4.81 (‘Cabernet Mitos’) to 19.12 g/kg (‘Schwarzriesling’) of defatted dry matter (DM; ‘Schwarzriesling’) for integral grape seeds, whereas their content in the press residues ranged from 2.80 (‘Cabernet Mitos’) to 13.76 g/kg of defatted DM (‘Spätburgunder’). This is the first study presenting comprehensive data on the contents of individual phenolic compounds comprising all polyphenolic subclasses of press residues from grape seed oil production also covering the determination of the antioxidant activities of each subclass (Folin–Ciocalteu, FRAP and TEAC assays). Additionally, the effects of different solvents on the yields of phenolic compounds were determined. Maximum yields were obtained using methanol/0.1% HCl (v:v), water [75 °C] and a mixture of ethanol and water [3:1; v:v], respectively, whereas pure ethanol resulted in poor polyphenol extraction. The results of the present study confirm the press residues of grape seed oil production still to be a rich source of polyphenolics with strong antioxidant activity.     

葡萄籽油的营养价值与生物活性综述

酿酒葡萄皮渣是葡萄酒加工副产物,包括葡萄皮、果梗和葡萄籽,其中葡萄籽中富含多酚、维生素、植物甾醇、不饱和脂肪酸等营养成分,具有极高的利用价值。该文在查阅大量国内外相关文献资料的基础上,详细阐述了葡萄籽油的营养价值、生理活性和利用现状,并对未来我国葡萄籽油的综合利用进行了展望,以期能为我国酿酒葡萄皮渣的有效利用提供一定的参考。     

Supercritical fluid extraction of grape seed: Process scale-up, extract chemical composition and economic evaluation

The scale-up of the supercritical fluid extraction (SFE) process for grape (Vitis vinifera L.) seed was studied from the laboratory (0.29 L) to the pilot scale (5.15 L) at 35 MPa and 313 K. The scale-up criterion adopted consisted of maintaining a constant solvent to feed ratio (S/F), and the criterion was successfully used to predict the approximate behavior of the SFE process from the laboratory at the pilot scale for a 17-fold scale-up. Linoleic acid was the major component of the extract; palmitic, stearic and oleic acids were also detected. The economic evaluation showed that it is viable to establish a SFE plant in Brazil for SFE processing of grape seed. From the technical-economic evaluation, for SFE of grape seed at 313 K/35 MPa, an extraction time of 240 min and S/F of 6.6 produced the best relationship between yield and cost.     

不同品种葡萄籽油脂肪酸含量的测定

建立同时测定37种脂肪酸的气相色谱-质谱(GC-MS)法,并对吐鲁番产区的40个品种的葡萄籽油中脂肪酸组成及含量进行检测分析。结果表明：葡萄籽油中可检测出19种脂肪酸,40个品种葡萄籽油样中,有14个品种的脂肪酸总含量在90 g/100g以上。沈农金皇后总脂肪酸含量最高,为99.75 g/100g。灰比诺、赤霞珠、沈农金皇后、巨玫瑰等品种可作为富含脂肪酸的葡萄籽油提取的优势品种,其中灰比诺中亚油酸含量最高,赤霞珠其次。对不同品种葡萄籽油进行聚类分析,可被明显分为两类,亚油酸和油酸对于品种间的分类具有较大贡献。本法具有操作简单,灵敏度高,定性定量准确等特点,为葡萄籽油中脂肪酸成分的监测和评估提供了技术支持。     

葡萄籽油的提取及精炼工艺优化

为获得优质精油,以发酵后葡萄籽为原料,比较索式提取法、回流浸提法、超声提取法和微波法提取葡萄籽油的提取率,选择提取率最高的微波提取方法,通过正交试验对其工艺进行优化,并对最佳工艺条件下毛油的理化指标进行测定,对毛油精炼工艺进行优化。结果表明：微波提取法最佳工艺条件为料液比1:15(g/mL)、提取时间10min、提取温度70℃、微波功率700W;毛油精炼的最佳条件为碱浓度4.13mol/L、超碱量0.5%、精炼初温50℃。精炼后葡萄籽精油的各项指标均符合GB/T 1684-2006《化妆品检验规则》化妆品检验的国家标准。     

The fatty acid and tocopherol constituents of the seed oil extracted from 21 grape varieties (Vitis spp.)

BACKGROUND: Fatty acids and tocopherols in appropriate quantities are invaluable attributes that are desirable in seeds of agricultural products. Studies have generally focused on the evaluation of the oil and tocopherol components of oil crops. Recently, investigations revealed that the grape seed has robust potential in the production of healthy fatty acids as well as tocopherols. This study was thus conducted to determine the oil and tocopherol components of grape seeds, obtained from various grape cultivars of different species, including two rootstock varieties. RESULTS: The grape seed oil concentration of the studied varieties ranged from 7.3 to 22.4%. The determined fatty acid profiles of the genotypes conformed to the pattern described in the literature for grapes. Linoleic acid is the major component comprising 53.6–69.6% of the total, followed by oleic (16.2–31.2%), palmitic (6.9–12.9%) and stearic (1.44–4.69%). The oils of all the seeds analysed showed a preponderance of α‐tocopherol (ranging from 260.5 to 153.1 mg kg^?1 oil extract). β‐Tocopherol, γ‐tocopherol and δ‐tocopherol were also detected with the general means of 0.98, 22.2 and 0.92 mg kg^?1, respectively. Linoleic acid showed a significantly negative correlation with all the fatty acids analysed. The strongest negative correlation existed between linoleic and oleic acids (r = ? 0.834, P < 0.01). CONCLUSION: Present investigations indicated that oil content, fatty acid composition and tocopherol constituents of grape seed show great variation among the genotypes. Markedly higher proportions of linoleic acid with considerable amounts of tocopherols found in the oil samples suggest that grape seed is a good source for culinary, pharmaceutical and cosmetic uses. Copyright © 2012 Society of Chemical Industry     

Extracting oil from grape seed using a combined wet enzymatic process and pressing

The novel method of wet enzymatic extraction and pressing (WEEP) was used to extract grape seed oil. Low-field nuclear magnetic resonance (LF-NMR) was applied to elucidate the water mobility and distribution of grape seeds during the process. The extraction variables were selected in accordance with a Plackett-Burman (PB) design, and the statistical model was constructed using response surface methodology (RSM). The results revealed that water mobility variations of the samples could be discriminated using the signal amplitude and peak position of the T₂ inversion spectrum. The increase in water content was affected by the time and temperature of the process. The water migration of the samples was monitored clearly and intuitively using magnetic resonance imaging (MRI). Three significant factors out of the six variables (enzyme additive amount, hydrolysis temperature, hydrolysis time, comminution degree, screw speed, squeezed water) were determined. The ideal values of the significant factors were confirmed to be 1% of enzyme additive amount, 60 mesh of comminution degree, and 8% of squeezed water. The residual oil proportion to the initial oil content decreased significantly with parameter optimization (33.24% ± 5.98%) compared with that of the unoptimized parameters (57.79% ± 4.13%).     

改良的DPPH与ABTS自由基法评价不同葡萄籽油抗氧化能力

本研究采用改良的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picryhydrazyl,DPPH)法和2,2'-联氮双-(3-乙基苯并噻唑林-6-磺酸)二胺盐[2,2'-azinobis(3-ethylbenzothi azoline-6-sulfonic acid)ammonium salt,ABTS]法测定不同方法提取葡萄籽油极性部分、非极性部分及全油的抗氧化能力,测定不同葡萄籽油多酚含量,研究多酚与葡萄籽油极性部分抗氧化能力的相关性。热榨毛油与溶剂法毛油在经过精炼后多酚含量和抗氧化能力显著降低;在溶剂法精炼油、热榨法精炼油、低温压榨油、超临界CO_2萃取葡萄籽油中,低温压榨油极性部分清除DPPH与ABTS自由基的能力最强,低温压榨油的多酚含量最高,超临界CO_2萃取葡萄籽油非极性部分与低温压榨油全油的DPPH与ABTS自由基清除能力最强;各不同葡萄籽油总酚含量与极性部分DPPH和ABTS自由基的清除能力具有显著的正相关性。     

A supercritical tuneable process for the selective extraction of fats and essential oil from coriander seeds

A selective supercritical CO₂ extraction process has been developed in order to extract selectively the vegetal oil and the essential oil from coriander seeds in a consecutive way by tuning experimental conditions. A 4-step process has been set up: (i) seeds preparation by grinding and sieving, (ii) extraction by supercritical CO₂ and (iii; iv) selective separation in two separators with different pressure levels. The first part of this study consisted in studying the effects of the operating conditions (T, P, CO₂ density, flow rate and particle size distribution of ground seeds) on the yield of extraction. The results showed that the global performance of the process depends mainly on the pressure level of extraction, on the CO₂ flow rate and on the size of the ground seeds. An optimization of the parameters led to an extraction ratio of 90%. The second part of this study dealt with the effects of the operating conditions on the quality of extracts, and more precisely on their composition in vegetal oil and essential oil. It was observed that the supercritical extraction had no major effect on the fatty acid composition of the vegetal oil compared to classical extraction techniques, while essential oil is enriched in components such as linalool and that a previous drying of the seeds is deleterious. Finally, we propose a procedure in order to extract separately each oil by adjusting CO₂ density and separation conditions.     

Nutrient composition of some less-familiar oil seeds

Seven less familiar oil seeds, namely gokhru, thumba, onion, tobacco, grape, niger seeds and mango seed kernels were analysed for their proximate composition, amino acid and fatty acid composition. Gokhru, niger, tobacco and onion seeds were found to be good sources of protein and fat. Crude fibre contents of thumba and grape seeds were high. The seeds of thumba, niger, onion and mango (seed kernel) contained 4 g lysine per 16 g N. The methionine content of onion-seed protein was very high. Fatty acid profiles of fat from these oil seeds revealed a high proportion of unsaturated fatty acids with the exception of gokhru.     

葡萄籽相关产品的研究与开发现状

以葡萄籽为原料生产的普通食品、保健食品和化妆品种类、剂型及其产品功能现状进行综述。普通食品有国标葡萄籽油、国标葡萄籽提取物食品添加剂以及葡萄籽粉、压片糖果等。保健食品有370多个,主要利用葡萄籽油、葡萄籽提取物等有效部位;主要剂型为胶囊剂、片剂以及口服液和粉剂;主要功能为抗氧化、祛黄褐斑、增强免疫力、辅助降三高等。葡萄籽粉、葡萄籽提取物、葡萄籽油均为准予备案的化妆品原料,已备案非特化妆品4900多个,几乎囊括所有化妆品类别。已有相关药品研究,但尚无相关药品批文。线上葡萄籽和葡萄籽粉售价与大米和面粉相当、油为其原料的5~10倍、提取物则为其原料的30多倍,相关的胶囊和片剂价格又进一步成倍增加,且销量远高于未装胶囊或压片的产品。显然,葡萄籽深加工产品有较大的开拓空间、利润空间和广阔的市场前景。     

功能性葡萄籽太谷饼配方工艺的研究

将葡萄籽进行处理后添加到传统食品太谷饼中,研制功能性葡萄籽太谷饼,以太谷饼感官评价结果为考核指标,分析不同葡萄籽添加方式对太谷饼品质的影响,采用正交试验优化生产工艺。结果表明:葡萄籽的最佳添加方式为普通粉碎葡萄籽粉,过60目筛;最佳配方工艺为:葡萄籽粉添加量50 g,蔗糖添加量100 g,亚麻油添加量150 g,烘焙条件220℃/15 min,在此配方工艺条件下生产的葡萄籽太谷饼葡萄籽含量丰富,口感松软,香味浓郁,且有葡萄籽烘焙香。     

Effect of cold press and soxhlet extraction systems on fatty acid,tocopherol contents,and phenolic compounds of various grape seed oils

In this study, fatty acids, tocopherol contents, and phenolic compounds of the grape seed oils obtained with cold‐pressed and soxhlet extraction systems from several grape seeds were investigated. Linoleic acid contents of cold‐pressed oils varied between 59.61 and 72.13%. In addition, linoleic acid contents of oils obtained with soxhlet system changed between 58.51 and 71.17%. While α‐tocotrienol contents of oil samples extracted with cold‐pressed change between 13.21 and 34.71 mg/100 g, α‐tocotrienol contents of oils obtained by soxhlet system in all grape varieties varied between 8.89 and 33.89 mg/100 g. In addition, while ?‐tocotrienol contents of cold‐pressed oils range from 15.47 to 39.95 mg/100 g, ?‐tocotrienol contents of soxhlet extraction oils in all grape varieties were determined between 13.47 and 35.75 mg/100 g. Both systems' oils are rich in catechin, gallic acid, and chlorogenic acid. While catechin contents of cold‐pressed oils change between 427.80 and 847.14 mg/kg, catechin contents of soxhlet extraction oils in all grape seeds ranged from 537.11 to 836.88 mg/kg.

Practical applications

Cold‐pressed grape seed oil stands out as a suitable alternative to other commonly used vegetable oils because of its higher amounts of essential fatty acid, and many others bioactive compounds. Grape seed oil is being used in various fields such as cosmetics and cooking. Because the cold‐pressing does not need both heat and chemical treatments, cold‐pressed oils are being preferred for natural and safe food products by consumer. The consumption of vegetable oils rather than solid fats is crucial to maintaining health. As known, grape seed oil is an environment friendly oil due to a by‐product of wine and grape juice‐making processes.     

Tocols in caneberry seed oils

The compositional analysis of tocols in oils extracted from Korean caneberry seeds was compared with commercial soybean, corn, olive, canola, perilla, and grape seed oils. The oils from caneberry seeds of six different species were extracted using either a chloroform–methanol–water system or hot hexane. Tocols from all of the oils were analysed using isocratic HPLC. The contents of total tocopherols in the caneberry seed oils were about 75–290 mg/100 g oil, whereas tocotrienols were not detected. γ-Tocopherol was the most abundant tocopherol (31.8–239 mg/100 g oil) in the caneberry seed oils, followed by α-tocopherol (7.6–58.2 mg/100 g oil). The contents of total tocols in soybean, corn, olive, canola, perilla, and grape seed oils were 99.9, 61.1, 28, 27, 45.4, and 52.2 mg/100 g oil, respectively. Total tocol content was higher in most of the caneberry seed oils including the refined ones than in the commercial vegetable oils.