Influence of solvent and temperature on extraction of phenolic compounds from grape seed,antioxidant activity and colour of extract

This study was aimed to investigate the influence of solvent (water and ethanol in concentration: 50%, 70% and 96%) and extraction temperature (25–80) °C on polyphenols extraction of grape seed (Vitis vinifera L. cv. “Frankovka”) cultivated in Eastern Croatia. The best results were reached using 50% ethanol at 80 °C. The most abundant individual polyphenolic compound was catechin which makes the average of 45.11% of the total phenolic content followed by epicatechin (34.45%), procyanidin B₂ (12.90%), gallic acid (5.34%), gallocatechin (1.58%), epicatechin gallate (1.01%). The antioxidant activity of extracts was determined by DPPH‐method and it was highly dependent on extraction solvent and temperature. The total extractable proanthocyanidins content of extract had the highest positive correlation (r = 0.994) with antioxidant activity, which indicated that these compounds might be the most important antioxidant in examined grape seed extracts. Relationship between phenolic content and colour of extracts was observed.     

葡萄籽多酚化合物抗氧化能力与抗癌细胞增殖活性的评价

目的:探讨葡萄鲜果及酿酒皮渣中葡萄籽提取物中的酚类化合物含量,抗氧化特性及对癌细胞增殖的抑制作用。方法:乙醇法提取葡萄籽中多酚化合物,分光光度计法测定三大酚类化合物参数(总酚、类黄酮类、黄烷-3-醇类)及3种抗氧化性能参数(DPPH及ABTS自由基清除能力,FRAP分析)。体外培养肝癌细胞HepG2,建立细胞模型,不同浓度的提取物作用于癌细胞后,采用四甲基偶氮唑盐比色法(MTT法)检测多酚提取物对癌细胞增殖的抑制作用。结果:不同样品葡萄籽所含酚类化合物、抗氧化性能、抗癌细胞增殖能力均不同,酿酒皮渣的葡萄籽中仍含有大量的多酚化合物,其中欧亚种赤霞珠鲜果及酿酒皮渣中葡萄籽所含酚类化合物、抗氧化能力及抗癌细胞增殖活性高于圆叶葡萄Noble鲜果及酿酒皮渣。结论:葡萄鲜果与酿酒皮渣中的葡萄籽多酚化合物具有抗氧化能力及抗癌细胞增殖活性。     

压榨对酿酒葡萄皮渣酚类物质提取及抗氧化活性的影响

酿酒葡萄皮渣（皮和籽）生物活性物质含量丰富,具有很高的再加工利用价值。对鲜葡萄皮渣进行压榨处理后再干燥,研究压榨对皮渣的酚类物质提取及抗氧化活性的影响。结果表明：压榨处理可以快速降低葡萄皮渣水分含量,缩短干燥时间、提高可溶性膳食纤维提取率。压榨葡萄皮总酚、原花青素的提取量均有所增加,其含量分别为19.56 mg/g和22.64 mg/g。压榨葡萄皮的抗氧化能力高于未压榨葡萄皮,其DPPH、ABTS及羟自由基清除率分别为62.90%、70.18%和41.09%,铁氰化钾还原能力及金属离子螯合能力分别为0.23%和21.33%。压榨籽和皮籽混合物的酚类物质和抗氧化活性则明显降低。抗氧化活性与总酚、原花青素存在显著的相关关系（P＜0.01）。     

茶叶籽油中酚类化合物的提取工艺优化及其抗氧化相互作用动力学研究北大核心CSCD

为揭示二元酚类复合物的抗氧化相互作用机制,采用碱解法结合有机溶剂对茶叶籽油中酚类化合物进行提取。通过单因素实验及正交实验优化酚类化合物提取工艺条件,采用超高效液相色谱-串联质谱(UPLC-MS/MS)分析酚类化合物组成,并对7种酚类化合物及其21组二元复合物的DPPH·清除动力学进行研究。结果表明:茶叶籽油中酚类化合物最佳提取工艺条件为乙酸乙酯为萃取剂、NaOH浓度2.0 mol/L、碱解温度45℃、碱解时间5 h、料液比1∶15,在最佳条件下总酚含量可达(91.37±1.83)μg/g;共鉴定出22种酚类化合物,总含量达152.181μg/g,以酚酸类化合物(82.021μg/g)为主;6,7-二羟基香豆素与龙胆酸的复合物具有强协同作用,二元酚类复合物对DPPH·的清除速率受单体相互作用及起主要抗氧化作用酚类化合物的清除速率的影响,同时酚类化合物的相互作用在抗氧化过程中会发生改变。因此,茶叶籽油的耐储藏性与酚类化合物间的抗氧化协同作用密切相关。     

Stability of phenolic compounds in dry fermented sausages added with cocoa and grape seed extracts

The level of eleven target phenolic compounds was evaluated in dry fermented sausages added with vegetable extracts. Grape seed (GSE1 and GSE2) and cocoa extracts, rich in phenolic compounds, were added in the formulation of dry fermented sausages (“salchichón” and “fuet”). Evolution of the major monomeric and oligomeric phenolic compounds of these extracts was evaluated during sausage shelf life by UHPLC-MS/MS. Kind of sausage did not affect significantly overall stability of the target compounds. At the end of the ageing process, catechin and epicatechin were at 54–61%, gallic acid and galloylated flavan-3-ols at 59–91%, oligomeric flavan-3-ols at 72–95% and glycosylated flavonols at 56–88% (in cocoa treatment) and 82–94% (in GSE treatment) of the contents that were added to the meat batter. All phenolic compounds levels did not decrease further significantly after ageing until the end of shelf life. Sensory analyses showed no important differences between control and cocoa added products, while grape seed addition gave these products abnormal sensory profiles. The 0.5% (w/w) addition of vegetal extracts was suitable to enrich dry fermented sausages with health-beneficial polyphenols.     

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.     

葡萄籽油的超声波辅助提取工艺研究

以赤霞珠葡萄籽为原料,利用超声波辅助法提取葡萄籽油,在单因素试验基础上,采用二次正交通用旋转组合试验建立数学回归模型,确定了在葡萄籽粉碎粒度为40目,以60～90℃沸程石油醚为浸提溶剂时,最佳提取工艺参数为:提取温度40℃,料液比1∶9,提取时间50 min,超声波功率360 W。在最佳工艺条件下,葡萄籽油提取率达93.21%。     

Syrah grape skin valorisation using ultrasound-assisted extraction: Phenolic compounds recovery,antioxidant capacity and phenolic profile

The influence of ultrasound power (1000–3000 W/L), citric acid concentration (0–3%) and solid:liquid ratio (1:5–1:15) on the phenolic compounds recovery and antioxidant capacity of Syrah grape skin extracts were evaluated. Total phenolic compounds varied from 6485 to 11732 mg gallic acid/100 g and monomeric anthocyanin content from 453 to 685 mg malvidin-3-glucoside/100 g. The antioxidant capacity measured by ORAC and ABTS methods ranged from 230 to 516 μmol Trolox/g and from 442 to 939 μmol Trolox/g, respectively. The most suitable conditions chosen for extraction, within the studied ranges, were 3000 W/L of power, 2.5% citric acid and solid:liquid ratio of 1:15. The extraction yield was satisfactory, with a recovery of 59% of the quantified phenolic compounds, with only 3 min of processing. Ultrasound was considered a suitable method as compared to the conventional extraction, improving the extraction of phenolic acids and facilitating their release.     

Degradation kinetics of grape skin and seed proanthocyanidins in a model wine system

Catechin (monomer), purified grape skin proanthocyanidin (polymer), and purified grape seed proanthocyanidin underwent monitored accelerated oxidation under continuous oxygenation and UV light, at a constant 20 °C. Compounds were dissolved in model wine solutions with (and without) catechol. Solutions were examined and then contrasted by absorbance measurements, phloroglucinolysis, and subsequent HPLC analysis. Oxidation of these monomers and polymers revealed significant colour changes (measurable increase in colour density). The presence of catechol increased the half-life of catechin, but the opposite was observed for total skin and seed proanthocyanidins. Skin and seed proanthocyanidin degradation half-life decreased with the addition of catechol. In general, based on second order rate reactions, total subunits of seed proanthocyanidin solutions degraded faster than that of skin proanthocyanidin solutions. As expected, there were decreases of measurable phenolics in both monomer and polymer solutions. Under the study conditions, flavanol monomer and polymer oxidation was chiefly dependant upon initial solution concentration.     

High‐pressure high‐temperature extraction of phenolic compounds from grape skins

This study focused on the use of a non‐conventional extraction technology by employing high‐pressure high‐temperature stirred reactor to extract polyphenols from grape skins. Extraction time (15–330 min) and temperature (30–150 °C) were selected as independent variables, and their effects were studied. A preliminary kinetic study on polyphenols extraction revealed that the second‐order model fitted satisfactorily the experimental results (R² ≥ 0.9798). Total polyphenol yield and total flavonoid (TF) yield, as well as the antiradical power (ARP) of the extracts, were analysed. The use of high‐pressure high‐temperature technology resulted in obtaining extracts rich in polyphenols with high ARP. The highest total polyphenol (60.7 mg_GAE ) and TF (15.1 mg_CE ) yields were obtained at 150 °C for 270 min and 150 °C for 15 min, respectively. HPLC was employed to analyse phenolic compounds. Considerable quantities of single phenolic compounds were extracted. The highest yields of gallic acid, 5‐hydroxymethylfurfural, protocatechuic acid, catechin, vanillic acid, syringic acid, cumaric acid, trans‐resveratrol and quercetin (163.2, 20.0, 69.9, 420.0, 20.6, 603.0, 20.1, 42.4 and 117.1 mg per 100 g_DS, respectively) were found. ARP values were found between 8.45 and 52.17 μg_DPPH .     

葡萄籽油提取工艺的研究

葡萄籽中油脂含量一般在14%～17%,其中不饱和脂肪酸含量在90%以上,亚油酸含量在70%以上.主要研究了提取溶剂、提取温度、提取时间、料液比、葡萄籽的含水量和粉碎度对葡萄籽中油的提取得率的影响,并采用正交试验对提取条件进行了优化.结果显示,提取溶剂、提取温度、提取时间、提取料液比、葡萄籽的含水量和粉碎度对提取效果均有显著性影响.通过研究,初步确定了葡萄籽油的适宜提取条件.即:以石油醚(30～60)作为提取剂;提取温度65℃;提取时间3h;提取料液比为1:12,葡萄籽含水量为9.5%,葡萄籽粒度80目.以该优化条件进行提取,葡萄籽中毛油的得率达到20.78%(w/w).将在正交试验所得的最优条件下制得的葡萄籽油的理化性质及脂肪酸组成进行检测,结果为:相对密度为0.907,酸价为3.21mgKOH/g,皂化值为136.4mgKOH/g,过氧化值为6.65mmol/kg,碘价为127.2I2g/100g.葡萄籽油中的主要不饱和脂肪酸为亚油酸和油酸,其中亚油酸占整个脂肪酸含量的71.20%,油酸占17.53%.     

Aqueous extraction kinetics of phenolic compounds from jamun (Syzygium cumini L.) seeds

In this study, aqueous extraction of phenolic compounds from jamun (Syzygium cumini L.) seed was undertaken. The effects of various parameters such as extraction temperature (34.8–85.2°C), extraction time (49.8–100.2 min), and liquid-to-solid ratio (9.8–60.2 mL/g) on the extraction yield, extract purity (i.e., total polyphenol content), and its antioxidant activities (1,1-diphenyl-2-picrlthydrazyl free radical scavenging assay and ferric reducing antioxidant power) were investigated. Response surface methodology was used to optimize the extraction conditions. The optimum extraction conditions (49.2°C, 89.4 min, and 51.6:1 mL/g) produced an extract with 17.3% extraction yield, high total polyphenol content (415 mg gallic acid equivalent/g dried extract) and significant antioxidant activity (IC₅₀: 35.4 ± 0.7 µg/mL). The high-performance liquid chromatography analysis of seed extract revealed the presence of gallic acid (90.8 mg/g dried extract), ellagic acid (36 mg/g dried extract), caffeic acid (26.07 mg/g dried extract), p-coumaric acid (0.26 mg/g dried extract), catechin (9.05 mg/g dried extract), epicatechin (0.42 mg/g dried extract), and quercetin (1.54 mg/g dried extract). Tannic acid (188.5 mg/g dried extract) was also identified as a major phenolic compound. The extraction kinetics was also studied and experimental data were fitted to four kinetic models such as first-order model, second-order model, Peleg’s model, and Minchev and Minkov model, to evaluate their applicability.     

葡萄籽原花青素的提取工艺研究

在单因素实验和正交实验的基础上,得出葡萄籽中原花青素的最佳提取工艺:丙酮浓度80％,提取温度50℃,料液比1:20。依此条件提取并根据标准曲线推测,一种陕西地产葡萄籽中原花青素含量约占2％。     

酿酒葡萄提取葡萄籽油的加工及开发应用

针对酿酒葡萄的现状,对开发葡萄籽油的性质、营养功能和应用做了系统阐述,并介绍了最新的加工工艺,预测未来葡萄籽油的发展前景.     

葡萄籽提取物生理活性及其提取研究

葡萄籽提取物具有多种生理活性而成为有关科研工作者的研究热点。综述了葡萄籽提取物生理活性及其提取分离研究进展,并对葡萄籽提取物的开发利用前景进行了展望。      

含葡萄籽提取物的维生素C的测定

目的对3种维生素C检测方法进行比较,探索检测含葡萄籽提取物的样品中维生素C含量的适宜方法。方法用滴定法、紫外风光光度法、高效液相色谱法分别检测维生素C含量。结果以汤臣倍健祛斑胶囊为例,因葡萄籽提取物本身的强抗氧化性和颜色深的特性,用滴定法和紫外风光光度法检测维生素C的准确度偏差分别为87.73%和54.79%,用高效液相色谱法检测结果准确度偏差为0.38%,符合检测法规GB/T27404-2008中要求(当含量在1%~10%时,准确度偏差小于10%)。结论当样品中含有葡萄籽提取物时,用高效液相色谱法检测维生素C的准确性高。     

梅鹿辄葡萄4个营养系果实酚类物质变化研究

酚类物质对葡萄酒的感官品质和生理活性功能有重要作用,该研究以梅鹿辄葡萄4个营养系（M-181、M-343、M-346、M-348）为材料评价酚类物质差异。结果表明,不同品系梅鹿辄葡萄可溶性固形物含量无显著差异（P＞0.05）,M-348平均粒质量高于其他三个营养系,且可滴定酸含量与M-181、M-343无显著差异（P＞0.05）。在成熟时,4个营养系果皮和种子总类黄酮含量差异不显著（P＞0.05）,但M-348果皮中单宁、黄烷醇和原花色素含量显著（P＜0.05）高于其他三个营养系;随着果实的发育,4个营养系果皮中花色苷含量逐渐增加,在花后120 d,M-348中花色苷含量为13.48 mg/g。梅鹿辄M-348葡萄果皮酚类物质含量丰富,可作为黄土高原区梅鹿辄种植品系。     

Potential health benefits of phenolic compounds in grape processing by-products

Food Science and Biotechnology - Prevention emerges as a powerful approach in minimizing the risk of deleterious lifestyle diseases because therapies do not necessarily guarantee a permanent cure....     

微波辅助提取葡萄籽原花青素的工艺研究

对微波辅助提取葡萄籽原花青素的工艺进行了研究,通过正交试验确定了微波辅助提取葡萄籽原花青素的最佳工艺条件,即微波功率为中低火、料液比为1：18、乙醇浓度为60％、微波作用时间50s,在最佳工艺条件下,原花青素的提取量为18．47mg／g。