刺葡萄皮花色苷的光热降解特性研究

为了解刺葡萄皮花色苷在光照及加热条件下的稳定性,明确其贮藏和应用条件,对刺葡萄皮花色苷的光热降解特性进行研究.结果表明:常温条件下,pH 1～3色素液花色苷稳定性较好;避光及室内自然光照条件下放置20 d内刺葡萄皮花色苷的稳定性无显著差异,但强光条件下,刺葡萄皮花色苷稳定性明显下降;刺葡萄皮花色苷热降解符合动力学一级反应规律,pH为1.0、3.0、4.5时,其热降解活化能Ea分别为99.385 6,83.364 5,73.741 9 kJ/mol,说明低pH条件下,刺葡萄皮花色苷的热稳定性较好,但pH 1.0色素液在≥80 ℃加热时的花色苷半衰期t1/2≤4.10 h,而pH 3.0、4.5色素液在同样加热条件下的t1/2≤14.12 h、13.20 h;高温处理(≥80 ℃)时,pH 3.0的色素液稳定性优于其余pH条件.     

野生毛葡萄皮渣花色苷稳定性研究

以野生毛葡萄皮渣为原料,用乙醇提取花色苷并研究其稳定性。结果表明:毛葡萄皮渣花色苷对p H、温度、光照、氧化剂、还原剂和防腐剂敏感;葡萄糖、果糖、蔗糖对该花色苷有一定的护色作用;金属离子K~+、Na~+、Mg~(2+)、Zn~(2+)对毛葡萄皮花色苷影响较小,Fe~(3+)、Cu~(2+)对该花色苷有明显的破坏作用。     

遗传算法优化双水相法提取葡萄皮渣花色苷工艺及其组分分析

以葡萄皮渣为原料,采用双水相法提取其中的花色苷并鉴定花色苷组分。在单因素实验的基础上,通过遗传算法优化双水相法提取葡萄皮渣花色苷的工艺;利用高效液相色谱-质谱联用鉴定葡萄皮渣花色苷提取物中花色苷组分。结果表明:双水相法提取葡萄皮渣花色苷的最佳工艺为:乙醇体积分数40%、硫酸铵质量分数26%、pH3.0、料液比1:38 g/mL,在此条件下花色苷得率（3.05±0.07） mg/g。经鉴定发现葡萄皮渣花色苷提取物含有2种花色苷组分,分别为飞燕草-3-葡萄糖苷和矢车菊素-3-葡萄糖苷,其纯度分别为90.16%和92.41%。研究结果为天然花色苷提取提供一种新的提取方式,并为进一步开发花色苷功能性食品提供依据。     

3种花色苷水溶液的货架期预测

以紫薯花色苷、葡萄皮花色苷和树莓花色苷的水溶液为研究对象,通过加速试验预测其货架期,研究在加速过程中花色苷相对浓度和颜色值的变化情况。结果显示,3种花色苷水溶液的降解均符合一级动力学。根据预测,紫薯花色苷水溶液的货架期可达33 d,其次是树莓和葡萄皮花色苷,预测结果与试验结果基本吻合。因此,该方法可缩短花色苷水溶液货架期预测试验的时间。     

刺葡萄皮花色苷的分离及检定

对刺葡萄皮花色苷(VSA)进行分离和检定.从刺葡萄皮花色苷水解物中得到两种花色苷元,经鉴定为锦葵啶、芍药啶;从刺葡萄皮色素中分离到5种花色苷组分,其中4种为3-,5-双糖苷,1种为3-糖苷,2种为酰化花色苷;经柱层析得到3种刺葡萄皮花色苷,经HPLC检测并计算,花色苷AN1、AN2、AN3分别占纯化样品的85.805%、1.364%及11.835%,其中AN1的纯度达99%.     

纤维素酶法提取葡萄皮花色苷工艺研究

探索纤维素酶法提取葡萄皮中花色苷的提取工艺。采用单因素试验和正交试验相结合的方法研究不同因素对葡萄皮花色苷提取的影响。最佳提取条件为pH 3、酶解温度45℃、酶添加量1.2%、料液比1∶15(g/mL)、酶解时间30 min。以期为葡萄皮花色苷的提取技术提供参考依据。     

甲基吡喃花色苷的制备优化及HPLC-MS/MS分析

以葡萄皮红色素提取物为原料,正交实验法研究花色苷在丙酮介质中反应合成甲基吡喃花色苷的最佳条件,探讨了反应物比例、底物浓度、温度、pH等因素对甲基吡喃花色苷生成量的影响,高效液相色谱(HPLC)监测反应过程,并利用高效液相色谱-二极管阵列检测-串联离子阱多级质谱(HPLC-DAD-EI-MS/MS)法对反应产物进行定性和定量分析。结果表明最佳反应条件是:反应物比例(葡萄皮红色素提取物mg∶丙酮mL)15∶1,葡萄皮红色素提取物浓度2.5mg/mL,反应pH3.0、温度45℃。高效液相色谱串联质谱结合多级质谱裂解分析表明,反应主要产物为甲基吡喃锦葵花色苷,反应第9d其得率为49.4%。经分离纯化后的甲基吡喃花色苷特征吸收峰在478nm,与原花色苷比较明显发生蓝移。实验结果为甲基吡喃花色苷的高效制备、功能与理化性质研究提供了一种经济有效的研究方法和物质基础。     

毛葡萄皮渣花色苷的真空辅助提取工艺优化

为充分利用“野酿2号”毛葡萄汁生产副产物——皮渣中的花色苷成分,该研究利用60 L真空提取和浓缩装置对毛葡萄皮渣花色苷进行提取、浓缩,以花色苷含量为评价指标,通过单因素试验和正交试验对其提取工艺进行优化,并对其浓缩效果进行比对。结果表明,毛葡萄皮渣花色苷的最佳真空辅助提取条件为：料液比1∶6(V/V),乙醇体积分数65%,pH值为1.0,油浴温度65℃,真空度0.08 MPa,提取时间120 min。在此优化条件下,花色苷的提取得率、浓缩得率分别为1.59%、1.42%,浓缩时间为5.12 h,浓缩损失率为10.92%。该研究为毛葡萄皮渣花色苷的工业化生产提取和浓缩提供了一定的技术参考。     

葡萄皮花色苷提取的研究进展

综述了国内外最近几年关于以葡萄皮为代表的植物花色苷的研究进展,主要是花色苷的提取方法及各种方法下的最优条件,分析评价了不同提取方法的优缺点,对花色苷提取的研究现状做出总结并展望了天然葡萄皮花色苷的发展前景。     

不同溶剂对酿酒葡萄皮渣多酚组成的提取效果比较

为测定不同极性溶剂对酿酒葡萄皮渣中5类非花色苷多酚的提取效果,分别采用乙酸乙酯、丙酮、甲醇、水作为提取溶液,通过HPLC-MS/MS检测葡萄皮和葡萄籽中31种非花色苷多酚的组成和含量。通过比较4种提取溶液的提取效果,发现甲醇对各类非花色苷多酚的提取效果最好;有机溶剂对黄酮醇类、黄烷-3-醇类、芪类多酚的提取效果较好;水对苯甲酸类、肉桂酸类酚酸的提取效果较好。比较酿酒葡萄皮和籽中非花色苷多酚差异,发现葡萄皮中最主要非花色苷酚为黄酮醇类、苯甲酸类,葡萄籽主要多酚为黄烷-3-醇类,而肉桂酸类和芪类多酚在葡萄皮渣中含量最少;酿酒葡萄皮渣中含量较高的多酚单体为杨梅素、儿茶素、表儿茶素、没食子酸、香草酸。由此推论酿酒葡萄皮和葡萄籽中多酚组成有一定差异,且其提取效率和分子结构、溶液极性等因素有关。     

葡萄果实花色苷合成调控研究进展

果皮颜色是葡萄果实重要的商品品质之一,也是决定葡萄酒质量的关键因素,尤其是红葡萄酒。因此,果皮颜色一直是葡萄品种选育的重要目标性状。葡萄果皮颜色主要取决于花色苷的组成与含量,花色苷积累与尿苷二磷酸葡萄糖-类黄酮葡萄糖基转移酶（UDP-glucose 3-O-flavonoid glucosyltransferase,UFGT）基因表达呈显著正相关,而基因表达主要受MYB（v-myb avian myeloblastosis viral oncogene homolog）转录因子的调节。本文从MYB转录因子调节花色苷合成的分子机理及研究现状进行评述,并对该领域研究发展方向做简要分析。     

High‐pressure recovery of anthocyanins from grape skin pomace (Vitis vinifera cv. Teran) at moderate temperature

The objective was to evaluate the influences of the high hydrostatic pressure extraction parameters on the recovery of anthocyanins from the grape skin pomace extracts (Vitis vinifera cv. Teran) under moderate temperatures. Studied parameters were: solvents (methanol and ethanol); solvent concentrations (30, 50, and 70%); pressures (300, 400, and 500 MPa); times (3, 6.5, 10 min); and temperatures (22, 26, 30 °C). Predominant anthocyanins in all extracts were malvidins (malvidin‐3‐glucoside as the main compound) representing 55.77% of overall anthocyanin content. The type of solvent did not significantly influence anthocyanin extraction yield, while decreased solvent concentration (increased solvent‐to‐water ratio) significantly improved extraction of anthocyanins. Increase of pressure enhanced extraction yield of the anthocyanins but temperature showed stronger impact on the anthocyanins recovery. This investigation evidenced that the best conditions for HHPE of anthocyanins from grape pomace were extraction time 3.39 min, extraction temperature 29.48 °C, pressure 268.44 MPa and solvent concentration 70%.

Practical applications

Due to increased interest for the use of cheap winery byproducts as a source of expensive polyphenols for functional food production, skins from grape pomace became valuable raw material. Therefore, there is a need to evaluate the influence of HHPE innovative extraction technology on its nutritive value during processing. Optimizing parameters for polyphenolic recovery from grape pomace is directly related with nutritional value and economics of food engineering during industrial processing. Obtained results showed that the HHPE under lower temperatures is suitable for the extraction process of anthocyanins from grape skin pomace, but more research is needed to identify other food‐grade solvents with their corresponding concentrations that are useful for the extraction assisted with high hydrostatic pressure.     

Subcritical Water and Sulfured Water Extraction of Anthocyanins and Other Phenolics from Dried Red Grape Skin

ABSTRACT: Water, an inexpensive and environmentally friendly solvent is an ideal solvent for industrial extraction of phenolics, but its use is limited due to poor extraction efficiency at low temperatures. In this study, subcritical water (SW) and subcritical sulfured water (SSW) (containing 1400 μg/mL sodium metabisulfite) extractions of grape skin phenolics were conducted over the temperature range of 100 to 160°C in 10°C increments for a short time (40 s), and compared with conventional hot water or aqueous 60% (v/v) methanol extractions (50°C, 1 h). The composition and contents of anthocyanins, flavonols, hydroxycinnamates, phenolic acids, and antioxidant capacities (Oxygen Radical Absorbing Capacity [ORAC]) in the extracts were determined. Increasing SW extraction temperature from 100 to 160°C resulted in a linear increase in ORAC values, but extraction temperatures > 110°C resulted in decreased contents of individual and total anthocyanins. Subcritical sulfured water extracts had higher levels of total anthocyanins and total phenolics than SW extracts. The SW and SSW extracts had comparable or higher levels of anthocyanins and ORAC values than extracts obtained using conventional hot water or 60% methanol. Subcritical water at 100 to 110°C appears to be an excellent alternative to organic solvents to extract anthocyanins and other phenolics from dried red grape skin and possibly other grape processing byproducts.     

Stabilization of grape skin anthocyanins by copigmentation with enzymatically modified isoquercitrin (EMIQ) as a copigment

The thermal and light stability of grape skin anthocyanins with enzymatically modified isoquercitrin (EMIQ) as a copigment was investigated at different pH levels of 3, 4 and 5. The ratios of anthocyanins to EMIQ were 2:1, 1:1, and 1:2 (w/w), respectively, in the thermal experiments at 90 °C, and EMIQ concentrations (0.25, 0.5, and 1%, w/w) were evaluated respectively in the light experiments. Results revealed that the degradation of anthocyanins copigmented with EMIQ followed first-order reaction kinetics. The half life of anthocyanins extended significantly with the increase of EMIQ concentration (p < 0.05), moreover, the color stability increased due to the addition of EMIQ as the total color difference values ΔE* were smaller for the copigmented anthocyanins. The magnitude of the bathochromic (λ_max) shifted to the longest wavelength absorption band with the increasing copigment concentration for all pH levels. Results demonstrated that EMIQ was an effective copigment to stabilize grape skin anthocyanins.     

酿酒葡萄成熟期间果实质地特性和花色苷含量变化

研究酿酒葡萄果实成熟期间质地特性和花色苷含量的变化规律,以酿酒葡萄赤霞珠（Vitis vinifera L.）为研究对象,采用物性分析仪对其果皮机械特性和果实质构多面特性进行分析,并测定了果皮中总花色苷和9 种花色苷组分的含量,以及花色苷可提取率。研究表明：赤霞珠葡萄果实成熟期间果皮中总花色苷和可提取花色苷含量逐渐增加,至转色后第6周达到最高,分别为880.29 mg/kg和841.38 mg/kg。果实成熟期间果皮厚度逐渐增加,并与花色苷含量呈极显著正相关（R2=0.568）,与花色苷可提取率呈极显著负相关（R2=－0.475）。表征果皮硬度的参数杨氏模量（Esk）与花色苷含量呈极显著正相关（R2=0.581）,与花色苷可提取率呈显著负相关（R2=－0.609）。果实质构多面分析各参数与果皮花色苷含量和可提取率之间均无相关性。     

不同时期摘叶对马瑟兰花色苷的影响

以烟台蓬莱产区马瑟兰为试材,高效液相色谱（HPLC）法测定果皮花色苷含量,研究转色期前后摘叶处理对果皮花色苷种类和含量的影响。结果表明,转色期前摘叶能够显著增加花色苷的种类和含量（P＜0.05）,共检测到16种花色苷单体,其五类基本花色苷总量是对照的3.16倍;而转色后摘叶处理和对照组均检测出12种花色苷单体,五类基本花色苷总量只略高于对照组。     

鲜食葡萄花色苷的研究进展

鲜食葡萄果皮中含有大量酚类活性物质,主要为胡萝卜素、花色苷和原花色素等,占多总酚量的95％.本文就近几年来国内外对葡萄果皮中的花色苷研究进行文献综述,系统介绍了葡萄果皮中主要花色苷的种类、结构与性质,进一步阐述了花色苷分析的主要提取及鉴定方法,应用与展望.对鲜食葡萄在贮藏过程中花色苷稳定性和功能性作用的研究提供一定的参考价值.     

HPLC-DAD detection of changes in phenol content of red berry skins during grape ripening

With increasing concern for a demand from consumers for natural products, there is a wide interest in bioactive substances. The new frontier of dietary quality is the study and promotion of functional foods. Phenols are among the most important functional molecules. Red grape and red wine contain bioactive products as phenols. Changes occurring in the concentrations of phenols, such as hydroxycinnamic tartaric acids (hctas), flavonols, and anthocyanins in berry skins, were measured during growth and ripening of four red grape cultivars, Alicante, Black Malvasia, Nerello, and Prunesta (Vitis vinifera L.), cultivated in a coastal location of the Reggio Calabria Province (Southern Italy). These cultivars are the most popular and are considered to be the most suitable grape cultivars for cultivation in the Tyrrhenian side of the Reggio Calabria Province. Fractioning of three phenolic classes was conducted through the adsorbing resin Serdolit XAD-2. Each single phenolic fraction was analyzed by liquid chromatography with diode array detector (HPLC-DAD). Each cultivar presented a different chromatographic profile particularly for anthocyanins. The cultivar Nerello was distinguished from other for its high content of anthocyanins. The rate, at which the concentration of hctas, flavonols and anthocyanins increased, varied greatly among the cultivars. The hydroxycinnamic tartaric acid profile varied in the studied cultivars, in fact in Alicante, Black Malvasia and Prunesta cultivars, the predominant was trans-coumaroyl tartaric acid, while in Nerello cultivar, trans-caffeoyl tartaric acid was the most abundant. In addition, the results showed that amounts of phenolic compounds contained in grape skin changed throughout the grape ripening process.     

Application of pulsed electric fields for improving the maceration process during vinification of red wine: influence of grape variety

The effect of the application of pulsed electric fields (PEF) treatments (2, 5 and 10 kV/cm) to the grape skin on the evolution of colour intensity, anthocyanins and index of total polyphenols along the vinification process of three grape varieties (Garnacha, Mazuelo and Graciano) has been investigated. It has been demonstrated that the ability of PEF to permeabilize cellular tissues is an effective treatment to improve the extraction of phenolic compounds. The influence of the intensity of the PEF treatment on colour intensity, anthocyanins and index of total polyphenols depended on the grape variety investigated. As compared with the control, the application of a PEF treatment was more effective in Mazuelo than in Garnacha and Graciano varieties. Increasing the electric field strength from 2 to 10 kV/cm led to a significant increment in treatment efficiency in Mazuelo but not in Garnacha and Graciano. The low energy consumption for cell permeabilization of grape skins (0.4–6.7 kJ/kg) and the short processing time required are key advantages of PEF technology to reduce the duration of the maceration during vinification or to increase the quantity of phenolic compounds in the final wine.     

Impact of Processing Parameters on the Phenolic Profile of Wines Produced from Hybrid Red Grapes Maréchal Foch,Corot noir,and Marquette

Phenolic extraction in hybrid and interspecific wine grape cultivars is poorly understood, especially in terms of the impact of fermentation and enological conditions on condensed tannins and anthocyanins. Following fractionation via solid‐phase extraction and high‐performance liquid chromatography, phenolic profiles of must and wine from red hybrid grape cultivars Maréchal Foch, Corot noir, and Marquette were examined to assess the impact of enzyme and tannin addition, cold soak, and hot press during vinification. Across cultivars, hot press treatments resulted in the greatest extraction of condensed tannin, anthocyanin, and other monomeric phenolic compounds in musts, and treatments that increased skin contact time or cellular degradation during fermentation produced higher concentrations of tannins, anthocyanins, and flavonols. However, these increases were transient, evincing incomplete carryover into finished wines. Depending on initial must extraction, diglucoside forms of anthocyanins were either selectively extracted or selectively retained throughout fermentation when compared to their monoglucoside counterparts. Typical of hybrid grapes, tannin concentrations across cultivars were low, even under hot press conditions. For condensed tannins and anthocyanins, a cultivar‐specific, stable‐state concentration and phenolic profile emerged regardless of fermentation conditions. Due to the high levels of diglucoside anthocyanins and low levels of condensed tannins, it is expected that the color development and profile in these wines produced from hybrid grape cultivars will be dictated by the monomeric anthocyanins and their potential role in copigmentation processes involving other monomeric phenolic species, as opposed to the formation of polymeric color pigments.