不同品种葡萄采后失水分析

鲜食葡萄采后果梗保绿和防止贮藏期间的干梗、果粒皱缩是衡量保鲜效果的重要指标.本文以我国近年来发展潜势较大的7个鲜食品种为试材,在室温条件下测定了果梗、果粒的失水情况,并对部分品种作了解剖学观察.研究结果表明:采后果梗失水由快到慢的顺序依次为:红地球、美人指、无核白鸡心、巨峰、意大利、秋黑、秋红葡萄;果粒失水由快到慢的顺序依次为:红地球、无核白鸡心、意大利、美人指、秋黑、秋红、巨峰葡萄.     

Effects of mild heat treatment on microbial growth and product quality of packaged fresh-cut table grapes

ABSTRACT:  The changes in packaged fresh-cut grape quality and microbial growth as affected by mild heat treatments and the retention of grape cap stems during 5 °C storage were evaluated. Each individual grape was either manually pulled off (stemless) from the stems, or cut (cut stem) to allow for a 1- to 2-mm cap stem remaining on the berry. The samples were sanitized in 100 mg/L chlorine solution for 1 min, followed by a mild heat treatment in a water bath (45 °C, 8 min) or an oven (55 °C, 5 min). After cooling, the berries were packaged in rigid trays sealed with a gas permeable film and stored at 5 °C. Product quality and decay rate were evaluated periodically during storage. The results indicate that in the package headspace for hot water treatment of stemless grapes, partial pressures of O₂ declined significantly ( P < 0.05) less and C₂H₄ increased significantly ( P < 0.001) less than for the control and hot air treatment. Stem removal and heat treatment had significant ( P < 0.05) effects on the decay rate of grapes during storage. Hot water treatment maintained a significantly lower decay rate than the control and hot air treatment throughout the entire storage. Color and texture were not significantly ( P > 0.05) affected by either heat treatment or stem removal. Grapes that retained the cap stems and received hot water treatment had the lowest decay rate and lowest microbial growth with the absence of any negative impact on grape color, texture, and flavor.     

Effects of exogenous 24‐epibrassinolide to control grey mould and maintain postharvest quality of table grapes

The potential of various concentrations of 24‐epibrassinolide (EBR) treatments on the control of grey mould in artificial Botrytis cinerea inoculation test and on the maintenance of postharvest quality of table grapes without inoculation in cold storage were researched. In the cold storage, clusters of grapes with exogenous EBR application (EBR1, 0.1 mg L^?1 EBR; EBR2, 0.4 mg L^?1 EBR; EBR3, 0.8 mg L^?1 EBR) were stored at 0 ± 1 °C. Fruits’ quality attributes including berry firmness, weight loss, berry drop, decay berry percentages, total sugar and titratable acidity were measured at 15, 30 and 60 days. The results showed that EBR treatments exhibited a higher berry firmness and a lower percentage of weight loss, berry drop and decay berry. In the artificial inoculation trial, single berries were immersed in EBR1, EBR2 and EBR3, then inoculated by spraying with a B. cinerea spore suspension and stored at 25 ± 2 °C and 95% relative humidity. Disease severity (DS), lipid peroxidation and defence‐related enzymes of these berries were analysed every 2 days. EBR‐treated berries resulted in an increase in activities of defence‐related enzymes including superoxide dismutase, peroxidase, catalase and phenylalanine ammonia‐lyase compared with control berries inoculated by B. cinerea. Simultaneously, significant decreases in DS and production of superoxide anion radical and malondialdehyde were observed. These results suggested that exogenous application of EBR could play a protective role in controlling the grey mould of postharvest grapes and maintaining the postharvest quality during cold storage.     

SO2处理对新疆3种葡萄香气成分的影响

采后SO2处理对新疆“无核白”、“木纳格”和“红提”3 种葡萄果实香气成分的影响。选4-壬醇做内标,采用顶空固相微萃取-气相色谱-质谱联用技术对SO2处理前3 种葡萄成熟果实的香气成分进行定性和定量分析,同时考察了添加焦亚硫酸钠对“无核白”葡萄香气成分的影响及采后不同贮藏时间SO2处理对3 种葡萄果实香气成分的影响。结果表明,3 种葡萄中分别鉴定出40、38、37 种香气成分,其中C6醛（即己醛和E-2-己烯醛）在3 种葡萄中的含量相对较高;添加焦亚硫酸钠对“无核白”葡萄中的C6醛含量影响较大,其他成分含量变化不大;采后SO2处理3 种葡萄果实香气成分中的C6醛的含量均随着贮藏时间的延长而逐渐降低。     

Alginate coatings containing grapefruit essential oil or grapefruit seed extract for grapes preservation

Biodegradable coatings based on 1% and 2% sodium alginate (NaAlg) with and without grapefruit seed extract (GSE) or grapefruit essential oil (GEO) were applied to table grapes to preserve their quality. Changes in weight loss, firmness and antioxidant activity were assessed over 15 days of cold storage. The effectiveness of developed coatings to control postharvest decay of inoculated grape berries stored for 5 days at 20 °C was also investigated. Biodegradable coatings based on pure NaAlg and those containing GSE were efficient in reducing weight loss and maintaining firmness during storage. Coatings incorporating either GEO or GSE were able to preserve the antioxidant activity of treated grapes and to reduce decay incidence in inoculated fruits. Coatings formulated with 2% NaAlg‐1% GSE showed the greatest preservation of antioxidant activity and the highest antifungal effect, with an effective control of water and firmness losses. These coatings can be recommended for maintaining table grapes quality.     

基于数字图像及随机最小二乘的红提串果粒尺寸检测分级方法

红提尺寸是衡量其品质的重要指标,为了实现整串红提的尺寸分级,本研究提出了一种基于机器视觉的尺 寸分级方法。通过双通道相机同时采集红提的红-绿-蓝（Red-Green-Blue,RGB）图像和近红外（near infrared,NIR） 图像,利用归一化超绿法去除RGB图像中干扰的绿色果梗信息,同时利用形态学重构的亮度局部极大值的方法对 NIR图像中的红提果粒进行识别和定位。采用梯度分割法有效地截取果粒轮廓并去除边缘轮廓中的干扰弧段,再利 用随机最小二乘椭圆检测的方法提取果粒尺寸,并对整串红提分级。采用该方法对42 串红提进行尺寸检测分级, 正确分级38 串,分级正确率为90.48%。实验结果表明：该方法分级正确率高,能够为葡萄市场分级提供技术支持。     

Postharvest evaluation of soilless-grown table grape during storage in modified atmosphere

BACKGROUND: Soilless growth systems, developed mainly for vegetables and ornamental crops, have also been used recently as an alternative to soil culture for table grape in order to achieve optimal production performance. In this study, sensory, physical and chemical parameters were analysed in table grapes obtained from soil and soilless growth systems at harvest and during storage in air or modified atmosphere. RESULTS: At harvest, soilless‐grown berries were 30% firmer than those grown in soil. Moreover, they showed 60% higher antioxidant activity and total phenol content than soil‐grown fruits. Modified atmosphere storage resulted in a better quality of table grapes compared with those stored in air. Furthermore, soilless growth was more suitable than soil growth for preserving visual quality and controlling rachis browning and weight loss. CONCLUSION: Since the soilless system produces berries that are cleaner and of higher quality than those grown in soil, the implementation of soilless growth for the production of health‐promoting and convenience fruits is suggested. Copyright © 2011 Society of Chemical Industry     

Different postharvest dehydration rates affect quality characteristics and volatile compounds of Malvasia,Trebbiano and Sangiovese grapes for wine production

Experiments were carried out using an innovative technology for dehydration based on the passage of air through a tunnel. It was possible to study the postharvest behaviour, at different rates of dehydration, of Malvasia, Trebbiano and Sangiovese grapes. Malvasia and Trebbiano grapes were picked with 17.5% SSC (soluble solids content), while Sangiovese grapes were harvested fully ripe with 26% SSC. All the grapes, in different experiments, were placed in the tunnel with an air speed of 1–1.5 m s^?1, 42% RH (relative humidity) and a temperature of 21 °C. After 18 days the weight loss was 50 and 34% respectively in tunnel‐treated Malvasia and Trebbiano grapes, while it was only 13–14% in control grapes (outside the tunnel: RH around 65% and temperature about 20 °C without ventilation). The SSC rose to 35 and 27% respectively in tunnel‐treated Malvasia and Trebbiano grapes compared with 23 and 21% respectively in control grapes. In the case of Sangiovese grapes, after 7 days (the end of treatment) the weight loss was 20.5% in tunnel‐treated grapes and 10.5% in control grapes. The SSC rose to 32% and the acidity increased from 4.8 to 5.8 g l^?1 in tunnel‐treated grapes compared with 29% and 5 g l^?1 respectively in control grapes. Total phenols and anthocyanins almost doubled in tunnel‐treated Sangiovese berries. Volatile compound analysis revealed a higher ethanol concentration in all tunnel‐treated grapes but a lower concentration of ethyl acetate and acetic acid. Copyright © 2004 Society of Chemical Industry     

臭氧对葡萄灰霉病的抑制效果

研究不同臭氧处理方式对离体及接种在活体葡萄上的灰霉菌的抑制作用,为降低采后葡萄贮藏过程中灰霉病带来的损失提供理论依据。在(20±1)℃条件下用不同剂量的臭氧(0、30、60、90μL/L)对离体灰霉菌分别处理不同时间(5、10、15 min),通过测定菌丝生长长度、孢子形成抑制率、孢子细胞膜完整性及扫描电镜观察来探究臭氧对其抑制效果。用上述4种剂量的臭氧分别对接种了灰霉菌的‘红地球’葡萄处理15 min后(20±1)℃条件下存放5 d。通过测定发病率、病斑直径及相关酶活性来观察臭氧对葡萄灰霉病的控制效果。结果表明:在离体实验中,与对照相比,不同剂量的臭氧对离体灰霉菌处理不同时间后,灰霉菌菌丝的生长均受到了不同程度抑制,随贮藏时间延长抑制效果逐渐减弱;灰霉菌的产孢子率显著下降,部分孢子的细胞膜完整性被破坏,臭氧剂量越高、处理时间越长,效果越好。在接种了灰霉菌的活体实验中,与对照组相比,用60μL/L和90μL/L剂量臭氧处理接种灰霉菌的葡萄果实后,灰霉菌在果实上的生长明显受到抑制;臭氧处理可以使果实丙二醛含量积累减慢,维持较高的抗氧化酶活性。综合分析,臭氧通过抑制灰霉菌菌丝在葡萄果实上的生长和诱导葡萄果实提高抗性来抵抗灰霉菌的侵染,采用90μL/L剂量臭氧处理15 min对离体条件下和接种在‘红地球’葡萄活体上的灰霉菌抑制效果均为最好。     

Effect of Micro-Perforated Film Packing on Fatty Acid-Derived Volatile Metabolism of “Red Globe” Table Grapes

The present study was aimed at understanding the effect of micro-perforated polyethylene film packing (MPFP) on the metabolism of fatty acid-derived volatiles and physicochemical attributes in “Red Globe” table grapes under storage at 0 °C for 50 days. Physicochemical properties evaluated in grapes were total soluble solids (TSS), texture profile, decay incidence, fatty acid content, and aroma-related enzyme activities including lipoxygenase (LOX), hydroperoxide lyase (HPL), alcohol dehydrogenase (ADH), and volatiles in grape peel and flesh. Aroma-related genes (VvLOX, VvHPL, and VvADH) were also evaluated. Grapes treated with MPFP was found to retain the texture profile and decay incidence was reduced (17.4% of reduction compared with control) significantly (P?≤?0.05). Linoleic acid (LA), the main substrate of LOX/HPL pathway, was the highest in table grapes packed in MPFP, indicating the use of MPFP was able to preserve LA compound. Micro-perforated film packing upregulated VvLOX and VvHPL, downregulated VvADH, increased LOX and HPL activities, and inhibited ADH activity, enhancing C6/C9 compounds. The results indicated that MPFP system was the best choice to improve aroma quality of “Red Globe” table grapes in comparison to polyethylene film packing (PFP) and control (no packing).     

采前水杨酸处理对红地球葡萄潜伏侵染及采后灰霉病的防控效果

为明确采前水杨酸处理对葡萄潜伏侵染及采后灰霉病的影响,本研究首先分离并鉴定红地球葡萄生长过程中的主要潜伏侵染真菌,并研究水杨酸（salicylic acid,SA）对灰葡萄孢菌（Botrytis cinerea）的抑菌效果及对果实抗性基因的诱导作用。本文以新疆红地球葡萄为试材,选取0（对照）、0.5、1.0、2.0 mmol/L水杨酸（SA）在膨大期、转色期和采收前2 d （预收期）喷施处理葡萄果穗,采用组织分离法分离不同时期潜伏侵染果实的病原真菌,通过形态学和分子生物学方法,对病原菌进行分类鉴定,明确主要潜伏侵染真菌的种类,统计果实采后损伤接种Botrytis cinerea后病斑直径和发病率的变化,并分析果实相关抗性基因的表达情况。结果表明:采前SA处理可以显著降低果实生长期间潜伏真菌率,对葡萄果实不同部位的潜伏侵染控制效果显著,1.0 mmol/L SA处理组优于其它组,其中对果实底部和果蒂潜伏侵染的控制效果优于顶部和果梗。此外,生长期果实共鉴定出4种主要潜伏病原真菌,分别为灰葡萄孢菌（Botrytis cinerea）、互隔交链孢霉（Alternaria alternate）、变色青霉（Penicillium discolor）和黑曲霉（Aspergillus niger）。1.0 mmol/L SA处理能显著抑制B.cinerea侵染造成灰霉病发病率上升和病斑直径的扩大,SA处理可在贮藏前期诱导采后葡萄果实VvPAL1、VvChi4D和VvGlu1基因的表达,中期后期诱导VvPAL2、VvPAL7和VvPAL15的基因表达,起到提高果实抗病性。因此,SA采前处理能提高红地球葡萄对潜伏侵染病害的抗性,对采后灰霉病也有较显著的抑制效果。     

基于机器视觉的红提串无损检测及分级

为实现整串红提的紧实度无损检测和分级,提出基于机器视觉检测的分级方法,通过工业摄像头采集新鲜红提串的彩色（red green and blue,RGB）和近红外图像,对整串红提RGB图像的三通道进行提取,采用归一化GB色差法提取红提图像中的果梗,运用形态学重构及局部亮度极大值方法定位红提串中的各个果粒中心,同时提取每串红提的质心,选取果梗面积、红提果粒个数与果串面积之比、红提果粒与红提质心距离之和与果粒个数之比等特征参数,分别建立基于线性判别分析、集成学习算法和支持向量机的紧实度分类模型,经检验支持向量机模型分类效果最佳,应用该模型对130 串红提进行紧实度检测和分类,分级正确率94.6%。结果表明该方法可为后续葡萄品质及产量预测提供参考。     

湿度条件对巨峰葡萄贮藏过程中水分及质构变化的影响

研究辽西地区巨峰葡萄在不同相对湿度90%、50%及环境湿度条件下贮藏时的水分变化规律,并与感官品质、全质构分析各参数（硬度、黏聚性、胶黏性、咀嚼性、弹性和黏附性）建立相关性联系。结果表明,90%相对湿度条件下葡萄贮藏效果要优于其他两个湿度条件。葡萄浆果总水分含量在贮藏期内总体呈现下降趋势,90%相对湿度贮藏时葡萄组织含水量相对较高,束缚水和自由水的变化也相对平稳,因此该条件更有利于维持葡萄水分的稳定。相关性分析结果表明,在高湿环境下（90%相对湿度）贮藏葡萄,对葡萄束缚水含量的追踪可以更好地表征和预测葡萄的贮藏品质;在低湿度环境下（50%相对湿度）贮藏葡萄,总水分含量是更合理的指标;环境湿度条件贮藏时,对自由水和总水分含量测定来间接表征葡萄贮藏品质较合理。     

Pectin-derived oligosaccharides increase color and anthocyanin content in Flame Seedless grapes

BACKGROUND: Grapes grown in warm weather do not develop a desirable red color and require the use of products to enhance berry color. Pectin‐derived oligosaccharides (PDOs) have been shown to have a role in various responses including plant defense, growth and development. In this work a mixture of PDOs with 3–20 degrees of polymerization was applied to Vitis vinifera cv. Flame Seedless grapes under field conditions and compared to the effects of ethephon (an ethylene‐releasing compound). The effect of treatments on grape color, anthocyanin content and phenylalanine ammonia lyase (PAL) mRNA levels was evaluated. RESULTS: PDOs treatment increased berry color measured by the Color Index of Red Grapes (CIRG) and anthocyanin content, compared to ethephon and untreated berries (control); 1.5, 1 and 0.5 mg mL^?1 PDOs increased berry color by 30%, 27% and 26%, respectively, when compared to control berries. Levels of PAL mRNA accumulating in berries treated with PDOs were elevated within the first 24 h of treatment. CONCLUSIONS: PDOs enhanced the color and anthocyanin content of Flame Seedless grape berries possibly due by the induction of PAL mRNA expression. The results demonstrated that PDOs can be used to improve fruit quality aspects such as berry skin color. Copyright © 2011 Society of Chemical Industry     

Influence of skin hardness on dehydration kinetics of wine grapes

BACKGROUND: Knowledge of the influence of initial mechanical properties on the evolution of the weight loss of berries through the drying process is scarce. Therefore, the main purpose of this work was to investigate the effect of skin hardness at two different physiological stages of off‐vine drying kinetics of grapes. Skin hardness was evaluated as the berry skin‐break force parameter, measured by the texture analysis test. RESULTS: The decrease of berry weight as a function of the drying time was linear, indicating that the drying rates were constant within each cultivar studied (Moscato bianco and Erbaluce), and for each ripening stage and berry skin hardness. The drying rates decreased as berry skin hardness increased for the ripest grapes in the cultivars studied. CONCLUSION: The study allowed the assessment of the correlation between the skin hardness of fresh berries and the weight loss determined for different drying days. Copyright © 2010 Society of Chemical Industry     

基于MCCV-CARS-RF建立红提糖度和酸度的可见-近红外光谱无损检测方法

利用USB2000＋微型光谱仪采集红提400～1?000?nm透过率光谱数据,并通过理化分析测得糖度和酸度值;利用SavitZky-Golay卷积平滑法对原始光谱进行预处理,结合蒙特卡罗交叉验证法剔除奇异点,再利用竞争自适应重加权采样法降维,最终建立随机森林预测模型。糖度预测模型的校正集相关系数和均方根误差分别为0.955?8和0.315?8;验证集相关系数和均方根误差为0.956?8和0.318?5。酸度预测模型的校正集相关系数和均方根误差分别是0.945?6和0.300?1;验证集相关系数和均方根误差为0.940?5和0.311?2。结果表明,该方法适用于红提糖度和酸度的快速无损检测,且具有较高的准确度。     

Effect of grape and other berries on cardiovascular health

Cardiovascular disease is a leading cause of death globally. Many cardiovascular risk factors can be modified through lifestyle modification, including dietary patterns that emphasize daily consumption of a variety of fruits and vegetables. Recent observational and clinical studies suggest that flavonoids, especially those abundant in grapes and other berries, may be associated with health benefits, particularly cardiovascular benefits. Human clinical data support cardioprotective benefits of grapes through inhibition of platelet aggregation, decreased low‐density lipoprotein (LDL) oxidation, reduction in oxidative stress and improvements in endothelial function. Emerging evidence suggests that grapes may also have a favorable effect on blood lipids, decrease inflammation and reduce blood pressure in certain populations. Studies to date have shown that berries can have a beneficial effect on reducing LDL oxidation. Limited data suggest that berries may have a favorable effect on endothelial health and blood pressure. This review summarizes the current literature on human clinical studies examining the cardioprotective benefits of grapes and berries. Collectively, these data support the recommendation to incorporate products made with grapes and other berries into a heart‐healthy diet. © 2014 Society of Chemical Industry     

Phenolics and antioxidant capacity of table grape (Vitis vinifera L.) cultivars grown in Chile

Grapes (Vitis vinifera L.) possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Juice and skin fractions of 4 varieties of table grapes: Red Globe, Crimson Seedless, Autumn Royal, and Ribier were prepared to determine and compare their total phenolics content, antioxidant capacity (DPPH, FRAP, and ORAC), anthocyanins, and specific phenolics (caffeic acid, gallic acid, resveratrol, and catechin) content, since a series of positive health benefits are expected from the intake of any of these fractions. Higher amounts of total phenolics and antioxidant capacity were observed in the skin fractions (P < 0.05). Blue grapes (Autumn Royal and Ribier) exhibited higher phenolics content and antioxidant capacity (P < 0.05) than red grapes. The most abundant phenolic compound observed was catechin (P < 0.05). Significant correlations between the antioxidant capacity and total phenolics were observed in grape juice and skin fractions. Autumn Royal juice provides a very high amount of phenolics, anthocyanins, and exhibits the highest antioxidant capacity, offering the best health promoting properties compared with the other grape varieties studied. PRACTICAL APPLICATION: Grapes possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Grape juice made with blue grapes (Autumn Royal, Ribier) exhibit higher phenolics content and antioxidant capacity than juice elaborated with red grapes (Red Globe, Crimson Seedless). The skin is a good source of phenolics and has a high antioxidant capacity. Specific health-promoting phenolics are more abundant in blue grapes, mainly in their skin fraction, which should not be discarded.     

高寒荒漠区延后栽培葡萄品质分析

为评价鲜食葡萄在高寒荒漠区延后栽培条件下的品质表现,以适应性较好的8个品种为研究对象,测定葡萄感官品质、内在品质、功效成分和糖酸品质,采用主成分分析法对果实品质进行综合分析和评价。结果表明,‘红地球’和‘紫地球’单果质量10 g以上,果粒大,能够保持原有的大果特征;无核品种较有核品种果粒小;8个品种果实果形指数均> 1,呈长椭圆形,除绿色品种外,果实着色较深;果皮颜色越深的品种,果皮花青素、类黄酮、总酚含量越高。2个无核品种(‘红宝石无核’和‘紫甜无核’)和‘红地球’可溶性固形物含量较高,在21%以上;糖酸组分及含量方面,果实中的糖分主要是果糖和葡萄糖,蔗糖未检出;酒石酸和苹果酸是主要有机酸,柠檬酸和草酸含量极微。酸甜风味方面,‘红宝石无核’口感最甜,其次为‘红地球’,‘瑞都香玉’和‘紫地球’口感较淡,‘摩尔多瓦’口感偏酸。通过主成分分析法提取了5个独立的主成分,累计贡献率87. 396%,以主成分为评价指标,对浆果品质进行综合评价,‘红宝石无核’、‘红地球’和‘玫瑰香’果实综合品质最好。     

Assessment of grey mould (Botrytis cinerea) impact on phenolic and sensory quality of Bordeaux grapes,musts and wines for two consecutive vintages

Background and Aims: The impact of grey mould (Botrytis cinerea (B. cinerea)) was quantified on chemical, phenolic and sensory qualities of grapes, derived musts and wines. Methods and Results: Analyses were carried out by using naturally or artificially infected grape berries at ripeness or overripeness. In grape seeds, chemical analyses revealed no major differences between healthy and rotten grapes. In grape skins of Botrytis‐affected berries, concentrations of all the phenolic compounds (anthocyanins and proanthocyanidin monomers, dimers and trimer) decreased drastically. Mean degree of polymerization of the proanthocyanidin polymeric fraction was also affected in skins. Chemical analyses of musts and wines made with different percentages of rotten berries showed a moderate impact of the pathogen on their phenolic composition. Nevertheless, sensory analyses underlined a loss of wine sensory quality perceptible from a threshold as low as 5% of Botrytis‐affected grapes onwards. Conclusion: Phenolic variations and the associated negative impact in grapes, derived musts and wines may be related to oxidation phenomena from B. cinerea. The main effects of severity/age of grey mould and the level of berry maturity are also discussed. Significance of the Study: B. cinerea drastically affects the phenolic and organoleptic properties of grape skins and derived wines. Therefore, prophylactic actions early in the vineyard, evaluation of the sanitary status of the harvested grapes and berry sorting are primordial even under low disease pressure.