Impact of Multicolored Asian Lady Beetles on the Sensory Properties of Concord and Niagara Grape Juice

ABSTRACT: The presence of Multicolored Asian Lady Beetles (MALB) in grape juice is increasingly problematic. The overall objective of this study was to determine the specific sensory impacts of MALB on Concord and Niagara grape juice. The aroma threshold for MALB-taint in both juices was determined and expressed as the best estimate threshold (BET). The aroma BET for MALB-taint in Concord grape juice was 1.8 and 0.65 MALB/L Niagara grape juice. The specific sensory attributes of the grape juices influenced by the presence of MALB were then described. In Concord grape juice, trained panelists (n = 9) found significant increases in vegetal aroma and earthy flavor as MALB concentration increased from 0.45 to 7.2 MALB/L. In Niagara grape juice, with increasing MALB concentration, trained panelists (n = 8) indicated significant decreases in honey and sweetness with corresponding increases in sourness, astringency, and vegetal and earthy aromas and flavors (P < 0.05). For both aroma and flavor, consumer rejection studies were performed using paired preference comparisons of control juice to MALB-tainted grape juice. For Concord grape juice, consumers (n = 60) rejected the aroma of MALB-tainted juice at 1.8 MALB/L and the taste/flavor of the MALB-tainted juice at 3.6 MALB/L. For Niagara juice, consumers rejected the aroma of the juice at 3.6 MALB/L. This study demonstrated the presence of MALB negatively impacts the sensory properties of Concord and Niagara grape juice. Grape juice processors may use this research for quality control measures and for establishing tolerance limits. Practical Application: The Multicolored Asian Ladybeetle (MALB), initially used for biocontrol, has been shown in previous literature to impact the sensory properties of wines. The presence of MALB in grape juice is now becoming problematic; however, there is little research describing the specific sensory impacts of MALB on grape juice. This study examined the sensory impact of MALB on both Concord and Niagara grape juice. While the threshold and trained panel evaluations from this study provide valuable sensory profile information, grape juice processors may be particularly interested in the consumer rejection of MALB-tainted grape juice as they can use this research for quality control measures and for establishing tolerance limits.     

Effects of pre-fermentation enzyme maceration on extraction and colour stability in Pinot Noir wine

Effects of pre-fermentation enzyme maceration on anthocyanins, phenolics, colour and colour parameters were investigated in Pinot Noir ( Vitis vinifera L.) wines made from musts that were macerated for 12 hours at 20°C with a commercial enzyme preparation, Rohapect VR-C (Rohm, Darmstadt, Germany), with and without additions of SO₂. Anthocyanins and phenolics were determined by spectrophotometric and HPLC methods. Standard triplicate microvinifications were conducted in glass vessels. Extraction of anthocyanins was not increased by enzyme treatment. However, wines produced by enzyme maceration had increased visible colour intensity, colour density and polymeric pigment formation. By the end of fermentation, enzyme-treated wines had more polymeric pigment, and less monomeric anthocyanins than non-enzyme-treated wines. The wines were bottled, stored at 12°C and sampled at three, six, eight and 18 months after bottling. Over 18 months, differences between the treatments were maintained. The promotion of the formation of polymeric pigments in enzyme-treated wines continued after the wines were bottled, and the greater content of polymeric pigment led to greater colour density in the enzyme-treated wines. The promotion of polymeric pigment formation in wines by macerating enzyme treatment of the must may be due to the breakdown of protective polysaccharide-protein colloids by hemicellulase and protease activities in the enzyme preparation.     

Effects of climate and anthocyanin variables on the zoning of Pinot Noir wine from the Casablanca Valley

The Casablanca Valley is one of the youngest wine grape regions of the Chilean appellation of origin. The growers of this area note the presence of microclimates within the valley as one of its main features. These microclimates have historically been associated with two geographical zones: the Zona Alta and the Zona Baja. The objective of this research was to explore the effects of climate variables and anthocyanin profiles in Pinot Noir wines of the Casablanca Valley as a differentiator of productive zones. The climate variables were measured using weather stations located at different points across the valley. Wine samples from the same locations were characterised according to their anthocyanin profiles. The data were processed using analysis of variance, principal components analysis and partial least squares discriminant analysis to determine differences between the two groups explored. The results indicate a strong correlation between variables and zones (98.3% R²Y), leading to the conclusion that there are significant differences between the Zona Alta and Zona Baja group. Finally, the existence of a vineyard that does not belong to the Zona Baja group suggests a reassessment should be performed of the vineyards belonging to the administrative areas defined as part of the Casablanca Valley.     

增糖方法对灰比诺葡萄酒质量的影响

对4种调整糖度方法对葡萄酒质量的影响进行了比较,采用的葡萄品种为灰比诺,可溶性固形物为19.5°Brix,通过不同的调整糖度措施使可溶性目形物提高2.5°Brix,达到22°Brix.4种调整糖度方法分别为:直接往葡萄汁中加入蔗糖;往葡萄汁中加入68°Brix浓缩葡萄汁;冷冻除冰使葡萄汁浓缩和借助反渗透机器浓缩葡萄汁.结果表明,在调整糖度幅度为2.5°Brix的情况下,不同调整糖度方法对葡萄酒的质量影响不大.     

基于模糊数学和聚类分析的鲜食葡萄品种综合品质评价

对2013年陕西渭北地区的14 个鲜食葡萄品种的17 项生物经济学指标进行观察测定,并运用模糊数学和聚类分析评价了不同葡萄品种果实的综合品质。结果表明：品种间果实的果粒形状、产量、花色苷含量、果粉厚度、果皮厚度和果皮颜色性状变异系数较大,而果实感官品质和内在品质相关指标的变异系数较小。模糊数学评价筛选出综合品质较好的品种为红地球、夏黑、红宝石、8611、金田0601和魏可,而秦龙大穗、弗雷无核的综合品质较差。聚类分析结果表明,品质优等的8611、红地球、红宝石和魏可聚为一类,为优良的鲜食葡萄栽培种,品质中等的玫瑰香、巨玫瑰和红乳聚为一类,而品质最差的弗雷无核单独聚为一类。模糊数学评价方法结合聚类分析可给予葡萄综合品质较全面、客观的评价。     

贺兰山东麓产区不同地块对酿酒葡萄果实香气物质的影响

为明确宁夏贺兰山东麓产区小产区划分的意义,以该产区4 个葡萄园的2 个酿酒葡萄品种成熟期果实为材料,采用气相色谱-质谱联用技术对果实游离态和结合态香气物质进行测定,就地块差异对果实香气物质组成的影响进行分析。结果表明,4 个地块的土壤都属于砂壤土类型,高家闸地块的土壤质地含有更多的黏土,志辉地块的土壤更靠近砂土,华西地块和金山地块的土壤质地介于两者之间;在‘霞多丽’葡萄果实中,志辉地块的果实百粒质量、百粒体积和可滴定酸含量显著高于高家闸地块,在‘赤霞珠’葡萄果实中,不同地块果实百粒质量和百粒体积不存在显著差异,而金山地块的‘赤霞珠’葡萄果实中有更低含量的可溶性固形物和更高的可滴定酸;‘霞多丽’和‘赤霞珠’浆果中的香气物质种类和含量在不同地块中有显著差异,主要体现在C6/C9、酯类、降异戊二烯类和萜烯类化合物。志辉地块的‘霞多丽’果实香气差异化合物中的游离态(E)-2-己烯醛、β-大马士酮以及结合态辛酸乙酯的含量更高,结合相应的香气活性值（odor activity value,OAV）,志辉地块的‘霞多丽’葡萄果实中有更加浓郁的生青味、花香和果香;金山地块的‘赤霞珠’葡萄果实香气差异化合物中有更高含量的游离态(E)-2-己烯醛和(Z)-3-己烯-1-醇,结合相应的OAV,其果实香气中有更多的生青味。总之,基于不同地块葡萄果实香气的差异分析,具有明确不同地块葡萄果实品质和葡萄酒风格的潜在价值,为小产区的划分提供一定理论基础。     

苹果与葡萄对烤牛肉饼体外消化过程杂环胺释放的影响

研究外源添加物在消化过程中对蛋白结合态杂环胺（heterocyclic aromatic amines,HAAs）释放的影响。在烤牛肉饼的体外消化实验中以加入新鲜苹果和葡萄泥作为实验组,以未添加新鲜苹果和葡萄泥为对照组,消化液中的游离HAAs和蛋白结合态HAAs分别通过乙酸乙酯和盐酸水解提取,经固相萃取后使用超高效液相色谱-质谱联用仪测定。结果表明：苹果与葡萄的添加并未引起总HAAs含量的显著变化,但都不同程度促进了蛋白结合态HAAs向游离态HAAs的转化,且转化效果随新鲜苹果和葡萄泥添加量增加呈增强趋势。     

组织培养技术在葡萄无核育种上的应用

葡萄组织培养技术，特别是胚、胚珠培养技术在无核葡萄育种研究中发展迅速。利用无核葡萄品种作母本，特别是利用假单性结实的无核葡萄品种作母本，用无核品种涂父本进行杂交，合子胚还未败育时，采用胚珠培养技术可以得到杂种实生苗．这种杂种实生苗无垓比例较高，可以达到８２％，理论上可达１００％。选择合适的亲本，掌握无核葡萄胚珠败育时期，培养基激素的选择，以及如何促进胚的萌发，是正确利用这项技术的关键。     

不同酿酒葡萄品种C6 醛、醇风味化合物的比较

采用顶空固相微萃取技术(HS-SPME),利用气相色谱- 质谱联用技术(GC-MS)对酿酒葡萄浆果中C6 醛、醇类化合物进行定性、定量分析,比较昌黎葡萄酒产区赤霞珠、品丽珠以及梅鹿辄3 种酿酒葡萄在成熟期六碳醇、醛类风味化合物的变化。结果表明：3 种酿酒葡萄浆果中主要的C6 化合物为己醛、己醇、2- 己烯醛、反-2- 己烯醇、顺-3- 己烯-1- 醇等;建立了定量分析葡萄C6 风味化合物的方法,该方法线性关系良好(R2 ＞ 0.99),检测限小于5μg/L,回收率85%～110%,相对标准偏差(RSD)3%～9%,该方法简易、快速、准确,可用于葡萄样品的测定;不同葡萄品种各C6 醛、醇类化合物含量差异极显著：赤霞珠中含有较多的己醇、反-2- 己烯醇、顺-3- 己烯-1- 醇,显著高于其他品种,品丽珠中己醇、顺-3- 己烯-1- 醇含量最低,而C6 醛类化合物含量则以梅鹿辄含量最高,其次为赤霞珠,品丽珠醛类含量最低;C6 醛类化合物对葡萄香气贡献大,而C6 醇类化合物对葡萄香气贡献小。     

氧化亚氮(N_2O)熏蒸对木纳格葡萄贮藏品质的影响

木纳格葡萄品质优良,但采后果实易出现失重软化、落粒以及果梗褐变等问题。为了探究小分子气体氧化亚氮(Nitrous oxide,N_2O)熏蒸对鲜食葡萄采后贮藏品质的影响。以新疆特色鲜食葡萄木纳格葡萄(Vitis vinifera L.cv.Munage)为试材,采用20、50和100μL/L的N_2O对木纳格葡萄进行间歇熏蒸处理(每7 d),在(0±0.5)℃的条件下贮藏70 d。测定了贮藏过程中木纳格葡萄的腐烂率、落粒率、失重率、硬度、可滴定酸、可溶性固形物、电导率、抗坏血酸过氧化物酶(Aseorbate peroxidase,APX)以及过氧化物酶(Peroxidase,POD)的变化。结果表明:50μL/L的N_2O熏蒸能保持可溶性固形物、可滴定酸的含量;有效抑制果实腐烂率、落粒率及相对电导率的上升,降低过氧化物酶和抗坏血酸过氧化物酶的活性,保持了较好的果实硬度,说明N_2O熏蒸能够延缓木纳格葡萄果实采后的衰老进程,较好的维持木纳格葡萄的采后品质。     

基于电子鼻和GC-MS评价不同品种葡萄采后品质和挥发性物质的变化

为明确不同品种葡萄果实采后品质和挥发性物质的差异,本文通过顶空固相微萃取及气相-质谱联用技术(HS-SPME-GC-MS)测定4个不同品种葡萄新鲜果实挥发性物质成分和相对含量,并以电子鼻辅助验证,对其品质特性进行分析与探讨。结果表明:4个品种葡萄成熟果实的品质指标品种间差异较大。无核寒香蜜品种果实的可溶性固形物含量和可滴定酸含量较高,香悦维生素C含量高,硬度大。4个品种葡萄成熟果实中共检测到87种挥发性物质,主要成分为醇类、酯类和醛类。不同品种间主要挥发性物质存在差异。香悦、玫瑰香、金手指和无核寒香蜜葡萄品种果实中挥发性物质相对含量最高的物质分别为乙酸乙酯、沉香醇、青叶醛和乙酸乙酯,呈现出的风味分别为草莓香味、浓郁玫瑰香味、新鲜绿叶香味和草莓香味。利用电子鼻对不同品种葡萄果实挥发性物质进行主成分分析和线性判别分析,可以将4个品种葡萄完全区分开。因此,本试验明确了不同品种葡萄果实采后品质的差异,电子鼻结合GC-MS方法可以有效评价其挥发性物质差异。     

保鲜剂不同组合对袋内SO2积累及葡萄保鲜质量的影响

采用不同剂型及包装形式、不同扎眼工艺、放置高分子吸水纸垫及其组合,形成6 种保鲜处理方式,在－1～0 ℃条件下对无核白葡萄进行贮藏,研究贮藏期间不同保鲜剂组合对袋内SO2积累量及无核白葡萄保鲜品质的影响,比较不同剂型保鲜剂及其组合对果肉SO2残留量、果柄耐拉力、果实汁液pH值、可溶性固形物含量以及果实腐烂率、漂白率、落粒率的影响。结果表明：3.5 kg包装的无核白葡萄,放入CT2号保鲜剂5 小包＋免扎眼保鲜剂1 小包效果最好,在贮藏50 d后,果柄耐拉力为2.44 N,果实汁液pH值为3.43,可溶性固形物含量为17.16%,在贮藏105 d后,果肉SO2残留量为10.21 mg/kg,残留量明显低于其他处理,且腐烂率、漂白率、落粒率均较低。     

温度和相对湿度对采后葡萄浆果硬度的影响

本文研究温度和相对湿度对采后葡萄浆果硬度的影响,并建立了相应的预测模型。以酶反应动力学为基础了建立葡萄浆果硬度变化的基础模型,并进一步引入温度、相对湿度和水蒸汽压差对硬度的影响,对基础模型进行了修正,结果表明模型的预测值和实验测量值间吻合良好(R2=0.93601,E=4.72%)。     

1-MCP对葡萄货架期间品质及挥发性物质的影响

为提高葡萄的保鲜效果,以4 个葡萄品种为试材,通过测定其落粒率、VC含量和可溶固形物含量等指标,并采用气相色谱-质谱联用技术测定其挥发性物质,研究1-甲基环丙烯（1-methylcyclopne,1-MCP）对葡萄货架品质特性及主要挥发性物质的影响。结果表明：1-MCP处理可以显著抑制4 个品种葡萄果实落粒率和腐烂率的下降,保持果实的新鲜度。与对照相比,1-MCP处理可以减缓可溶性固形物含量的波动,同时可以保持可滴定酸含量的稳定性,有效抑制4 个品种葡萄果实硬度的下降,在贮藏前期可以有效抑制VC含量的下降,但后期作用效果不明显。4 个品种葡萄成熟果实中的挥发性物质主要成分为醇类、醛类和酯类。货架期间,与对照组相比,处理组主要挥发性物质波动小,整体风味优于对照组。     

4 个葡萄品种葡萄籽冷榨油的性质与体外抗氧化活性

目的：评价4 种葡萄籽冷榨油脂肪酸组成、总酚含量及体外抗氧化活性。方法：收集单品种葡萄籽榨油,气相色谱法测定脂肪酸组成,Folin-酚法测定总酚含量,用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picryhydrazyl,DPPH）法、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、Fenton反应和总抗氧化能力法分析其体外抗氧化能力。结果：4 个品种葡萄籽冷榨油均富含亚油酸（72.77%～77.36%）,不饱和脂肪酸含量为88.12%～91.06%;总酚含量为60.77～100.53 μg GAE/g,爱格丽葡萄籽冷榨油总酚含量最高,其次是北冰红、媚丽、赤霞珠葡萄籽冷榨油;4 个品种的葡萄籽冷榨油都有良好的清除DPPH自由基和ABTS＋·的能力,且随着葡萄籽冷榨油浓度的增大,清除能力增强,清除DPPH自由基的IC50变化范围为10.19～13.82 mg/mL,清除ABTS＋·的IC50变化范围为11.62～19.25 mg/mL;清除羟自由基（·OH）的能力范围为13.18～27.08 U/mL;总抗氧化能力范围为1.08～3.68 U/mL。4 个品种的葡萄籽冷榨油的体外抗氧化能力强弱顺序为爱格丽＞北冰红＞媚丽＞赤霞珠。     

外源脱落酸处理对葡萄果实及葡萄酒中抗氧化成分的影响

以天津蓟州区栽培的"美乐"和"赤霞珠"葡萄为试验品种,分别在其始熟期的初、中和末期3个阶段利用外源脱落酸(200 mg/L)处理果实,采用分光光度法测定葡萄和葡萄酒中酚类总含量和抗氧化活性,利用液质联用技术分析花色苷的含量和组成.研究结果表明:始熟期的外源脱落酸处理对成熟果实的质量、可溶性固形物、可滴定酸和pH值,以及葡萄籽的酚类含量和抗氧化活性没有显著影响,但对葡萄皮和葡萄酒的酚类物质含量和活性具有显著影响.在始熟期中期(30％ ～50％果实转色)以前,对果实喷施外源脱落酸可以显著提高葡萄皮和葡萄酒的酚类总含量、花色苷总含量和抗氧化活性.始熟期外源脱落酸处理使"美乐"和"赤霞珠"果实的酚类总含量分别提高了14％ ～39％和73％ ～172％,花色苷总含量和抗氧化活性分别提高了18％ ～143％和88％ ～178％;外源脱落酸处理使葡萄酒的3个指标(酚类总含量、花色苷总含量和抗氧化活性)分别提高了17％ ～69％、18％ ～36％和21％ ～46％,而这些影响可以有效改善葡萄酒的感官品质和营养价值.外源脱落酸处理时期的精准控制可以提高酿酒葡萄及葡萄酒中酚类物质含量及抗氧化作用,进而提高葡萄酒品质和营养价值.     

1-MCP采前处理对葡萄采后相关酶活性与品质的影响

以不同剂量（1、2、3 μL/L）1-甲基环丙烯（1-methylcyclopropene,1-MCP）处理无核寒香蜜葡萄,研究1-MCP采前处理对冷藏期间葡萄贮藏品质和生理指标的影响。结果表明：与对照相比,3 个1-MCP剂量采前处理均在不同程度上抑制了葡萄质量损失率、落粒率和腐烂率的上升,保持较好的可溶性固形物和可滴定酸含量,降低了果实的呼吸强度和乙烯生成速率,抑制了丙二醛含量和脂氧合酶活性的增加,贮藏后期维持较高的过氧化物酶、过氧化氢酶活性和较低的多酚氧化酶活性。3 个1-MCP剂量处理中,采前1 μL/L 1-MCP处理葡萄保鲜效果最好,能够显著延缓葡萄的衰老进程,保持较高的贮藏品质。     

2,4-表油菜素内酯对葡萄果实采后灰霉病的抑制作用机理

为研究2,4-表油菜素内酯（2,4-epibrassionolide,EBR）处理对‘巨峰’葡萄果实采后灰霉病的抑制效果及作用机制,将葡萄果实经5 μmol/L EBR溶液处理12 h后刺伤接种灰葡萄孢（Botrytis cinerea）病原菌,然后置于25 ℃下贮藏60 h。结果显示：EBR处理有效抑制了葡萄采后灰霉病的发生和病斑直径的扩展,与单一接种病原菌和EBR处理相比,先用EBR处理后接种B. cinerea葡萄果实展现出更强、更快的抗病反应,表现为几丁质酶、β-1,3-葡聚糖酶和苯丙氨酸解氨酶等抗病相关酶活力及总酚含量显著提高（P＜0.05）,H2O2积累及超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶活力提高,同时VvCHI、VvGNS和VvPAL-like抗病基因表达显著增加（P＜0.05）;体外实验发现,EBR处理可显著抑制B. cinerea孢子的萌发,但对芽管伸长长度没有显著影响。结论：EBR处理主要是通过敏化反应机制诱导提高葡萄果实的抗病性,从而减轻灰霉病的发生。