不同品种猕猴桃制汁适应性评价

为了研究不同品种猕猴桃果实制汁的品质特性,选取了全国5个地区,3个种系,12个品种猕猴桃,对其理化品质、营养成分、加工性能等22项指标进行测定,对测定结果进行描述性评价和相关性分析,运用主成分分析对不同品种猕猴桃汁进行综合评价,建立了猕猴桃制汁品质评价模型,得出12个品种综合评分值排列顺序,筛选出适宜加工制汁的品种;并用电子鼻对猕猴桃汁香气进行测定和分析,得出不同品种果实香气成分之间的差异。结果表明:软枣猕猴桃中绿迷、益玉,中华猕猴桃中脐红、华优制汁品质较好,经主成分综合得分模型计算,综合得分 F均大于0,适合做为果汁类产品的加工原料。东红、海沃德不适宜作为制汁品种,F均小于-1。12种猕猴桃果汁主要的挥发性物质为甲基类、无机硫化物、氮氧化物和芳香醇类,响应值G/G0分别为20.43、19.90、17.95、8.06。研究结果为猕猴桃果汁等加工企业选择适宜的制汁品种提供了科学依据。     

杂柑类品种制汁加工适应性研究

选取了湖南省八个具有代表性的杂柑品种．对果实的解剖性状、营养成分及制汁加工适应性进行研究。通过对出汁率、口感、色泽、风味进行比较和综合分析．象山红和金瓜适宜做加工制汁专用型品种。     

不同胡萝卜品种制汁加工特性的灰色关联度分析评价

以目前市场上销售的主要胡萝卜品种为实验材料,应用灰色关联度分析法,对与胡萝卜加工制汁有关的品种特性--总胡萝卜素含量、可溶性固形物含量、出汁率、亩产量四个主要性状指标进行综合评价。结果表明,品系H4与参考品种关联度最大,综合性状最好,具有较好的市场开发前景;在市场上销售的商业品种中,适宜加工制汁的胡萝卜品种排序依次为橘红一号、超级五寸、改良黑田五寸、橘红二号、红心大根和Chanteney,橘红一号具有较好的加工特性,最适宜用作制汁品种。     

基于灰色关联度和层次分析法的油桃果汁品质评价

为了研究不同品种油桃的制汁特性,对北京平谷地区10个品种油桃果汁的理化与营养指标(p H、总糖、总酚、抗坏血酸、可溶性固形物、可滴定酸、糖酸比、蛋白质)和加工指标(果汁色泽、粘度、褐变度、出汁率)进行测定。首先利用相关性分析、主成分分析和聚类分析法筛选核心指标,然后运用层次分析法确定指标的权重,最后采用灰色关联度分析法建立油桃品种制汁适宜性综合评价模型。结果表明:糖酸比、出汁率、L*值、黏度和总酚是油桃果汁品质评价的核心指标。通过灰色关联度分析,综合制汁品质较好的品种有瑞光51号、瑞光29号、瑞光18号等,而意大利5号的制汁品质最差,此结果可为油桃的育种和生产加工提供科学的依据。     

不同品种橄榄汁理化性质与制汁特性的研究

通过对我国橄榄主产区福建主栽的5个橄榄品种的果汁理化性质进行测定、分析,结果表明:惠圆橄榄出汁率最高,果汁褐变度轻、色泽鲜亮、感官品质良好,适合作为澄清型果汁的加工原料;长营橄榄的果汁糖酸含量最高,色泽鲜艳,适合加工成浑浊型果汁,但是其果汁褐变速率最快,耐贮性较差,因此加工过程应注意护色;檀香橄榄汁的可溶性糖含量最高、褐变程度轻、出汁率较高,且酚糖比最低、果汁风味好,是制汁与鲜食兼用的良好品种。因此,所研究的5个品种中,惠圆、长营及檀香橄榄具有较好的制汁特性,而自来圆和诏安橄榄两个品种各项制汁指标均没有显著的优势。试验结果为果农和橄榄汁生产者选择适宜的橄榄品种提供了科学参考。     

不同柑橘品种全果制汁适宜性分析

为了研究不同品种柑橘全果制汁的品质特性,对全国7 个地区30 个不同品种柑橘（包括蜜橘、椪柑、冰糖橙、脐橙等）的理化、营养、加工等18 项指标进行测定,并采用主成分分析法筛选出适宜全果制汁的品种。结果表明：不同品种的柑橘全果中籽数和总黄酮、柠檬苦素、诺米林含量差异较大,而出汁率、色度等指标差异较小。经主成分分析提取出6 个特征值大于1的因子,前6 个主成分分别对应柑橘全果苦味因子、加工因子、颜色因子、营养因子、酸度因子和甜度因子,其累积方差贡献率为82.566%。从6 个因子综合考虑,发现‘纽荷尔脐橙-II’、‘福本脐橙-I’、‘福本脐橙-II’、‘冰糖甜橙’、‘道州脐橙’、‘崀丰7904脐橙’为较适宜全果制汁的品种。本研究结果为选择适用于全果制汁的柑橘品种提供了参考依据。     

不同品种枇杷制汁适宜性分析

为探究不同品种枇杷加工制汁的适宜性,以9个枇杷品种为原料进行制汁,对其营养品质、功能成分、有机酸及酚类单体进行测定,并运用主成分分析法、聚类分析法对不同品种枇杷果汁进行综合分析。结果表明：不同品种枇杷果汁品质存在显著差异,通过主成分分析在16项指标中确定3个主成分,累计方差贡献率达到87.054%。根据主成分综合评价函数,排名前三的分别为‘长崎早生’、‘ADVANCE’、‘长生早生’,排名靠后的为‘大五星’、‘西农枇杷二号’。聚类分析将枇杷果汁分为3类,与主成分分析结果基本一致。     

橄榄制汁技术的研究

本文介绍了橄榄不同品种的加工特性和不同采收期檀香橄榄果实各营养成分的变化;果胶酶处理可提高制汁得率25～30％,且提高过滤速度;以及橄榄汁饮料的加工方法。     

多维复合蔬菜汁的生产

多维复合蔬菜汁是利用不同种类的蔬菜原料取汁,并以一定的配合比例进行混合,进而制成的一种蔬菜汁产品。该类产品根据人体营养素的需要和嗜好调配而成。 一、对多维复合蔬菜汁制汁品种原料的要求 (一)原料的成熟期和耐贮运性 多维复合蔬菜汁加工要求选择成熟期相对集中,一般相差在30d以内,便于加工的蔬菜品种,因为长期贮     

不同品种莲藕加工制汁适宜性评价

为探究不同品种莲藕加工制汁的适宜性,选用了10个具有代表性的莲藕品种为实验材料,测定了莲藕原料的理化指标和基本营养成分,并对制得的莲藕鲜榨汁的加工品质、营养价值及物理性质进行分析,结合主成分分析和聚类分析方法对莲藕鲜榨汁品质进行综合评价。结果表明:10种莲藕原料及其鲜榨汁的各项品质指标均存在显著性差异(P＜0.05),通过主成分分析将莲藕鲜榨汁9个品质指标降维为3个因子,累计贡献率达88.279%。聚类分析将10种莲藕划分为4类,第Ⅰ类为鄂莲5号、鄂莲6号和鄂莲11号;第Ⅱ类为庐江花香藕、浠水巴河莲藕、鄂莲9号、杭州白莲藕和新35;第Ⅲ类为武植二号;第Ⅳ类为沔城藕。进一步对莲藕鲜榨汁品质指标与莲藕原料品质指标的相关性分析发现,藕肉亮度小、淀粉含量低和出汁率高的品种更适合加工制汁。因此,杭州白莲藕、浠水巴河莲藕、鄂莲9号和庐江花香藕更适合作为制汁专用品种。     

Effect of freezing grape berries and heating must samples on extraction of components and composition parameters of red wine grape varieties

Juices from grape samples subjected to two storage methods (fresh and frozen) and two post-homogenisation treatments (21^oC and 71^oC) were examined for extraction of grape berry components and compared to a microvinified wine made from the same lot of fresh grapes. Cabernet Franc ( Vitis vinifera ) and Cynthiana ( Vitis aestivalis ) grapes were evaluated in 2003. Cabernet Franc, Cabernet Sauvignon ( Vitis vinifera ), Chambourcin (interspecific hybrid) and Cynthiana grapes were evaluated in 2004. Fresh grapes from each variety were sampled, analysed and prepared for microvinification. Frozen grapes of all varieties were thawed and analysed at the same time. For all varieties in both years, heating the must of fresh or frozen grapes increased the titratable acidity (11–58%), tartaric acid levels (12–110%), potassium content (15–62%), darkness (31–97%), red colour (54–1517%) and total red pigment values (36–1171%) of juice as compared to the juice from unheated must. For all varieties in 2004, heating the must from fresh or frozen grapes increased total phenolics (43–619%) of juice as compared to the juice from unheated must. Compared to fresh grape processing, freezing the grapes and then processing at 21^oC or 71^oC had varying results (increases and decreases) regarding the extraction of components in all varieties and both years but usually provided juice with composition most similar to that of the red wine produced by microvinification. Although the degree of extraction of individual components in the juice is influenced by selection of grape storage and must processing procedures, consistency of handling and procedure provided consistent results with low variability.     

The effect of mechanical harvesting and long-distance transport on the concentration of haze-forming proteins in grape juice

The concentration and composition of soluble, haze-forming protein in juice of hand-harvested (HH) and mechanically harvested (MH) Pinot Noir and Sauvignon Blanc grapes was determined. The major soluble proteins in both varieties were pathogenesis-related (PR) proteins, specifically thaumatin-like proteins and chitinases. Comparison among HH berries, MH intact berries and the mixture of broken fruit and juice, the predominant form of MH fruit, indicated that little if any protein was produced as a result of stress caused by MH. Nevertheless, MH coupled with long-distance transport which caused a delay in pressing the mechanically damaged fruit, resulted in juice with a higher concentration of PR proteins compared to juice obtained from pressing HH fruit. Soluble PR proteins were detected in the berry skin of both varieties. Increases in protein content of juice from MH fruit are predominantly caused by extraction of protein from skins and solids of broken grapes during transport to the winery.     

Effect of processing treatments on the characteristics of juices and still ciders from Ontario‐grown apples

Recent interest in the commercial production of cider in Ontario, Canada revealed a lack of information on cider prepared from apples grown in North America. A study was conducted using locally grown culinary and dessert varieties of apples, since there is a lack of true cider varieties grown in Ontario. Four processing methods (treatments) were evaluated with respect to their effect on juice and cider characteristics; the chemical and microbiological characteristics of the juices and still ciders are reported. Sulphite addition to the juice at the time of juice extraction had no effect on the characteristics evaluated. Storage of fruits at 13 °C until they showed signs of shrivelling or senescence decreased juice yield and affected titratable acidity and pH levels of juices and ciders. Freezing fresh apples and thawing prior to processing produced juices that did not undergo keeving and had higher mould and yeast populations; methanol was present in juices and ciders from thawed apples. The significant effects of storage and freezing on apple juice characteristics should be taken into account when considering a delay in the processing of apples for cider production. © 2003 Society of Chemical Industry     

甜高粱的基础分析与榨汁试验

通过对甜高粱的基础分析,了解甜高粱秆糖分的垂直变化和径向变化以及甜高粱糖品的成分与甘蔗的差异;通过榨汁和水洗试验,比较了不同品种间的出汁率、采收时带叶与不带叶对出汁率的影响以及水洗次数与糖分被浸出的规律.     

COMBINED EFFECTS OF ENZYME DOSAGE AND REACTION TIME ON PAPAYA JUICE EXTRACTION WITH THE AID OF PECTIC ENZYMES – A PRELIMINARY REPORT

Pectic enzymes are widely used in the food industry for fruit juice extraction as well as in the clarification of cloudy juices. Our laboratory has been using pectic enzymes produced from a strain of Saccharomyces cerevisiae (ATCC 52712) in different applications including fruit juice extraction. The enzyme was produced in the laboratory by culturing the yeast in papaya juice supplemented with 1% pectin for 6 days. Known amounts of enzyme preparation (0–40 mg protein) were added to a measured weight of papaya mash for varying reaction periods (30–90 min) and the amount of free‐run juice obtained in each treatment compared with a control sample. Treatment of 200 g of papaya mash with different dosages of the pectic enzyme extract resulted in rapid increases in flow rate of free‐run juice. Mash treated with 32 mg of total protein extract with a 30‐min reaction time was the optimum for a maximum rate of juice flow (25 mL/min) when initial rates were measured. There was no significant difference (P > 0.05) between the red‐ and yellow‐fleshed varieties of the papaya used. When juice flow was monitored over 6 min, the treated samples gave a flow rate that was more than twice those of the untreated samples. This biotechnological approach could be adopted to enhance papaya‐juice production by local fruit juice processors when parameters for scale‐up processes are established.     

橙汁主要芳香成分的研究进展

我国柑橘资源丰富,品种优良繁多,柑橘果实营养和经济价值都很高,柑橘的加工产品之一的橙汁一直是全球最重要的果汁产品.柑橘果汁加工中芳香物质的损失是目前一个比较难以解决的问题,所以对橙汁芳香物质的研究对橙汁的加工具有重要意义.本文介绍了提取橙汁芳香物质的方法,主要包括同时蒸馏萃取法、静态顶空进样法、固态微萃取法和分子蒸馏法,以及分析鉴定芳香物质的方法,最后总结了国内外的研究进展,国外对于橙汁的芳香成分的研究比较多,而国内研究比较少,本文为橙汁芳香物质的研究提供了理论依据.     

DILUTION AND SOLIDS ADULTERATION OF APPLE JUICE

The adulteration of apple juice with pear juice and corn drived syrups has been practiced in many countries. The sorbitol/sucrose ratios and the sorbitol/total sugar ratios were determined for the juices of 14 apple varieties and 3 pear varieties. A multivariate normal test was applied to develop an equation for the detection of apple juice adulteration with sugar solutions or pear juice. Adulteration of apple juice with more than 10% sugar solution or pear juice were detectable with this method.     

草莓汁中糖酸组成分析及其在掺假鉴别中的应用

为了解草莓汁的糖酸组成特点并探索其在掺假鉴别中的应用,采用高效液相色谱法对10个品种草莓果汁中可溶性糖、有机酸组成与含量进行分析,结合化学计量学方法探索其在草莓汁掺假鉴别中的应用。结果表明,草莓汁中可溶性糖主要由蔗糖、葡萄糖和果糖组成,有机酸主要是柠檬酸和苹果酸。不同品种草莓果汁中各种可溶性糖和有机酸的含量存在较大差异,但葡萄糖与果糖的比值受品种影响较小,柠檬酸占检测到总有机酸含量的62.39%~82.73%。通过分析草莓原汁及其掺假样品中可溶性糖和有机酸组成,结合主成分分析和线性辨别分析等模式识别方法,可以实现对草莓果汁与掺加梨汁、苹果汁、杏汁和桃汁等掺假样品的区分,而且掺假量越大,区分效果越好。草莓果汁可溶性糖和有机酸组成特征结合化学计量学分析能够对掺假草莓果汁进行较好地区分,可用于草莓果汁掺假鉴定和质量控制。