不同抗氧化剂对NFC 梨汁品质的影响

研究非浓缩还原(not from concentrate,NFC)梨汁在添加还原性谷胱甘肽、偏重亚硫酸钾、D-异抗坏血酸3种不同抗氧化剂后品质的变化。采用紫外-可见分光光度计、色度仪、电子鼻、电子舌等设备探究3种不同抗氧化剂对NFC梨汁的褐变度、色度、风味及滋味的影响。结果表明,添加还原性谷胱甘肽的NFC梨汁颜色改善,色泽更加金黄,褐变度最低(P<0.05);添加偏重亚硫酸钾的NFC梨汁会使金属传感器W1C、W3C、W5C(均对芳香类物质灵敏)响应值显著提高(P<0.05)。     

新梨7号梨汁加工过程中品质的变化

为探究新梨7号梨汁加工过程中灭酶、酶解、离心、灭菌过程对梨汁品质的影响,测定各加工过程后可溶性固形物、pH值、可溶性糖、还原糖、多酚、黄酮、还原能力和DPPH自由基清除率及指标间相关性.结果表明:加工过程中可溶性糖和多酚先升高后下降,还原糖、黄酮、还原能力和DPPH自由基清除率呈下降趋势.灭酶对可溶性固形物影响显著,酶...     

梨优良品种制汁性能研究

目的：研究了14 个主栽梨品种的制汁性能,为选择制汁品种和制汁工艺提供依据。方法：从理化指标(总糖、还原性糖、可滴定酸、可溶性固形物、出汁率)、褐变程度(总酚含量、多酚氧化酶活性、OD420nm 值、L 值)和感官鉴评(外观、滋味、气味)3 个方面进行评价。结果：发现果实可溶性固形物变化范围为10.94%～ 13.00%,可滴定酸含量变化范围为0.062%～0.76%。总酚含量和多酚氧化酶活性在果实中分布不均衡,果皮中的总酚含量最高,与果汁的OD420nm 值显著正相关,与L 值极显著负相关。果皮中多酚氧化酶的活性也很高,与果汁的OD420nm 值有显著的正相关性。结论：综合评价,所选14 个梨品种中锦香、黄金、安梨为较好的制汁梨品种。     

不同品种和成熟度苹果汁品质及贮藏稳定性研究

以秦冠、华冠、新红星、乔纳金、富士、澳洲青苹六种苹果作为研究对象,分别在生理成熟和完全成熟时进行采摘。对其苹果汁的p H、酸度、总酚、黄烷醇、原花青素、可溶性固形物含量、苹果汁酶促褐变和非酶促褐变进行测定,结果得到:秦冠苹果汁酶促褐变率最低,华冠、乔纳金非酶促褐变率最低,澳洲青苹最高。相比生理成熟的苹果,完全成熟的苹果更适合用于制作果汁。     

GC-MS结合PCA探究不同加工方式对香梨汁风味品质影响

为探究不同加工方式对库尔勒香梨汁加工中其挥发性物质和感官品质的影响,采用静态顶空-气相色谱-质谱联用(HS-GC-MS)技术对不同加工方式下制备的香梨汁中的挥发性成分进行分离鉴定,并结合主成分分析技术对其挥发性成分与感官属性进行相关性分析。研究发现:果胶酶酶解和巴氏杀菌对香梨汁挥发性物质组成影响极为显著(p0.05),其中酯类物质丧失或显著降低,而醇类、烃类和杂环类物质则明显增多。果胶酶酶解和巴氏杀菌处理使香梨汁感官品质降低,巴氏杀菌使香梨汁异味和蒸煮味异常明显.结合主成分分析(PCA)分析得出,乙酸乙酯、己酸乙酯、丙酸乙酯、丁酸乙酯、己醇和壬醛与香梨汁的梨果香感官属性有很好的正相关性,乙酸己酯与香梨汁的花青香感官属性有很好的正相关性。     

加工条件对富硒绿叶蔬菜汁品质稳定性的影响

探讨了 3种富硒绿叶蔬菜在制汁过程中 2个主要品质指标 (叶绿素含量和硒含量 )的变化规律 .着重研究了蔬菜汁漂烫、护色后杀菌等加工条件对叶绿素含量、总硒含量和有机硒比例的影响 ,讨论了产前农艺富锌与产后浸泡富锌对青菜叶绿素含量的影响以及复合菜汁的叶绿素保存及贮藏期分层问题 .     

Calcium Supplementation and Processing Variable Effects on Orange Juice Quality

Untreated, pectinesterase treated, low pulp, and pectinase treated orange juices were fortified to 20% RDA of calcium with calcium carbonate or calcium phosphate/lactate (75/25). Neither calcium supplement adversely affected flavor, cloud density, settling pulp, or viscosity in untreated, low pulp, or pectinase treated juices. PME exposed orange juice held 4 hr before pasteurization and calcium supplementation had less cloudy density, increased viscosity and more settling pulp. Calcium carbonate fortified PME exposed and pectinase treated juices had lower flavor scores, while calcium phosphate suspensions caused slightly lower color scores of all juices.     

Effects of Maturity, Skin Contact and Carbonation on the Quality of Sterile-Filtered White Muscadine Grape Juice

The effects of grape maturity, skin contact and carbonation on the quality of sterile-filtered muscadine grape juice were investigated. A sensory panel preferred the late maturity juices that had a higher degree of muscadine character and lower total phenolics. Tartaric and malic acid levels decreased with increasing maturity, with malic decreasing to a greater extent. A 24 hr skin contact. at 2°C had no significant effect on sensory results, but increased color intensity, phenolic and organic acid levels as compared to immediate pressing. Carbonated juices were lighter in color and were preferred equally to non-carbonated juices. Juice obtained from a hard pressing regime had slightly higher levels of organic acids than free run juice at the early harvest only.     

Effects of Fruit Storage and Processing on Clarity, Proteins, and Stability of Granny Smith Apple Juice

Granny Smith apples were processed into juices and concentrates from fruits which had been stored at 1°C for three months (short-term, ST) and nine months (long-term, LT). Total soluble proteins decreased with storage time of fruits. Juices processed from ST fruits were more resistant to haze formation (heat stability test) than those processed from LT fruits. For juices processed from ST apples, haze formation was related to proteins in the MW range of 21,000 to 31,000 daltons. For juices processed from LT apples, haze formation was not only related to proteins but also to other components in the juices. Fining was recommended to prevent haze and sediment formation.     

野生软枣猕猴桃与苦瓜复合果蔬汁的工艺研究

以野生软枣猕猴桃、苦瓜为主要原料,通过单因素试验、正交试验及感官评价等探究了野生软枣猕猴桃与苦瓜复合果汁的最佳工艺及配方。结果表明,野生软枣猕猴桃汁和苦瓜汁的体积比为7∶3,白沙糖添加量为8%,CMC-Na添加量为0.4%。制得的产品稳定性好、味酸甜可口、色泽淡绿,无杂质,均匀一致,久置无分层和沉淀,具有猕猴桃与苦瓜复合风味。     

不同加工工艺对黑莓浆果出汁率及果汁品质的影响

三种取汁方法的实验结果表明,制取黑莓果汁采用酶法液化法,出汁率、果汁澄清度、可溶性固形物含量高;直接榨汁法出汁率和可溶性固形物含量较高,但果汁浑浊;浸提取汁法出汁率低,果汁稀薄,可溶性固形物含量低,但色素获得率高.酶解正交试验结果表明,果胶酶用量0.04%～0.06%,处理时间1～2h,处理温度45～55℃,黑莓浆果出汁率高,果汁得率在80%以上,果汁澄清,质量好,果汁透光率在90%左右.     

芝麻蛋白饮料稳定性研究

以芝麻蛋白饮料的沉淀率为评价指标,通过单因素试验和正交试验对影响芝麻蛋白饮料稳定性的因素进行研究,优化筛选出最佳的乳化剂和稳定剂的组合和用量.结果表明:采用0.015％的单脂肪酸甘油酯(HLB3.5)、0.085％的蔗糖脂肪酸酯(LHB11)、0.005％的黄原胶和0.15％的羧甲基纤维素钠复合而成的稳定剂可有效提高芝...     

银杏汁的加工工艺及品质测定

银杏的果仁含淀粉62.4%、粗蛋白11.3%、粗脂肪2.6%、蔗糖5.2%,还含有钙、钾、磷、硒等矿物质、微量元素和多种维生素等生物活性物质。天然银杏汁既有利于人体对银杏营养成分的吸收,又降解了银杏的有毒成分银杏酸、银杏酚等物质,具有安全性。银杏汁在制作工艺、风味及稳定性等方面存在问题。通过对天然银杏汁在生产中的均质压力、稳定剂的选择、风味的调配等进行了对比实验,得出最佳配比和工艺参数。银杏汁的配比为银杏每瓶6.00 g,含糖量为3.05 g/100 mL,含酸量为0.5 g/L,0.15%海藻酸钠,0.1%CMC-Na(羧甲基纤维素钠),均质压力为40 MPa,品质最好。     

血脂干预型复合苹果汁果实品种筛选与果汁品质评价

为制备血脂干预型复合苹果汁,以具有降血脂功效的多酚单体为依据,通过主成分分析法及聚类分析法评价20个苹果品种的10种多酚单体及果汁的理化特性,筛选出多酚单体含量高及果汁品质评价好的2个苹果品种。结果表明:1)20个苹果品种中多酚单体的含量存在较大差异,其中阿克苏和秦冠含有的绿原酸含量居前2位,儿茶素、表儿茶素和根皮苷含量也居前列;2)以具有血脂干预功效的多酚单体成分绿原酸、表儿茶素、儿茶素和根皮苷为主要成分,对10种多酚单体进行主成分及聚类分析,结合果汁品质评价,确定阿克苏和秦冠是血脂干预型且果汁品质较好的2个苹果品种。     

为士果胶酶加工砀山酥梨浓缩清汁的应用

酶制剂在加工果蔬浓缩清汁方面起着重要的作用,酶制剂的功能影响着果蔬汁质量的好坏,现对为士果胶酶在线生产砀山酥梨清汁的研究,说明该种酶制剂结合其他工艺条件表现出来的功能,结果表明,可以提高产品色值稳定性,提高生产过程超滤通量,降低产品浊度。     

成熟度、品种及其互作对烤烟多酚类物质的影响

为探讨成熟度、品种及其互作对烤烟多酚类物质的影响,采用两因素随机区组试验设计,选择烤烟品种K326、豫烟11、云烟87,分别在其未熟、成熟和过熟时采收,研究其对烟叶中的多酚类物质总量、绿原酸、芸香苷和莨菪亭含量的影响。结果显示,不同成熟度、品种及组合间多酚类物质含量均有显著性差异。多酚含量主要受成熟度的影响,其次受品种影响。成熟度、品种及其互作对总酚、绿原酸、芸香苷、莨菪亭含量变异的贡献率各不同,其中成熟度对总酚、绿原酸、芸香苷、莨菪亭含量的贡献率分别为52.93%、55.83%、48.38%、73.58%,总体以成熟采收时含量最高;品种贡献率分别为32.31%、31.57%、32.97%,16.04%,以K326含量最高;成熟度与品种互作的贡献率分别为14.64%、12.32%、18.29%、9.43%。K326、豫烟11在成熟采收时总酚、绿原酸、芸香苷、莨菪亭含量较高;云烟87在过熟采收时总酚、绿原酸、芸香苷含量较高,在成熟采收时莨菪亭最高。采取与种植品种相适应的采收标准,是提高烟叶多酚类物质含量的重要调控手段。     

Pulsed Electric Field Processing of Orange Juice: A Review on Microbial,Enzymatic, Nutritional,and Sensory Quality and Stability

During the last decades pulsed electric field (PEF) processing received considerable attention due to its potential to enhance food products or create alternatives to conventional methods in food processing. It is generally acknowledged that PEF processing can deliver safe and chill‐stable fruit juices with fresh‐like sensory and nutritional properties. Relatively low‐processing temperature and short residence times can achieve highly effective inactivation of microorganisms while retaining product quality. A first commercial application of PEF for preservation of fruit juices was launched in 2006 in the United States. Since then, industrial‐scale processing equipment for liquid and solid products were developed and, in Europe in 2009, an industrial juice preservation line was installed using 20 kV/cm pulses at 40 to 50 °C to extend the chill‐stability of fruit juices, including citrus juices and smoothies, from 6 to 21 d. The related PEF processing costs are in the range of US $0.02 to 0.03 per liter and are justified due to access to new markets and reduced return of spoiled product. However, despite its commercial success there are still many unknown factors associated with PEF processing of fruit and citrus juices and many conflicting reports in the literature. This literature review, therefore, aims to provide a comprehensive overview of the current scientific knowledge of PEF effects on microbial, enzymatic, nutritional, and sensory quality and stability of orange juices.     

圆黄梨浊汁贮藏过程中品质变化的研究

通过测定圆黄梨浊汁贮藏期间的各种指标,对圆黄梨浊汁贮藏期间各项品质的变化进行了研究。结果表明:圆黄梨浊汁在室温、4℃及0℃三种不同温度贮藏过程中,pH值、还原糖、氨基态氮、可溶性蛋白随时间的延长均呈明显下降趋势;总色差和5-羟甲基糠醛含量上升的趋势。圆黄梨浊汁在4℃和室温比在0℃贮藏过程中各项指标的变化明显,说明0℃条件下圆黄梨浊汁的美拉德反应进行缓慢,是较适合圆黄梨浊汁贮藏的温度。     

制汁工艺对紫薯汁品质及香气成分的影响

为探究加工工艺对紫薯汁品质的影响,以渝紫7号为原料,采用生浆、熟浆、蒸料3 种工艺将紫薯加工成 紫薯汁。比较分析3 种制汁工艺对紫薯汁糖类质量分数、花色苷含量、总酚质量浓度、褐变指数、抗氧化活性、色 泽等品质指标的影响,并进行感官评价和香气成分分析。结果表明：生浆汁对1,1-二苯基-2-三硝基苯肼自由基的清 除率（72.26%）和羟自由基清除率（81.27%）显著高于熟浆汁和蒸料汁（P＜0.05）,但褐变最严重,色泽及香气 不佳;蒸料汁花色苷含量（0.78 mg/100 g）显著高于熟浆汁和生浆汁（P＜0.05）,但色泽偏暗,感官评分及香气 不如熟浆汁;熟浆汁抗氧化活性居中,但褐变指数（0.63）显著低于蒸料汁和生浆汁（P＜0.05）,色泽较好,综 合感官评分最高,呈现透亮的深紫色,口感柔和,香气品质最佳。共鉴定出40 种香气成分,其中熟浆汁中鉴定出 21 种,占总峰面积的82.38%,主要香气成分为酯类（28.19%）和醇类（20.14%）。综合考虑,熟浆汁品质最佳。     

苦瓜汁饮料的研银

探讨了苦瓜汁的配方、生产工艺.