果胶酶在果蔬汁生产中的应用

介绍了果胶酶的组成与结构，讨论了果胶酶在果蔬汁的出汁率、澄清、超滤等方面的应用。     

Portable, low-cost equipment for small-scale fruit juice processing

Simple, low-cost portable equipment to extract citrus juice, and pasteurize it and other fruit juices by passing through a coil of stainless steel tube in boiling water was designed, constructed and tested. Temperature reached was varied by altering the hydrostatic feed height, and the product was directly hot-bottled and capped. Pasteurization was microbiologically effective, and had little effect on ascorbic acid, furfural and colour of freshly prepared pineapple orange, Valencia orange and apple juices, and an orange squash drink, and only the expected changes occurred on storage at 21°C for periods up to 6 months, although with no indication of microbial activity. Taste panel ratings showed a loss of liking for treated orange juice, but not for apple. The equipment is suitable for improved utilization of crops by community technology in less-developed areas.     

酶法澄清西番莲果汁的工艺研究

通过单因素试验分析探讨了果胶酶的种类、添加量、pH、温度和时间对西番莲果汁澄清效果的影响；淀粉酶Amylase AG 300L添加量为0.02ml／kg可有效除去果汁中的淀粉物质。进行正交试验确定酶法澄清西番莲果汁的最佳工艺条件，结果表明，果胶酶PECTINEX@ BE XXL的添加量为0．14ml／kg、pH5．0、温度45℃、时间50min，可得到澄清透明，具有新鲜西番莲风味的果汁，澄清效果理想。     

桃形李果汁饮料的研制

对桃形李果汁的提取、澄清及其饮料的研制进行了探讨。实验结果表明：桃形李果汁浸提可以采用0．15％果胶酶和0．05％纤维素酶浸提；澄清剂采用壳聚糖，剂量为0．25g/L。桃形李果汁饮料主要质量指标为：原果汁含量50％，糖度11％，酸度为0．48％（以柠檬酸汁）。     

果胶酶处理和超滤相结合加工澄清型果汁

介绍了果胶酶处理和超滤相结合加工澄清型果汁的机理、工艺参数以及超滤膜的选择、清洗等问题，并举出该工艺在生产上应用的成功例子．     

果胶酶对芦荟凝胶汁澄清效果的研究

芦荟凝胶中因含有果胶物质,制得的原汁易产生浑浊、沉淀等现象,严重影响产品的稳定化,澄清是芦荟凝胶稳定化关键技术之一。利用果胶酶澄清芦荟凝胶汁有快速、简便、效果好等特点,在生产中有重要的应用价值。该文用果胶酶对芦荟原汁进行了单因素试验及最佳澄清工艺条件的研究。结果表明,果胶酶用量为60～80mg/L,温度为40～50℃,反应时间在1h左右,透光度可达到97%以上,芦荟凝胶汁中的多糖含量基本不变;在单因素试验的基础上,通过正交试验,得到果胶酶用量为60mg/L,反应温度为50℃,反应时间为45min的果胶酶对芦荟凝胶汁澄清的优化工艺条件。     

果胶酶澄清菠萝汁最佳工艺研究

用果胶酶对菠萝浆进行酶解及最佳澄清工艺条件试验。单因素试验研究了果胶酶用量、酶解温度和酶解时间分别对菠萝汁透光率、可溶性固形物、出汁率、果胶含量的影响。在此基础上,通过二次正交旋转回归试验,得出了酶解条件的回归方程,确定了果胶酶对菠萝汁澄清的最佳工艺条件为果胶酶用量为80mg/kg、温度25℃、时间为60min。     

果胶酶和纤维素酶对芒果出汁率及品质的影响

为提高芒果的出汁率,采用果胶酶和纤维素酶对芒果浆进行酶解,通过正交实验研究了果胶酶添加量、纤维素酶添加量、酶解温度、酶解时间4个因素对芒果出汁率的影响。结果表明:当果胶酶添加量为0.01%、纤维素酶添加量为0.007%、酶解时间为60min、酶解温度为40℃时,芒果的出汁率最高,达到71.15%;酶解得到的芒果汁可溶性固形物为16.7%±0.1%,可滴定酸为0.51%±0.08%,类胡萝卜素为(1.23±0.07)mg/100g,还原糖为7.6%±0.08%,果胶含量为(357±1.32)mg/100g,保留了鲜芒果的营养成分。     

果葡糖浆在果汁饮料中的应用研究

对使用蔗糖与果葡糖浆生产的果汁饮料的成分进行了分析，比较了两类产品的糖成分和感官差异。结果表明：使用蔗糖生产的果汁饮料与使用果葡糖浆生产的果汁饮料比较，果葡糖浆对产品色泽的影响与蔗糖没有明显区别；但在产品风味方面，后者甜味消失快，果香味与酸味变浓；在果汁生产过程中，采用果葡糖浆部分替代蔗糖的产品风味不受影响．     

苹果渣果醋发酵初探

本文介绍了以废弃苹果渣为原料，经过酒精发酵和醋酸发酵酿制果醋的生产工艺及产品的质量标准。     

乳酸链球菌素(Nisin)的特性及在果汁饮料中的应用

简述了天然食品防腐剂乳酸锭球菌素的特性,并研究了Ｎｉｓｉｎ对苹果汁、桔子汁和葡萄柚汁中酸土芽孢杆菌的抑制作用。结果表明,在巴氏灭菌前添加适量的Ｎｉｓｉｎ能有产地防止果汁饮料的酸败。     

果汁牛奶的流变性质测评

对自制果汁牛奶和市售类似产品进行了流变学研究。结果表明,与市售类似产品相比,自制产品的初始黏度及剪切稳定后的黏度均较高,具有明显的“假塑性”,黏度对温度的变化较敏感,感官特征良好。     

Purification of polygalacturonase from Aspergillus awamori Nakazawa MTCC 6652 and its application in apple juice clarification

Polygalacturonase (PG) is necessary during fruit juice clarification process for the degradation of insoluble viscous pectinacious compounds. In the present study, PG from Aspergillus awamori Nakazawa MTCC 6652 produced by solid-state fermentation of mosambi (Citrus sinensis var mosambi) peel was decolorized and purified 34.8 fold with 69.8% recovery exploiting activated charcoal. The SDS-PAGE profiling revealed molecular weight of the purified PG as 30 kDa. The optimum pH and temperature of the purified enzyme were 4.5 and 50 °C, respectively. After decolorization and purification it was applied in the apple juice clarification process. The clarified juice exhibited 38% viscosity reduction with % T₆₆₀ of 93%, A₄₂₀ of 0.3 and pH 3.     

果胶酶与高效淀粉酶液化澄清枸杞汁的效果对比研究

选用果胶酶和高效淀粉酶对枸杞汁进行澄清,在不同浓度、温度、pH和作用时间的条件下,比较了果胶酶和高效淀粉酶对枸杞汁澄清度及可溶性固形物含量的影响效果。结果表明:高效淀粉酶不具有良好的澄清效果,增加了枸杞汁的可溶性固形物含量;果胶酶的澄清效果优于高效淀粉酶,不增加枸杞汁的可溶性固形物含量,其最佳澄清工艺条件为:浓度0.004%,pH4.0,60℃,作用时间3h。     

桶装果浆快速冷却设备的设计

研究设计的果浆无菌大桶装冷却设备采用偏心轮、动轨和静轨组成摇摆与行进机构，喷淋水冷却与桶的摇摆、前进相结合，强化桶内果浆的换热，缩短了冷却时间，保证了果浆的自然色泽和纯正口味。     

Optimisation of electroplasmolysis application for increased juice yield in carrot juice production

Electroplasmolysis (EP) which is among electrical methods and helps to increase cell permeability was used in this study as a pretreatment on carrot juice production for improving yield. A voltage range of 20–60 V and an application time of 30–90 s were studied using the electroplasmolyzator. Response surface methodology (RSM) was used for determining the appropriate voltage gradient and time that are effective on breakage of vegetable tissues. After the conditions were optimised, carrot juice was produced and compared with untreated control juices on the aspect of yield and some quality characteristics. As a result, yield was increased 10.49% by EP application. Relative to control samples total pectin (14.78%) and total phenolic content (4.73%) have significant increase. In addition by the effect of electrical pretreatment there was an improvement in soluble solid, pulp content and acidity of juices. The results suggested that juice yield and functional properties were improved by EP application.     

利用果胶酶澄清西番莲果汁的工艺研究

通过单因素试验分析探讨了果胶酶的种类、添加量、pH、温度和时间对西番莲果汁澄清效果的影响,确定最佳的澄清工艺参数。     

Improving the storage stability of Bifidobacterium breve in low pH fruit juice

Bifidobacterial food applications are limited since bifidobacteria are sensitive to e.g. acidic conditions prevalent in many food matrices. The aim of the present study was to investigate whether a low pH selection step alone or combined to UV mutagenesis could improve the viability of an acid sensitive Bifidobacterium strain, B. breve 99, in low pH food matrices. Furthermore, the potential of carriers and an oat fibre preparation to further improve the stability was studied. The best performing low pH tolerant variants in the present study were generated by UV-mutagenesis with 70-700 μJ/cm² followed by incubation in growth medium at pH 4.5. The most promising variants regarding the low pH tolerance showed, in repeated tests with cells grown without pH control, about one Log-value better survival in pH 3.8 fruit juice after one week storage at 4 °C compared to wild-type B. breve 99. Cells grown with pH control, PDX formulated and then frozen showed poorer viability in low pH fruit juice than cells grown with no pH control. For frozen concentrates pH 3.8 was too stressful and no or small differences between the variants and the wild-type strain were seen. The differences detected at pH 3.8 with the cells grown without pH control were also seen with the frozen concentrates at pH 4.5. Some improvement in the stability could be achieved by using a combination of trehalose, vitamin C and PDX as a freezing carrier material, whereas a significant improvement in the stability was seen when oat fibre was added into the fruit juice together with the frozen cells. Due to the initial very poor fruit juice tolerance of B. breve 99 the obtained improvement in the stability was not enough for commercial applications. However, the same methods could be applied to initially better performing strains to further improve their stability in the fruit juice.     

茶(果)汁真空低温连续干燥与其它干燥工艺的应用比较研究

采用烘箱干燥、喷雾干燥、冷冻干燥和真空低温连续干燥工艺分别对浓缩的绿茶汁、绿橙汁进行干燥实验,并对各个样品的化学成分及品质进行分析。结果表明:四种干燥工艺对速溶绿茶粉、绿橙提取物中主要化学成分及品质的影响明显不同。以真空低温连续干燥方式进行干燥,能有效保持产品的感官品质和有效成分,适用性强。     

聚乙烯醇降解菌的选育及降解特性研究

从印染废水及污水处理厂污泥中分离得到7株聚乙烯醇(PVA)降解菌，经紫外线诱变，获得高活性变异菌株UV2．对UV2进行PVA降解试验，确定了其降解特性参数，并与出发菌株B自的降解性能相比较．研究表明，诱变菌株W2对模拟废水中PVA的降解速率及降解活性均明显高于出发菌株B白，且适应环境的能力更强．在最佳降解条件下，对PVA的降解率达93％以上，比出发菌株提高了30％．