壳聚糖澄清沙棘果汁工艺条件的研究

用壳聚糖对沙棘果汁进行澄清试验，研究了壳聚糖用量、pH、温度等工艺条件对果汁澄清效果的影响，并通过正交试验确定壳聚糖澄清沙棘果汁的最适工艺条件为：壳聚糖用量0．05％、温度45℃、pH3．5、反应时间1．5h，澄清后，果汁透光率达98．9％，果汁中的营养及活性成分损失较小。     

壳聚糖澄清猕猴桃果汁对果汁成分影响的研究

首先采用离子交换色谱分离壳聚糖k,得到三个壳聚糖组分(壳聚糖a、b、c)。再对未经离子交换色谱分离的壳聚糖k和经离子交换色谱分离所得的三个组分壳聚糖a、b、c澄清猕猴桃果汁前后猕猴桃果汁中化学成分变化和澄清后猕猴桃果汁的透光率、色泽的研究。可以得出,1:未经离子交换色谱分离的壳聚糖k和经离子交换色谱分离所得的三个组分壳聚糖a、b、c都可以有效的澄清猕猴桃压榨果汁,透光率达到94.6%以上;2:壳聚糖k和壳聚糖a、b、c对澄清后猕猴桃清汁的色泽有不同的影响,壳聚糖k澄清后的猕猴桃清汁色泽浅,壳聚糖c澄清后的猕猴桃清汁色泽较深;3:壳聚糖k和壳聚糖a、b、c澄清猕猴桃压榨果汁前后果汁中的可溶性固形物和VC含量相同,不影响猕猴桃果汁的营养价值;4:壳聚糖k和壳聚糖a、b、c澄清猕猴桃压榨果汁前后猕猴桃果汁中总糖、还原糖、蛋白质、总酚含量都有所变化,但是不同壳聚糖对果汁中成分的影响是不同的。     

三种澄清剂对枸杞酒澄清效果及其对枸杞多糖含量影响的研究

本文对皂土、壳聚糖、ZTC1 1澄清剂对枸杞酒澄清效果及其对枸杞多糖等各种成分含量的影响进行研究，结果表明皂土的澄清效果最好，透光率能达到95％以上，枸杞多糖的损失率在25．7％以下，蛋白质和总酚去除率可分别达到86．1％和44．6％。壳聚糖和ZTC1 1澄清剂的澄清速度快，壳聚糖澄清枸杞酒最大透光率为90．5％，多糖、蛋白质和总酚的最大去除率分别为15．1％、11．6％、8．8％。ZTC1 1澄清剂澄清后枸杞酒的最大透光率为91．45％，总多糖、蛋白、总酚的最大损失率分别为：30．3％、9．5％、16％。     

柚苷酶处理对琯溪蜜柚果汁澄清度和营养品质的影响

目的:以琯溪蜜柚果汁为对象,研究柚苷酶处理对柑橘果汁澄清度和营养品质的影响。方法:利用反向高效液相色谱法测定柚苷酶对琯溪蜜柚果汁中柚皮苷的水解作用,考察柚苷酶去除琯溪蜜柚果汁中柚皮苷的动态规律;通过检测柚苷酶处理前、后琯溪蜜柚果汁的澄清度、pH值、总酸、抗坏血酸、游离氨基酸、可溶性固形物、总糖及总酚含量,评价柚苷酶处理对琯溪蜜柚果汁品质的影响。结果:柚苷酶能有效去除琯溪蜜柚果汁中的柚皮苷,该动态过程符合经典米氏方程的双曲线特征,柚皮苷分解的Vmax为56.2 U/mL,Km为1.78 mmol/L,柚皮素生成符合酶促反应的1级反应特征;在柚苷酶处理过程中加热导致果汁总酸、总糖、可溶性固形物和抗坏血酸含量降低及游离氨基酸含量和pH值上升;柚苷酶作用也引起总糖、可溶性固形物、抗坏血酸含量降低,同时增加酸和酚类物质的释放,减少游离氨基酸的产生,并可显著提高果汁的澄清度;在柚皮苷去除率为98.5%的条件下,琯溪蜜柚果汁澄清度上升了44.9%,总酸、游离氨基酸含量无明显变化,而总糖、抗坏血酸、总酚含量分别下降10%,14.6%和12.2%,其损失量远远小于树脂吸附法和超滤法。结论:用柚苷酶处理柑橘果汁,能够高效去除柚皮苷的苦味且可提高果汁澄清度并较好保持果汁的营养品质,该过程可通过米氏方程进行有效控制。     

壳聚糖对桑椹汁澄清度及理化成分的影响

研究了壳聚糖对桑椹汁的澄清作用.试验结果表明,壳聚糖是一种有效的果汁澄清剂,在4℃条件下、壳聚糖用量为0.8g/L时对桑椹汁的澄清效果最好.壳聚糖在提高澄清度的同时,降低了桑椹汁中总酚、单宁和可溶性蛋白的含量,且不影响其他主要成分.     

五种果汁的酚类组成及其抗氧化、抗肿瘤细胞增殖活性研究

本文对比研究了五种果汁中维生素C与总酚含量,采用高效液相色谱法测定了果汁中的酚类组成,并采用化学法和细胞法评价了果汁的抗氧化和抗肿瘤细胞增殖活性.刺梨汁的维生素C含量最高,为14.13 g/L.刺梨汁和沙棘汁的总酚含量最高,分别为13.06和12.53 g GAE/L,且二者无显著性差异(P>0.05).从5种果汁中共...     

黑莓干红澄清处理技术研究

采用单因素和L9(34)正交试验研究壳聚糖用量、搅拌速度和作用时间对黑莓干红的澄清效果。以澄清度和色度为考核指标确定壳聚糖澄清处理条件。通过测定壳聚糖澄清处理前、后干红中主要成分含量的变化,研究壳聚糖对黑莓干红的澄清作用。研究结果表明:壳聚糖用量0.5 g/L、搅拌速度50 r/min、作用时间36 h为最佳处理条件。在此条件下做澄清处理,黑莓干红的澄清度提高了41.98%,色度降低30.63%;黑莓干红中蛋白质含量下降21.20%,总酚含量下降7.01%,总糖含量下降3.37%,说明壳聚糖具有较好的去除蛋白、酚类物质和糖类物质的能力,是1种有效的黑莓干红澄清剂。     

不同澄清方式对石榴果汁澄清效果的比较

研究以果汁透光率为指标,比较膨润土、果胶酶、壳聚糖三种澄清方式对石榴果汁澄清效果,结果表明,果胶酶澄清效果最好,壳聚糖次之,膨润土最差,果胶酶澄清后的果汁稳定性最好,壳聚糖和膨润土澄清后的果汁稳定性较差。通过比较三种澄清方式对石榴果汁中主要物质含量的影响发现,果胶酶对果汁中的蛋白质、果胶及酚类物质去除能力最高,壳聚糖次之,膨润土最差。通过比较三种澄清方式对果汁色差的影响发现,果胶酶处理后的果汁L值最大,壳聚糖次之,膨润土最小。通过正交试验优化石榴果汁澄清工艺,结果表明,当果胶酶用量为0.08%,酶解时间为1.5 h,酶解温度为50℃时,果汁澄清效果最好。     

沸石负载壳聚糖对高酸苹果发酵酒澄清工艺

以鲁加6 号苹果发酵酒为原料,根据Box-Behnkend 的中心组合试验设计原理,在单因素的基础上采用响应面分析法,建立沸石负载壳聚糖澄清苹果酒的二次多项数学模型,并以苹果酒澄清度为响应值和等高线建立响应面,研究沸石负载壳聚糖添加量、处理时间、处理温度对苹果酒澄清效果的影响。结果表明：沸石负载壳聚糖澄清苹果酒的最佳工艺条件为沸石- 壳聚糖澄清剂添加剂量11.6g/L、处理时间47.6min、处理温度27℃;与常规法澄清苹果酒相比,经过处理的苹果酒澄清度提高了16.8%,可溶性蛋白含量、总酚含量均有显著降低,而总酸、可溶性固形物含量、儿茶素、绿原酸、咖啡酸含量变化不明显,表儿茶素含量降低。     

壳聚糖在红枣汁澄清中的应用

在采用壳聚糖澄清红枣汁中，研究了壳聚糖用量、温度、pH对澄清效果的影响。结果表明：壳聚糖澄清枣汁透光率可达98％以上，清汁与原汁相比，VC含量、可溶性固形物含量稍有下降。总糖含量变化不明显，其澄清优化工艺条件是壳聚糖用量3％(1％壳聚糖醋酸溶液)、温度45℃、pH3．5。     

INFLUENCE OF CONVENTIONAL CLARIFICATION AND ULTRAFILTRATION ON THE PHENOLIC COMPOSITION OF GOLDEN DELICIOUS APPLE JUICE

Abstract The effects of conventional clarification and ultrafiltration techniques on the phenolic composition of apple juice was studied. Since the health benefit of fruits and fruit juices have been ascribed, in part, to the phenolic antioxidants, it is very important to know what the effects of processing steps are on the level of phenolic compounds in fruit juices. The total losses of phenolic compounds were determined to be 28% and 7% during conventional clarification using gelatin and bentonite, and ultrafiltration, respectively. A total of 14 phenolic compounds were identified in apple juice prepared from Golden Delicious apples. The phenolic compounds were found to be based mainly on hydroxycinnamic acids (∼ 50% of total phenolics) and chlorogenic acid was found to be the major phenolic compound with its concentration as high as 465.45 mg 1⁻¹ in raw apple juice.     

小麦谷朊蛋白对霞多丽葡萄汁澄清效果的研究

本实验以小麦谷朊蛋白为澄清剂,添加浓度分别为250、375、500、625mg/L,对霞多丽葡萄汁进行澄清效果研究。结果表明:小麦谷朊蛋白添加量为500mg/L时,沉淀物最多,葡萄汁澄清透亮。与对照相比,小麦谷朊蛋白处理的葡萄汁,其色价、总酸及总酚含量均降低,但蛋白质含量有所升高。通过与皂土、单宁-明胶澄清效果比较,认为小麦谷朊蛋白可以作为葡萄汁的澄清剂。     

Changes in total phenolic and flavonoid content and antioxidative activities during production of juice concentrate from Asian pears (Pyrus pyrifolia Nakai)

The total phenolic and flavonoid content and antioxidative activities during production of pear juice concentrate (PJC) from two cultivars, Hwasan and Niitaka, were investigated. The main processing steps in PJC production are washing, pressing, pasteurization, clarification, filtration, evaporation, and packaging. Total phenolic and flavonoid content of end-product PJC from Niitaka decreased by 53.11 and 46.47%, respectively, while those from Hwasan decreased by 55.46 and 36.09%, respectively, compared to the phenolic and flavonoid content of original fresh fruit. DPPH radical-scavenging activities, reducing power and nitrate radical-scavenging activities showed a similar tendency as total phenolic and flavonoid content; that is, they decreased in juice concentrate made from both cultivars. Also, antioxidant activities of press cake waste (skin and seeds) from Niitaka and Hwasan pears were higher than fresh pears. In conclusion, antioxidant levels were significantly affected during processing of PJC, especially during the pressing step in which press cake waste retains the seeds and skin.     

蒲公英汁的加工工艺

以干燥蒲公英叶子为原料,使用纤维素酶处理、壳聚糖澄清、微孔滤膜过滤等方法,围绕酶用量对蒲公英汁中绿原酸和总黄酮含量的影响,壳聚糖对蒲公英汁的澄清效果,澄清、过滤等对蒲公英汁品质影响等问题进行了研究。得出料液比1∶30和温度50℃条件下,随着纤维素酶用量的增加,蒲公英汁中绿原酸和总黄酮含量增加,当酶用量达1%后,蒲公英汁中绿原酸和总黄酮含量基本稳定;低分子量壳聚糖澄清效果优于高分子量壳聚糖,最佳的澄清工艺条件是低分子量壳聚糖加入量0.4g/L,温度50℃,时间40 min,此条件下得到的蒲公英汁澄清度96.4%,绿原酸含量为0.50 mg/mL,总黄酮含量为0.55 mg/mL,损失分别为26.47%和14.06%;0.45μm混合微孔滤膜过滤后蒲公英汁澄清度为98.1%,绿原酸含量为0.496 2 mg/L,损失率为27.03%,总黄酮含量为0.530 4 mg/L,损失率为17.13%,进一步提高了汁液澄清度,并基本保持了蒲公英主要功能性成分的含量。     

Study on the development of pomegranate juice processing technology: clarification of pomegranate juice

The effects of clarification agents and methods on pomegranate juice quality were studied. Fruits were pressed as whole, and extracted juice was clarified with gelatin, polyvinylypolypyrrolidone (PVPP) and natural sedimentation. In order to determine the effects of these clarifying techniques on product quality, pH, total phenolic substances (TPS), anthocyanin, turbidity, and total colour density tests were applied to each sample. In clarification, the main purpose was to reduce the amount of phenolic substances. Phenolic substances were controlled in each clarification method. The most effective method was the application of 1 g/L gelatine for clarification. Sensory evaluation also applied for clarified juices and gelatin application was selected by panelists to be superior.     

灭菌和贮藏温度对荔枝汁中多酚化合物组成、含量及其抗氧化活性的影响

以俊红荔枝汁为研究对象,探究不同的灭菌方式（70 ℃和121 ℃）和不同的贮藏温度（4 ℃和45 ℃）对荔枝汁中酚类物质释放的影响。主要测定其酚类物质含量、抗氧化活性和酚类物质组成的变化。结果表明,121 ℃高温灭菌荔枝汁中的酚类物质含量和抗氧化活性显著高于荔枝原汁和70 ℃巴氏杀菌荔枝汁（P<0.05）。贮藏时间为0 h时,高温灭菌荔枝汁的氧化自由基吸收能力（Oxygen Radical Absorbance Capacity,ORAC）与荔枝原汁和巴氏杀菌荔枝汁相比分别增加了40.24%和39.00%。且在高温灭菌荔枝汁中没食子酸含量显著增加 （P<0.05）,没食子儿茶素大量生成,其中没食子儿茶素的含量约占121 ℃热处理荔枝汁中酚类化合物的91.74%。4 ℃和45 ℃贮藏条件对于荔枝汁中酚类化合物含量的变化有显著影响,其中荔枝原汁和巴氏杀菌荔枝汁在45 ℃贮藏条件下,酚类物质含量显著增加（P<0.05）,而高温灭菌荔枝汁中酚类物质含量则显著降低（P<0.05）。综上,热处理和高温贮藏对荔枝汁中酚类化合物含量的变化具有显著影响,热处理能够促进荔枝汁中酚类物质的释放进而提高其抗氧化活性。     

Application of sepiolite in clarification of pomegranate juice: changes on quality characteristics during process

In this study, for the first time, the function of acid‐activated sepiolite clay was evaluated for clarification of pomegranate juice. The optimum conditions of clarification process were achieved using response surface methodology based on juice turbidity as a response. After that, under optimal condition, efficiency of sepiolite, bentonite and combination of these fining agents with gelatin and kieselgel was compared for clarifying pomegranate juice. The results showed that the best conditions for juice clarification were 0.05% (w/v) clay concentration, temperature of 50 °C and time of 2 h. The results revealed that treatments of bentonite–gelatin–kieselgel and sepiolite–gelatin–kieselgel were the most active fining agents that their use led to a reduction of 99.7% in turbidity of pomegranate juice. Kinetic study for different features was performed, and the results indicated that rate of changes in turbidity, viscosity, total phenolic contents and colour with time followed first‐, first‐, zero‐ and zero‐order kinetic models, respectively.     

响应面优化黑果腺肋花楸汁澄清工艺及其抗氧化活性评价

该研究以壳聚糖为澄清剂,采用响应面法优化黑果腺肋花楸汁的澄清条件,筛选出最佳澄清工艺,并对其总黄酮、总酚、花色苷等活性成分进行测定,且通过测定DPPH自由基、羟自由基清除能力,Fe 3+还原能力以及总抗氧化能力评价其体外抗氧化活性。结果表明,黑果腺肋花楸汁最佳澄清条件为壳聚糖添加量0.56 g/100mL,澄清温度49℃,澄清时间67 min,在此条件下其透光率可达到93.89%;黑果腺肋花楸清汁与原汁相比各成分含量发生显著降低(P<0.05),且原汁的抗氧化能力总体上强于清汁。相关性分析表明,黑果腺肋花楸清汁中的总酚和总黄酮含量与清汁DPPH自由基清除率、羟自由基清除率、Fe 3+还原能力和总抗氧化能力呈现较好的相关性。研究结果显示,采用响应面法可优化黑果腺肋花楸汁的澄清工艺,提高汁液透光率,且黑果腺肋花楸汁具有较强的抗氧化活性,该研究为黑果腺肋花楸汁的实际开发利用提供数据支撑和理论基础。     

果胶酶澄清香梨汁的工艺优化

此次试验优化了果胶酶澄清香梨汁工艺。以库尔勒香梨为原料,以酶添加量、酶解时间及酶解温度三个单因素试验为基础,以香梨汁的透光率为响应值,进行试验分析,通过响应面分析法对香梨汁澄清工艺条件进行优化。结果表明,优化后的澄清条件为果胶酶添加量0.06%、酶解温度40℃、酶解时间120 min,透光率平均值可以达到95.27%,澄清效果最好,与模型预测值相符。同时,对酶解前后的香梨汁进行部分基本营养物质含量比较,发现果胶酶的使用对可溶性固形物、总酚、维生素C的含量没有明显的影响。