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摘要：澄清及稳定技术是果汁生产中的关键技术。本实验分别研究了果胶酶处理、超声波处理、以及果胶酶结合超声波处理对葡萄汁澄清度和稳定性的影响。其中酶处理浓度为0.2、0.4g/L，超声波功率为130、260W/L，以及0.2、0.4g/L的果胶酶结合130、260W/L的超声波处理。处理温度为50℃，处理时间为50min，葡萄汁储藏温度为4℃。研究发现，经130W/L的超声波、0.2g/L果胶酶及0.2g/L果胶酶结合130W/L的超声波处理的葡萄汁澄清度相对于对照葡萄汁显著提高，同时，色度和花色苷含量较对照葡萄汁也显著下降；0.2g/L果胶酶处理后葡萄汁样品的pH值(3.72)相对于空白对照（3.94）以及可滴定酸含量（4.41g/L）相对于空白对照(4.53 g/L)都略有降低但无显著差异；三种方式处理后样品的可溶性固形物含量、可溶性蛋白含量、抗氧化活性等与对照样品相比无显著差异。在4oC贮藏过程中葡萄汁样品中可溶性蛋白、总酚及可滴定酸等成分随储藏时间的延长逐渐降低，抗氧化性减弱。在三种处理方式中，超声波处理澄清效果较果胶酶略差但对葡萄汁成分保留更好。此外，在本实验中果胶酶结合超声波对葡萄汁的澄清度和稳定性无明显加乘作用。29080
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毕业论文关键词：葡萄汁；果胶酶；超声波；澄清度；稳定性
The effect of the combination of ultrasound and enzyme on the clarity and stability of grape juice
Abstract: Clarification and stabilization are key procedures during juice processing. In this paper, enzyme, ultrasound and combined ultrasound and enzyme were used for the clarification and stabilization of grape juice. Enzyme concentrations were 0.2 and 0.4 g/L, while ultrasound intensities were 130 and 260 W/L. the processing temperature was 50 oC and processing duration was 50 min. After each treatment, grape juices were stored in 4 oC. Studies have found that by 130 W/L ultrasonic, 0.2 g/L pectinase and 0.2 g/L pectin enzyme combined with 130 W/L ultrasonic processing grape juice clarification degree relative to control grape juice increased significantly. Meanwhile, color intensity and anthocyanin content decreased after ultrasound, enzyme, and combined ultrasound and enzyme treatments. Furthermore, 0.2 g/L after enzyme treatment of grape juice samples pH value (3.72) compared with the blank control (3.94) and the content of titratable acid (4.41 g/L) compared with the ck (4.53 g/L) is slightly lower, but there was no significant difference. All the treatments did not affect the contents of total solids, soluble protein content, total phenolics and titratable acid significantly. Besides, contents of soluble protein, total phenolics and titratable acid decreased gradually during storage. Among all the three treatments, ultrasound treatment alone better retained grape juice components, whereas the clarification effect of ultrasound treatment alone was weaker than that of other treatments. There was no interaction effect when ultrasound was combined with enzyme treatment.
Keywords: grape juice; pectin enzyme; ultrasound; clarity; stability
目 录
摘要1
关键词1
Abstract1
Key words1
引言（或绪论）1
1材料与方法2
1.1 材料与试剂 2
1.2 仪器与设备 3
1.3 试验方法 3
1.3.1葡萄汁的制备3
1.3.2 果胶酶澄清试验3
1.3超声波澄清实验3
1.3.4超声波结合果胶酶澄清试验3
1.3.5理化分析3
2实验结果及分析5
2.1葡萄汁贮藏过程中吸光值变化5
2.2 葡萄汁贮藏过程中可溶性固形物含量变化 6
2.3葡萄汁贮藏过程中pH值变化6
2.4葡萄汁贮藏过程中可溶性蛋白含量变化7
2.5葡萄汁贮藏过程中总花色苷含量变化7
2.6葡萄汁贮藏过程矢车菊素-3-葡萄糖苷含量变化8
2.7葡萄汁贮藏过程中可滴定酸含量变化8