真空预冷上海青及其保鲜实验研究

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摘要

真空预冷技术由于其快速，洁净等优点，已经成为当前应用广泛的蔬菜保鲜

技术之一。上海青由于其质地鲜嫩，极易失水萎缩，在常温条件下采后 2 天内即

变色、变质，降低了食用品质和价值。因此，对上海青的预处理及贮藏保鲜进行

研究，延长上海青的贮藏保鲜期，具有重要意义。

本研究选取上海青为研究对象，研究了在相同贮藏条件下，不同真空预冷处

理条件对上海青品质的影响。得出了真空预冷过程中上海青温度、真空室压力随

时间的变化规律以及贮藏过程中上海青品质的变化规律，并探讨了不同预冷终温

和预冷压力对上海青质量、质构、色差、过氧化物酶活性和微生物指标（菌落总

数、大肠杆菌数）的影响。

实验结果表明：预冷终温越低，上海青预冷前后的质量、硬度差异越大，在

贮藏期内，预冷终温为 4℃的上海青质量、硬度、色差变化率最低，8℃变化率最

高，保鲜效果不佳；预冷压力越低，质量、硬度损失越大，在贮藏期内，预冷压

力为 1000Pa 的上海青质量损失，硬度减少率最低；经真空预冷处理的样品在贮藏

过程中色差改变量均小于对照，说明真空预冷能有效延缓上海青的黄化、其 POD

活性始终维持在较高水平、能更好保持微观结构及外观品质。

经真空预冷处理后，上海青中微生物的增长被有效地抑制。在相同预冷压力

下，预冷温度越低，对其抑制效果越佳。在相同预冷温度下，不同预冷压力对微

生物的生长影响显著，预冷压力越低，抑制其生长作用越明显，预冷压力为 800Pa

的效果最好。

真空预冷后蔬菜的货架期得到明显的延长，对保持上海青品质效果最好的真

空预冷条件为：预冷压力为 1000Pa，预冷温度为 4℃。

关键词：真空预冷上海青质构色差过氧化物酶微生物

ABSTRACT

Vacuum pre-cooling has become one of the most widely used techniques for

keeping vegetables fresh because of its fast and clean,etc. Chinese little greens was

easy to lose its commercial value because of its tender texture and easy to rot.

Therefore, there is a very important practical significance to research the pretreatment

and storage physiology of Chinese little greens to extend its storage and preservation.

In this paper, The quality variations of Chinese little greens, affected by different

vacuum pre-cooling treatment conditions have been studied. Some experimental

parameters such as pressure and temperature have been analyzed during vacuum

cooling process. Moreover, the effect of vacuum pre-cooling on the keeping freshness

of Chinese little greens during storage were studied and the variations of mass, texture,

chromatic aberration, POD activity and microbiological indicators (total bacteria and

E.coli) were detected.

The results showed that: when the pre-cooling temperature was lower, the mass

loss and hardness loss were greater after the vacuum pre-cooling treatment. In the

storage period, the pre-cooling temperature of 4 ℃made the quality, hardness,

chromatic aberration change of the lowest, while 8℃made the highest rate of change.

When the pre-cooling pressure was lower, the mass loss and hardness loss were greater.

In the storage period, the pre-cooling pressure of 1000Pa made the lowest loss rate of

quality and hardness. The chromatic aberration change of Chinese little greens which

were vacuum pre-cooled was less than the control group during the storage. The

vacuum pre-cooling could delay the Chinese little greens turning yellow and maintain

the POD activity at a high level. The micro-structure and appearance of quality was

also better during the storage. As a conclusion, compared with the control group,

vacuum pre-cooling did a positive role to keep Chinese little greens fresh.

The growth of microorganisms in Chinese little greens was effectively suppressed

after the vacuum pre-cooling treatment. Pre-cooling at the same pressure, the

inhibitory effect was better with the lower temperature. Pre-cooling at the same

temperature, different pre-cooling pressures effected on the growth of microorganisms

significantly. The lower pre-cooling pressure made the more obviously role in

inhibiting the growth of microorganisms. The best pre-cooling pressure is 800Pa.

Vacuum pre-cooling was proved to be effective to extend of Chinese little greens’

shelf life in this paper. The best vacuum pre-cooling treatment condition to maintain

the quality of Chinese little greens is pressure of 1000Pa and temperature of 4 ℃.

Key word ：Vacuum pre-cooling, Chinese little greens, Texture,

Chromatic aberration, POD, Microbe

中文摘要

ABSTRACT

第一章绪论 ................................................................................................................ 1

1.1 鲜切蔬菜及加工现状 ............................................. 1

1.1.1 蔬菜的营养价值和商品价值 ................................... 1

1.1.2 鲜切蔬菜加工业发展状况 ..................................... 1

1.1.2.1 国外鲜切蔬菜加工现状 ....................................2

1.1.2.2 我国鲜切蔬菜加工现状 ....................................2

1.2 真空预冷的特点及其应用 ......................................... 3

1.2.1 温度的重要性和冷却的必要性 ................................. 3

1.2.2 常用农产品预冷方法 ......................................... 4

1.2.3 真空预冷的原理和特点 ....................................... 5

1.2.3.1 真空预冷的原理 ..........................................5

1.2.3.2 真空预冷的特点 ..........................................5

1.3 真空预冷的实验研究与应用现状 ................................... 6

1.3.1 国外真空预冷实验研究现状 ................................... 6

1.3.2 我国真空预冷实验研究现状 ................................... 7

1.3.3 真空预冷技术应用现状 ....................................... 8

1.4 本论文的研究内容及意义 ..........................................9

1.4.1 研究内容 ................................................... 9

1.4.2 研究意义 ................................................... 9

第二章上海青真空预冷过程研究 ...............................................................................11

2.1 材料与方法 .................................................... 11

2.1.1 材料与仪器 ................................................. 11

2.1.2 实验方法 ................................................... 13

2.2 结果与分析 .................................................... 13

2.2.1 1000Pa 下 4℃真空预冷过程分析 .............................. 13

2.2.2 不同预冷终温试验研究 ....................................... 15

2.2.3 不同预冷压力试验研究 ....................................... 16

2.3 本章小结 ...................................................... 17

第三章不同预冷终温对上海青品质的影响 .............................................................. 18

3.1 材料与方法 .................................................... 18

3.1.1 材料与仪器 ................................................ 18

3.1.2 实验方法 .................................................. 18

3.1.2.1 失重率的测定 ...........................................18

3.1.2.2 硬度的测定 .............................................19

3.1.2.3 色差的测定 .............................................19

3.1.2.4 过氧化酶活性的测定 .....................................20

3.1.2.5 显微结构的测定 .........................................20

3.1.2.6 感官分析 ...............................................20

3.1.3 数据处理 .................................................. 21

3.2 结果与分析 .................................................... 21

3.2.1 不同预冷终温对上海青质量的影响 ............................ 21

3.2.2 不同预冷终温对上海青硬度的影响 ............................ 22

3.2.3 不同预冷终温对上海青贮藏期间色差的影响 .................... 24

3.2.4 不同预冷终温对上海青过氧化酶活性的影响 .................... 25

3.2.5 显微结构分析 .............................................. 25

3.2.6 感官分析 .................................................. 27

3.3 本章小结 .......................................................28

第四章不同预冷压力对上海青品质的影响 .............................................................. 29

4.1 材料与方法 .................................................... 29

4.2 结果与分析 .................................................... 29

4.2.1 不同预冷压力对上海青质量的影响 ............................ 29

4.2.2 不同预冷压力对上海青硬度的影响 ............................ 30

4.2.3 不同预冷压力对上海青色差的影响 ............................ 32

4.2.4 不同预冷压力对上海青过氧化酶活性的影响 .................... 33

4.2.5 感官分析 .................................................. 34

4.3 本章小结 .......................................................35

第五章真空预冷对上海青微生物的影响 .................................................................. 36

5.1 材料与方法 .................................................... 36

5.1.1 材料与仪器 ................................................ 36

5.1.2 实验方法 .................................................. 36

5.2 不同预冷终温对上海青微生物的影响 .............................. 37

5.3 不同预冷压力对上海青微生物的影响 .............................. 39

第六章结论与展望 ...................................................................................................... 41

6.1 结论 .......................................................... 41

6.2 展望 .......................................................... 42

参考文献 .........................................................................................................................43

在读期间公开发表的论文和承担科研项目及取得成果 ............................................ 48

致谢 .................................................................................................................................49

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摘要：

摘要真空预冷技术由于其快速，洁净等优点，已经成为当前应用广泛的蔬菜保鲜技术之一。上海青由于其质地鲜嫩，极易失水萎缩，在常温条件下采后2天内即变色、变质，降低了食用品质和价值。因此，对上海青的预处理及贮藏保鲜进行研究，延长上海青的贮藏保鲜期，具有重要意义。本研究选取上海青为研究对象，研究了在相同贮藏条件下，不同真空预冷处理条件对上海青品质的影响。得出了真空预冷过程中上海青温度、真空室压力随时间的变化规律以及贮藏过程中上海青品质的变化规律，并探讨了不同预冷终温和预冷压力对上海青质量、质构、色差、过氧化物酶活性和微生物指标（菌落总数、大肠杆菌数）的影响。实验结果表明：预冷终温越低，上海青预冷前后的质...

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