温湿度对菠菜品质影响的研究

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3.0 高德中 2024-11-19 5 4 2.65MB 63 页 15积分
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摘 要
本课题以市售的菠菜为试验材料,系统地研究了环境温度和相对湿度对菠菜
储藏效果的影响,以得到适合菠菜储藏的最佳环境条件,并对其储藏过程中的失水
机理进行了阐述和分析,论文主要进行了如下的工作:
1论文研究了不同堆放方式和相对湿度(RH)对菠菜储藏过程水分蒸发量的影响。
储藏温度为 5℃,RH 99%时,储存 44 小时后,单颗菠菜和捆绑菠菜的失水率
分别为 41.32%22.99%。在前述条件下,RH 99%80%40%单颗菠菜的
失水率分别为 41.32%66.70%54.60%。利用图像处理软件测量了菠菜的表面
积,一般市售菠菜的比表面积为 48.05cm2/g。建立了菠菜贮藏过程中失水速率和
面积的关系。
2对菠菜低温储藏中的传质进行了简要的理论分析,建立了低温下菠菜的失水模
型。测量了菠菜的平均含水率。测定了菠菜的吸附等温线,其属于Ⅱ型,由吸附
等温线获得菠菜的结合水含量为:6.466kg/kg(干基)为分析叶菜类蔬菜贮藏过程
中失水机理,延长保鲜期提供了实验数据和理论依据。
3研究了不同的储藏温度和相对湿度下,菠菜的生理变化和营养品质的变化。
量了相对湿度为 99%,温度分别为 2℃、5℃和 8℃时,菠菜失水率、呼吸强度、
叶绿素含量、可溶性糖含量、可溶性蛋白含量及丙二醛MDA含量的变化。
度为 2℃,相对湿度分别为 99%80%60%时,菠菜失水率、呼吸强度、叶绿
素含量、可溶性糖含量、可溶性蛋白含量及丙二醛MDA含量的变化。结果表
明随着储藏时间的延长,菠菜的失水率、呼吸强度、叶绿素的含量、可溶性糖含
量、可溶性蛋白的含量呈现下降的趋势,MDA 的含量呈上升趋势;低温高湿环
境能够促进菠菜的呼吸作用,抑制菠菜的失水率、可溶性糖、叶绿素及可溶性蛋
白含量的下降,减缓 MDA 生成;随着储藏时间的延长,菠菜的失水率呈直线
上升的趋势;MDA 的含量在储藏前期增加缓慢,但第三天含量急剧增加。
4通过正交试验,探讨了温度和相对湿度及它们之间的相互作用对菠菜储藏效果
的影响,优化了影响因素的参数。结果表明温度是影响储藏过程中菠菜的呼吸强
度、可溶性糖、叶绿素及 MDA 含量的主要因素,相对湿度是影响储藏过程中菠
菜的失水率和可溶性蛋白含量的主要因素。对失水率、可溶性糖、可溶性蛋白、
叶绿素及 MDA 而言,温度越低越好,相对湿度越高越好,而对呼吸强度来说,
温度和相对湿度都是越低越好。综合温湿度对各测量指标的影响,得出菠菜的最
优储藏条件是温度为 2,相对湿度为 99%。通过对正交试验的方差分析,温湿
度的交互作用对菠菜的失水率MDA 的影响达到了显著水平,而对呼吸强度、
可溶性糖、可溶性蛋白和叶绿素的影响不显著。温度是影响菠菜储藏效果的主要
因素。失水率和可溶性蛋白受相对湿度的影响较大,菠菜中可溶性蛋白的下降可
能和菠菜的失水率有一定的相关性,菠菜的衰老过程可能和储藏过程中水分的损
失有很大的关系。
关键词:菠菜 温度 相对湿度 失水机理 品质变化 正交试验
ABSTRACT
This paper studied the effect of the environmental temperature and relative
humidity on the commercial spinash, and tried to find the optimal storing condition for
spinach ,its dehydrate mechanism during the storage was discussed.
1)The effects of storage method and relative humidity on spinach’s Evaporation rate were
measured. When the temperature was 5and the relative humidity was 99%after 40
hours ,the dehydration rate of single spinach was 41.32% while that of binding
spinaches was 22.99%. When the temperature was 5and the relative humidities
were 99% 80% and 40%,the dehydration rates of single spinach were 66.70%
54.60%and41.32% respectively after 44 hours. The specific surface area of spinach
was measured by image processing software,and the value of surface area per unit
weight was 48.05cm2/g.It established relationship between water loss rate and surface
area.
2)A brief theoretical analysis on mass transfer of the spinach which was stored in the
low temperature was given. On the basis of the previous studies,it estsblished the water
loss model of spinach. Measuring the moisture content of spinach,and the average
moisture content of spinach is 93%. Made the adsorption isotherms of spinach ,which
belonged to the type .And from the adsorption isotherms of spinach ,we can
obtained the content of combined water of spinach ,which is 6.466kg / kg ( dry
weight ).And it provided theoretical bases for analyzing the water loss mechanism and
extending the preservation period of leafy vegetables.
3) It studied the physiological and nutritional quality changes of spinach which was
stored in different temperatures and relative humidity. Measuring the water loss
rate,respiration intensity,chlorophyll,soluble sugar, soluble protein and
malondialdehyde(MDA) content,when the relative humidity was 99% and
temperatures were 2, 5and 8.Measuring the water loss rate, respiration
intensitychlorophyllsoluble sugarsoluble protein and malondialdehyde(MDA)
content, when the temperature was 2and the relative humidities were 99%
80% and
60%.The results show that along with the extension of storage time, the water loss
rate ,respiratory intensity ,chlorophyll ,soluble sugar and soluble protein content
showed a downward trend ,and the content of MDA rose. Low temperature and high
humidity environment can inhibit spinach water loss rate, soluble sugar, chlorophyll
and soluble protein content from decreasing, and slow the generation of MDA. And
along with the extension of storage time ,the water loss rate of spinach rose in a linear
trend. MDA content increased slowly early in storage, but the third day ,the content of
MDA increased sharply. High humidity can promote the respiration intensity of spina
4) It carried out the orthogonal experiment to study the effect of temperature and
relative humidity and their interactions on spinach storage, and optimized influencing
factors. The results showed that during the storage ,temperature was the main
influencing factor that affected respiration intensitysoluble sugarchlorophyll and
MDA content of spinach, and the relative humidity was the main influencing factor
that affected the water loss rate and the soluble protein content of spinach. With the
water loss ratesoluble sugarsoluble proteinchlorophyll and MDA, the storage
temperature should be as low as possible, and relative humidity should be as high as
possible, while with respiration intensity, both storage temperature and relative
humidity should be as low as possible. Synthesized the impact of temperature and
relative humidity on every index of spinach, it can be obtained that the optimal storage
condition for spinach was that temperature was 2and relative humidity was 99%. By
analysis of variance of orthogonal trail, it could obtain that the impact of interaction of
temperature and relative humidity on water loss rate and MDA content reached a
significant level, while on respiration intensity soluble sugar soluble protein and
chlorophyll had no significant effect. Temperature was the major factor that effected
spinach storage. Relative humidity had a tremendous influence on the water loss and
soluble protein content of spinach. Decline in soluble protein and water loss rate might
have some relevance, and the aging process of spinach might has a great relationship
with the water loss rate.
Key Words: Spinach, Temperature, Relative humidity, Changes in
quality, Dehydration mechanism, Orthogonal experime
目 录
中文摘要
ABSTRACT
第一章 绪 论...................................................................................................................1
§1.1 研究目的与意义...............................................................................................1
§1.2 国内外对菠菜保鲜的研究...............................................................................1
§1.2.1 菠菜的营养成分及药用价值.................................................................1
§1.2.2 国外对菠菜保鲜的研究.........................................................................2
§1.2.3 国内对菠菜保鲜的研究.........................................................................4
§1.3 菠菜的采后生理...............................................................................................5
§1.3.1 菠菜采后呼吸作用.................................................................................5
§1.3.2 菠菜采后蒸腾作用.................................................................................6
§1.3.3 菠菜采后品质变化.................................................................................7
§1.4 菠菜的失水机理的理论分析...........................................................................7
§1.4.1 菠菜中的水分.......................................................................................8
§1.4.2 低温下果蔬中的水分迁移过程..............................................................9
§1.4.3 菠菜失水模型的建立.........................................................................10
§1.5 研究内容.........................................................................................................10
第二章 不同相对湿度对单颗菠菜低温保鲜的研究...................................................12
§2.1 器材和方法......................................................................................................12
§2.1.1 实验仪器...............................................................................................12
§2.1.2 材料及处理...........................................................................................12
§2.1.3 方法.......................................................................................................12
§2.2 相对湿度 99%下菠菜的失水率..................................................................... 13
§2.3 不同 RH 对单颗菠菜储存过程中失水率的影响 ......................................... 14
§2.4 菠菜的吸附等温线及结合水含量.................................................................15
§2.5 菠菜的比表面积.............................................................................................16
§2.6 不同 RH 对菠菜单位面积失水量的影响 ..................................................... 16
§2.7 温度 5℃,不同相对湿度下单颗菠菜单位面积内失水速率......................17
§2.8 讨论与结论.....................................................................................................18
第三章 温湿度对捆绑菠菜低温保鲜品质的影响.......................................................19
§3.1 材料与方法.....................................................................................................19
§3.1.1 实验仪器与试剂...................................................................................19
§3.1.2 材料及处理...........................................................................................19
§3.1.3 方法.......................................................................................................19
§3.2 结果与分析.....................................................................................................24
§3.2.1 温度对失水率的影响...........................................................................24
§3.2.2 温度对呼吸速率的影响.......................................................................25
§3.2.3 温度对叶绿素的影响............................................................................26
§3.2.4 温度对可溶性糖的影响........................................................................26
§3.2.5 温度对可溶性蛋白的影响....................................................................28
§3.2.6 温度对菠菜 MDA(丙二醛)含量的影响 ........................................ 29
§3.2.7 RH 对菠菜失水率的影响 ..................................................................... 30
§3.2.8 RH 对菠菜呼吸强度的影响 ................................................................. 31
§3.2.9 RH 对菠菜叶绿素含量的影响 ............................................................. 32
§3.2.10 RH 对菠菜可溶性糖含量的影响 ....................................................... 33
§3.2.11 RH 对菠菜可溶性蛋白含量的影响 ................................................... 34
§3.2.12 RH 对菠菜 MDA(丙二醛)含量的影响 .........................................35
§3.3 结论与讨论.....................................................................................................36
§3.3.1 结论........................................................................................................36
§3.3.2 讨论.......................................................................................................36
第四章 温湿度条件对菠菜储藏的优化试验...............................................................38
§4.1 引 言...............................................................................................................38
§4.2 实验材料与仪器.............................................................................................38
§4.2.1 实验材料...............................................................................................38
§4.2.2 实验试剂...............................................................................................38
§4.2.3 实验仪器...............................................................................................38
§4.3 试验方法.........................................................................................................38
§4.3.1 设计方案...............................................................................................38
§4.3.2 分析方法...............................................................................................39
§4.4 结果与讨论.....................................................................................................39
§4.4.1 正交试验的极差分析结果与讨论.......................................................39
§4.4.2 正交试验的方差分析结果与讨论.......................................................44
§4.5 小结.................................................................................................................48
第五章 结论与展望.......................................................................................................50
§5.1 结论.................................................................................................................50
摘要:

摘要本课题以市售的菠菜为试验材料,系统地研究了环境温度和相对湿度对菠菜储藏效果的影响,以得到适合菠菜储藏的最佳环境条件,并对其储藏过程中的失水机理进行了阐述和分析,论文主要进行了如下的工作:1)论文研究了不同堆放方式和相对湿度(RH)对菠菜储藏过程水分蒸发量的影响。储藏温度为5℃,RH为99%时,储存44小时后,单颗菠菜和捆绑菠菜的失水率分别为41.32%和22.99%。在前述条件下,RH为99%、80%、40%,单颗菠菜的失水率分别为41.32%、66.70%和54.60%。利用图像处理软件测量了菠菜的表面积,一般市售菠菜的比表面积为48.05cm2/g。建立了菠菜贮藏过程中失水速率和面积的...

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作者:高德中 分类:高等教育资料 价格:15积分 属性:63 页 大小:2.65MB 格式:PDF 时间:2024-11-19

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