刁恩杰, 李向阳, 丁晓雯. 脱水菠菜贮藏过程中颜色变化动力学[J]. 农业工程学报, 2010, 26(8): 350-355.
    引用本文: 刁恩杰, 李向阳, 丁晓雯. 脱水菠菜贮藏过程中颜色变化动力学[J]. 农业工程学报, 2010, 26(8): 350-355.
    Kinetics of colour changes of dehydrated spinaches during storage[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2010, 26(8): 350-355.
    Citation: Kinetics of colour changes of dehydrated spinaches during storage[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2010, 26(8): 350-355.

    脱水菠菜贮藏过程中颜色变化动力学

    Kinetics of colour changes of dehydrated spinaches during storage

    • 摘要: 为了探讨脱水菠菜在贮藏过程中叶绿素变化及其与颜色损失的关系,鲜菠菜经过热烫处理后冷冻干燥,包装后在25、35、45和55℃下贮藏,测定贮藏过程中叶绿素和颜色变化,以确定脱水菠菜叶绿素和颜色变化动力学。结果表明:无论是否经过热烫前处理,经过冻干技术得到的脱水菠菜,在贮藏过程中其叶绿素的降解与颜色损失都遵循一级反应动力学方程,且叶绿素的减少与颜色损失密切相关(R2>0.95,p<0.05)。在未经热烫和经热烫处理后冻干的菠菜其叶绿素降解的活化能分别为39.99 kJ/mol和41.44 kJ/mol。而用色度计测定的红绿值a*和色彩角值h中,经过热烫前处理的脱水菠菜其活化能分别是18.93 kJ/mol和48.08 kJ/mol,而未经烫漂的分别为18.20 kJ/mol和44.04 kJ/mol。与热烫处理的样品相比,未热烫的脱水菠菜更容易失去叶绿素,热烫处理有利于延长脱水菠菜的货架期。相同前处理的脱水菠菜,在设定的贮藏温度下,叶绿素降解、红绿值a*和色彩角值h的速率常数随贮藏温度的升高均逐渐增大,低温贮藏有利于延长脱水菠菜的货架期。在常温下(20℃)脱水菠菜的货架期为168 d(未热烫)或465 d(热烫)。

       

      Abstract: In order to study the relationship between chlorophyll changes and visual green colour loss in dehydrated spinaches, fresh spinaches were freeze-dried and packed after being blanched. Chlorophyll and colour loss of dehydrated spinaches were investigated for deciding their kinetics during storage at 25, 35, 45 and 55℃. The results showed that chlorophyll degradation and colour loss followed a first-order reaction. A significant relationship was found between the colour loss and chlorophyll destruction (R2>0.95, p<0.05) whether or not blanching prior to dehydration. The activation energies for chlorophyll degradation were determined as 39.99 kJ/mol and 41.44 kJ/mol for unblanched and blanched spinaches, respectively. For unblanched samples, the activation energies of colour loss determined on the basis of a* and h values were 18.20 kJ/mol and 44.04 kJ/mol, while those for blanched samples determined as 18.93 kJ/mol and 48.08 kJ/mol, respectively. It was highly more susceptible to chlorophyll degradation for unblanched dehydrated spinaches than blanched ones, due to lower activation energy. Blanching prior to dehydration was favorable for extending the shelf life of dehydrated spinaches. The rate constants of chlorophyll degradation, a* and h values of dehydrated spinaches were all increased with the rise of set storage temperature at the same pre-treated conditions. Storage at low temperature was good for extending the shelf life of dehydrated spinaches. The shelf life of dehydrated spinaches were 168 days (unblanched) or 465 days (blanched) during storage at 20℃.

       

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