温度对果蔬焓值变化规律的影响

Effect of Temperature on Enthalpy of Fruits and Vegetables

利用差式量热扫描仪(Differential Scanning Calorimetry,DSC),研究不同类型的果蔬在同一温度段(-40~30℃)下的焓值,分析了果蔬焓值随温度的变化趋势,并且建立了相关因素与焓值的预测模型。研究发现:果蔬焓值随温度上升分为三段,糖类、淀粉类、纤维类、蛋白质类从-40℃开始缓慢增,中期增长速率加快,且在-10℃以后进入快速增长阶段,15℃后呈线性增长;而脂肪类在-20℃之前缓慢增长,然后进入快速增长阶段,最终达到稳定状态后增长速率均不超过2 kJ/(kg·℃)。各个种类果蔬的焓值在同一温度下,水果类的焓值高于蔬菜类,通过分析温度与焓值的拟合情况,可以预测果蔬的焓值。

The enthalpy of different varieties fruits and vegetables in the same temperature range(-40~30℃)was measured by differential scanning calorimetry(DSC).The trend of its change with the temperature was analyzed.Then a prediction model relative factors and enthalpy was built.It was found that the enthalpy value could be divided into three stages with the increase of temperature.Sugars,starches,fibers and proteins began to increase slowly from-40℃.In the middle stage,the enthalpy value increased rapidly,and entered a rapid growth stage after-10℃.The enthalpy value increased linearly after 15℃.However,the growth rate of lipids increases slowly before-20℃,then enters the stage of rapid growth,and finally reaches a stable state,and the growth rate does not exceed 2kJ/(kg·℃).At the same temperature,the enthalpy of fruits was higher than that of vegetables.The enthalpy of fruits and vegetables could be predicted by analyzing the fitting situation of temperature and enthalpy.