基于时间序列模型的荔枝预冷过程果肉温度变化特性

Temperature Change Characteristics of Pulp during Litchi Pre-cooling Process Based on Time Series Model

目的解决荔枝在采后预冷过程中预冷时间难把握、预冷后处理时间长导致的果肉温度偏高等问题。方法通过研究不同环境下荔枝果肉温度变化与时间的关系,设计荔枝果肉的温降和温升试验,模拟荔枝预冷和晾干包装阶段的温度变化过程,提出一种时间序列下的荔枝果肉温度预测模型。结果基于时间序列模型的荔枝果肉温度变化预测值与试验值具有高度的一致性,均方差均在80%以上,表明预测结果稳定、可靠。在2~3℃冰水预冷环境下,荔枝果肉从26℃降至5℃约需14 min,将预冷后在室温(25℃)下晾干的处理时间控制在4~6 min内,可以有效地减少荔枝入库贮藏前果肉温度过高的问题,提高了荔枝的冰水预冷效果,保证荔枝在贮藏期间具有较佳的品质。结论通过构建时间序列模型,研究荔枝预冷过程中果肉的温度变化特性,可为荔枝在预冷、晾干、包装环节的过程参数控制提供参考依据。

The work aims to solve the problems that the pre-cooling time of litchis is difficult to be controlled during the post-harvest pre-cooling process,and the long pre-cooling processing time leads to high pulp temperature.By studying the relationship between the temperature change and time of litchi pulp in different environments,the temperature drop and rise experiment of litchi pulp were designed.The temperature change process of litchi pre-cooling and drying packaging stage was simulated.And the litchi pulp temperature prediction model under time series was proposed.Experimental results showed that the predicted value of litchi pulp temperature change based on the time series model was highly consistent with the experimental value,and the mean variance was more than 80%,indicating that the prediction results were stable and reliable.In the pre-cooling environment of ice water at 2-3°C,it took about 14 min for the litchi pulp temperature to be reduced from 26°C to 5°C,and the drying treatment time controlled within 4-6 min at room temperature(25°C)after pre-cooling could effectively reduce the problem of high pulp temperature before litchi storage,improve the pre-cooling effect of litchi ice water,and ensure good quality of litchis.Construction of the time series model to study the change characteristics of pulp temperature during litchi pre-cooling process can provide a reference basis for control of process parameters in pre-cooling,drying and packaging of litchis.