基于水分吸附数学模型的花桥板栗2号贮藏安全水分估算

Estimation of the storage safe moisture of Huaqiao chestnut Ⅱ using moisture absorbing math model

为充分了解花桥板栗2号的等温吸附规律为贮藏、运输过程中板栗的品质保持提供理论依据。本研究基于热力学基本理论,采用传统静态称量法测定了花桥板栗2号在20、30、40℃,水分活度为0.11~0.92条件下的吸附等温线,选用5种水分吸附数学模型对其进行拟合,并通过模型方程计算得到花桥板栗2号的贮藏安全水分。结果表明:花桥板栗2号在20、30、40℃条件下的吸附等温线的类型为"J"型,属于Ⅲ型等温线;Peleg模型是最佳的吸附等温线拟合模型,并由该模型计算得到20、30和40℃下花桥板栗2号的绝对安全水分分别为11.04%、10.40%、9.95%;相对安全贮藏水分为13.71%、12.15%、11.56%。通过计算水同物料结合能可知当板栗含水量超过20%时,水分较易去除。

In order to fully understand the isothermal adsorption rule of Huaqiao chestnut II, and to provide theoretical foundation of how to keep the chestnut＇s quality during the storage and transportation process. Based on the basic theory of thermodynamics, this paper uses traditional static weighing method to determine the adsorption isotherm of Huaqiao chestnut II under the temperature of 20, 30 and 40 ℃, water activity between 0.11-0.92. Then this paper uses five moisture absorbing math models to fit the result thus to calculate the storage safe moisture of Huaqiao Chestnut II through model equation. The result shows that the adsorption isotherm of Huaqiao chestnut II under the temperature of 20, 30 and 40 ℃ is in the shape of ＂J＂, which belongs to the type III isotherm. The Peleg model is the best fitting model. After model calculation, the absolute safe moistures of Huaqiao chestnut II under the temperature of 20, 30 and 40 ℃ are 11.04%, 10.40% and 9.95%, respectively; and the relative safe moistures are 13.71%, 12.15% and 11.56% respectively. By calculating the binding energy of water and chestnut, this paper shows that it＇s easy to lower the moisture of chestnut when the moisture content is over 20%.