Abstract: In order to explore the changes of total polysaccharide, mannitol and algin content of fresh kelp under drying conditions, grasp its drying characteristics and establish a drying model that can accurately predict the drying process. The wet base moisture content of kelp reaches less than 18% as the drying end point. It is analyzed that the kelp in the Rongcheng sea area of Shandong Province is dried under the condition that the light intensity is greater than 30 000 Lx and the relative humidity is less than 70% in Shanghai from June to July. Changes in the content of alcohol and algin, and the kelp drying model was established by fitting six drying mathematical models. The results show that the root thickness of kelp is different, but the initial moisture content is similar, which is between 88% and 92%. The drying process is mainly divided into adjustment stage, fast precipitation stage and slow precipitation stage, and the drying rate goes through two stages of acceleration and deceleration. Different fresh kelp had different initial total polysaccharide, mannitol and algin content. After long-term drying, the total polysaccharide content decreased the most, followed by alginate, and mannitol changed the least. Using six common drying mathematical models to fit and analyze, the mean value of Page model R2 is 0.990, and the mean value of root mean square error RMSE is 0.022 4, which can best describe the moisture change of kelp during drying. A set of data outside the modeling was selected for verification analysis, and the correlation coefficient between the simulated and measured MR values was 0.995 (P<0.05), and the two were significantly correlated, indicating that the model can relatively well describe the natural drying of fresh kelp. Changes in moisture content over time during drying. The research results can provide a theoretical reference for the later joint drying research with heat pump.

Key words: Fresh kelp, Sun drying, Functional active substance, Drying model;Aquatic product processing

摘要： 为探究新鲜海带在晾晒情况下海带总多糖、甘露醇和褐藻胶含量的变化，掌握其晾晒干燥特性并建立可准确预测干燥进程的干燥模型，以湿基含水率、干燥速率、干燥时间为指标，海带湿基含水率达到18%以下作为干燥终点，分析山东荣成海域海带在光照度大于30 000 Lx且相对湿度小于70%情况下晾晒，湿基含水率以及海带总多糖、甘露醇和褐藻胶含量的变化，并用6个干燥数学模型拟合建立海带晾晒干燥模型。结果显示：海带根部厚度不同，但初始含水率接近，均在88%~92%之间。晾晒过程主要分为调整阶段、快速降水阶段和慢速降水阶段，干燥速率经历加速和降速两个阶段。不同的新鲜海带，其初始总多糖、甘露醇、褐藻胶含量有差异，经长时间晾晒后，总多糖含量下降最大，褐藻胶次之，甘露醇变化最小。使用6个常见的干燥数学模型拟合分析，Page模型R2的均值为0.990，均方根误差RMSE的均值为0.022 4，最能准确描述海带晾晒干燥过程中的水分变化情况。选择建模外的一组数据进行验证分析，得出MR模拟值和实测值的相关系数为0.995(P<0.05)，两者显著相关，表明该模型可以相对较好地描述新鲜海带在自然晾晒干燥过程中水分含量随时间变化情况。本研究成果可为后期与热泵的联合干燥研究提供理论参考。

关键词: 新鲜海带, 晾晒干燥, 功能活性物质, 干燥模型, 水产品加工