Wu Li, Chen Shouhui, Li Yibin, Xie Wei, Tang Baosha
Institute of Food Science and Technology, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, 350003, PR China.
Key Laboratory of Subtropical Characteristic Fruits, Vegetables and Edible Fungi Processing (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Fuzhou, Fujian, 350003, PR China.
Curr Res Food Sci. 2024 Aug 22;9:100825. doi: 10.1016/j.crfs.2024.100825. eCollection 2024.
Low-field nuclear magnetic resonance (LF-NMR) was used to analyze the moisture migration characteristics and water distribution of instant (ITF) during heat pump drying at 35 °C, 45 °C and 55 °C. A fuzzy mathematical evaluation method was then used to investigate the effect of heat pump drying temperatures (35 °C, 45 °C and 55 °C) on the quality of ITF. Based on the screened appropriate temperature of 45 °C, the thin layer heat pump drying curve and drying rate curve of ITF were drawn, then four mathematical models were tested based on the coefficient of determination (R). The result showed three water components (bound water ( ), immobilized water ( ), and free water ( )) in ITF before drying. During the drying process, the heat pump drying of ITF was carried out gradually from the outer to the inner. The sensory total score (77.66 ± 6.57), rehydration ratio (4803.00 ± 90.00%), and viscosity (45.01 ± 3.61 Pa s) of ITF in heat pump drying at 45 °C were the best. The optimal drying temperature of 45 °C was obtained by the fuzzy comprehensive evaluation with the highest comprehensive score of 77.85%. With the prolongation of drying time, the water content of ITF showed a gradual decreasing trend, and the water content was controlled to below 8.51% after 6 h. The drying curve shows that the drying phase of the ITF is divided into three phases, including preheat, constant speed and deceleration. The drying speed first increases, remains constant in the middle and then decreases. Among the four models tested, the cubic regression equation aligned with the change rule of the ITF drying curve (R = 0.99397). By studying the effect of drying temperature on the moisture migration characteristics and the quality of ITF, we aim to provide more data support for the production of . .
采用低场核磁共振（LF-NMR）分析了即食食品（ITF）在35℃、45℃和55℃热泵干燥过程中的水分迁移特性和水分分布。然后采用模糊数学评价方法研究了热泵干燥温度（35℃、45℃和55℃）对ITF品质的影响。基于筛选出的45℃适宜温度，绘制了ITF的薄层热泵干燥曲线和干燥速率曲线，然后根据决定系数（R）对四个数学模型进行了测试。结果表明，干燥前ITF中有三种水分成分（结合水（ ）、束缚水（ ）和自由水（ ））。在干燥过程中，ITF的热泵干燥从外到内逐步进行。45℃热泵干燥的ITF感官总评分（77.66±6.57）、复水率（4803.00±90.00%）和粘度（45.01±3.61Pa·s）最佳。通过模糊综合评价得到最佳干燥温度为45℃，综合得分最高为77.85%。随着干燥时间的延长，ITF的含水量呈逐渐下降趋势，6h后含水量控制在8.51%以下。干燥曲线表明，ITF的干燥阶段分为预热、恒速和减速三个阶段。干燥速度先增大，中间保持恒定，然后减小。在所测试的四个模型中，三次回归方程与ITF干燥曲线的变化规律相符（R=0.99397）。通过研究干燥温度对ITF水分迁移特性和品质的影响，旨在为……的生产提供更多的数据支持。
