基于温度滞后效应高温瞬时热辐射核桃仁种皮脆化脱落机理与场参数智能调控策略

我国核桃产量居世界第一，但深加工水平相对落后，特别是种皮去除工序。目前广泛应用的碱液浸泡化学法和湿式物理法导致核桃仁污染、损失率高且种皮无法利用；而干式烘烤法存在热辐射强度低、加热时间长而导致营养物质高损伤的瓶颈。依此，基于温度滞后效应及种皮热膨胀率高于核桃仁的事实，大幅提高热源温度瞬时辐射加热，使种皮快速膨胀、爆裂而核桃仁低膨胀免损伤。项目研究核桃仁/种皮理化特性参数与热辐射强度的量化映射关系，揭示种皮膨胀热力学规律及几何形态动态演变机制。研究高温瞬时热辐射条件下，核桃仁/种皮复合材料由表及里热传导机理及动态温度场模型，揭示种皮快速脱水脆化、膨胀机制及裂纹生成、扩展力学行为；果胶质裂解速度-温度量化关系及其对粘连强度的影响规律；高温度梯度对多酚油脂蛋白质等指标的影响规律。研究温度/振动/输运等多场参数协同作用规律及核桃仁/种皮低损伤智能化分离调控策略，为核桃深加工提供理论指导和技术支持。

Walnut production in China ranks first in the world, but the level of deep processing is relatively backward, especially the seed skin removal process. At present, the widely used lye immersion chemical method and wet physical method lead to the contamination of walnut kernel, high loss rate and the inability to use seed skin. The dry baking method has the bottleneck of low thermal radiation intensity and long heating time of oil oxidation and rancidity. Based on this, using the temperature hysteresis effect and the fact that the thermal expansion rate of seed skin is higher than that of walnut kernel, greatly increasing the heat source temperature to instantaneous radiation heat, making the seed skin expand rapidly and burst, while the walnut kernel is not damaged by the low expansion. This project will research the quantitative relationship between physical and chemical characteristic parameters of walnut kernel/seed skin and thermal radiation to reveal the thermodynamic law of seed skin expansion and the dynamic evolution mechanism of walnut kernel quality. Under the condition of instantaneous radiation at high temperature, the mechanism of heat conduction from surface to inside and the dynamic model of temperature field of sandwich walnut kernel composite were studied, which firstly ,to reveal the mechanism of rapid dehydration embrittlement, thermal expansion, crack generation and propagation of seed skin. Secondly, to reveal the quantization of temperature-velocity relation of pectin cracking and its effect on adhesion strength. Thirdly, to reveal the dynamic evolution law and intelligent regulation mechanism of high temperature gradient on polyphenol lipid protein and other indexes. The synergistic law of field parameters such as temperature/vibration/speed of walnut kernel transportation and the low damage regulation strategy of walnut kernel /seed skin were studied to provide theoretical guidance and technical support for the further processing of walnut.