利用洞道干燥设备模拟工业化的焙烤环境，测定粤式杏仁饼的干燥特性，采用扫描电镜和图像分析法测定粤式杏仁饼的孔隙微观结构，基于分形理论探究粉料粒度对粤式杏仁饼干燥及其品质的影响。研究表明：对于低水分含量的杏仁饼而言，其内部为多孔结构，具有明显的分形特征。随着粒度的减小，杏仁饼孔隙结构变得更加复杂。在100 ℃或120 ℃下焙烤时，140目粉料制饼的干燥速率都明显高于60目和100目粉料制饼的干燥速率。成品质构分析表明，随着粉料粒度的减小（60目→100目→140目），杏仁饼的硬度、内聚性和咀嚼性都分别有显著减低（p<0.05）。从感官评价结果来看，140目粉料制饼要优于60目、100目粉料制饼。因此，在制备杏仁饼粉料时，在一定范围内减小粉料的粒度，既可以提高干燥速率又可以保证产品品质。

A tunnel drying equipment was used to simulate the industrial tunnel oven and determine the drying characteristics of Cantonese almond cookie. Scanning electron microscopy (SEM) followed by image analysis were done to determine the pore microstructure of almond cookie. The effect of particle size on the drying properties and quality of Cantonese almond cookie was explored based on fractal theory. The results showed that the almond cookie with low moisture content had an internal porous structure and an apparent fractal feature. The smaller the particle size was, the more complex the pore structure was. Under the same baking temperature of 100 ℃ or 120 ℃, the drying rate of almond cookies made of 140-mesh powder were significantly higher than that of almond cookies made of 60-mesh and 100-mesh powders. Texture property analysis (TPA) indicated that with a decrease in particle sizes (60 mesh→100 mesh→140 mesh), the hardness, cohesiveness, and chewiness of almond cookies decreased significantly (p<0.05). According to the sensory evaluation, the almond cookie made of 140-mesh powder had better quality than those made of 60 mesh and 100 mesh. Therefore, the drying rate and quality of Cantonese almond cookie can be improved by reducing particle size within a certain range during the production of almond cookie powder.

广东省天然产物绿色加工与产品安全重点实验室项目资助