干燥方式对毛竹笋全粉理化特性及结构的影响

李艳艳; 史早; 冉莎; 杨金来; 李彬; 吴良如; 郑炯

doi:10.13386/j.issn1002-0306.2023090111

干燥方式对毛竹笋全粉理化特性及结构的影响

Effects of Drying Methods on Physicochemical Properties and Structure of Phyllostachys pubescens Shoot Powder

摘要

摘要: 为探究干燥方式对毛竹笋全粉（Phyllostachys pubescens shoot powder，PPSP）理化特性及结构的影响，该实验以毛竹笋为原料，采用喷雾干燥（Spray drying，SD）、热风干燥（Hot air drying，HAD）和低温真空干燥（Low-temperature vacuum drying，LVD）3种方式制备PPSP，比较3种PPSP的营养成分、持水力、持油力、膨胀力、色泽等理化特性，并通过红外光谱、X-射线衍射、扫描电镜分析其结构。结果表明，不同干燥方式制备的PPSP营养成分差异显著（P<0.05），LVD组的蛋白质、不溶性膳食纤维、灰分、总糖含量均显著高于其他2组（P<0.05），而水分、可溶性膳食纤维含量最低；HAD组中可溶性膳食纤维含量最高，达5.79%；HAD组样品的持水力和持油力分别为4.10、1.91 g/g，显著高于SD组和LVD组（P<0.05）；SD样品的膨胀力最高，达到3.85 mL/g；3组PPSP的滑角和休止角差异显著（P<0.05），其中，SD>LVD>HAD；3组PPSP的L^*值、a^*值、b^*值均有显著差异（P<0.05），LVD样品的L^*值为77.32，显著高于SD和HAD样品（P<0.05），且其a^*值和b^*值最低，分别为3.74、14.50；SD和LVD显著降低了样品的热稳定性（P<0.05）。干燥方式未改变PPSP的基本结构和官能团以及晶体结构。扫描电镜观察到SD制备的PPSP颗粒尺寸明显减小，分布更为均匀。综上所述，LVD制备的毛竹笋干制品营养、理化特性及结构整体最佳，其次是SD。研究结果可为高品质PPSP的制备提供理论参考。

Abstract: In order to explore the effects of drying methods on the physicochemical properties and structure of Phyllostachys pubescens shoot powder (PPSP), this research used bamboo shoots as raw materials, and used spray drying (SD), hot air drying (HAD) and low-temperature vacuum drying (LVD) to get 3 kinds of PPSP. The nutrient content, water holding capacity, oil holding capacity, swelling capacity, color, and other physicochemical properties of samples were compared, and their structures were analyzed by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The results showed that the nutritional characteristics of PPSP prepared by different drying methods were significantly different（P<0.05）. The contents of protein, insoluble dietary fiber, ash, and total sugar in LVD samples were significantly higher than those in the other two groups (P<0.05), while the contents of water and soluble dietary fiber were the lowest. The content of soluble dietary fiber in HAD samples was the highest (5.79%). The water holding capacity and oil holding capacity of HAD powder were 4.10 and 1.91 g/g, respectively, which were significantly higher than those of SD group and LVD group. The swelling capacity of SD powder was the best, reaching 3.85 mL/g. The angle of repose and slip angle of PPSP in 3 groups were significantly different (P<0.05), which was SD>LVD>HAD. The L^*, a^* and b^*value of PPSP in the three groups were significantly different in color. The L^* value of LVD sample was 77.32, which was significantly higher than that of SD and HAD samples (P<0.05), and the a^* and b^* value were the lowest, which were 3.74 and 14.50, respectively. SD and LVD significantly reduced the thermal stability of the sample (P<0.05). The drying method did not change the basic structure, functional group, and crystal structure of PPSP. The particle size of PPSP prepared by SD decreased significantly and the distribution was more uniform. In summary, the nutrition, physicochemical properties, and structure of dried bamboo shoots prepared by LVD were the best, followed by SD. The results can provide experimental basis for the preparation of high quality PPSP.