Effect of Combined Drying on Cell Breakage and Anthocyanin Content of Purple Sweet Potato Granules(复合干燥对紫薯全粉细胞破损及花青素含量的影响)
摘要
Fresh purple sweet potatoes (PSP) were used as raw material. The effect of combined drying on the free starch content of PSP granules was studied using the indexes of iodine blue value and anthocyanin content. And the correlation of combined drying on cell breakage and anthocyanin content was explored to reflex the effect of combined drying on cell breakage of PSP granules. The single factor experiment and response surface methodology were used to optimize the process parameters of the combined drying of PSP granules. It was concluded that the optimal process parameters of combined drying were hot air drying temperature of 70℃, intermediate conversion moisture content of 25%, and freeze-drying time of 7hours. The PSP granules prepared according to the optimal parameters had an iodine blue value of 10.25 and anthocyanin content of 16.23mg/100g. At this time, the PSP granules had the lowest iodine blue value, and the anthocyanin retention was better, which was higher than the anthocyanin content of PSP granules at the optimal level of single factor. It indicated that the combined drying could reduce the free starch content of PSP granules and avoid huge losses of anthocyanins, and proved that combined drying could prevent the cell breakage of PSP granules, and better maintain the cell integrity of PSP granules.(以新鲜紫薯为原料,紫薯全粉碘蓝值和花青素含量为评价指标,研究紫薯全粉加工过程中复合干燥对紫薯全粉游离淀粉含量的影响,同时探讨紫薯全粉花青素含量与全粉细胞破损之间的关系,以此说明复合干燥对紫薯全粉细胞破损的影响。采用单因素实验和响应面分析法优化紫薯全粉复合干燥的工艺,得到复合干燥优化工艺参数为:热风干燥温度70℃、中间转换含水率25%、冷冻干燥时间7h。在优化条件下,紫薯全粉碘蓝值为10.25,花青素含量为16.23mg/100g,此时紫薯全粉的碘蓝值最低,花青素保留情况较好,其含量高于单因素最佳水平下紫薯全粉的花青素含量。这说明复合干燥可以减少紫薯全粉游离淀粉含量,避免花青素大量损失,从而证明复合干燥能够减少紫薯全粉细胞破损,较好地保持了紫薯全粉的细胞完整性。)