蒸烫预处理对铁棍山药片干燥及品质变化的影响

Effect of Steaming Pretreatment on Drying and Quality Change of Iron Stick Yam Slices

以铁棍山药片为试材,采用不同的烫漂时间对铁棍山药片进行烫漂预处理,测定了干燥前后铁棍山药片色泽、质构、多酚氧化酶(Polyphenol oxidase,PPO)和过氧化物酶(Peroxidase,POD)的活性,并观察了水分迁移规律及微观结构,以期获得铁棍山药最佳的预处理工艺。结果表明:蒸烫预处理增加了山药片干燥时间,降低了干燥速率;烫漂60 s和90 s时,山药片总色差值较低;烫漂干燥后的山药片硬度值、弹性值、黏性值随着烫漂时间增加而增加,烫漂时间0~60 s时,其值均显著低于鲜样(P<0.05),烫漂90 s和120 s时显著增大;烫漂90 s后,山药片中的POD已完全失活;烫漂后山药片内部水分在60 s至120 s区间显著增加(P<0.05);从微观结构分析,烫漂超过90 s时,过度烫漂导致细胞组织严重破坏。综合分析,铁棍山药片蒸烫预处理的最佳时间在60~90 s,该研究可为探究山药片蒸汽烫漂的品质调控提供理论参考依据。

Iron stick yam slices were used as test material for steaming pretreatment at different steaming times.The color,texture,polyphenol oxidase(PPO),peroxidase(POD),and water transfer law and microstructure of iron stick yam slices before and after drying were measured,in order to obtain the optimal pretreatment process for iron stick yam slices.The results showed that steaming pretreatment increased the drying time of yam slices and decreased the drying rate.When steaming for 60 s and 90 s,the total color difference value of yam slices is relatively low.The hardness value,elasticity value,and viscosity value of dried yam slices increased with the increase of steaming time.When steaming time was 0–60 s,their values were significantly lower than those of fresh samples(P<0.05),and significantly increased at 90 s and 120 s of steaming.After 90 s of steaming,the POD in yam slices has completely inactivated;After steaming,the internal water content of yam slices significantly increased between 60 s and 120 s(P<0.05);From a microstructure analysis,excessive steaming over 90 s could result in severe damage to cellular tissue.Based on comprehensive analysis,the optimal time for steaming of iron stick yam slices is 60–90 s.This study provides a reference theoretical basis for exploring the quality control of steaming of yam slices.