不同聚合度糖渗透对苹果片干燥特性及品质的影响

摘要

Osmotic dehydration is a pre-treatment for drying of fruits and vegetables,which can reduce the drying time and improve food quality.The effects of different osmotic pretreatments on apple hot-air drying behavior and physical characteristics of instant controlled pressure drop dried apple chips were investigated.Samples were immersed in monosaccharide (fiuctose,glucose),disaccharide (sucrose,maltose),trisaccharide (raffinose),and tetrasaccharide (stachyose),respectively.Sugar gain and water loss were analyzed.The samples were further hot air-dried and the experimental data were fitted successfully using the Page model.Compared with the untreated samples,osmotic dehydration using selected sugar solutions contributed to better texture and color retention.Samples pretreated by raffinose and stachyose immersion exhibited the highest crispness.This study could provide a reference for the choice of osmotic solutions for pretreatment prior to drying of fruits and vegetables.%渗透作为果蔬干燥预处理方式,能减少干燥时间、提高产品质量.为探宄不同聚合度糖渗透对苹果片热风-压差闪蒸联合干燥特性及产品品质的影响,采用单糖(果糖、葡萄糖)、二糖(蔗糖、麦芽糖)、三糖(棉子糖)、四糖(水苏糖)对苹果片进行渗透和热风-压差闪蒸联合干燥实验.对渗透苹果片热风干燥特性曲线进行干燥动力学模型拟合,选择热风干燥至水分比为0.1的样品进行压差闪蒸处理,并对所得苹果脆片质构和色泽进行分析.结果表明:除麦芽糖外,随着渗透所用糖的聚合度增加,渗透效率降低;Page模型能准确地(R2＞0.998)描述渗透后苹果片的热风干燥规律;与未渗透处理的对照组样品相比,实验所选不同聚合度糖能显著提高苹果脆片的硬度,其中棉子糖和水苏糖对脆度提高作用最显著;此外,渗透可以保护苹果片色泽,但不同糖液渗透后苹果片的△E差异并不显著.本研究可为果蔬干燥渗透预处理的糖种类的选择提供理论依据.