辣椒渗透脱水处理及渗后热风干燥特性及品质分析

以脱水率、固形物获取率、脱水率与固形物获取率比值、有效水分扩散系数、活化能、VC保留率、辣度、复水比、复原率和感官评价为考察指标,通过渗透脱水实验、渗后热风干燥实验和复水实验,考察了辣椒的渗透脱水特性、渗后热风干燥特性、复水特性和品质。结果表明:随着渗透温度的升高或渗透液中食盐含量的增加,辣椒的脱水率和固形物获取率增大。对渗透后的辣椒样品进行热风干燥处理发现,热风温度是影响热风干燥的最主要因素,其次是风速。辣椒样品的有效水分扩散系数随着温度的升高而增大,在风速为1.8 m/s的条件下,直接热风干燥辣椒样品和渗后热风干燥辣椒样品的活化能分别为(53.25±1.08)k J/mol和(44.42±0.88)k J/mol。渗后热风干燥样品的有效水分扩散系数、VC保留率、辣度、复水比和复原率均高于直接热风干燥样品,渗后热风干燥样品的复水特性和品质更好。

Characterization of Osmotic Dehydration and Subsequent Hot-Air Drying of Chili Pepper

Osmotic dehydration, hot-air drying and rehydration experiments were sequentially carried out to investigate the osmotic dehydration, hot-air drying and rehydration characteristics of chili pepper as well as final product quality by measuring water loss, solid gain, ratio between water loss and solid gain, effective moisture diffusion coefficient, activation energy, VC retention rate, pungency degree, rehydration rate, recovery rate, and sensory evaluation. The results showed that with the increase in temperature or salt concentration of the osmotic solution, water loss and solid gain of chili pepper increased. Hot-air temperature was the main factor that affects the hot-air drying, followed by air velocity. With the increase in hot-air temperature, the effective moisture diffusion coefficient of chili pepper samples increased and the activation energy of direct hot-air drying and hot-air drying after osmotic dehydration were (53.25 ± 1.08) and (44.42 ± 0.88) kJ/mol, respectively at an air velocity of 1.8 m/s. The effective moisture diffusion coefficient, VC retention rate, pungency degree, rehydration rate and recovery rate of dehydrated and hot-air dried chili pepper processed by osmotic ion followed by hotair drying were higher than those of the hot-air dried sample, and the rehydration characteristics and quality of the former sample were better than those of the latter one.