单液滴干燥过程中载体组分对植物乳杆菌的保护作用

Protective Effects of Carrier Components on Lactobacillus plantarum during Single Droplet Drying

喷雾干燥是目前制备益生菌微胶囊最常用的方法,而研究喷雾干燥塔内液滴的干燥历程有一定的难度。本试验中采用单液滴干燥(SDD)技术模拟喷雾干燥条件,以不同DE值糖浆和不同熔点棕榈油包埋植物乳杆菌,研究90℃和110℃两种干燥条件下对植物乳杆菌的保护作用。研究结果表明,两种干燥条件下含高熔点棕榈油的液滴中植物乳杆菌的存活率均高于低熔点棕榈油的液滴。扫描电镜观察到干燥后的单液滴颗粒表面均无游离的植物乳杆菌。结合液滴干燥过程中水分含量变化推断糖浆的DE值越高越利于表面结构的稳定。对液滴干燥参数以及乳状液的热稳定分析表明,植物乳杆菌的存活率主要与液滴温度有关,棕榈油的熔点越高在干燥过程中吸收的热就越多,从使植物乳杆菌的存活率越高。

Spray drying is the most commonly used method of preparing probiotic microcapsulation. Because of the difficulty in the study of the drying process of the droplets in the spray drying tower, the experiment is carried out to study the protective effects of the different DE syrups and different melting palm oil on the survival rate of L. plantarum in the simulated spray drying conditions using the single droplet drying technology. The results showed that the survival rate of high melting point palm oil droplets was higher than that of low melting point palm oil during the drying process under different drying conditions. It was observed that there was no free L. plantarum on the surface of the single droplet after drying by Scanning electron microscopy(SEM), and the higher the DE value of the syrup was more favorable for the stability of the surface structure combined with the changes in droplet of moisture content. The survival rate of L.plantarum was mainly related to the temperature of the droplets by analyzing the droplet drying parameters and the thermal stability of the emulsion. The higher the melting point of the palm oil, the more heat is absorbed during the drying process so that L. plantarum can get a higher survival rate.