乳酸菌喷雾冷冻干燥机理及干燥行为控制机制研究

The results of former research showed that the droplet vacuum flashing/freezing effect could be applied to spray freeze drying process(SFD). It would simplify the procedures, reduce the cost of drying.Lactic acid bacteria (LAB) is very good health care food. It reveived More and more attention. It's survival rate of spray drying is low, the cost freeze drying is high.In this project, LAB is as the research object. The spray flashing/freezing and freeze drying process were studied. Theory and experiment method using mathematical model and computer simulation, the equilibrium thermodynamics and CFD methods were carried out to explore the droplet vacuum flash vaporating freezing effect mechanism in SFD. The SFD process of LAB in macroscopic and the microscopic scale was descripted. Through the detection of physiological indexes of LAB, failure mechanism of LAB cell in droplet atomization, vacuum flashing/freezing and SFD process is shown. The biological activity mechanism in SFD was revealed.This project aims to provide a new method for drying of LAB. It would be effective control the drying behavior and heat and mass transfer ofLAB. On the other hand, this sudty would supply a new way for low energy consumption and high efficient green freeze drying technology.

前期研究表明，液滴真空闪蒸冻结效应可以应用于喷雾冷冻干燥过程，从而简化操作步骤，降低干燥成本。乳酸菌由于具有很好的保健作用，越来越受到重视，但是喷雾干燥方式存活率较低，冷冻干燥方式成本较高。本项目以乳酸菌为研究对象，对喷雾冻结过程和冷冻干燥过程进行研究，从理论和实验两个角度出发，运用数学模型和计算机模拟，采用平衡热力学和CFD等方法，探索液滴真空闪蒸冻结效应在喷雾冷冻干燥过程中的运行机制，在宏观和微观两个尺度对乳酸菌的喷雾冷冻干燥过程进行描述；通过乳酸菌存活率、活性和理化指标的检测，阐明液滴雾化、真空闪蒸冻结和喷雾冷冻干燥三个过程对乳酸菌细胞破坏机理，揭示这种干燥方式对乳酸菌生物活性损伤机制。本项目旨在提出乳酸菌干燥新方法，探索乳酸菌的干燥行为及热质传递的有效控制机制，同时为低耗、高效、绿色冻干技术提供新的解决途径。

研究表明，液滴真空闪蒸冻结效应可以应用于喷雾冷冻干燥过程，从而简化操作步骤，降低干燥成本。乳酸菌由于具有很好的保健作用，越来越受到重视，但是喷雾干燥方式存活率较低，冷冻干燥方式成本较高。本项目以乳酸菌为研究对象，对喷雾冻结过程和冷冻干燥过程进行研究，从理论和实验两个角度出发，运用数学模型和计算机模拟，采用平衡热力学和CFD等方法， 探索液滴真空闪蒸冻结效应在喷雾冷冻干燥过程中的运行机制，在宏观和微观两个尺度对乳酸菌的喷雾冷冻干燥过程进行描述；通过乳酸菌存活率、活性和理化指标的检测，阐明液滴雾化、真空闪蒸冻结和喷雾冷冻干燥三个过程对乳酸菌细胞破坏机理，揭示这种干燥方式对乳酸菌生物活性损伤机制。本项目旨在提出乳酸菌干燥新方法，探索乳酸菌的干燥行为及热质传递的有效控制机制，同时为低耗、高效、绿色冻干技术提供新的解决途径。