复合凝聚法及反溶剂法对乳酸菌的包埋研究

发布时间：2018-04-23 18:21

本文选题：乳酸菌 + 复合凝聚　；参考：《湖北工业大学》2017年硕士论文

【摘要】：乳酸菌产品的常温储藏是食品工业亟待解决的热点问题。乳酸菌常温储藏降低了产品运输和储藏成本,且配送、分销、消费者食用等环节更方便易行,因而更符合实际需求。微胶囊技术可提高乳酸菌对温度、湿度、氧气等环境因素的胁迫抗性,一直是食品科学的研究热点。复合凝聚法和反溶剂法是近年发展起来的新型微囊化技术,本论文拟研究这两种技术对干态乳酸菌常温定湿储藏的适用性,考察制备因素和储藏因素对乳酸菌储藏效果的影响规律。本研究采用WPI/GA复合凝聚法包埋乳酸菌,研究了WPI/GA复合凝聚法包埋对乳酸菌的常温定湿储藏保护效果;通过GE/GA复合凝聚提高复合凝聚pH,研究了GE/GA复合凝聚法包埋对乳酸菌的常温定湿储藏保护效果;反溶剂法构建了壳核结构的油/Zein微米颗粒,并研究了其对乳酸菌的保护效果。主要结论如下:(1)优化了WPI/GA复合凝聚工艺,探究了WPI/GA复合凝聚法包埋对乳酸菌喷雾干燥后存活率的影响,及不同温度、湿度条件下乳酸菌的储藏稳定性影响。WPI/GA最佳复合凝聚条件为pH=4.5、WPI/GA配比为4、总浓度为3%(w/w)。与WPI组相比,WPI/GA组对乳酸菌喷雾干燥和常温定湿储藏中的保护效果并不显著,WPI/GA/蔗糖组显著提高了菌体在喷雾干燥过程中的存活率,从56.3±8.0%提高至78.7±5.7%,但没有明显改善菌体储藏稳定性。这可能是由于WPI/GA体系复合凝聚pH较低,在喷雾干燥过程中加剧了对菌体的酸伤害和热伤害,蔗糖在喷雾干燥过程中发挥了一定的乳酸菌保护效果,但未能在常温定湿储藏中有效阻止菌体存活恶化。(2)优化了GE/GA复合凝聚工艺,探究了GE/GA复合凝聚法包埋对乳酸菌喷雾干燥后存活率的影响,及不同温度、湿度条件下乳酸菌的储藏稳定性影响。GE/GA最佳复合凝聚条件为pH=5.0或5.5、GE/GA配比为4、总浓度为2%(w/w)。相比WPI/GA体系,GE/GA复凝聚明显提高了复合凝聚pH。与GA_(5.5)组相比,GE/GA_(5.5)组对乳酸菌喷雾干燥和常温定湿储藏中具有明显保护效果;与GE5.5组相比,GE/GA_(5.5)组对乳酸菌喷雾干燥和常温定湿储藏中的保护效果并不显著;相比GE/GA_(5.0)组,复合凝聚pH的提高可以改善GE/GA_(5.5)组菌体储藏稳定性。GE/GA/S5.5组显著提高了菌体在喷雾干燥过程中的存活率,从102.6±5.9%提高至131.3±8.0%,且明显改善菌体储藏稳定性,微胶囊在30oC、11%RH下储藏56 d后乳酸菌数量仅下降1.63个对数。(3)优化了Zein反溶剂法制备油/Zein微米颗粒的最佳工艺条件,以中链甘油三酯(MCT)和棕榈油(PO)为代表性油脂,研究了油/Zein微米颗粒对乳酸菌的包埋效果,及微胶囊的结构和理化性质。基于Zein反溶剂法,以GA为O/W乳化剂和Zein微米颗粒水相分散剂,制备了具有良好稳定性及明显壳核结构的MCT/Zein微米颗粒。通过反溶剂法制备的LAB/MCT/Zein微米颗粒和LAB/PO/Zein微米颗粒形态良好、分散性好,对乳酸菌实现了包埋,但由于乙醇的存在造成乳酸菌的存活较低。
[Abstract]:The storage of lactic acid bacteria products at room temperature is a hot issue to be solved in food industry. The storage of lactic acid bacteria at room temperature reduces the cost of product transportation and storage, and distribution, distribution, consumer consumption and other links are more convenient and easy to carry out, thus more in line with the actual needs. Microencapsulation can improve the stress resistance of lactic acid bacteria to environmental factors such as temperature, humidity and oxygen. Compound coagulation and antisolvent are new microencapsulation techniques developed in recent years. In this paper, the applicability of these two techniques to dry lactic acid bacteria storage at room temperature and humidity was studied. The effects of preparation factors and storage factors on the storage effect of lactic acid bacteria were investigated. In this study, lactic acid bacteria were encapsulated by WPI/GA complex coagulation method, and the protective effect of WPI/GA composite coagulation method on lactic acid bacteria stored at room temperature and humidity was studied. The protective effect of GE/GA composite coagulation method on the storage of lactic acid bacteria at room temperature and humidity was studied by raising the pH of complex coagulation by GE/GA complex coagulation, and the oil / Zein micron particles with shell core structure were constructed by anti-solvent method, and the protective effect of GE/GA on lactic acid bacteria was studied. The main conclusions are as follows: (1) the process of WPI/GA compound coagulation was optimized, and the effect of WPI/GA composite coagulation method on survival rate of lactic acid bacteria after spray drying and different temperatures were investigated. The effect of storage stability of lactic acid bacteria on the storage stability of lactic acid bacteria. The optimum conditions of WPI / GA were as follows: pH = 4.5% WPI / GA = 4, and the total concentration of WPI / GA = 3 / W ~ (-1). Compared with WPI group, the protective effect of WPI / GA group on lactic acid bacteria spray drying and storage at room temperature and humidity was not significant. WPI / GA / sucrose group significantly increased the survival rate of the bacteria during spray drying from 56.3 卤8.0% to 78.7 卤5.7%, but did not significantly improve the storage stability. This may be due to the low pH value of compound condensation in WPI/GA system, which increases the acid and thermal injury to the bacteria during spray drying, and sucrose plays a protective role in the spray drying process by lactic acid bacteria, while in the process of spray drying, sucrose plays an important role in the protection of lactic acid bacteria. But it failed to effectively prevent the deterioration of cell survival in normal temperature and humidity storage.) the process of GE/GA compound coagulation was optimized, and the effect of GE/GA compound coagulation method on survival rate of lactic acid bacteria after spray drying and different temperatures were investigated. Under the condition of humidity, the effect of storage stability of lactic acid bacteria. GE / GA is as follows: pH=5.0 or 5.5% GE / GA ratio is 4, total concentration is 2 w/ w / w ~ (-1). Compared with WPI/GA system, GE / GA complex coacervation improved the complex coagulation pH. Compared with the group of Gal / Gah (5.5), the group of GE / GA _ 5) had obvious protective effects on spray drying of lactic acid bacteria and storage of humidity at room temperature; compared with the group of GE5.5, the protective effect of group GE / GA _ 5) on spray drying of lactic acid bacteria and storage of humidity at room temperature was not significant; compared with group GE / GA _ (5.0), it had no significant protective effect on lactic acid bacteria spray drying and humidity storage at room temperature. The stability of GE / GA / GA / S5.5 group was significantly improved by increasing the pH value of complex condensation from 102.6 卤5.9% to 131.3 卤8.0%, and the storage stability of the bacteria was improved obviously in the group of GE / GA / GA / S 5.5, which increased the survival rate of bacteria during spray drying from 102.6 卤5.9% to 131.3 卤8.0%. The microcapsule was stored under 30oC ~ (11) RH for 56 days, the number of lactic acid bacteria decreased only 1.63 log.K3) the optimum conditions for preparing oil / Zein micron particles by Zein antisolvent method were optimized. The typical oils were medium-chain triglyceride (Zein) and palm oil (PO3). The embedding effect of oil / Zein micron particles on lactic acid bacteria and the structure and physicochemical properties of microcapsules were studied. Based on Zein antisolvent method, MCT/Zein micron particles with good stability and obvious shell core structure were prepared by using GA as o / W emulsifier and Zein micron particle aqueous dispersion agent. The LAB/MCT/Zein micron and LAB/PO/Zein micron particles prepared by antisolvent method have good morphology and good dispersibility. They are encapsulated by lactic acid bacteria, but the survival of lactic acid bacteria is low due to the presence of ethanol.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS201.3

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