脂肪球的低温失稳机制及其对冰淇淋质构形成的影响

发布时间：2018-01-20 18:46

  本文关键词： 冰淇淋质构 脂肪球失稳作用 结晶 界面作用 组成成分 加工方式　出处：《哈尔滨工业大学》2017年博士论文　论文类型：学位论文

【摘要】：冰淇淋是一种复杂的搅打充气胶体体系,在老化过程中,要求冰淇淋乳状液具有静态稳定性,蛋白质和多糖间的热力学不相容性影响冰淇淋乳状液在静态下的储存。而在搅打凝冻过程中,脂肪球发生一定程度的失稳才有利于冰淇淋质构的形成。冰淇淋中的脂肪、蛋白质和乳化剂之间的相互作用会引起蛋白质在脂肪球表面吸附特性以及脂肪结晶特性的改变,进而影响脂肪球的失稳作用和冰淇淋质构的形成。为了保证冰淇淋乳状液在储存过程中的稳定性,研究了两种常用的多糖稳定剂对冰淇淋乳状液静态稳定性的影响;在搅打凝冻过程中,系统地研究了不同乳化剂/脂肪/蛋白质的界面作用、不同蛋白质组成以及加工方式条件下脂肪球的低温失稳机制及其对冰淇淋质构形成的影响。采用荧光光谱法研究了羧甲基纤维素钠(CMC)和瓜尔胶(GG)与乳蛋白之间的相互作用,通过测定油-水界面张力、多糖与乳蛋白在脂肪球表面的吸附量、zeta的变化研究了多糖/乳蛋白在脂肪球表面的吸附特性,基于多糖与乳蛋白在体系中的作用特性研究和探讨了多糖对冰淇淋模拟乳状液静态稳定性和起泡特性的影响。结果表明,CMC能与乳蛋白通过静电相互作用形成非共价复合物,以复合物形式吸附在脂肪球表面和存在连续相中,从而形成黏性增强的网络结构;而GG与乳蛋白不能形成复合物,GG作为亲水胶体存在于连续相中,引起了冰淇淋模拟乳状液显著的相分离;CMC与乳蛋白的非共价结合增强了乳化体系对形变的抵抗能力,增加了乳状液起泡性和泡沫稳定性。当CMC浓度为0.25%时,乳状液的静态稳定性较好,起泡能力和气泡稳定性最佳。研究了单硬脂酸甘油酯、单油酸甘油酯、蔗糖酯与蛋白质在脂肪球表面的竞争性吸附特性,基于DSC法对乳状液中椰子油和奶油的成核特性和晶体生长特性进行了研究,探讨了不同乳化剂/脂肪/蛋白质的界面作用对搅打凝冻过程中脂肪球的失稳作用机制。结果表明,单硬脂酸甘油酯能够替代脂肪球表面的蛋白质,但对无水奶油和椰子油结晶特性影响不同,单硬脂酸甘油酯能降低奶油的成核温度,使晶体生长维数增加,利于脂肪球发生部分聚结作用,但能提高椰子油成核温度,使晶体生长维数降低,不利于脂肪球发生部分聚结作用;单油酸甘油酯不能对蛋白质产生替代作用,脂肪球的失稳主要是因为脂肪晶体生长速率降低和晶体生长维数增加引起的;蔗糖酯浓度高于0.2%时与蛋白质在脂肪球表面发生竞争性吸附作用,蔗糖酯对蛋白质的替代作用是引起脂肪球部分聚结的主导因素;蔗糖酯浓度为0.2%~0.3%时能够使奶油冰淇淋和椰子油冰淇淋获得理想的膨胀率和抗融性。研究了乳蛋白、乳清蛋白、大豆蛋白和蔗糖酯在脂肪球表面的吸附特性对搅打凝冻过程中脂肪球失稳作用的影响,采用乳清蛋白和大豆蛋白对乳蛋白部分替代,研究了混合蛋白体系中脂肪球的低温失稳机制及对冰淇淋质构形成的影响。蔗糖酯与酪蛋白、乳清蛋白以及大豆蛋白能够产生复合作用,与蛋白质在脂肪球表面的吸附存在复合吸附机制和竞争吸附作用机制;不同的乳蛋白-乳清蛋白比例以及乳蛋白-大豆蛋白比例影响蛋白质在脂肪球表面的吸附特性和脂肪结晶特性。相比于对晶体形态的改变,蔗糖酯与蛋白质的竞争性吸附作用在影响脂肪球的失稳程度上占主导。在混合蛋白体系中,当乳蛋白与乳清蛋白比例为3:7,乳蛋白与大豆蛋白比例为7:3时,脂肪球的部分聚结度最高。此时,冰淇淋具有理想的膨胀率和抗融性。对不同蛋白质组成的物料采用先杀菌后均质和先均质后杀菌的工艺步骤,研究了加工方式对脂肪球低温失稳作用的影响,并进一步研究和探讨了脂肪球稳定性变化对冰淇淋质构形成的作用和影响。先杀菌后均质和先均质后杀菌对乳蛋白冰淇淋乳状液的静态稳定性、脂肪球在搅打凝冻过程中的失稳程度以及冰淇淋的质构特性没有显著影响;对于乳蛋白-乳清蛋白和乳蛋白-大豆蛋白冰淇淋而言,杀菌过程中的热效应引起蛋白质在脂肪球表面吸附和聚集行为的变化,降低了乳状液的静态稳定性,提高了搅打凝冻过程中脂肪球的聚集度,促进了空气泡的充入,但是又降低了脂肪球的部分聚结度,加快了融化过程中气泡的破裂;采用先均质后杀菌的加工方式获得的三种蛋白质冰淇淋的膨胀率、抗融性、气泡的均匀度,以及冰淇淋的感官评定均符合产品的质构和感官质量要求。
[Abstract]:Ice cream is a complex whipping colloidal system in the aging process, for ice cream emulsion with static stability, thermodynamics of protein and polysaccharide between incompatible storage of ice cream emulsion under static. While in whipped freezing process, fat globules in a certain degree of instability is conducive to the formation of ice cream texture. The fat in the ice cream, the interaction between the protein and the emulsifier can cause the protein on the surface adsorption characteristics of fat globules and fat crystallization characteristics change, thereby affecting the fat globule instability and the formation of ice cream texture. In order to ensure the stability of ice cream emulsion during storage, effects two kinds of polysaccharide stabilizers on the static stability of ice cream emulsion; in whipped freezing process, a systematic study of the different emulsifier / fat / protein interface Effect of different protein composition and processing conditions of the low fat ball instability mechanism and its influence on the forming quality of ice cream. Sodium carboxymethyl cellulose by fluorescence spectroscopy (CMC) and guar gum (GG) and the interaction between milk protein, by measuring the oil-water interfacial tension, and polysaccharide milk protein adsorption on the surface of fat globules, zeta of polysaccharide / milk protein adsorption on the surface of fat globules, properties of polysaccharide and protein in milk in the system and discussed the influence of Polysaccharide on the simulation of the static stability of the emulsion and cream based on foaming properties. The results show that CMC can with milk protein through electrostatic interactions to form non covalent complexes, in the form of complex adsorption in the continuous phase and the fat globule surface exists, thus forming the network structure and GG with enhanced viscosity; milk protein can not form complexes, GG as the hydrophilic colloid is present in the continuous phase by phase separation simulation of ice cream emulsion significantly; non covalent CMC and milk protein with improved resistance to deformation of the emulsion system, adding emulsion foaming and foam stability. When the concentration of CMC was 0.25%, the static stability of milk like liquid good foaming bubble ability and best stability. Glycerol monostearate of glycerol monooleate, sucrose ester and protein in the competitive adsorption of the fat globule surface, DSC method of coconut oil and butter in emulsion nucleation and crystal growth characteristics were investigated based on different emulsifier / fat / interface effect of protein on the whipping fat ball in the process of freezing instability mechanism. The results showed that glycerol monostearate can replace the fat globule surface proteins, but the anhydrous butter and coconut oil crystal. The effect of different glycerol monostearate can reduce the nucleation temperature of cream, make the crystal growth dimension increases to fat partial coalescence occurs, but can increase the nucleation temperature of coconut oil, which is not conducive to reduce the dimension of crystal growth, partial coalescence of fat globules occurs; glycerol monooleate cannot substitute the role of protein, fat globule instability is mainly due to the lower growth rate of fat crystals and crystal growth caused by the increase of dimension; sucrose ester concentration higher than 0.2% with proteins at the fat globule surface competitive adsorption, the substitution effect of sucrose ester on protein is caused by fat partial coalescence of the dominant factor; concentration of sucrose esters 0.2%~0.3% can make ice cream and ice cream coconut oil to obtain the ideal expansion rate and melting resistance. The study of milk protein, whey protein, soybean protein and sucrose ester in the fat ball table The influence of adsorption characteristics on the whipping process conceeded fat freezing stabilization effect, using whey protein and soy protein instead of milk protein, fat of Hybrid Ball protein system in low temperature instability mechanism and the forming effect on ice cream. Quality of sucrose ester and casein, whey protein, soybean protein can produce composite effect there, and protein composite adsorption mechanism and the competitive adsorption mechanism in the adsorption of the fat globule surface; milk protein - different whey protein and milk protein percentage of soy protein affects the ratio of protein in fat globule surface adsorption properties and crystallization properties. Compared to the fat on the crystal morphology of competitive adsorption effect of sucrose ester and protein the effect of fat ball instability degree is dominant. In the mixed protein system, when milk protein and whey protein ratio 3:7, milk protein and soybean protein White ratio is 7:3, partial coalescence is the highest. At this time, the ice cream has the ideal expansion rate and melting resistance. After the sterilization process steps after homogenization and sterilization by first after homogenization of different protein composition of the material, studied the processing methods for the instability of fat ball and low temperature. To further study and discuss the change of structure stability of fat ball effect and influence on the formation of ice cream. First after sterilization and sterilization of homogeneous homogenized milk protein ice cream emulsion of fat globules in static stability, whipping instability in the process of freezing and ice cream to textural properties had no significant effect for milk protein; whey protein and milk protein - protein soybean ice cream, the thermal effect of sterilization process caused by the change of protein aggregation in the fat globule surface adsorption and, reduced the static stability of the emulsions, high Stir the aggregation in the process of playing ball frozen fat promotes air bubbles, filling, but also reduces the partial coalescence of bubbles, accelerate the rupture during melting process; the expansion rate of three kinds of protein obtained by ice cream processing sterilization first after homogenization, melting resistance, uniformity bubble, and ice cream products are in line with the sensory evaluation of texture and sensory quality requirements.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TS277
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本文编号：1449192