海藻酸盐水凝胶和单甘酯油凝胶双凝胶体系的制备与理化性质表征

Preparation and Physicochemical Properties of Bigel Based on Alginate Hydrogel and Glycerin Monostearate Oleogel

双凝胶包含水凝胶和油凝胶,是一种新型的复合胶体体系,然而,目前在食品领域的研究非常有限。本研究以基于单硬脂酸甘油酯的油凝胶和基于海藻酸钠的水凝胶制备双凝胶,探究油水相比例、乳化剂添加量、钙离子浓度对双凝胶质构特性、冻融稳定性及流变特性等的影响,阐释调控双凝胶结构性质的关键因素。结果表明:钙离子浓度增加导致双凝胶具有较高的硬度和较低的持水性;乳化剂(TW-20)含量对双凝胶性质产生复杂的影响,对于低油凝胶含量(20%与30%)的样品,体系的持水力与乳化剂添加量成正比,持油力接近100%。油水相比例对双凝胶体系影响显著,随着油凝胶含量的增加,体系硬度降低,黏性增加。体系内水凝胶的存在有助于双凝胶(10%油凝胶)在经过升、降温后恢复到原有结构。随着油凝胶含量的增加(30%与50%),体系恢复性与热稳定性降低。这些信息的获得将有助于拓展双凝胶在食品体系中的深入应用。

Bigels are novel complex biphasic systems composed by two different semi-solid networks(hydrogel and oleogel), but the researches in food area were considerably limited. In this study, bigel based on glycerol monostearate oleogel and alginate hydrogels were studied to explore the effect of different parameters(oleogel ∶ hydrogel ratio, emulsifier content and CaCOcontent) on mechanical properties, freeze-thaw stability and rheological properties of bigel, which was intended to interpret the key factors exerting the most significant influence on bigels. The results show: the increase of CaCOcontent results in higher hardness and lower water holding capacity. It was observed that the emulsifier content has a complex effect on the properties of bigels. A monotonously increasing trend of the freeze-thaw stability were observed for bigel samples(20% and 30% oleogel content) with increasing TW-20 content. It is worth noting that the oleogel ∶ hydrogel ratio has a great effect on the bigel system. With the increase of the oleogel content, the hardness of the system decreased while the viscosity followed an opposite trend. The existence of hydrogel in system(10% oleogel)contributes to recover to the original structure after heating and cooling. With the increase of the oleogel content(30% and 50%), the recovery and the thermal stability of bigels decreased. The acquisition of these information will help expand the application of bigels in food systems.