Rheological characterization and stability study of an emulsion made with a dairy by-product enriched with omega-3 fatty acids

This study involved a rheological characterization of a W/O emulsion manufactured on a pilot scale using omega-3 fatty acids as part of the oil phase and butter milk as the emulsifier. Polyunsaturated omega-3 fatty acids are essential to prevent cardiovascular diseases, improve pulmonary function and also form part of the neurological structure. Buttermilk is a by-product of the dairy industry and has a high organic load which possesses surfactant properties and constitutes a good substitute for conventional emulsifiers in the food industry. The microstructural nature of the emulsion was characterized from the viscoelastic parameters and mechanical spectra. The linear viscoelastic range was determined, from which the maximum stress that the emulsion could withstand from the processing conditions without altering its microstructure was established. In addition, the storage stability of the emulsion was studied to instrumentally predict the rheological behaviour before sensory destabilization of the emulsion was observed. At the frequencies used, a significant decrease in dynamic viscoelastic parameters was periodically observed (G 'and G''), showing a structural change during storage. Furthermore, a coalescence phenomenon was observed after 18 months. The formulation with added omega-3 fatty acids and buttermilk provided a basis for obtaining a functional food as well as adding value to an industrial by-product.本研究对以ω-3脂肪酸（omega-3 fatty acids）作为油相组分、酪乳（buttermilk）作为乳化剂，于中试规模下制备的油包水（W/O）乳液开展了流变学表征。多不饱和ω-3脂肪酸是人体必需营养物质，可预防心血管疾病、改善肺功能，同时也是神经系统结构的组成部分。酪乳是乳制品工业的副产物，其有机负荷较高且具备表面活性剂特性，可作为食品工业中传统乳化剂的优质替代品。本研究通过粘弹性参数与力学谱表征了该乳液的微观结构特性，测定了其线性粘弹性区间，并由此确定了乳液在不改变微观结构的前提下可承受的加工条件最大应力。此外，本研究还对该乳液的贮藏稳定性展开了研究，旨在通过仪器分析在感官层面出现乳液失稳现象前，对其流变行为进行预测。在所用频率范围内，研究人员周期性观测到动态粘弹性参数（G'与G''）出现显著下降，表明贮藏过程中乳液发生了结构变化。同时，在贮藏18个月后观测到了聚结现象。添加了ω-3脂肪酸与酪乳的配方，不仅为功能性食品的开发提供了基础，同时也为工业副产物实现增值提供了可行路径。