Liquid whey protein concentrates as primary raw material for acid dairy gels

Abstract The replacement of dehydrated products such as whey protein concentrates and isolates (WPC and WPI) by liquid whey protein concentrates (LWPC) obtained by ultrafiltration can be an excellent alternative for the production of innovative dairy products. Thus, the aim of this work is to study the gelation properties of LWPC as raw material for acid-induced dairy gels. Acid-induced gels were produced with non-defatted LWPC, with or without fortification with skimmed milk powder (SMP), by bacterial fermentation and by glucono-δ-lactone (GDL) acidification. The fermented systems (yogurt type acid gels) produced weaker gel structures than the equivalent chemically acidified gels (dessert type acid gels). It was also observed that molecular rearrangement continues during cold storage and that fortification with SMP favoured gelation. Whey-based dairy gels obtained by fermentation or by glucono-δ-lactone acidification presented viscoelastic behaviour, appealing functional and nutritional properties, and their utilization can effectively contribute to the reduction of waste.摘要 采用超滤法制得的液态乳清蛋白浓缩物（LWPC）替代乳清蛋白浓缩物与分离物（WPC和WPI）等脱水产品，可作为开发创新乳制品的优质备选方案。本研究旨在探究以液态乳清蛋白浓缩物（LWPC）为原料制备酸诱导乳凝胶的凝胶特性。实验分别通过细菌发酵法与葡萄糖酸δ-内酯（GDL）酸化法，制备了未添加脱脂乳粉（SMP）及经脱脂乳粉强化的非脱脂液态乳清蛋白浓缩物体系的酸诱导凝胶。结果显示，发酵体系（酸奶型酸凝胶）的凝胶结构弱于同等条件下化学酸化制备的凝胶（甜点型酸凝胶）。此外还观察到，冷藏过程中分子重排仍在持续，且添加脱脂乳粉可促进凝胶形成。经发酵或葡萄糖酸δ-内酯酸化制得的乳清基乳凝胶，均表现出黏弹性行为，具备优异的功能特性与营养属性，其应用可有效助力减少食品加工废弃物。