Román Laura, Martínez Mario M, Gómez Manuel
Food Technology Area, College of Agricultural Engineering, University of Valladolid, 34004 Palencia, Spain.
Food Technology Area, College of Agricultural Engineering, University of Valladolid, 34004 Palencia, Spain.
Food Res Int. 2015 Aug;74:72-79. doi: 10.1016/j.foodres.2015.04.035. Epub 2015 Apr 24.
Extruded flour represents an economical and environmental friendly alternative as fat replacer. In this research, the potential use of an extruded flour-water paste as fat replacer in an oil-in-water emulsion was studied. The effect of flour-water ratio and level of oil replacement (30, 50 and 70%) on the microstructure, rheological properties and stability of mayonnaise-like emulsion was evaluated. Fat replacement by extruded flour gradually increased the number and reduced the size of oil droplets. All the emulsion samples showed a pseudoplastic behaviour. At low shear rates a Newtonian region characterised by Carreau model appeared (R>0.99). In general, the limiting viscosity of the Newtonian region and the consistency index increased with the decreased water content of the paste and increased the level of oil substitution. A decrease in oil concentration led to a greater thixotropic behaviour. Oscillatory test revealed that predominance of the continuous or dispersed phase influenced viscoelastic behaviour. Reduction in oil content resulted in an increased freeze-thaw stability. Results suggested that if the flour-water ratio of the paste is controlled, extruded flour is appropriate for preparing reduced-fat oil-in-water emulsion with similar rheological properties to the full fat and greater freeze-thaw stability.
挤压面粉作为脂肪替代品是一种经济且环保的选择。在本研究中，对挤压面粉 - 水糊剂作为水包油乳液中脂肪替代品的潜在用途进行了研究。评估了面粉与水的比例以及油替代水平（30%、50%和70%）对蛋黄酱状乳液的微观结构、流变特性和稳定性的影响。用挤压面粉替代脂肪逐渐增加了油滴的数量并减小了其尺寸。所有乳液样品均表现出假塑性行为。在低剪切速率下出现了由Carreau模型表征的牛顿区（R>0.99）。一般来说，牛顿区的极限粘度和稠度指数随着糊剂含水量的降低以及油替代水平的提高而增加。油浓度的降低导致更大的触变性行为。振荡试验表明，连续相或分散相的主导地位影响粘弹性行为。油含量的降低导致冻融稳定性提高。结果表明，如果控制糊剂的面粉 - 水比例，挤压面粉适合制备具有与全脂产品相似流变特性且冻融稳定性更高的低脂水包油乳液。
