Department of Food Science, Purdue University, 745 Agriculture Mall Dr, West Lafayette, IN 47907, United States.
Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907, United States.
Food Res Int. 2023 Dec;174(Pt 1):113603. doi: 10.1016/j.foodres.2023.113603. Epub 2023 Nov 3.
Pea protein is a popular source of plant-based protein, though its application in meat and dairy analog products is still lacking. This is particularly true in the development of products with fatty and creamy textures. Cold denaturation may be a way to induce these types of textures in food since this is a universal phenomenon in protein that occurs due to a weakening of hydrophobic interactions at cold temperatures. This work utilizes a single screw extruder to systematically study the impacts of moisture content (50-65 %) and pH (2,4.5,8) on the outlet temperatures, specific mechanical energy, specific thermal energy, and texture of cold-extruded pea protein. It was found that at pH 2 and moistures of 60 % and greater, the temperature of the product exiting the extruder is <5.5 °C, and also produced 13.7 %-36.5 % more specific thermal energy, indicating the occurrence of cold denaturation in these products. Based on these findings, a comparison of hot and cold extrusion was conducted as a function of pH and oil content. It was found that cold extrusion imparts 43.0 %-56.2 % more mechanical energy into the protein than hot extrusion, and the cold extruded protein had higher values of Young's modulus and breaking stress. The protein extruded at low temperatures was also able to bind 32.93 % more oil than hot extruded proteins when extruded with 10 % added oil, which may aid in the formation of protein-based fat memetics for the food industry.
豌豆蛋白是一种常见的植物性蛋白质来源，但它在肉类和奶制品替代品中的应用仍有待开发。在开发具有高脂肪和奶油质地的产品时尤其如此。冷变性可能是在食品中诱导这些质地的一种方法，因为这是蛋白质中一种普遍现象，是由于在低温下疏水相互作用减弱而发生的。本工作利用单螺杆挤出机系统地研究了水分含量（50-65%）和 pH 值（2、4.5、8）对出口温度、比机械能、比热能和冷挤压豌豆蛋白的质地的影响。结果发现，在 pH 值为 2 和水分含量为 60%及以上时，挤出机出口产品的温度<5.5°C，并且比热能增加了 13.7%-36.5%，表明这些产品中发生了冷变性。基于这些发现，进行了热挤压和冷挤压的比较，考察了 pH 值和油含量的影响。结果表明，与热挤压相比，冷挤压将 43.0%-56.2%更多的机械能传递给蛋白质，冷挤压的蛋白质具有更高的杨氏模量和断裂应力。低温挤出的蛋白质在添加 10%油时比热挤出的蛋白质多结合 32.93%的油，这可能有助于形成基于蛋白质的脂肪模拟物，用于食品工业。
