Fabrication of soy protein isolate-konjac glucomannan emulsion gels to mimic the texture, rheological behavior and in vitro digestion of pork fat

Abstract

Fats are essential nutrients, but excessive intake can lead to obesity and certain cardiovascular diseases. In this study, an emulsion gel was prepared using alkali heat treatment with soy protein isolate (SPI) and konjac glucomannan (KGM) as a fat substitute, while pork fat was used as the control. Gel strength, rheological properties, and water holding capacity of soy protein isolate-konjac glucomannan (SPI-KGM) emulsion gel improved progressively with higher KGM content. For instance, the SPI-5 % KGM emulsion gel exhibited a hardness of 384.77 g, a gel strength of 9.62 kPa, and a water-holding capacity of 98.03 %, comparable to pork fat in terms of texture and moisture retention. Furthermore, scanning electron microscopy images revealed that a more compact and regular emulsion gel network was formed with increasing KGM concentration. Therefore, this SPI-KGM emulsion gel shows promise as a substitute for pork fat and holds great potential for developing plant-based meat products.