Effect of Xanthan Gum Concentration on Structure and Functional Properties of Porcine Plasma Protein-Xanthan Gum Oleogel

In this paper, a kind of oleogel with mechanical strength and physical absorption of soybean oil was prepared by foam templated by using porcine plasma protein and xanthan gum as raw materials, and its thermal stability was analyzed. The results showed that with the increase of xanthan gum concentration, the apparent viscosity and foam stability of porcine plasma protein and xanthan gum mixed solution system significantly increased, and the foaming property significantly decreased (P<0.05). The microstructure results showed that the addition of xanthan gum resulted in a decrease in the size of bubbles and the number of large bubbles in the aqueous foam system. After freeze-drying, the cryogel sample had an ordered internal structure and dense overall pores. The pores were clearly visible, which could better trap the liquid oil in the internal structure. At the same time, the oleogels formed by porcine plasma protein and xanthan gum had stronger oil restraint ability and more semi-solid rheological behavior. With the increase of xanthan gum concentration, the oil absorption capacity tended to increase and then decrease, and it had the maximum value (46.43 g/g) at 0.6% xanthan gum concentration, when the oil restraint ability of the oleogel was 84.69%. The addition of xanthan gum could significantly increase the oil restraint ability of the oleogels at different temperatures (P<0.05), which enhanced its thermal stability. Therefore, a relatively stable porcine plasma protein-xanthan gum oleogel was formed when the xanthan gum concentration was 0.6%, which provided a theoretical basis for developing a novel protein and polysaccharide-based oleogels for use in low-fat products.