Effect of palm oil content and melting point on the freeze-thaw stability of fat substitutes

Abstract

Animal or plant-based meat products are typically stored and transported using freezing. Freezing-thawing cycles can lead to detrimental changes in the texture, appearance, and mouthfeel of fat substitutes, thus affecting their quality. In this work, a protein/polysaccharide composite emulsion gel was created by emulsifying soybean isolate protein (SPI) and palm oil (PO), and incorporating curdlan (CL). It can serve as a potential replacement for animal fat in meat products, such as sausage, and plant-based meat. The study aimed to investigate the stability of the complex fat substitutes during freeze-thaw at various melting points and palm oil content. The results showed that the 52°C-palm oil samples were the most freeze-thaw stable compared to samples with other melting points. 52°C-palm oil samples were tested for texture and water holding capacity (WHC), increasing the oil content from 5g/100g–20g/100g improved the gel strength and WHC after freeze-thaw. The samples containing high melting point palm oil were less affected by temperature changes and showed higher stability as detected by low-field NMR and differential calorimetric scanning. The confocal laser scanning and rheological detection further confirmed the enhanced structural strength and freeze-thaw stability of the emulsion gels containing solid fat particles with high melting points.