SPI/SA microgels prepared by phase separation improved the water retention and sensory perception of low-salt pork gels

Abstract

The SPI/SA microgels was prepared using protein-polysaccharide phase separation technology. The morphology, secondary structure, rheological properties and physical properties of the SPI/SA microgels were characterized and evaluated. SPI/SA microgels were added to low-salt pork gels to evaluate their effect on water retention and mechanical properties. The results indicated that the phase separation of SA and SPI in the mixed solution facilitated the formation of a SPI-rich region, reaching the gelation concentration. Upon heating, the hydrophobic groups in the SPI folded inward, resulting in a decrease in α-helix content and an increase in β-sheet content. This led to the formation of SPI/SA microgels with specific storage modulus and swelling properties. The microgels exhibited a uniform particle size, which could be precisely controlled by adjusting the concentrations of SPI and SA or the heating temperature. The addition of SPI/SA microgels improved sensory evaluation and gel strength, increased water holding capacity, and reduced cooking loss of low-salt pork gels. In addition, the SPI/SA microgels have the ability to convert free water into fixed water that is contained within the structure of the SPI/SA microgels in low-salt pork gel, thereby improving their properties in low-salt pork gels.