Processing optimization and gel properties of silver carp (Hypophthalmichthys molitrix) surimi gels fortified with psyllium husk powder

Psyllium husk powder (PHP) is a food hydrocolloid rich in both soluble and insoluble dietary fiber. Previous studies have shown that the interaction between polysaccharide hydrocolloids and proteins could affect the ability to form gels, which suggests that the addition of PHP to surimi paste may have an impact on the properties of surimi gels. In order to study the the development and application of PHP in surimi products, three factors including the amount of PHP added, gelation temperature and gelation time on the gel properties of surimi were investigated, using frozen silver carp (Hypophthalmichthys molitrix) surimi as the research object, gel strength and water holding capacity (WHC) as the inspection indicators. On the basis of single factor experiments, three-factor and three-level orthogonal experiment and verification experiment were carried out. The best processing conditions obtained through orthogonal test result were as follows: PHP addition amount 0.1%, gelation temperature 45 °C, and gelation time 2 h. The cooking loss rate, protein pattern and microstructure of fish sausage prepared by the traditional process (without PHP, gelation temperature 40 °C, gelation time 1 h), optimized process (0.1% PHP addition, gelation temperature 45 °C, gelation time 2 h) and optimized control process (without PHP, gelation temperature 45 °C, gelation time 2 h) were analyzed and compared to verify the properties of surimi gels under different conditions. The single factor test results showed that the addition of an appropriate amount of PHP (0.1%-0.3%) could increase the hardness and WHC of the surimi gel, but PHP might have an adverse effect on the deformation, and compared with the traditional technology, slightly higher temperature and longer time would help the surimi mixture to form better gel; the results of cooking loss rate, SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy (SEM) in the verification experiment indicated that the participation of PHP might reduce the cooking loss of surimi gel formed at higher gelation temperature, promote cross-linking between myosin heavy chain molecules, retard protein degradation and help to form a denser gel structure. PHP as a new food raw material used in the development of high-quality and healthy surimi products was preliminarily explored in this study. And it is expected to be able to provide some reference for enriching the research content about application of hydrocolloid in the performance of surimi gel properties.