Effects of the Addition of Different Pomelo Peel Powder on Gel Quality of Silver Carp Surimi

The pomelo peel is a good source of natural antioxidants. To investigate the effects of different kinds of pomelo peel powder on the gel quality of silver carp surimi. In this study, pomelo peel powder of Citrus×sinensis, Citrus maxima cv. Dongshizao, Citrus maxima cv. Anjiang Yu, Citrus maxima cv. JinlanYu was selected and subjected to analysis for its antioxidant capacity. Furthermore, the powders were mixed with silver carp surimi respectively, to explore the effects on surimi gel quality. Results showed that among the selected four different pomelo peel powders, the content of flavonoids and polyphenols in Citrus maxima cv. Dongshizao peel was the highest, which was 32.6 mg GAE/kg and 19.4 mg QUE/kg, respectively. Correspondingly, the extract of Citrus maxima cv. Dongshizao peel had the lowest IC₅₀ values for DPPH and ABTS⁺ free radicals, and their concentrations were 2.92 and 0.76 mg/mL, respectively. The ABTS⁺ free radical scavenging rate and β-sheet content of the surimi were added with Citrus×sinensis and Citrus maxima cv. Dongshizao peel powder were higher than those of the control group, and they increased with the increase of pomelo peel powder content from 1% to 3%. However, the endogenous fluorescence intensity and total sulfhydryl content decreased with the increase of pomelo peel powder content. In addition, the hardness, adhesiveness, and chewiness of surimi gels prepared by adding pomelo peel powder, Citrus maxima cv. Dongshizao peel powder, and Citrus maxima cv. JinlanYu peel powder were higher than those of the control group. Scanning electron microscopy showed that compared with the control group, the surimi gel added with pomelo peel powder showed a more uniform and dense network structure, and the internal pores were smaller with the increase of the additional amount. Sensory evaluation showed that the surimi gel with 3 % Citrus maxima cv. Dongshizao pomelo had the highest score in odor and taste. Based on the above results, the addition of 3 % Citrus maxima cv. Dongshizao pomelo peel powder can significantly improve the quality of silver carp surimi gel. These findings can provide guidance for the utilization of pomelo peel and the quality improvement of surimi gel.