Antioxidant Properties of Soluble Dietary Fiber and Its Impact on the Edible Quality of Stored Pork Meatballs

This study investigated the antioxidant properties of soluble dietary fibers (SDF) extracted from eggplant and red sweet pepper using ultrasound-assisted acid extraction. Furthermore, it examined the effects of adding these SDFs at varying concentrations (0, 0.1, 0.15, 0.2, 0.25, and 0.3 g per 10 g meatball) on the edible quality of pork meatballs during different refrigeration storage periods (1, 3, 5, 7, and 9 days) at 4 °C as well as their impact on the molecular structure of myosin in the oxidized meatballs. Compared with the control group (without the addition of soluble dietary fiber), the pork meatballs with the addition of soluble dietary fiber from eggplants (ESDF) and soluble dietary fiber from red sweet peppers (SPSDF), respectively, had a better color and microstructure. The hardness and elasticity of the pork meatballs in the addition groups were improved and the cooking loss was reduced. ESDF and SPSDF can inhibit lipid oxidation and the formation of nitrogenous substances during the storage of pork meatballs. As the amount of soluble dietary fiber increases, the inhibitory effect is enhanced. Adding ESDF and SPSDF can stabilize the conformation of myosin molecules after oxidation. Considering all factors, the optimal amount of soluble dietary fiber added to eggplants is 1.5%, and the optimal amount of soluble dietary fiber added to red sweet peppers is 2%. To sum up, the addition of ESDF and SPSDF can improve the quality of pork meatballs and increase the storage stability of pork meatballs.