Plackett-Burman Test Combined with Box-Behnken Response Surface Method to Optimize the Formulation of Pork Meatball Added with Soluble Antioxidant Dietary Fiber from Sponge Layer of Guanxi Pomelo

In order to further develop and improve the quality of pork meatballs, Plackett-Burman combined with Box-Behnken experimental design was used to optimize the processing formula of pork meatball added with soluble antioxidant dietary fiber (SADF) from sponge layer of Guanxi pomelo, based on the texture comprehensive score of hardness, cohesion, elasticity and chewability. The effects of addition of SADF (the hydroxyl radical scavenging rate was IC₅₀=0.92 mg/mL), corn starch, salt, complex phosphate and water on hardness (X₁), cohesiveness (X₂), elasticity (X₃), chewability (X₄) and the texture comprehensive score (Y) of pork meatballs were investigated, respectively. Based on the above results, the Plackett-Burman design was used to screen the factors (SADF addition, corn starch addition and water content addition) that had significant impact on the experimental results for subsequent response surface optimization using Box-Behnken experimental design. The microstructure of pork meatballs was observed by optical microscope and scanning electron microscope. The results showed that two common factors were obtained by dimensionality reduction analysis, and the formula for calculating Y value of pork meatball was established as follows: Y=(84.055Y₁+15.627Y₂)/99.681 (Y₁=0.234X₁+0.259X₂+0.297X₃+0.296X₄, Y₂=0.989X₁−0.784X₂−0.010X₃−0.084X₄). The optimal formula of pork meatballs was finally obtained as follows: The addition of SADF from sponge layer of Guanxi pomelo was 6.49%, the addition of corn starch was 18.64%, and the addition of water was 29.98%. In this case, the texture comprehensive score of pork meatballs was the highest (1.2782), which was of moderate hardness and excellent viscoelasticity. The test of optical microscopy and scanning electron microscopy showed that compared with the non-SADF group, the 6.49% SADF supplemented group could significantly improve the overall structure of the meatballs, make the microstructure fine and uniform, and enhance the cross-linking degree of internal gel networks. To sum up, this study not only improved the nutritional and structural quality of pork meatballs, but also realized the comprehensive utilization of pomelo waste, providing a new idea to optimize and improve the quality of minced meat food.