Formulation Optimization and Quality Evaluation of Walnut Protein Sausage Based on Fuzzy Mathematics Sensory Evaluation Combined With Random Centroid Optimization

To explore new plant protein resources and develop novel walnut-based protein products, sensory scores were adopted as an evaluation index, and seven optimization factors, which included salt, sugar, modified starch, egg white powder, walnut oil, lab-prepared spices, and walnut tissue protein, were selected. A fuzzy mathematics sensory evaluation model integrated with random centroid optimization was developed to optimize the processing parameters of walnut protein sausage. A comparative analysis was conducted, with soy protein sausages, wheat protein sausages, and commercially available vegetarian sausages, based on the basic physicochemical properties, texture characteristics, nutritional functions, and biomimetic sensory qualities of walnut protein sausages. The results demonstrated that the optimal formulation for walnut protein sausage comprised 1.8% salt, 3.4% sugar, 7% modified starch, 5.1% egg white powder, 1.8% walnut oil, 0.8% lab-prepared spices, and 66.1% walnut protein. Walnut protein sausages prepared with this formula had the highest sensory score (92.01 points). The prepared walnut protein sausages had a distinct walnut aroma, smooth surface, uniform and firm texture, and compact structure. The sausages were high in dietary fiber (7.40 g/100 g), low in crude fat (6.59 g/100 g), and demonstrated good water-holding capacity (7.78%) and oil-holding capacity (19.92%). Pearson correlation analysis revealed significant relationships between the physicochemical, functional, and nutritional properties of various vegetarian sausages, with indicators such as crude protein, crude fat, and moisture content closely associated with flavor. The walnut-based sausages met the food safety requirements for healthy products. This study facilitates the development of plant-based vegetarian sausages from walnut protein, which in turn increases the added value of walnut by-products.