Development of Chinese-Style Sausage Enriched with Djulis ( Koidz) Using Taguchi Method: Applying Modern Optimization to Indigenous People's Traditional Food.

Djulis (Taiwanese quinoa) has gained popularity among researchers due to its biological characteristics and rich nutritional value. Incorporating Djulis is expected to enhance the sausage's texture, flavor, and storage stability due to the presence of antioxidants and nutritional components. However, limited studies focus on product development based on this emerging health-promoting ingredient in the food industry. This study aims to develop Chinese-style sausage enriched with Djulis using the Taguchi L(3) orthogonal matrix methodology and evaluate the influence of four factors, including un-hulled to hulled Djulis ratios of 0, 50, 100% (A), backfat-to-lean meat ratios of 0/100, 30/70, 50/50% (B), cooking temperature of 55, 75, 95 °C (C), and nitrite content of 0.03, 0.05, 0.07 g/kg (D) on products' sensory and physicochemical properties. The optimal Taguchi formulation was then verified and compared with conventionally formulated sausage (original sausage) in terms of hardness, springiness, gumminess, CIE color values, and peroxide value (POV). The optimal formulation was ABCD, which consisted of 16.8% hulled Djulis, 30/70 backfat-to-lean meat ratio, 75 °C cooking temperature, and 0.03 g/kg nitrite content. The most influential independent parameters were identified as B > A > C > D, placing Djulis incorporation as the first runner-up, just after the backfat-to-lean meat ratio. Optimized condition verification identified the Signal-to-Noise ratio (S/N) of 16.63. Comparing the optimized Djulis-enriched sample and the original sausage indicated similar CIE L*, a*, b*, hardness, and springiness but different gumminess according to Texture Profile Analysis (TPA). The Djulis-enriched sausage at the optimized formulation had a significantly lower POV compared to the control sample (4.65 vs. 9.64 meq/kg), which was found to be correlated with Djulis antioxidant effects with 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical antioxidant activity of 62.37%. This suggests that Djulis effectively mitigates sausage organoleptic deterioration. Djulis sausage, with natural antioxidants and reduced fat content, could cater to consumer preferences and enhance the market for the food industry and indigenous farmers.