Mixture design optimization of Nile tilapia (Oreochromis niloticus) pâté formulated with mechanically separated meat: integration of sensory acceptance and formulation cost

Abstract A significant portion of aquatic food industry by-products is still directed to low-value applications, even though they have technological potential for food products, such as mechanically separated meat (MSM) in emulsified products. This study optimised theformulation of a pasteurised Nile tilapia ( Oreochromis niloticus ) fish pâté using mixture design with component constraints, evaluating the combined effects of MSM, fat, and water on sensory performance and formulation cost. Eleven formulations were produced and assessed by 87 untrained panellists using a 9-point hedonic scale. The use of MSM met microbiological safety requirements. Significant differences were observed among formulations for sensory attributes, including odour, texture, flavour, overall acceptance, and purchase intention ( p < 0.05). Quadratic models demonstrated high predictive capacity, with adjusted coefficients of determination exceeding 0.99 for most responses. The optimal formulation based on desirability contained 0.53 MSM, 0.23 fat and 0.25 water, reaching an overall acceptance score of 7.71. An Economic-Sensory Efficiency Index (EI = overall acceptance/formulation cost, USD kg⁻¹) was proposed as a complementary decision criterion. Formulations with lower MSM content showed the highest EI values, maintaining acceptance above 7.1 while reducing formulation cost by up to USD 0.19 per kilogram. Redirecting MSM from fishmeal (USD 0.18 kg⁻¹) to pasteurised pâté production generated USD 3,633–4,831 in incremental gross profit per tonne of MSM, representing a value multiplication factor more than 20-fold.