Sensory Perceptions, Evoked Emotions, and Instrumental Parameters of Plant-Based and Hybrid Meatballs Added With Fermented Cashew Apple Waste: A Multifactorial Approach.

Growing demand for proteins has driven exploration of unconventional plant matrices combined with fermentation technologies. Cashew apple bagasse, a byproduct of juice production, is a potential fermentation substrate for microbial protein production (single-cell protein). This study evaluated the effects of 10%, 20%, and 30% cashew bagasse flour enriched with Saccharomyces cerevisiae protein on the instrumental properties (proximate composition, color, texture, and volatile compound profile), sensory profile (Preferred Attribute Elicitation [PAE] and Free Choice Profiling [FCP]), and consumers' emotional responses (using a validated food-specific emoji list) to plant-based and hybrid meatballs. Incorporation at 30% significantly increased hardness and gumminess while reducing elasticity in all samples (p < 0.05), with more pronounced changes in hybrid meatballs. The enriched flour increased volatile complexity, introducing ester compounds in hybrid products and imparting a "fermented" character in analogs, which masked and/or reduced terpene contribution. The L* value increased significantly in hybrid products, from 26.08 in the control to 30.85 at 30% incorporation, indicating greater color lightness (p < 0.05). In descriptive tests, consumers perceived intensity differences among products but described them using similar terms, generating 19 attributes in the check-all-that-apply (CATA) test. Acceptance thresholds were 20% incorporation for plant-based analogs and 10% for hybrid products, influenced by familiarity with meat matrices and lack of reference standards for plant-based foods. Regarding emotional profiling, enriched flour had a greater impact than product type, reducing positive emotions and increasing feelings of confusion and surprise, without leading to rejection. Consumer responses varied by the base matrix (plant or animal), while moderate incorporation levels maintained technological and sensory balance.