Desenvolvimento de análogo a filé de peixe usando fermentação semi-sólida de cogumelos de Pleurotus ostreatus por bactérias láticas produtoras de exopolissacarídeos

Abstract

The increase in demand for non-animal protein sources, driven by environmental, health, and animal welfare concerns, has opened up possibilities for the market of products known as analogs. Edible mushrooms, the fruiting bodies of certain fungi, are comprised of various nutrients, the consumption of which is increasing in countries like Brazil. The aim of this study was to evaluate the effect of formulation and fermentation variables of a medium based on Pleurotus ostreatus (PO) mushroom for the production of fish fillet analogs. Two microorganisms were tested for fermentation: Leuconostoc pseudomesenteroides (LM) and Weissella cibaria (WC). A Plackett&Burman 8 (PB8) design was conducted to assess the thermal treatment of mushrooms, with four independent variables: temperature, time, citric acid concentration (%w/v), and bicarbonate concentration (%w/v). The optimal temperature/time binomial for thermal treatment of mushrooms was 80°C/10 min, without the addition of citric acid or bicarbonate, resulting in a reduction of enzymatic activity from 109 and 182 (u.E/min)/g of fresh mushroom to 18 and 16 (u.E/min)/g of mushroom, for polyphenoloxidase (PPO) and peroxidase (POD), respectively. The microorganism W. cibaria (WC) was selected for its superior exopolysaccharide (EPS) production compared to LM. Subsequently, a PB12 design with 4 central points and 8 independent variables was conducted: soy protein isolate - PIS (%w/w), pea protein - PE (%w/w), oat flour - FA (%w/w), white bean flour - FFB (%w/w), microalgae oil - Ô3 (%w/w), sucrose - S (%w/w), thermal treatment time - TT (min), ultrasound time - TU (min). The responses included: texture profile of the analog before and after cooking (hardness, elasticity, cohesiveness, gumminess, chewiness, and resilience), luminosity and chromaticity pattern of the analog before and after cooking (L*, a*, b*), initial and final fermentation pH, EPS production (g/L), WC growth (Log CFU/g), protein content on a wet basis (%), and sensory parameters: appearance, aroma, texture, taste, and total defect fraction. It was found that ultrasound during the thermal treatment of analogs was unnecessary; SPI, when used at the highest level in this study (8% w/w), resulted in increased hardness and fewer defects in the sensory texture evaluation. In conclusion, W. cibaria was able to ferment the mushroom-based medium and inputs and also produce EPS, resulting in a potential fish analog prototype, however, taste, aroma, and texture still need to be optimized.