Pre-extrusion addtion of thiamine as meat odor and flavor precursor in textured soy protein: from development to application

Author(s)

Talita Maira Goss Milani

• Document type: Doctoral Thesis
• Press: São José do Rio Preto. 2018-06-12.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências Letras e Ciências Exatas. São José do Rio Preto
• Defense date: 2018-05-16
• Advisor: Ana Carolina Conti Silva

Abstract

Textured soy protein (TSP) is obtained through the thermoplastic extrusion process and, due to its texture characteristics, similar to those of muscle meat fibers, it is commonly used as a substitute for animal protein. TSP flavoring may render the product sensorially more attractive; using flavor precursors as a pre-extrusion flavoring method is a good choice in order to avoid an increase in the lipid content of the final product. Therefore, the objective of this study was to develop a meat flavored TSP through the pre-extrusion addition of thiamine (aroma precursor) and to apply it in the elaboration of two products: seasoned ground TPS (meat analogue) and soy burger. Concentrated soy protein (CSP) was added with 1.5% thiamine and extruded under different conditions, using the Response Surface Methodology. A first experimental design was applied with three independent variables (CPS moisture, extrusion temperature and screw speed), from which the desirability technique was used to apply a second experimental design with two independent variables (CPS moiture and screw speed). The CSP moisture influenced negatively expansion ratio, cutting force of the rehydrated extrudate and solubility of the protein in water. On the other hand, it positively influenced for density, ideal meat odor intensity and amount of volatile compounds hexanal, 2-pentylfuran, 2-pentylthiophene and 1-butyl-2-octenal. The strongest meat odor was noticed when CSP moisture was close to central point, still assuring a good score to the ideal meat odor intensity. Chroma was positively influenced by the screw speed, while the red chromaticity, the chromatic hue and the emulsion stability had an effect on the CSP moisture and the screw speed. Extrudates added of thiamine, with 34% CSP moisture and 216 or 242 rpm of screw speed stood out for their meat odor, as they had high amounts of volatile compounds with meaty notes. Two extrudates of the design (CSP with 28.4 and 34% moisture) and one without thiamine were used in the elaboration of the meat analogue and the soy burger, and the products were analyzed for their physical properties, sensory acceptance and descriptive profile, using the Rate-All-That-Apply (RATA) method. Meat analogue 28.4% U/with thiamine showed lower water absorption capacity and higher compressive force, which are adequate results for this product. Global acceptance described the sample 34.0% U/with thiamine, due to its attributes of white color, meat odor, salty taste, meat flavor, instant noodles flavor, residual flavor of burnt, and good aroma; on the other hand, the odor acceptance was due to its meat odor. Sample 28.4% U/with thiamine was characterized by a low texture acceptance, due to its dry, gritty/sandy and moist texture. The soy burger 28.4% U/with thiamine had lower cooked shrinkage, but all the results were much lower when compared to products made with meat. Odor and flavor acceptance as well as overall acceptance were higher for burgers with thiamine. The intensity of the chicken odor and the odorous attributes were higher for burgers with thiamine, while the intensity of the soy/vegetable odor was higher for thiamine-free burger. Burger 34.0% U/with thiamine stood out for its chicken taste, white color and soft texture. Burger 28.4% U/with thiamine had good acceptance by its odor, texture, flavor and had an overall acceptance due its meat and chicken odors, being described as delicious and having good aroma, as well as a low intensity of soy/vegetable odor , soy and instant noodles flavor. Thus, the use of thiamine as a precursor of meat odor and taste in textured soy protein enables us to obtain extrudates with adequate physical and functional properties, and a more intense meat odor and higher sensorial acceptance of the meat odor. In addition, when applied to soy-based products, the presence of TSP with thiamine grants the products with a greater acceptance for its meat odor and taste. (AU)