Estudo da viabilidade da utilização de subprodutos da indústria vitivinícola e arrozeira para elaboração de biscoito tipo Cookie

Abstract

The aim of this work was the use of grape pomace waste and processing of parboiled rice as flour for preparation of the biscuit cookie. The grape pomace waste marc was subjected to drying from an experimental design with 2² with a triplicate in the central point in order to determine the influence of temperature and air velocity in response final moisture. The grape pomace waste, rice bran and flour grapes were characterized physic-chemically. The equilibrium isotherms were analyzed at temperatures of 50, 60 and 70°C (desorption) and 30ºC (adsorption) by the models GAB and BET. The drying kinetics was analyzed at the best drying conditions obtained in the experimental design, by the models from Henderson & Pabis, Page, Lewis e Midilli et al. The cookies were prepared with flour grape and parboiled rice bran in a partial replacement of wheat flour. The final product was subjected to microbiological analysis, sensory analysis and the formulation with greater acceptance was characterized physic-chemically. The temperature factor influenced the final moisture, having negative effect on the response, in other words, with increasing temperature there was a reduction in the final moisture, thus, the best drying condition was the temperature of 70°C and air velocity at 1m/s. The experimental data of equilibrium isotherms was best fitted to the GAB model presented and the monolayer moisture values were 0,053, 0,041 e 0,024 kg.kg-1(b.d) at temperatures of 50, 60 and 70°C, respectively and 0,044 and 0,024 kg.kg-1 (b.d) at temperature of 30°C (flour grape and parboiled rice bran, respectively). The drying showed the two periods of constant rate drying followed by decreasing rate. All experimental data presented a good fitting to the drying models at the condition proposed (70°C, 1m/s), however, the Henderson & Pabis model was chosen due to the physical importance in the interpretation of Def estimates, with found value 5,477x10-11 m².s-1. The results of microbiological analysis are in agreement with the legislation about cookies, allowing the consumption of it without any risk to health. The most preferable formulation by the tasters was the one containing 10% of rice bran and 5% of flour grape. The physic-chemical characterization of the cookie more accepted in sensory analysis demonstrated that this biscuit is source of fiber and proteins, this way being suitable for consumption from the microbiological and nutritional point of view and enables the aggregation of value to both by-products used.