Secagem do bagaço de malte: estudo experimental e modelagem matemática

Abstract

Beer is one of the bestknown drinks in the world and its reception has a 2% share of the Brazilian Gross Domestic Product (PIB). However, a brewery can generate up to 3% of waste compared to the production of the beer. Malt bagasse is a solid residue from breweries and has a wide applicability, the main one being animal feed. However, the inappropriate use of this byproduct can cause some diseases to the animal that consumes it, such as poisoning and botulism. One way to avoid these diseases is drying, as it helps in food conservation. There are several types of drying, such as hot air, freezing, microwave drying, infrared drying, among others. One of the ways to save on Sample and predict drying time is to make use of mathematical simulation. Mathematical models dimension and optimize the drying kinetics, thus avoiding the waste of raw material in experimental studies. Related to problems and properties of this type of bagasse, this work carried out the drying of malt bagasse in two different ways: through convective drying, at temperatures of 50, 60, 70 and 80 ℃ and through microwave drying, in the powers of 160, 480 and 640 W, in order to increase the quality and lifetime of the product. In addition to the experimental tests, mathematical modeling of all experiments was performed using 5 models and the simulated data were compared to the experimental data using 5 statistical analyses: authority coordinator (𝑅2), mean absolute deviation (𝑑𝑚𝑎), mean relative error (𝑃), Chisquare test (𝑋2) and estimated mean error (𝑆𝐸). Based on the methodology employed, it is possible to state that drying performed at 80 ℃ obtained greater efficiency when compared to the others, however, temperatures above 60 ℃ can cause unpleasant flavors. In this way, a temperature of 60 ℃ is indicated, as it performed better than a temperature of 50 and there is no risk of burning or toasting the malt bagasse. When too much observed, and in relation to microwave drying, a better performance was obtained for the one carried out with a power of 640 W. Through the mathematical modeling, it was observed that the Parabolic model had the best performance for both forms of drying, which is confirmed by the values of 𝑅2, 𝑑𝑚𝑎, 𝑃, 𝑋2 and 𝑆𝐸 found. In this sense, it is possible to state that drying is an effective alternative to improve the storage time of malt bagasse and that its kinetics can be described by means of mathematical models that simulate the time required for this process.