Análise de modelos matemáticos do teor de umidade no café em pó torrado e moído

Abstract

The greatest loss of quality in roasted and ground coffee occurs with the increase in moisture, which results in agglomeration and loss of product flavor when levels above 5% are reached. Considering the parameters established by legislation, the objective of this work was to estimate the moisture content in relation to the storage time of roasted and ground coffee after exposure to the environment, when the product packaging was opened, adopting exposure to humidity as the main factors ambient air and temperature. Four brands of roasted and ground coffee (1, 2, 3 and 4) were analyzed, in which the shelf life of the coffee was evaluated by comparing the initial humidity until stabilization of the final humidity and the shelf life of coffee without packaging, considering the temperature of storage, in relation to the increase in humidity, applying mathematical models to improve the analysis of the samples. The two-term model was the one that best applied to the tests. In the salt with the highest water activity (KCL), samples 2 and 4 had the highest moisture increases, with their weight stabilized after 10 days of storage. In the NaCl salt, samples 2 and 4 took about 25 days to stabilize the moisture gain. The magnesium nitrate Mg(NO3)2 salt was the best used in the tests due to the stability of its water activity, sample 4 had the longest period of time to reach stability, about 25 days. Sample 3 showed the best stability against moisture gains, with coffee being the most stable against all tests.