Evaluation of mass loss of pineapple bagasse pretreated with alkaline hydrogen peroxide / Avaliação da perda de massa de bagaço de abacaxi pré-tratado com peróxido de hidrogênio alcalino

In this work, the mass loss caused by the pre-treatment, with alkaline hydrogen peroxide, of the dried and ground pineapple bagasse was studied. The bagasse was separated granulometrically. The fractions with an average diameter of 1.242 mm (20 mesh) and 0.564 mm (48 mesh) showed the highest volumes among the sieves used. For this reason, these two fractions were chosen to evaluate the influence of particle size on the mass loss during the pre-treatment. The dry pineapple bagasse was characterized for the contents of moisture, ash, soluble and insoluble lignin, cellulose and hemicellulose, and carbohydrates. Central composite rotatable designs were carried out for each particle size in order to assess the influence of pre-treatment time (h), temperature (°C) and concentration of alkaline hydrogen peroxide (%) on the mass losses caused in the samples. The mass losses observed in the pineapple bagasse fractions, after pretreatment, varied between 80.467 ± 0.722% and 89.495 ± 0.985% for the 20 mesh bagasse and 79.641 ± 0.856% and 88.576 ± 0.170% for the 48 mesh bagasse. Mass losses were very high, which may indicate that pretreatment with alkaline sodium hydroxide is too aggressive for pineapple bagasse.