Enriquecimento nutricional por bioconversão de resíduos agroindustriais para utilização na alimentação animal.

Abstract

Brazil stands out among the big world-wide producers of pineapple (Ananas comosus L. Mer) and passion fruit (Passiflora edulis Sims), with a great amount of wasted residues, which has become a serious problem for the pineapple and passion fruit producers and the aliment industries in general. In developed countries, the farming production is characterized by low operational costs, because of the use of the remaining portions of cultures and agro-industrial residues as an alternative in animal feed, which also contributes to minimizing pollution problems. The aim of this work was to define actions in the field of research of nutritional alternative feed for animals, in order to carry through the exploitation of these nutritionally enriched (protein, vitamin, mineral and energy) residues by using Saccharomyces cerevisiae yeast as an agent of metabolism, in a technical viable way, aiming at the availability of the product to the producers. Desorption isotherms of the residues in study were done at the usual temperatures of fermentation processes, 25, 30, 35 and 40 oC, fitting the data through the application of mathematical models, and it was verified that the process of fermentation must be initiated with the initial moisture content of the substratum for the three residues above of 84% (w.b), which is equivalent to the water activity above of 0.90. In the kinetic study it was verified that optimum time where the microorganism reached the highest content was, on average, 48 hours, for all the residues analyzed. Methodology of factorial design plus configuration star was used to study the influences of the entrance variable on the process of nutritional enrichment of the residues of pineapple rind (PR), crown of pineapple (CP) and rind of passion fruit (PF), with concentrations of yeast at 1, 3 and 5% and temperatures of 30, 34 and 38 °C. The factorial design plus configuration star was performed for the three residues, with two exit variables (response: gross protein content and protein increase content). The protein increase content (PI) found for the three analyzed residues was on average of 2.40 times in relation to in natura. The optimized values of the three residues of pineapple rind (PR), crown of pineapple (CP) and passion fruit rind (PFR) (concentration around 3-5.8% and Oliveira M.M.de 16 temperatures of 34-40 °C), in the time of 48 hours, aiming to lower the costs of the enrichment and to obtain an adequate protein content in the animal feed were of; 24.66, 23.88 and 22.74%, respectively. Gross protein (GP), dry substance (DS), leached ashes (LA), organic substance (OG), phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), fiber neutral detergent (FND), acid fiber detergent (AFD), rude energy (RE) and digestibility in vitro (DIVMS in vitro) analysis were performed in the residues, operating with the entrance variables (concentration of yeast and temperature) with optimized values. It can be concluded that through bioconversion, the residues reach nutritional concentrations that can be transformed into a nutritional supplement alternative, being an option to feed animals at times of food scarcity in semi-arid climates.