Hibiscus sabdariffa L. BY-PRODUCTS FLOUR

Hibiscus is an excellent source of minerals, vitamins and antioxidant compounds whose economic interest is in the chalice. Unconventional parts (leaves and stems) are marketed natural, where their high water content reduces their shelf life. The dehydration is a way to minimize the loss by making a stable and safe product for the market. The objectives of this study were to produce and characterize Hibiscus sabdariffa L. leaf and stem flour and investigate drying, determining the most suitable mathematical model for drying. For the prediction of the model was carried out a study of the dehydration of the leaves and stems of the Hibiscus in circulation kiln and forced air renewal at constant temperature, whose parameters were Aw and humidity. The flour production F1 (30% leaf/70% stem), F2 (50% leaf/50% stem) and F3 (70% leaf/30% stem) followed the stages of: triage, selection, sanitation, bleaching, centrifugation, grinding, dehydrating, grinding, sieving, formulation e packaging. These were then submitted to analyzed of Aw, pH, total acidity, antioxidant activity, phenolic compounds, total coliforms and E. coli and yest and mold counts. All adjusted models were adequate, but the Logarithmic model presented higher R2 value and lower DMR than others, better fitting the drying curves. The flours were characterized by: Aw (0,53-0,57); pH (2,62-3,08); total acidity (8,30-11,59 g/100 g); iron (13,18-25,57 mg/100 g); antioxidant activity (ABTS - 2,34 a 4,86 µM/g de Trolox; DPPH - 15,45 a 79,97%); phenolic compounds (163,72-259,75 mg GAE/100 g). There was no microbial growth. It was concluded that it was possible to produce flours from Hibiscus by-products with similar identity and quality characteristics, with high iron content, antioxidant activity, safe and less susceptible to deterioration.