Produção de farinhas de pimentões e resíduos mediante secagem convectiva: compostos bioativos e da capacidade antioxidante.

Abstract

Capsicum annuum (L.) is a species that produces fruits of different shapes and colors, rich in nutrients and with functional potential. Its fruits are subject to post-harvest losses due to their perishability, what requires the application of techniques that prolong their shelf life. Thus, the main purpose of this thesis was to evaluate the physicochemical quality, bioactive compounds and antioxidant capacity of green, yellow and red peppers, as well as to produce flours by convective drying of pepper fruits and residues at different temperatures, in addition to studying the kinetics of drying of green, yellow and red peppers. For fresh peppers, the (DIC) composed of (green, yellow and red) peppers was used in five repetitions. For the pepper flours, DIC was applied in a double factorial scheme which consisted of three types of (green, yellow and red) peppers, 5 drying temperatures (122, 131, 140, 149 and 158 °F) in five repetitions. For the pepper residues flour, it was used DIC composed of three drying temperatures (122, 140 and 158 °F) with five repetitions. The means obtained were compared by analysis of variance followed by Tukey's test at the 5% probability level. The fruits and residues of green, yellow and red peppers were dried until constant weight. The physicochemical characteristics, bioactive compounds and antioxidant capacity of fresh fruits, pepper fruit flours and their residues were analyzed. The drying kinetics of the peppers were evaluated, and Lewis’s, Page’s, Henderson’s and Pabis-Midilli’s mathematical models were applied. The results showed that fresh fruits are excellent sources of phenolic compounds with 262.9 mg 100 g-1 in green peppers, 347.7 mg 100 g-1 in yellow peppers, and 254.1 mg 100 g-1 in red peppers. The green, yellow and red pepper flours concentrated the contents of soluble solids, sugars, phenolics, flavonoids and anthocyanins. A greater inhibition of the DPPH free radical was found after increasing the drying temperature, being 85.0% in green pepper flours, 83.0% in yellow flours and 80.5% in red flours. The pepper residue flours retained the phenolic compounds, with contents of 200.2 mg 100 g-1 at a temperature of 122 oF, 174.9 mg 100 g-1 at 140 oF and 196.3 mg 100 g-1 at 158 °F. Midilli's mathematical model fitted the experimental data with R2 above 0.99, DQM below 0.03, and X2 below 0.0013 for green, yellow and red peppers. It was concluded that fresh peppers have bioactive components and antioxidant potential. Yellow pepper flours stood out in terms of ascorbic acid, phenolic compounds and antioxidant capacity, showing that convective drying is a viable technique for the production of these flours. It was found that the pepper residues are rich in phenolic compounds and have antioxidant potential, adding value to peppers. It was identified that the Midilli’s mathematical model obtained the best fit to the experimental data.