Effect of processing on the stability of bioactive compounds from red guava (Psidium cattleyanum Sabine) and guabiju (Myrcianthes pungens)

Brazil is rich in wild fruits and stands out for presenting the greatest number of species with food potential, which could be commercialized or used to products development. However, processing may reduce or destroy the quality of a food product. This study assessed the effect of processing on the antioxidant activity of fruits native to Brazil: red guava (Psidium cattleyanum Sabine) and guabiju (Myrcianthes pungens), as well as on their carotenoid and anthocyanin contents. Both fruits were shown to be sources of carotenoids and anthocyanins; however, guabiju had higher levels of bioactive compounds than red guava. In the DPPH method, the fruits dried at 70 °C and freeze-dried had significantly greater antioxidant activity, 604.8 g DPPH/g fruit and 548.4 g DPPH/g fruit, respectively, for red guava; and 496.2 g dry fruit/g DPPH and 428.5 g dry fruit/g DPPH, respectively, for guabiju; whereas for the ABTS method, red guava dried at 70 °C and guabiju frozen for 90 days had the highest antioxidant levels, 248.6 g and 428.5 g, respectively. For both fruits, the lowest levels of pigments were found after drying by hot air (70 °C). Freezing increased while the freeze-drying process helps both fruits to retain the carotenoid concentrations. For anthocyanins, the highest levels were found in freeze-dried guabiju and fresh red guava.