Valorização do fruto de castanhola (terminalia catappa Linn) como fonte de bioativos e substrato para a produção de enzimas por fermentação em estado sólido (FES)

Abstract

The fruits of castanets (Terminalia catappa Linn) are edible but have no commercial value. In this context, the present study investigated the potential of the castannet fruit for the development of an extract with bioactive properties aiming to inhibit the αamylase enzyme and the encapsulation by nanoemulsion. In addition, the fruit was also used as a substrate for obtaining pectinases and cellulases from solid state fermentation (SSF). The pulp extracts showed values of phenolic compounds (2.984 mg/g ± 0.38), flavonoids (1.644 mg/g ± 0.21), flavonols (0.123 mg/g ± 0.001) and total anthocyanins (0.505 mg/g ± 0.21) 0.09) and the inhibition of α-amylase enzyme reached 100% with concentrated extract. For the encapsulation by nanoemulsions, using distilled water as the aqueous phase, Crodamol OQLQ as the oil phase and Tween 80 as the emulsifier, it was verified the formation of emulsified systems with droplets in the range between 41.1 nm and 68.9 nm. In the FES experiments, the best values found in the fermentation process for polygalacturonase (PG) and pectin lyases (PMGL) were 32.61 U/g (30 °C, pH 8.0 and 80% humidity) and 189 .91 U/g (30 °C, pH 4.0 and 80% humidity), respectively. Using multivariate analysis, it was possible to observe that the effects of pH and the temperature-pH and temperature-humidity interactions were significant for the PG responses. In turn, the effects of moisture and temperature-pH interaction were significant for PMGL. The enzymatic extracts of PG and PMGL were stable at temperatures between 30 and 70 °C, however both enzymes were sensitive to pH changes. The castanna seed residue, after pretreatment, showed high cellulose content after pretreatment (22%), with CMCase and FPase production of 13.2 U/g and 0.232 U/g, respectively. The enzymatic extracts performed better at neutral pH and at temperatures above 50 °C the enzymatic activity decreased to 37.18% and 18.48% respectively.