The main objective of this study was to evaluate the drying kinetics, extraction yields, and the antioxidant, antimicrobial, and antifungal activities of papaya seeds dried at different temperatures (45 °C and 55 °C) using various extraction methods. Drying of papaya seeds reduced the moisture content from 49.9 ± 1.2%–0.094%, taking 600 min at 45 °C and 510 min at 55 °C. Extraction yields using hexane were significantly higher, with values of 33.20% and 34.28% at 45 °C and 55 °C, respectively. Subcritical CO2 extraction yielded similar results across temperatures, while hydrodistillation showed the lowest yields. The concentration of benzyl isothiocyanate was highest in extracts obtained by subcritical CO2 (7.81% at 45 °C and 7.22% at 55 °C), demonstrating superior effectiveness compared to hydrodistillation and hexane methods. Subcritical CO2 extracts exhibited the highest antimicrobial activity against Staphylococcus aureus, with the lowest minimum inhibitory concentrations (MIC). The antifungal activity was also superior against Penicillium crustosum with subcritical CO2 extracts. In terms of antioxidant activity, subcritical CO2 extracts showed the lowest IC50 values, indicating the highest antioxidant efficacy. Both extracts showed slight toxicity, though to a minimal extent. These results suggest that subcritical CO2 extraction is superior in preserving and concentrating bioactive compounds, resulting in better yields and enhanced antimicrobial, antifungal, and antioxidant activities.
Read full abstract