Bioactive characterization of Persea americana Mill. by-products: A rich source of inherent antioxidants

Avocado (Persea americana Mill.) is a worldwide consumed fruit, with great interest for cosmetic and pharmaceutical industries; however, 30% of avocado fruits are bio-wastes (peels and kernels), converting them into a potential source of bioactive compounds, such as phenolic compounds. Therefore, the hydroethanolic extracts of peels and kernels of Persea america Mill. var. Hass were analysed regarding their individual phenolic profile by HPLC-DAD/ESI-MS and correlated with their antioxidant, antimicrobial and cytotoxic activities. Avocado by-products presented a very distinct phenolic profile, presenting higher concentration in peels (227.9 mg/g of extract for total phenolic content), mainly in (epi)catechin derivatives (175 mg/g of extract), followed by chlorogenic derivatives (42.9 mg/g of extract). In this study hydrophilic and lipophilic antioxidant assays were performed together for the first time in P. americana by-products, and although kernels showed a great antioxidant potential (EC50 values ranging from 18.1 to 276 mu g/mL), peels presented the highest potential (EC50 ranging from 11.7 to 152 mu g/mL), mainly due to the presence of phenolic compounds, and an overall better performance in the antibacterial assays. Further studies needs to be conducted to better understand the correlation between the presence of phenolic compounds and bioactivities, however, the main objective is to implement these biocompounds in different products and industries, due to results obtained, P. americana peels could be a great alternative in the substitution of synthetic antioxidants.