Bioactive Compounds, Antioxidant, and Antibacterial Activity Against MDR and Food-Borne Pathogenic Bacteria of Psidium guajava. L Fruit During Ripening

Psidium guajava fruits are highly appreciated for their nutrients and bioactive compounds content, which contribute to their antioxidant and antimicrobial capacities. The purpose of this study was to determine bioactive compound (phenolic, flavonoids, and carotenoid contents), antioxidant activity (DPPH, ABTS, ORAC, and FRAP), and antibacterial potential against MDR and food-borne pathogenic strains of Escherichia coli, and Staphylococcus aureus during different stages of fruit ripening.The results elucidated that ripe fruits (methanolic extract) contain the highest total phenolic, flavonoids, and carotenoid contents (417.36 +/- 2.63 mu g GAE/gm of FW, 711.78 +/- 0.70 mu g QE/gm of FW and 0.683 +/- 0.06 mu g/gm of FW) followed by hexane, ethyl acetate, and aqueous. Methanolic extract of the ripe fruits showed the highest antioxidant activity when measured by DPPH (61.55 +/- 0.91%), FRAP (31.83 +/- 0.98 mM Fe(II)/gm of FW), ORAC (17.19 +/- 0.47 mM TE/ gm of FW), and ABTS (41.31 +/- 0.99 mu mol Trolox/gm of FW) assays. In the antibacterial assay, the ripe stage had the highest antibacterial activity against MDR and food-borne pathogenic strains of Escherichia coli, and Staphylococcus aureus. The methanolic ripe extract was found to possess maximum antibacterial activity ZOI, MIC, and IC50 18.00 +/- 1.00 mm, 95.95 +/- 0.05%, and 0.58 mu g/ml; 15.66 +/- 0.57 mm, 94.66 +/- 0.19%, and 0.50 mu g/ml, respectively, against pathogenic and MDR strains of E. coli and 22.33 +/- 0.57 mm, 98.97 +/- 0.02%, and 0.26 mu g/ml; 20.33 +/- 1.15 mm, 96.82 +/- 0.14%, and 0.39 mu g/ml, respectively, against pathogenic and MDR strains of S. aureus. Considering the bioactive compounds and beneficial effects, these fruit extracts could be promising antibiotic alternatives, avoiding antibiotic overuse and its negative effects on human health and the environment, and can be recommended as a novel functional food.

Automated summary

This study aimed to determine the bioactive compounds, antioxidant activity, and antibacterial potential of Psidium guajava fruits at different ripening stages. The ripe fruits showed the highest content of phenolic, flavonoids, and carotenoids, as well as the highest antioxidant activity. Additionally, the ripe fruits exhibited the strongest antibacterial activity against MDR and food-borne pathogenic strains of Escherichia coli and Staphylococcus aureus. These fruit extracts could be recommended as a novel functional food and antibiotic alternative.