Antioxidant Capacity and Food Pathogenic Bacteria Inhibition of Citrus limetta and Citrus reticulata

In this study, phenolic compounds in the juice, seed and bagasse of C. limetta and C. reticulata cultivated in Mexico at two ripening stages were determined, and their antioxidant capacities were evaluated using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2′-azin-bis-(3-etilbenzotiazolin-6-sulfonic acid) (ABTS) and oxygen radical absorption capacity test (ORAC) methods, as well as their antibacterial growth inhi - bition. We found that bagasse had the highest total phenol content and the highest total flavonoid content. The dominant flavonoid, hesperidin, was observed to be the highest in bagasse. Ascorbic acid was analyzed and C. limetta juice and C. reticulata bagasse had the highest contents. Antioxidant capacity showed variations in both, C. limetta and C. reticulata , juices which had the highest ABTS value; C. limetta juice and C. reticulata bagasse had the highest DPPH value; C. limetta juice and C. reticulata bagasse had the highest ORAC value. C. limetta and C. reticulata extracts showed the bactericidal effect at the range of 4–40 mg/mL, assayed against Escherichia coli , Listeria monocytogenes , Pseudomonas aeruginosa , Salmonella enterica and Staphylococcus aureus . Overall, ripeness increased total phenol content (TPC), total flavonoid content (TFC), hesperidin content, antioxidant capacity and bactericidal effect. These results may provide useful information for future utilization of C. limetta and C. reticulata . 7305). The TPC in mg equivalents of Gallic acid (GAE) by g of dry matter (DM) of bagasse and seeds and in mg GAE/mL for the juices. The total flavonoid content (TFC) analyzed a method A mL of solution g/50 and the resulting was diluted a final of The it left to rest for 30 min and its absorbance was measured at 510 nm. The TFC was calcu lated using a calibration curve of quercetin (Aldrich, USA) and the results were expressed in mg equivalent of quercetin (QE) per grams of dry matter (DM) of bagasse and seeds and in mg QE/mL for the juices. The quantitative analysis of hesperidin and ascorbic acid was per formed in a high-performance liquid chromatography (HPLC) Varian LC920 equipped with a column C18 Varian, 25 cm × 4.6 mm I.D. and a diode array detector. The TFC was calculated using a calibration curve of quercetin (Aldrich, USA) and the results were expressed in mg equivalent of quercetin (QE) per grams of dry matter (DM) of bagasse and seeds and in mg QE/mL for juices. The quantitative analysis of hesperidin and ascorbic acid was performed in a high-performance liquid chromatography (HPLC) Varian LC920 equipped with a column C18 Varian, 25 cm × 4.6 mm I.D. and a diode array detector. Mobile phases of KH 2 PO 4 20 mM, We investigated the content and antioxidant activity of the phenolic compounds and flavo noids from two Mexican varieties of C. reticulata and C. limetta . Bagasse, juice and seeds of C. reticulata and C. limetta contain phenolic compounds and flavonoids. Its content increases as the maturity increases. The extracts show microbicide effect on microorganisms of study under in vitro conditions. The effect increases when rising the ripening of the fruit. Extracts of C. reticulata have a higher bactericide effect than those obtained C. limetta , test microorganisms. As a result, the inhibition is directly related to the content of phenolic compounds and flavonoids. The extracts show antioxidative effect in vitro tests. The effect increases when rising the ripening of the fruit C. reticulata has antioxidant capacity and content of secondary metabolites greater than C. limetta . Inhibition of oxidation is directly related to the content of phenolic compounds and flavonoids. Our findings suggest that C. reticulata and C. limetta , especially its bagasse, are good sources of antioxidant and antibacterial compounds. The results of citrus species analyzed in this study can motivate more widely used them in the pharmaceutical and food products.