In this study, total phenolics, total flavonoids, hesperidin and ascorbic acid contents in bagasse, juice and seed of mexican sweet lime (Citrus limetta) and mandarine (Citrus reticulata) were determined at two commercial maturity stages (maturation index), as well as their bactericidal effect on Escherichia coli and Staphylococcus aureus. The results showed that bagasses had the highest total phenolics, total flavonoids, and hesperidin content for both, C. limetta, and C. reticulata; highest ascorbic acid contents were found in C. limetta juice (3.36 ± 0.25 mg g -1 DW) and C. reticulata bagasse (3.83 ± 0.37 mg g -1 DW). All tested extracts showed bacterial growth inhibition at 50 and 800 lg mL -1 . Bagasse extracts of both fruits showed the highest inhibitions ([90%) on tested bacteria. Total phenolics, total flavonoids, and hesperidin contents, as well as bactericidal effect increased with maturity. Results indicated that both Mexican citric fruits (C. limetta and C. reticulata) were good sources of antioxidant and bactericidal agents.

<p>En la industria alimenticia, los agentes microbicidas son usados para preservar la calidad y seguridad de los alimentos procesados. Los flavonoides encontrados en extractos cítricos han mostrado capacidad de inhibición del crecimiento celular de un gran grupo de microorganismos infecciosos, por lo tanto, éstos compuestos pueden ser útiles como agentes antivirales, antifúngicos y antibacteriales. Los flavonoides que se pueden encontrar principalmente en varias de las especies cítricas son hesperetina, hesperidina, luteolina, naringenina, naringina, narirutina, neohesperidina, nobiletina y tangeretina. A continuación se resumen los procesos utilizados recientemente para extraer, purificar y analizar los flavonoides principales en frutas cítricas.</p>

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 inhibition. 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.