Bioactive compounds from vegetal sources are a potential source of natural antifungic. An ethanol extraction was used to obtain bioactive compounds from Carica papaya L. cv. Maradol leaves and seeds of discarded ripe and unripe fruit. Both, extraction time and the papaya tissue flour:organic solvent ratio significantly affected yield, with the longest time and highest flour:solvent ratio producing the highest yield. The effect of time on extraction efficiency was confirmed by qualitative identification of the compounds present in the lowest and highest yield extracts. Analysis of the leaf extract with phytochemical tests showed the presence of alkaloids, flavonoids and terpenes. Antifungal effectiveness was determined by challenging the extracts (LE, SRE, SUE) from the best extraction treatment against three phytopathogenic fungi: Rhizopus stolonifer, Fusarium spp. and Colletotrichum gloeosporioides. The leaf extract exhibited the broadest action spectrum. The MIC(50) for the leaf extract was 0.625 mg ml(-1) for Fusarium spp. and >10 mg ml(-1) for C. gloeosporioides, both equal to approximately 20% mycelial growth inhibition. Ethanolic extracts from Carica papaya L. cv. Maradol leaves are a potential source of secondary metabolites with antifungal properties.

Tangerine (Citrus reticulata. CRP) and grapefruit (Citrus paradisi. CPP) pectins obtained by ultrasound-assisted extraction (UAE) and conventional extraction (CE) using citric acid were characterized to establish their potential uses as an alternative source of commercial pectin. The pectins obtained by UAE and CE presented a pseudoplastic fluid characteristic with shear thinning behavior, a high esterification degree (CRP 82.30-71.81% and CPP 84.25-72.15%) and were of commercial quality based on galacturonic acid content (CRP 76.03% and CPP 76.03-71.01%). CPP presented greater viscosimetric molecular weight than CRP. Meanwhile, CRP presented greater polyphenol and protein content with respect CPP. The functional properties were influenced by citrus source and extraction method. UAE favored greater yields in a shorter time (CPP: 26.05%, 30 min; CRP: 13.46%, 15 min) compared to CE. UAE combined with the use of citric acid offers an effective alternative for obtaining high-quality pectins with lower polluting effluent, time and energy requirements. Pectina cítrica obtenida por extracción asistida por ultrasonido: propiedades fisicoquímicas, estructurales, reológicas y funcionales RESUMEN Pectinas de mandarina (Citrus reticulata, PCR) y pomelo (Citrus paradisi, PCP) obtenidas vía extracción asistida por ultrasonido (EAU) y convencional (EC) con ácido cítrico fueron caracterizadas para establecer su potencial uso como una fuente alternativa de pectina comercial. Las pectinas obtenidas por EAU y EC presentaron características de fluido pseudoplástico con un comportamiento de adelgazamiento por cizalladura, alto grado de esterificación (CRP 82.30-71.81% and CPP 84.25-72.15%), y calidad comercial por el contenido de ácido galacturónico (CRP 76.03% and CPP 76.03-71.01%). PCP presentaron mayor peso molecular viscosimétrico comparado a PCR. Mientras PCR presentaron mayor contenido de polifenoles, y proteínas con respecto a PCP. Las propiedades funcionales fueron influenciadas por la fuente cítrica y el método de extracción. La EAU favoreció los mayores rendimientos a menor tiempo: PCP (26.05±0.49%, 30 min) y PCR (13.46±1.79%, 15 min) comparada con EC. La EAU representa una alternativa eficaz para la obtención de pectinas de alta calidad, con menores efluentes contaminantes, tiempo y energía.

Bioactive Phenols-loaded chitosan nanoparticles (PL-CNps) were developed by ionic gelation from Persian lemon (Citrus latifolia) waste (PLW) and chitosan nanoparticles. Response Surface Methodology (RSM) was used to determine the optimal Ultrasound-Assisted Extraction (UAE) conditions for the total phenolic compounds (TPC) recovery from PLW (58.13 mg GAE/g dw), evaluating the ethanol concentration, extraction time, amplitude, and solid/liquid ratio. Eight compounds expressed as mg/g dry weight (dw) were identified by ultra-performance liquid chromatography coupled photo diode array (UPLC-PDA) analysis: eriocitrin (20.71 ± 0.09), diosmin (18.59 ± 0.13), hesperidin (7.30 ± 0.04), sinapic acid (3.67 ± 0.04), catechin (2.92 ± 0.05), coumaric acid (2.86 ± 0.01), neohesperidin (1.63 ± 0.00), and naringenin (0.44 ± 0.00). The PL-CNps presented size of 232.7 nm, polydispersity index of 0.182, Z potential of −3.8 mV, and encapsulation efficiency of 81.16%. The results indicated that a synergic effect between phenolic compounds from PLW and chitosan nanoparticles was observed in antioxidant and antibacterial activity, according to Limpel’s equation. Such results indicate that PLW in such bioprocesses shows excellent potential as substrates for the production of value-added compounds with a special application for the food industry.

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