OBTENCIÓN Y CARACTERIZACIÓN DE CAPSAICINA Y OLEORRESINA DE DOS ESPECIES DE Capsicum, PROVENIENTES DE LA COSTA PERUANA

En la presente investigación se llevó a cabo la extracción y caracterización de la oleorresina y capsaicina de Capsicum chinense y Capsicum baccatum, en la Facultad de Agronomía de la Universidad Nacional del Centro del Perú, con el apoyo de otro laboratorio particular de la ciudad de Lima, evaluando el rendimiento y la calidad en función de dos factores: concentración de alcohol etílico de 70% y 95%, y para el segundo factor 2 niveles fresco y seco con una humedad del 10%. Los resultados obtenidos de porcentaje de Capsaicina en la oleorresina y porcentaje de capsaicina se obtuvieron mediante el método de Cromatografía Liquida de alta resolución HPLC ISO 7543-2 las cuales se interpretaron utilizando el análisis de varianza, llegando a concluir que: en el rendimiento de oleorresina obtenida, existe efecto significativo en la interacción de la concentración del solvente con el nivel de deshidratación. Los factores estudiados influyen en el porcentaje de capsaicina contenido en la oleorresina, pero de manera individual: comparativamente existen mayores porcentajes de alcaloide para Capsicum chinense frente a Capsicum baccatum en material seco sobre el fresco y para la concentración del alcohol etílico del 95% sobre el 70%. Después de aislar el alcaloide sin embargo no hay diferencia significativa para el contenido de capsaicina por efecto de los factores estudiados. De esta manera se logró determinar las condiciones para obtener el mejor porcentaje de capsaicina en la oleorresina.

Green Synthesis of Silver Nanoparticles Using Natural Extracts with Proven Antioxidant Activity

Natural extracts are a rich source of biomolecules that are useful not only as antioxidant drugs or diet supplements but also as complex reagents for the biogenic synthesis of metallic nanoparticles. The natural product components can act as strong reducing and capping substrates guaranteeing the stability of formed NPs. The current work demonstrates the suitability of extracts of Camellia sinensis, Ilex paraguariensis, Salvia officinalis, Tilia cordata, Levisticum officinale, Aegopodium podagraria, Urtica dioica, Capsicum baccatum, Viscum album, and marine algae Porphyra Yezoensis for green synthesis of AgNPs. The antioxidant power of methanolic extracts was estimated at the beginning according to their free radical scavenging activity by the DPPH method and reducing power activity by CUPRAC and SNPAC (silver nanoparticle antioxidant capacity) assays. The results obtained by the CUPRAC and SNAPC methods exhibited excellent agreement (R2~0.9). The synthesized AgNPs were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), dynamic light scattering (DLS) particle size, and zeta potential. The UV-vis absorption spectra showed a peak at 423 nm confirming the presence of AgNPs. The shapes of extract-mediated AgNPs were mainly spherical, spheroid, rod-shaped, agglomerated crystalline structures. The NPs exhibited a high negative zeta potential value in the range from −49.8 mV to −56.1 mV, proving the existence of electrostatic stabilization. FTIR measurements indicated peaks corresponding to different functional groups such as carboxylic acids, alcohol, phenol, esters, ethers, aldehydes, alkanes, and proteins, which were involved in the synthesis and stabilization of AgNPs. Among the examined extracts, green tea showed the highest activity in all antioxidant tests and enabled the synthesis of the smallest nanoparticles, namely 62.51, 61.19, and 53.55 nm, depending on storage times of 30 min, 24 h, and 72 h, respectively. In turn, the Capsicum baccatum extract was distinguished by the lowest zeta potential, decreasing with storage time from −66.0 up to −88.6 mM.

The Capsicum baccatum-Specific Truncated NLR Protein CbCN Enhances the Innate Immunity against Colletotrichum acutatum

Chili pepper (Capsicum annuum) is an important fruit and spice used globally, but its yield is seriously threatened by anthracnose. Capsicum baccatum (C. baccatum) is particularly valuable as it carries advantageous disease resistance genes. However, most of the genes remain to be identified. In this study, we identified the C. baccatum-specific gene CbCN, which encodes a truncated nucleotide-binding and leucine-rich repeat protein in the anthracnose resistant chili pepper variety PBC80. The transcription of CbCN was greater in PBC80 than it was in the susceptible variety An-S after Colletotrichum acutatum inoculation. In order to investigate the biological function of CbCN, we generated transgenic tobacco lines constitutively expressing CbCN. Notably, CbCN-overexpressing transgenic plants exhibited enhanced resistance to C. acutatum compared to wild-type plants. Moreover, the expression of pathogenesis-related (PR) genes was remarkably increased in a CbCN-overexpressing tobacco plants. In order to confirm these results in chili pepper, we silenced the CbCN gene using the virus-induced gene silencing system. The anthracnose resistance and expressions of PR1, PR2, and NPR1 were significantly reduced in CbCN-silenced chili peppers after C. acutatum inoculations. These results indicate that CbCN enhances the innate immunity against anthracnose caused by C. acutatum by regulating defense response genes.

Efecto de la aplicación de vapor saturado como Sistema de Esterilización Orgánica (OSS) en el ají mirasol (Capsicum baccatum var. pendulum) y en el ají panca (Capsicum chinense Jacq.)

Se determinó la influencia del peso, temperatura y tiempo de inyección de vapor saturado en el Sistema de Esterilización Orgánica (OSS por sus siglas en inglés) sobre la carga microbiana, análisis proximal y contenido de capsaicina en el ají mirasol y el ají panca. Se trabajó con 3 y 4 kg de ají, 100 y 105 °C (20 y 25 kPa), por 2 y 3 min. Los análisis pre y pos-OSS fueron los siguientes: recuento de aerobios mesófilos viables, coliformes totales, E. Coli, Salmonella, mohos y levaduras, proximal y contenido de capsaicina. Las muestras de 3 kg del ají mirasol, sometidas a 105 °C por 3 min, y las de 3 y 4 kg del ají panca, sometidas a 105 °C por 3 min, lograron mayor reducción de aerobios mesófilos y mohos. En la evaluación estadística se encontraron interacciones entre las variables peso y temperatura en ají mirasol; entre peso, temperatura y tiempo en el ají panca, sobre la reducción de aerobios mesófilos y mohos; esto influye en la composición proximal y reducción del contenido de capsaicina de 863.2 a 751.9 ppm (ají mirasol) y 405.6 a 315.1 ppm (ají panca); evidenciando que el tratamiento OSS es un método eficiente en procesos de descontaminación microbiana.

Phenotypic, molecular and pathogenic characterization of Colletotrichum scovillei infecting Capsicum species in Rio de Janeiro, Brazil

Anthracnose is a disease caused by Colletotrichum spp., one of the world’s most damaging sweet and chili pepper pathogens, especially in tropical and subtropical regions. In the state of Rio de Janeiro, anthracnose is one of the main obstacles for pepper crops. However, to date no research has focused on the identification and characterization of the pathogen, which is fundamental to understand the scope of the disease in the state. Thus, the correct identification of the fungal species and pathogenicity studies can provide important support for disease management and control, apart from identifying possible resistance sources for exploitation in peppers breeding programs. In this study, 11 Colletotrichum isolates were collected from peppers with typical symptoms in the Rio de Janeiro state. These isolates were characterized based on morpho-cultural characteristics and sequencing data from five regions (ITS, ACT, CAL, β-TUB and GAPDH), and the genetic variability was estimated by AFLP markers. Simultaneously, microscopy images of the colonization by the fungal species on unripe Capsicum annuum fruits were taken. Pathogenicity was tested and resistance sources were sought by means of infection of ripe and unripe fruits of 50 Capsicum baccatum accessions. The resulting data showed that all isolates belong to Colletotrichum scovillei specie. About the pathogenicity of Capsicum baccatum, differentiated, stage-specific responses, with higher resistance of ripe fruits were recorded. In addition, four possible sources of Colletotrichum scovillei resistance were detected among the tested accessions. The combination of these data can contribute to future studies on the interaction of Colletotrichum scovillei-Capsicum spp., a research line that is still unexploited in the main areas of this anthracnose fungus.