Scientia Agropecuaria

Identification of the 5s rDNA locus in Physalis peruviana L. chromosomes, first report

Resumen Physalis peruviana (aguaymanto) es un fruto nativo del Perú de importancia en la agricultura andina. Aunque hay evidencia de investigación en citogenética clásica en la especie, no existe información detallada basada en estudios de citogenética molecular. En el presente estudio se ha utilizado la técnica Hibridización Fluorescente in Situ (FISH) para identificar sitios 5S ADNr en los cromosomas de P. peruviana de las poblaciones de San Pablo y Celendín (Cajamarca, Perú). Se ha identificado el locus 5S ADNr en las dos poblaciones de aguaymanto, reportándose seis señales en 3 pares de cromosomas lo que indicaría que la especie es poliploide; así mismo no se encuentran diferencias en el número de locus 5S ADNr entre ambas poblaciones por lo que podríamos señalar que no se tratarían de diferentes ecotipos.

Abstract Physalis peruviana (Golden berry) a native fruit of Peru, is an important Andean agricultural crop. Although classical cytogenetics research on this berry has been conducted there is no precise evidence based on molecular cytogenetic studies. The Fluorescent In Situ Hybridization (FISH) technique was applied to reveal 5S rDNA sites in chromosomes of San Pablo and Celendín populations, Cajamarca, Perú. This research was identified the 5S rDNA locus in the two populations of Golden berry, reporting six signals in 3 pairs of chromosomes which would indicate that the species is polyploid. Likewise, no differences were found in the number of 5S rDNA loci between both populations, so we could point out that they would not be different ecotypes.

New cadmium bioremediation agents: Trichoderma species native to the rhizosphere of cacao trees

Resumen La absorción de cadmio (Cd) por la planta de cacao y la mayor acumulación en granos, representa un problema para las exportaciones y la industria chocolatera. En este estudio, se evaluaron cepas de Trichoderma spp. nativas con capacidad de remoción y tolerancia a Cd, colectadas del suelo rizosférico de árboles de cacao. Para evaluar tales capacidades en condiciones in vitro, fueron inoculadas 10 cepas Trichoderma spp. nativas en medio de cultivo papa dextrosa agar (PDA) contaminado con tres concentraciones de Cd (25 ppm, 100 ppm y 250 ppm) y en medio de cultivo papa dextrosa (PD) contaminado con 5 ppm de Cd. Con los datos de ritmo de crecimiento (RC) de la colonia del hongo en presencia de Cd y porcentaje de remoción de Cd (RCd), se realizaron el análisis de varianza y las medias se compararon con la prueba de Scott-knott (p = 0,05). Los resultados mostraron que Trichoderma spp. fueron sensibles a la presencia de Cd y capaces de remover Cd. Entre las cepas con alta capacidad de remoción significativa (p < 0,05) de Cd fueron T. brevicompactum M43D (83,1%), T. harzianum M1P (67,0%) y T. spirale M55SM (65,8%). Mientras, las cepas más tolerantes fueron T. harzianum M1P y T. koningiopsis M3B, en comparación al tratamiento control sin Cd. Por lo tanto, T. brevicompactum M43D y T. spirale M55SM se suman a la lista de especies de Trichoderma como nuevos agentes potenciales de biorremediación de Cd que pueden ser explorados.

Abstract The cadmium absorption by cacao plant and increased in beans accumulation, represents a problem for the exports of cacao beans and chocolate industry. In this study, native strains of Trichoderma spp. were evaluated for their capacity of tolerate and removal to Cd, collected from rhizospheric soil of cacao trees. In order to evaluate such capacities under in vitro conditions, 10 native strains of Trichoderma spp. were inoculated in potato dextrose agar (PDA) culture medium contaminated with three concentrations of Cd (25 ppm, 100 ppm and 250 ppm) and in potato dextrose (PD) culture medium contaminated with 5 ppm Cd. With data of growth rhythm (RC) of the fungus colony in Cd presence and percentage of Cd removal (RCd), the analysis of variance was performed, and the means were compared with Scott-knott test (p = 0.05). The results showed that, Trichoderma spp. were sensitive to Cd presence and capable of Cd removing. Among the strains with high significant removal Cd capacity (p < 0.05) were T. brevicompactum M43D (83.1%), T. harzianum M1P (67.0%) and T. spirale M55SM (65.8%). While the most tolerant strains were T. harzianum M1P and T. koningiopsis M3B, in comparison to the control treatment without Cd. Therefore, T. brevicompactum M43D and T. spirale M55SM unite to the list of Trichoderma species as potential new Cd bioremediation agents that can be explored.

Optimization of processing parameters for the microencapsulation of soursop (Annona muricata L.) leaves extract: Morphology, physicochemical and antioxidant properties

Abstract Soursop leaves contain bioactive compounds which degrade after being separated from their native matrix. In order to protect their functionality, encapsulation can be applied. This investigation aimed to optimize the parameters for microencapsulating a hydroethanolic extract of soursop leaves after selecting a technique among freeze (FDM) and spray drying (SDM). Selection was performed through a factorial design (23) including as factors: the technique (FDM and SDM), the encapsulant (Gum Arabic and maltodextrin) and its concentration (5% and 10%), for maximizing encapsulation efficiency (EE). Spray drying microencapsulation with maltodextrin at 10% showed the highest EE. Subsequently, the drying temperature and the feeding rate were optimized through a multilevel factorial design to minimize moisture and to maximize the powder solubility and the EE. A significant effect on the response variables (p < 0.05) was found, resulting in 140 ºC and 7 mL/min as optimum parameters. Optimized treatment powder was characterized in terms of microstructure (spherical particles with a random size and irregular surfaces), annonacin content via HPTLC (0.904 ± 0.054 mg/g), color (L* 66.89 ± 0.67, a* 0.06 ± 0.56 and b* 6.01 ± 0.20) and antioxidant capacity (17.88 ± 0.86 and 90.59 ± 1.19 µmol ET/g, by DPPH and ABTS assays). Proposed SDM conditions could be taken into account for preserving bioactive compounds from soursop leaves.

Transplanting colonies of Cladophora crispata susceptible to die to increase the available biomass: Strategy for sustainability and food security in Lake Titicaca

Resumen El alga Cladophora crispata “Llaska” es una especie alimenticia importante para las poblaciones que viven en la zona circunlacustre del lago Titicaca. Sin embargo, su biomasa se ve afectada por la disminución del nivel de lago en la época seca. Por ello, los objetivos fueron determinar la biomasa fresca de la Llaska en época lluviosa y seca en tres comunidades del área circunlacustre del lago; y, evaluar el nivel de éxito del trasplante de colonias de la Llaska para el aumento de su biomasa disponible. Para la determinación de la biomasa se utilizó un cuadrante metálico de 0,25 cm de lado. Para el trasplante se utilizaron colonias de Llaska susceptibles de morir, las cuales fueron distribuidas en hileras, a una distancia no mayor a 10 m con respecto a la orilla del lago. En la época lluviosa se encontró una mayor biomasa, particularmente en marzo (785,28 ± 89,98 g/m2). La biomasa fue similar entre las tres zonas de estudio, aunque en la comunidad de Llachón fue donde se encontró una mayor biomasa. El trasplante de las colonias de Llaska fue exitoso, ya que tanto la altura como el diámetro de las colonias incrementaron durante el tiempo de evaluación. Particularmente, la altura fue quien tuvo una mayor respuesta al tiempo de evaluación. Entonces, con el trasplante de colonias susceptibles de morir se podría aumentar su biomasa disponible para fines alimenticios.

Abstract The algae Cladophora crispata “Llaska” is an important food species for populations that live around of Lake Titicaca. However, its biomass is affected for level decreasing of Lake Titicaca. Therefore, the aims were to determine the fresh Llaska biomass in the rainy and dry season on three communities around the lake and to assess the level success of Llaska colonies transplanted to increase the available biomass. The biomass assessment was using a 0.25 cm side metal quadrant. For transplanting Llaska colonies susceptible to die were used, which were distributed in rows at 10 m from the lake shore. The highest biomass was found in the rainy season, particularly in March (785.28 ± 89.98 g/m2). The biomass was similar between the three study areas, although it was high in Llachon community. Transplant of Llaska colonies was successful, since both the colonies height and diameter increased during the assessment time. In particular, Llaska height had the greatest response during the evaluation time. Therefore, with the transplantation of dying colonies we could increase the biomass available to food purposes.

Bacterial composition in maca (Lepidium meyenii Walp) crop soils analyzed by metagenomics: a study in the central Andes of Peru

Resumen El cambio e intensificación de uso del suelo ha dado lugar al empobrecimiento de los suelos con efectos negativos en las comunidades biológicas. Se analizó la composición bacteriana de suelos de cultivo de maca (Lepidium meyenii Walp) mediante secuenciación Illumina en la meseta de Bombón, durante el año 2019. Se definieron tres sectores de muestreo, un sector control (suelo natural) y dos sectores con presión de uso (suelos “primer uso” y “segundo uso”, respecto al cultivo de maca). Se determinaron los indicadores fisicoquímicos del suelo mediante métodos analíticos y la composición de las comunidades bacterianas mediante secuenciación Illumina de los amplicones del gen de ARNr 16S. Los resultados de pH y CE, en suelos control y con presión de uso, variaron de 7,51 a 4,53 y de 0,06 a 0,47 dS/m, respectivamente. Los contenidos más altos MO, N, P, K y Ca se registraron en los suelos control disminuyendo significativamente en suelos con presión de uso. El análisis de componentes principales (ACP) presentó un porcentaje de variación total del 97,1 %. La secuenciación Illumina reveló 3776 familias bacterianas. El análisis SIMPER mostró que los mayores porcentajes de contribución lo realizaron las familias Acidobacteriaceae (2,95%), Verrucomicrobiaceae (2,68%), Thermoactinomycetaceae (2,11%) y Akkermansiaceae (2,10%). El análisis de redundancia (AR) mostró una buena asociación entre las variables fisicoquímicas y las familias bacterianas. El análisis metagenómico ha permitido identificar familias bacterianas que pueden ser usadas como indicadores de buena y mala calidad fisicoquímica del suelo según presión de uso por cultivos de maca; así como, a los mejores indicadores fisicoquímicos predictores de los cambios de la composición de las comunidades bacterianas.

Abstract The change and intensification of land use has been generating impoverishment of soils with negative effects on biological communities. It was analyzed the bacterial composition of maca (Lepidium meyenii Walp) cultivation soils by Illumina sequencing in the Bombón plateau, during 2019. Three sampling sectors were defined, a control sector (natural soil) and two sectors with use pressure ("first use" and "second use" soils). Soil physicochemical indicators were determined through analytical methods and the composition of bacterial communities through Illumina sequencing of 16S rRNA gene amplicons. The results of pH and EC, in control soils and with use pressure, varied from 7.51 to 4.53 and from 0.06 to 0.47 dS/m, respectively. The highest OM, N, P, K and Ca contents were recorded in control soils, decreasing significantly in soils with use pressure. Principal components analysis (PCA) presented a percentage of total variation of 97.1%. Illumina sequencing revealed 3776 bacterial families. SIMPER analysis showed that the highest contribution percentages were made by the Acidobacteriaceae (2.95%), Verrucomicrobiaceae (2.68%), Thermoactinomycetaceae (2.11%) and Akkermansiaceae (2.10%) families. Redundancy analysis (RDA) showed a good association between physicochemical variables and bacterial families. The metagenomic analysis has allowed the identification of bacterial families that can be used as indicators of good and bad soil physicochemical quality according to the pressure of use by maca crops. As well as the best physicochemical indicators predictive of changes in the composition of bacterial communities.

Estimation of arsenic contents in rice purchased on Peruvian markets and estimation of dietary intake by Peruvians through rice consumption

Abstract Rice (Oryza sativa L) is an important source of essential elements but also can contain high As concentrations, which may be consumed and causes health effects. This work aimed to contribute to the lack of information quantifying the total arsenic (tAs) in 31 domestic rice (white rice, n=19; brown rice, n=7; parboiled rice, n=5) of different brands purchased in Peruvian markets. The tAs content was conducted by ICP-MS. The tAs concentration was compared to the maximum limits prescribed by regulatory agencies. Dietary intake (DI), dietary exposure (DE), and margin of exposure (MOE) were estimated. tAs concentration in white, brown and parboiled rice were 0.292 ± 0.106 mg/kg, 0.401 ± 0.081 mg/kg, 0.229 ± 0.03 mg/kg, respectively. Arsenic concentration in white rice exceeded limits recommended by FAO/WHO (0.20 mg kg-1), and European legislation (0.25 mg kg-1), but no Mercosul limits (0.3 mg kg-1). The DE showed that, on average, Peruvians consume 5.60 μg As kg-1 BW weekly. The MOE value was higher than 1 at the mean dietary exposure level. Our findings suggest that the health risk from dietary arsenic exposure is low for the Peruvian population. However, more studies are needed to reduce dietary arsenic exposure in Peru.

Consumer attitudes towards ultrasound processing and product price: Guava juice as a case study

Abstract Several kinds of emerging technology have begun to be applied to food processes as prospective alternatives to conventional methods. Among these, ultrasound has been used. Despite the vast literature on the subject, some important aspects, including the sensory and hedonic perception of consumers towards this technology have not been properly addressed. In this study, consumer attitudes toward expected acceptance, pricing and purchase intention of guava juice processed with ultrasound technology were analyzed by using the conjoint analysis. The holistic perception of guava juice using projective mapping was also evaluated. The results indicate that consumers have greater acceptance and purchase intention for products that inform them of the benefits of the ultrasound process, while purchase intention was mainly influenced by the lowest price. Moreover, the product information regarding the ultrasound technology -displayed on individual packages- was a predominant factor which also served as a criterion for grouping the stimuli. Overall, the information highlighting the use of ultrasound technology during the processing of guava juice did not have any negative effect on the consumers’ acceptance and purchase intention. These findings can be considered as a positive indicator towards the possible application of this technology to industrial juice processing.

An insight into the pasting properties and gel strength of starches from different sources: effect of starch concentration

Abstract This work aims to evaluate the starch/water concentrations (3.6%, 7.1%, 10.7% and 14.3%) effect of different commercial starch sources (namely cassava, maize, high-amylose maize, waxy maize and potato) regarding their pasting properties by using a Rapid Visco Analyser (RVA), gel strength, and intrinsic characteristics (such as morphology, granules size and distribution). The results showed that the 10.7% concentration (standard concentration usually used for evaluating starch properties) is not always predictive for the starches rheological behaviour. Meanwhile, the characteristics of the formed gels were not only related to RVA properties. For instance, decisions based on the results using the concentration of 10.7% can be far different from those used in industrial applications. The data reported can be useful to demonstrate how conditions, properties and starches characteristics are correlated, also to facilitate the selection of the best conditions that are closer to the desired application.

Effect of climatic factors on the phenological phases of Mauritia flexuosa Lf. in low terrace plantations in Ucayali, Peru

Resumen El objetivo en este estudio fue determinar la influencia de la temperatura del aire y la precipitación pluvial en el desarrollo fenológico deMauritia flexuosaen plantaciones ubicadas en Ucayali, Perú. Para ello, durante un periodo de 24 meses, se evaluaron 191 palmeras de 19 años, distribuidas en tres plantaciones establecidas en suelos de terraza baja. Los resultados mostraron que el 45% de palmeras no manifestaron su madurez sexual, no obstante, fue verificado 42% y 13% de individuos con sexo masculino y femenino, respectivamente. Fue constatado que el ciclo fenológico fue bianual, con superposición de fenofases y eventos escalonados. En individuos femeninos se observó máxima floración en fenofase FLA1 (4-5%) de setiembre a noviembre de 2018 y máxima fructificación FRM1 (4-6%) de octubre 2018 a enero de 2019; en individuos masculinos la fenofase de floración FLA2 se presenta en dos periodos entre setiembre de 2018 y febrero de 2020, entre tanto, la fenofase de flores abiertas de ambos sexos, es sincrónica en mayor proporción entre setiembre y noviembre. Fue determinado que la precipitación pluvial y la temperatura del aire (máxima y mínima) no presentaron correlación (p ≤ 0,05) con las fenofases productivas deMauritia flexuosa. La precipitación pluvial, la temperatura máxima y temperatura mínima del aire presentaron asociación nula con cada una de las fases fenológicas de las palmeras deMauritia flexuosadurante el periodo de evaluación. Con la finalidad de obtener información para la planificación de actividades de manejo silvicultural para su conservación de la especie, se recomienda evaluar por más años la influencia de los elementos climáticos sobre el desarrollo productivo deMauritia flexuosa.

Abstract The aim of this study was to determine the influence of air temperature and rainfall on the phenological development of Mauritia flexuosa in plantations located in Ucayali, Peru. For this, during a 24-month period, 191 19-year-old palm trees were evaluated, distributed in three plantations established on low terrace soils. The results showed that the 45% of palm trees did not manifest their sexual maturity, meanwhile, 42% and 13% of individuals with male and female sex, respectively, were verified. It was found that the phenological cycle was biannual, with overlapping phenophases and staggered events. In female individuals, maximum flowering was observed in phenophase FLA1 (4-5%) from September to November 2018 and maximum fruiting FRM1 (4-6%) from October 2018 to January 2019; In male individuals, the FLA2 flowering phenophase occurs in two periods between September 2018 and February 2020, meanwhile, the open flower phenophase of both sexes is synchronous in a higher proportion between September and November. It was determined that pluvial precipitation and air temperature (maximum and minimum) did not show correlation (p ≤ 0.05) with the productive phenophases of Mauritia flexuosa. The pluvial precipitation, the maximum temperature and the minimum air temperature showed null association with each one of the phenological phases of the Mauritia flexuosa palm trees during the evaluation period. In order to obtain information for the planning of silvicultural management activities for the conservation of the species, it is recommended to evaluate for more years the influence of climatic elements on the productive development of Mauritia flexuosa.

Lupinus mutabilis oil obtained by expeller press: Yield, physicochemical characterization, antioxidant capacity, fatty acids and oxidative stability analyses

Resumen Se extrajo por prensa expeller el aceite de los granos desamargados y descascarados de las variedades peruanas de tarwi (Lupinus mutabilis “Común” y “Andenes”). Se evaluó el rendimiento de extracción y, composición proximal de ambas variedades. Se caracterizaron propiedades fisicoquímicas, contenido total de polifenoles y capacidad antioxidante del aceite, la torta y la harina desengrasada para la variedad con el mayor rendimiento de extracción. Se extrapoló el tiempo de vida útil del aceite a 25 ºC por el test Rancimat. La variedad andenes presentó un rendimiento de 22,1% m/m (frente al 18,4% m/m de la variedad Común), color CIELAB L *= 36,5; a *= 2,2; b* = 20, índice de refracción a 25 ºC de 1,469, densidad a 25 ºC de 0,903 g/mL, índice de acidez de 3,2 mg KOH/g, ácidos grasos libres de 1,6% m/m, índice de peróxidos de 2,7 meq O2/kg, índice de p-Anisidina de 1,3, contenido de insaponificables del 58,0% m/m, capacidad antioxidante ABTS total de 21,4 µmol TE/g y, contenido de compuestos polifenólicos totales de 7,0 mg AGE/100g. El ácido graso, tocoferol y fitoesterol predominantes en el aceite fueron el ácido oleico (56,2% m/m), el γ-tocoferol (555 mg/kg) y el β-sitosterol (41900 mg/100g), respectivamente. A 25 ºC la vida útil del aceite fue de 2,7 años. El aceite de Lupinus mutabilis extraído por expeller presentó una calidad aceptable, pero con un menor impacto ambiental negativo, en comparación con la extracción de aceites utilizando solventes.

Abstract The oil of debittered and dehulled grains from two Andean lupins (Lupinus mutabilis) from Peru, Andenes and Común, was extracted by expeller press. The extraction yield and the proximal composition of both varieties were assessed. The oil and the cake, as well as the defatted flour from the variety with the highest extraction yield, were characterised for physico-chemical properties, total polyphenol content and antioxidant capacity. The oil shelf-life at 25 °C was extrapolated by Rancimat test. Andenes presented an oil yield of 22.1% (vs. 18.4% of Común), CIELAB colour coordinates of L* = 36.5, a* = 2.2, b* = 20, refractive index and density at 25 ºC of 1.469 and 0.903 g/mL, acid number of 3.2 mg KOH/g, free fatty acids content of 1.6%, peroxide number of 2.7 meqO2/kg, p-anisidine number of 1.3, unsaponificable content of 58%, total antioxidant capacity 21.4 µmol TE/g and total polyphenol content of 7.0 mg AGE/100 g. The predominant fatty acid, tocopherol and phytosterol in the oil were oleic acid (56.2%), γ-tocopherol (555 mg/kg) and β-sitosterol (41900 mg/100 g), respectively. The oil shelf-life at 25 ºC was 2.7 years. The Lupinus mutabilis oil extracted by expeller presented an acceptable quality with a lower environmental negative impact than the oils obtained by solvent extraction.

Edible films gelatin-based obtained from mahi-mahi skin (Coryphaena hippurus) and oregano extract: Physicochemical, antimicrobial, structural and surface characteristics

Resumen Se elaboraron películas comestibles a partir de soluciones de gelatina (4% p/v) de piel de mahi-mahi (Coryphaena hippurus) con 2,5; 5; 7,5 y 10% v/v de extracto de orégano (EO) y se determinaron sus propiedades fisicoquímicas, antimicrobianas, estructurales y de superficies. Las películas control y con 2,5 % de EO mostraron los valores más bajos de humedad y opacidad y los valores más altos de viscosidad. Todas las películas con EO inhibieron el crecimiento de Staphylococcus aureus y Proteus vulgaris. Sólo las películas con 10% de EO mostraron actividad antimicrobiana frente a todas las cepas evaluadas. La microscopía electrónica de barrido mostró que la incorporación del extracto de orégano en las soluciones formadoras de película, SFP, se relacionó con un incremento en la presencia de gotas de aceite en las películas evidenciándose la fracción lipídica del EO. Los análisis de espectroscopía infrarroja por transformada de Fourier (FTIR) y microscopía electrónica de barrido (SEM) mostraron la interacción entre la gelatina, el plastificante y el extracto de orégano en todas las películas. En conclusión, este estudio demostró la viabilidad de las películas comestibles de gelatina de piel de mahi-mahi con EO incorporado para su aplicación como empaque con acción antimicrobiana en alimentos susceptibles al deterioro por microorganismos.

Abstract Edible films were elaborated from gelatin solutions (4% w/v) of mahi-mahi skin (Coryphaena hippurus) with 2,5; 5; 7,5 and 10% v/v of oregano extract (OE) and its physicochemical, antimicrobial, structural and surface properties were determined. The control and with 2.5% OE films showed the lowest moisture and opacity values and the highest viscosity values. All films with OE inhibited the growth of Staphylococcus aureus and Proteus vulgaris. Alone films with 10% OE showed antimicrobial activity against all the strains evaluated. Scanning electron microscopy showed that the incorporation of oregano extract in the film-forming solutions, FFS, was related to an increase in the presence of oil droplets in the films, showing the lipid fraction of OE. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyzes showed the interaction between gelatin, plasticizer, and oregano extract in all films. In conclusion, this study demonstrated the viability of mahi-mahi skin gelatin edible films with OE incorporated for their application as packaging with antimicrobial action in foods susceptible to spoilage by microorganisms.

Postharvest storage of three chayote (Sechium edule (Jacq.) Sw.) varieties

Abstract The consumer demand for chayote (Sechium edule (Jacq.) Sw.) fruits has increased in recent years, virens levis being the most important variety, although other chayote varieties are gaining importance such as nigrum xalapensis and n. spinosum. However, the postharvest behavior of these varieties is different, so it is important to evaluate the factors that limit the shelf life of each variety. Therefore, in this study, fruits of each variety from the Mexican National Germplasm Bank of Sechium edule were used. The following fruit quality variables were evaluated: weight loss, humidity (%), color, chlorophyll, titratable acidity, total soluble solids (TSS), total sugars, and stomatal characteristics. In addition, the storage potential of each variety was evaluated for two weeks at different temperatures, 7°, 13° (85% RH) and 24 °C (60% RH), with the application of 1-methylcyclopropene (1-MCP). The variables evaluated were viviparism, disease severity, weight loss, dehydration and chilling injury (CI). The fruits of n. xalapensis and n. spinosum have a higher content of chlorophylls and carotenoids, but similar contents of TSS, acidity and total sugars than v. levis fruits. The use of 1-MCP reduced viviparism in all varieties, and the severity of blisters was higher in v. levis. The fruits of the three varieties presented severe CI when stored at 7 °C but the most susceptible to dehydration and diseases severity is n. spinosum.

Fungi associated with necrosis of vascular bundles in organic banana crop: symptoms, isolation and identification, and integrated management alternatives

Resumen El banano Musa spp. (Musaceae) es un cultivo tropical perenne de mayor consumo en el mundo, las principales regiones productoras son; Asia (54,1%), América (25,5%), África (18,4%). En Perú, Piura participa con el 72% del volumen total de las exportaciones de banano orgánico. En los últimos años en Perú y en otras zonas productoras del mundo, se viene presentando los síntomas de necrosis en los haces vasculares del pseudotallo ocasionando la muerte temprana de plantas en producción. El objetivo de este estudio fue identificar los principales patógenos fúngicos asociados a la necrosis vascular del banano. La identificación de los hongos aislados del pseudotallo, rizoma y raíces se realizó a través de claves taxonómicas. Los síntomas externos de la enfermedad fueron amarillamiento y necrosis de las hojas desde el borde hacia la nervadura central, colapso del peciolo y muerte de la planta. Los síntomas internos fueron necrosis en los haces vasculares y lesiones necróticas internas en rizoma y raíces. Por sus características morfométricas los aislados fúngicos se identificaron como; Fusarium oxysporum, F. verticillioides y F. solani. Para el control de esta enfermedad se recomienda implementar un plan de manejo integrado.

Abstract The banana Musa spp. (Musaceae) is a tropical perennial crop of major consumption in the world, the main producing regions are; Asia (54.1%), America (25.5%), Africa (18.4%). In Peru, Piura accounts for 72% of the country's total volume of organic banana exports. In recent years in Peru and in other producing areas of the world, symptoms of necrosis in the vascular bundles of the pseudostem have been occurring, causing the early death of plants in production. The objective of this study was to identify the main fungal pathogens associated with vascular necrosis of banana. The fungi isolated from the pseudostem, rhizome and roots were identified using taxonomic keys. The external symptoms of the disease were yellowing and necrosis of the leaves from the edge towards the midrib, collapse of the petiole and death of the plant. The internal symptoms were necrosis of the vascular bundles and internal necrotic lesions in the rhizome and roots. The fungal isolates were identified by their morphometric characteristics as Fusarium oxysporum, F. verticillioides and F. solani. For the control of this disease, it is recommended to implement an integrated management plan.

First report of Tanaostigmodes sp. as the main pest of Caesalpinia spinosa: Morphological and biological aspects

Resumen La tara (Caesalpinia spinosa (Mol.) Kuntze) es una especie forestal no maderable cuyas vainas son de importancia económica para diversas industrias; sin embargo, ataques de plagas como Tanaostigmodes sp. a las hojas y tallos jóvenes disminuye la producción de esta especie. El objetivo de este estudio fue determinar las características morfológicas y biológicas de Tanaostigmodes sp. y porcentaje de incidencia en C. spinosa. Fueron identificadas 1399 puestas del insecto en las cuales se realizaron evaluaciones de la duración de los estadios, la morfometría y los daños en la planta. El huevo, larva, pupa y adulto miden 0,2; 2,0; 2,1 y de 2,0 a 2,3 mm de largo, duran 13,1; 71,8; 20,6 y 10,1 días respectivamente, totalizando su ciclo de desarrollo en 115,1 días; las larvas al alimentarse realizan minas en los raquis de las hojas y en tallos jóvenes, alcanzando ataques máximos de hasta 84,5% provocando defoliación. Tanaostigmodes sp. es una plaga principal de tara, con registros de ataques medios de 24,6% en hojas. Conocer sus aspectos biológicos y su interacción con la fenología de tara, permitirá adoptar estrategias eficientes para su manejo integrado y control.

Abstract The tara (Caesalpinia spinosa (Mol.) Kuntze) is a non-timber forest species whose pods are of economic importance to various industries; however, attacks by pests such as Tanaostigmodes sp. the leaves and young stems decrease the production of this species. The aim of this study was to determine the morphological and biological characteristics of Tanaostigmodes sp. and percentage of incidence in C. spinosa. 1399 insects were identified in which evaluations of the duration of the stages, the morphometry and the damage to the plant were carried out. The egg, larva, pupa and adult measure 0.2, 2.0, 2.1 and 2.0 to 2.3 mm long, last 13.1, 71.8, 20.6 and 10.1 days respectively, totaling its development cycle in 115.1 days; the larvae when feeding make mines in the rachis of the leaves and in young stems, reaching maximum attacks of up to 84.5% causing defoliation. Tanaostigmodes sp. it is a major tare pest, with average attack records of 24.6% on leaves. Knowing its biological aspects and its interaction with tara phenology will allow the adoption of efficient strategies for its integrated management and control.

Microalgal biomass with high potential for the biofuels production

Resumen El estudio de los biocombustibles sigue en constante desarrollo, desde hace cinco décadas. Este artículo resume el análisis de diversas publicaciones científicas recientes, relacionadas con biocombustibles de tercera generación utilizando microalgas. Se presenta una visión general de biocombustibles y su clasificación, las bases teóricas de microalgas, técnicas para su cultivo, cosecha y pretratamiento de su biomasa. También se describen brevemente tecnologías prometedoras para obtener biocombustibles de gran demanda potencial mundial, considerando las características técnicas del proceso, en función de las especies de microalgas que tienen los más altos rendimientos y productividades para cada tipo de biocombustible: Biodiesel (extracción de lípidos, transesterificación y purificación), etanol (hidrólisis de azúcares, fermentación y purificación) y biogás (digestión anaerobia). La mayoría de los estudios están enfocados en la producción de lípidos, siendo Chlorella vulgaris, Nanochloropsis sp. y Botryococcus braunii (A) las microalgas más utilizadas para obtener biodiesel. Sin embargo, existen pocos estudios centrados en la producción de biomasa microalgal para producir bioetanol, así, las microalgas Porphyridium cruentum y Spirogira sp. podrían utilizarse para producir bioetanol, con la ventaja de no contener lignina. El biogás se produce por biodigestión anaeróbica de los residuos de biomasa microalgal en biorrefinerías, pero su producción comercial está muy limitada por los altos costos productivos y porque existen otras biomasas muy competitivas económicamente. La necesidad de producir biocombustibles utilizando biomasa microalgal, está alcanzando un mayor auge, siendo la propuesta trascendental, poner en marcha una biorrefinería, principalmente enfocada en la producción optima de biomasa microalgal como la clave principal de todo el proceso.

Abstract The study of biofuels continues in constant development, for five decades. This article summarizes the analysis of several recent scientific publications, related to third generation biofuels using microalgae. An overview of biofuels and their classification, the theoretical bases of microalgae, techniques for their cultivation, harvesting and pretreatment of their biomass are presented. Promising technologies for obtaining biofuels of great potential worldwide demand are also briefly described, considering the technical characteristics of the process, depending on the microalgae species that have the highest yields and productivity for each type of biofuel: Biodiesel (extraction of lipids, transesterification and purification), ethanol (hydrolysis of sugars, fermentation and purification) and biogas (anaerobic digestion). Most studies are focused on the production of lipids, being Chlorella vulgaris, Nanochloropsis sp. and Botryococcus braunii (A) the most used microalgae to obtain biodiesel. However, there are few studies focused on the production of microalgal biomass to produce bioethanol, thus, the microalgae Porphyridium cruentum and Spirogira sp. they could be used to produce bioethanol, with the advantage of not containing lignin. Biogas is produced by anaerobic biodigestion of microalgal biomass residues in biorefineries, but its commercial production is very limited due to high production costs and because there are other economically very competitive biomasses. The need to produce biofuels using microalgal biomass is reaching a greater boom, the transcendental proposal being the launching of a biorefinery, mainly focused on the optimal production of microalgal biomass as the main key to the entire process.

Phenolic compounds of mango (Mangifera indica) by-products: Antioxidant and antimicrobial potential, use in disease prevention and food industry, methods of extraction and microencapsulation

Abstract Globally, a large amount of agri-food waste is generated as a result of industrial processes or direct consumption of raw materials, and when discarded, they represent a factor of environmental pollution. Mango by-products have a great bioactive potential, especially because they contain phenolic compounds in which mangiferin predominates, in addition to a great variety of phenolic acids, flavonoids and tannins, which confer antioxidant effects against cancer, cardiovascular and neurological diseases, among others. In addition, it was demonstrated that they have an effect against a broad microbial spectrum, including multiple pathogenic bacteria and fungi such as Escherichia coli and Candida albicans, respectively. According to the literature, mango peel and seed extracts also have potential as an additive, by influencing the sensory and physicochemical characteristics of foods, which has been proven by their addition to products such as shrimp, yogurt and cookies. Considering the importance of mango by-products, this work focused on their phenolic properties, the mechanism of antioxidant and antimicrobial action, their fields of pharmacological and food applications, in addition to evaluating their extraction methods and proposing microencapsulation as a suitable technology to avoid their degradation and control their release under appropriate conditions. Based on the analysis performed, further studies are suggested on the application in different foods and to evaluate the interaction of polyphenols with the compounds of the product, to avoid possible negative effects. It is also recommended to experiment with the use of combined technologies to improve results during extraction and microencapsulation.