Coaquira Quispe, Joel Jerson
Preferred name
Coaquira Quispe, Joel Jerson
Main Affiliation
Email
joelk@upeu.edu.pe
ORCID
7 resultados
Mostrando 1 - 7 de 7
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Item type:Publicación, Evaluación de la cinética de degradación térmica de la vitamina C en la pulpa de tumbo (Passiflora mollissima b.)(2022-09-16); Vitamin C is an important micronutrient, which is found in acidic fruits such is the case of tumbo, studies have shown beneficial effects of vitamin C on health due to its antioxidant and free radical scavenging capabilities. The objective of the research was to evaluate the thermal degradation kinetics of vitamin C of the pulp of tumbo (Passiflora mollissima b.). The pulp of tumbo was prepared and subsequently subjected to different temperatures (60, 70 and 80 ° C) and times (0, 5, 10, 15 and 20 min). The vitamin C content in the pulp of tumbo was 77.01 mg / 100g which was analyzed by spectrophotometry. The results showed that vitamin Cdegradation followed second-order kinetic models. The degradation rate constants for ascorbic acid in the tumbo pulp were: k60 = 0.014 min-1, k70 = 0.019 min-1 and k80 = 0.023 min-1 and the decimal reduction times are: D60 = 162.17 min, D70 = 121.74 min and D80 = 101.76 min. The z value was 99 ° C, the Ea in the temperature range of 60-80 ° C is 22.84 kJ / mol and the value of Q10 is 1.60. The optimal time and temperature of pasteurization in the pulp of tumbo is 10.69 min at 60 ° C, for presenting the best correlation index, retaining the greatest amount of ascorbic acid, presenting a lower reaction rate and requiring a longer time of decimal reduction. It was concluded that the higher the temperature, the higher the degradation of vitamin C, the data obtained will help to predict the best conditions of processing of the pulp of tumbo and minimize degradation since it is an important quality factor. - Some of the metrics are blocked by yourconsent settings
Item type:Publicación, Discrimination of foreign bodies in quinoa <i>(Chenopodium quinoa</i> Willd.) grains using convolutional neural networks with a transfer learning approach(2023-01-30); Willd.) is due to its high protein content and gluten-free condition; nonetheless, the presence of foreign bodies in quinoa processing facilities is an issue that must be addressed. As a result, convolutional neural networks have been adopted, mostly because of their data extraction capabilities, which had not been utilized before for this purpose. Consequently, the main objective of this work is to evaluate convolutional neural networks with a learning transfer for foreign bodies identification in quinoa samples. For experimentation, quinoa samples were collected and manually split into 17 classes: quinoa grains and 16 foreign bodies. Then, one thousand images were obtained from each class in RGB space and transformed into four different color spaces (L*a*b*, HSV, YCbCr, and Gray). Three convolutional neural networks (AlexNet, MobileNetv2, and DenseNet-201) were trained using the five color spaces, and the evaluation results were expressed in terms of accuracy and F-score. All the CNN approaches compared showed an F-score ranging from 98% to 99%; both color space and CNN structure were found to have significant effects on the F-score. Also, DenseNet-201 was the most robust architecture and, at the same time, the most time-consuming. These results evidence the capacity of CNN architectures to be used for the discrimination of foreign bodies in quinoa processing facilities. - Some of the metrics are blocked by yourconsent settings
Item type:Publicación, Efecto de Temperatura y Velocidad de Agitación en el Deshidratado Osmótico de Jengibre (Zingiber Officinale)(2022-08-25); El objetivo de esta investigación fue evaluar el efecto de la temperatura y la velocidad de agitación sobre la pérdida de peso (PP%), la pérdida de agua (PA%) y la ganancia de sólidos (GS%) en el deshidratado osmótico de cubos de jengibre (Zingiber officinale). Los parámetros aplicados fueron: temperatura de la solución osmótica 26, 36 y 46°C, velocidad de agitación de 30, 50 y 80 rpm, relación muestra / solución osmótica de 1:16 (p/p), concentración de sacarosa al 60% y tiempo de experimento 0, 15, 30, 45, 60, 75, 90, 105 y 120 min. Los resultados mostraron que la temperatura fue el parámetro que más influyó sobre la PA%, PP% y GS%; en comparación, la velocidad de agitación tuvo una menor influencia sobre la PA%, PP% y GS%; esto indica que las altas temperaturas provocan cambios en la permeabilidad de la membrana celular del alimento, lo que genera mayor transferencia. El tratamiento a 26°C y 30 rpm mostró una mayor difusividad (De) con 5.20 x 10-4. El tratamiento a 46 °C y 30 rpm reportó mayores pérdidas de humedad con un 35%, el tratamiento a 26°C y 30 rpm presentó mayor variación de pH de 6.62 a 5.27, el tratamiento a 36 °C y 50 rpm mostró una acidez constante de 0.05% y el tratamiento a 46°C y 80 rpm presentó una mayor ganancia de sólidos soluble con 35.16 °Brix. Se demostró que la temperatura es el parámetro que más influeyó sobre PA%, PP% y GS%. - Some of the metrics are blocked by yourconsent settings
Item type:Patent, SECADOR DE LECHO FLUIDIZADO DE AIRE FRÍO CONVECTIVO CON MONITORIZACIÓN EN TIEMPO REAL DE TEMPERATURA Y HUMEDAD(Instituto Nacional de Defensa de la Competencia y de la Proteccion de la Propiedad Intelectual, 2022-10-13); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publicación, Análisis Cinemático de la Masticación de una Granola Prototipo en Contraste con la Masticación de Maní(2020-02-28); - Some of the metrics are blocked by yourconsent settings
Item type:Publicación, Supercritical fluid extraction of polyphenols from lees: overall extraction curve, kinetic data and composition of the extracts(2015-11-30); ; M. Ângela A. MeirelesThe increasing incidence of degenerative diseases has attracted the interest in the obtaining of bioactive compounds. Since seeds and skins from grapes are important sources of polyphenols which have been associated with cancer incidence decreasing, then, one of the pisco (alcoholic beverage made of grape) manufacturing byproduct such as lees, could be a potential source of polyphenols. Supercritical fluid extraction is an environmentally friendly technique that has been applied for obtaining polyphenols. Carbon dioxide is used as unique or main extraction solvent instead of organic solvents, most of them toxics and responsible for reducing the application fields of the extracts. For that reason, among others, supercritical fluid extraction is preferred over conventional techniques for obtaining bioactive compounds. The aim of this work was to study the supercritical fluid extraction of polyphenols from lees of pisco-making. Supercritical carbon dioxide with 10 % of ethanol (w/w) was used as extraction solvent. Overall extraction curves were determined at 20 and 35 MPa; and the experimental data were used to estimate the kinetic parameters. Conventional techniques using ethanol as extraction solvent were performed for comparative purposes. The extracts were analyzed by thin-layer and high-performance liquid chromatography. Lower global yield was obtained by supercritical fluid extraction than conventional techniques. From the kinetic parameters, the mass transfer rate and the amount of the extract dissolved in supercritical phase were higher at 20 than 35 MPa. Phenolic acids (gallic, protocatechuic, vanillic, syringic, ferulic derivatives and p-coumaric derivatives) and flavonoids (quercetin and its derivatives) were identified in the extracts obtained by all extraction techniques. Polyphenols were rapidly extracted with supercritical fluid and more concentrated extracts were obtained at 20 MPa. However, for longer extraction times, the highest values of extracted polyphenols were obtained by conventional techniques. Lees from pisco-making are a promising source for recovery polyphenols. Low global yields were obtained when elevated pressures were used. Although supercritical fluid extraction at 20 MPa was the most efficient technique on the extraction of polyphenols from lees of pisco-making due to highly concentrated polyphenols, extracts were rapidly obtained. - Some of the metrics are blocked by yourconsent settings
Item type:Publicación, Efecto antimicrobiano in vitro de aceite esencial de eucalipto (<i>Eucalyptus globulus </i>labill) y muña (<i>Minthostachys mollis</i>)(2024-01-31); The objective of this research work was to evaluate the antimicrobial effect of 2 oil sources against Staphylococcus aureus and Fecal Coliforms. For the oil extraction, the steam drag method was applied where 5000g of sample was used (muña, Eucalyptus leaves), in which the yield presented: muña 50ml = 0.9268%, eucalyptus 52ml = 0.9717%, a Physicochemical characterization whose result was: in muña oil: peroxide index: 0.75 (Meq / Kg), Iodine index: 6.87 (IV), Acidity index: 1.78 (% FFA), Refractive index: 1.486 (n), density: 0.898 (Kg / L). In eucalyptus leaves: peroxide index: 0.68 (Meq / Kg), Iodine index: 8.08 (IV), Acidity index: 1.82 (% FFA), Refractive index: 1.495 (n), density: 0.845 (Kg / L). Inhibition halos were determined in millimeters (mm), with muña oil in dilutions at 25, 50 and 75% against Fecal Coliforms, where it was at 25%: 9.7950mm, 50%: 10.7467mm, 75%: 13.2700 mm, against Staphylococcus aureus, 25%: 9.9600mm, 50%: 10.7408mm, 75%: 13.1533mm; with dilution of Eucalyptus essential oil against Fecal Coliforms at 25%: 12.0983mm, 50%: 13.2900mm, 75%: 14.5875mm; then against Staphylococcus aureus in 25%: 11.7200mm, 50%: 13.5608mm, 75%: 14.3767. It was possible to establish the inhibitory effect in 2 sources of oils against Fecal Coliforms and Staphylococcus aureus, for which it is concluded that the more dilution of the oil, more microbial inhibition, these species have their respective active principles such as monoterpenes, alcohols, ketones and terpenic oxides that prevent microbial growth.