Application of mathemathical models to infrared assisted drying process of lemon waste (Citrus limon (l.) Burm. F. Cv. genova)

Los desechos agroindustriales son uno de los principales problemas ambientales a nivel mundial. Debido a las altas exigencias de calidad, la comercialización de limones de exportación genera grandes cantidades de desechos. Los descartes de limón contienen fibra, pectina, potasio, calcio y vitamina C. Por lo tanto, es importante desarrollar alternativas de procesamiento de estos sub-productos para agregarles valor y aumentar su vida útil. El objetivo de la presente investigación fue la aplicación del secado asistido por infrarrojos, como tecnología emergente, para estudiar el efecto de la temperatura de proceso sobre las cinéticas de secado de descartes de limón a 30, 40 y 50°C. Se utilizaron seis modelos matemáticos de capa fi na encontrados en literatura para representar la cinética experimental. Basándose en análisis estadístico, el modelo Logarítmico presentó el mejor ajuste. Los valores de la difusividad efectiva del agua se estimaron en el rango de 9.45× 10-10 – 3.71× 10-9 m/s2 . El valor de la energía de activación fue 55.90 kJ/mol.Agroindustrial wastes are a major environmental problem worldwide. Due to high quality requirements, commercialization of export lemons generates huge amounts of wastes. Lemon wastes have fi ber, pectin, potassium, calcium and vitamin C. Therefore, it is important to develop alternative processing methods to add value and improve their shelf life. The aim of this work was to apply infrared drying, as an emergent technology, to study the effect of drying temperature on the drying kinetics of lemon waste at 30, 40 and 50°C. Six thin layer models found in literature were used to represent the experimental drying kinetics. Based on statistical tests, the Logarithmic model presented the best fi t. Values of moisture effective diffusivities were in the range of 9.45× 10-10 ? 3.71× 10-9 m/s2 . The value of activation energy was 55.90 kJ/mol.Fil: Puente Diaz, Luis. Universidad Católica de Chile. Facultad de Ciencias Químicas y Farmacéuticas; ChileFil: Echegaray Pacheco, Eric. Universidad Católica de Chile. Facultad de Ciencias Químicas y Farmacéuticas; ChileFil: Castro Montero, Eduardo. Universidad Católica de Chile. Facultad de Ciencias Químicas y Farmacéuticas; ChileFil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata; Argentin

Evaluación de fibra dietética, isoflavonas y compuestos fenólicos con propiedades antioxidantes y antimicrobianas de quinoa (Chenopodium quinoa Willd.)

The consumption of quinoa (Chenopodium quinoa Willd.) has been steadily increasing due to its high nutritional value and health benefits associated with its high antioxidant capacity. The objective of this study was to determine the contents of dietary fiber, polyphenols, flavonoids and isoflavones, and how they contribute to the antioxidant and antimicrobial activity of six ecotypes of quinoa cultivated in three different zones of Chile. The ecotypes studied were: Ancovinto and Cancosa (Northern zone), Cáhuil and Faro (Central zone), and Regalona and Villarrica (Southern zone). The results indicate that all Chilean quinoa ecotypes could be considered as good sources of dietary fiber (12.23 g 100 g-1 dry matter) and polyphenols (161.32 mg Gallic Acid Equivalents (GAE) 100 g-1 dry matter). The North and Central ecotypes exhibited the highest isoflavone concentration. The Northern Cancosa was the ecotype that showed the highest flavonoid content (211.06 mg Catechin Equivalents (CAE) 100 g-1 dry matter). Based on the ORAC (Oxygen Radical Absorbance Capacity) assay, Ancovinto, Cancosa and Faro presented the highest antioxidant capacity (67.6 mmol Trolox Equivalents (TE) 100 g-1 dry matter). Regarding antimicrobial activity, Regalona ecotype showed the best performance against Saccharomyces cerevisiae and Listeria innocua. The bioactive compounds found in this study add new knowledge to the antioxidant and antimicrobial activity of Chilean quinoa seeds.El consumo de quinua (Chenopodium quinoa Willd.) está aumentando debido a su valor nutricional y beneficios para la salud relacionados con su capacidad antioxidante. El objetivo de presente estudio fue determinar los contenidos de fibra dietética, polifenoles, flavonoides e isoflavonas, y cómo estos compuestos contribuyen a la actividad antioxidante y antimicrobiana de seis ecotipos de quinua cultivados en tres zonas de Chile. Las muestras de quinua de la zona Norte se denominan Ancovinto y Cancosa, de la zona Centro se llaman Cáhuil y Faro, y de la zona Sur se denominan Regalona y Villarrica. Los resultados mostraron que todos los ecotipos de quinua chilena pueden considerarse buena fuente de fibra dietética (12,23 g 100 g-1 materia seca) y de polifenoles (161,32 mg de Equivalentes de Acido Gálico (EAG) 100 g-1 materia seca). Los ecotipos de la zona Norte y Centro mostraron la mayor concentración de isoflavonas. El ecotipo Cancosa, de la zona Norte, fue el que mostró el mayor contenido de flavonoides (211,06 mg Equivalentes de Catequina (ECA) 100 g-1 materia seca). Basado en el ensayo ORAC (del inglés Oxigen Radical Absorbance Capacity), los ecotipos Ancovinto, Cancosa y Faro, presentaron en promedio la mayor capacidad antioxidante (67,6 mmol de Equivalentes Trolox (ET) 100 g-1 materia seca). El ecotipo Regalona mostró la más alta actividad antimicrobiana frente a Saccharomyces cerevisiae y Listeria innocua. Los compuestos bioactivos encontrados en este estudio aportan nuevos conocimientos a la actividad antioxidante y antimicrobiana de las semillas de quinua chilena.Fil: Vega Gálvez, Antonio. Universidad de La Serena; ChileFil: Zura, Liliana. Universidad de La Serena; ChileFil: Lutz, Mariane. Universidad de Vlparaíso; ChileFil: Jagus, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Agüero, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Pastén, Alexis. Universidad de La Serena; ChileFil: Di Scala, Karina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Uribe, Elsa. Universidad de La Serena; Chil

An artificial neural network model for prediction of quality characteristics of apples during convective dehydration

In this study, the effects of hot-air drying conditions on color, water holding capacity, and total phenolic content of dried apple were investigated using artificial neural network as an intelligent modeling system. After that, a genetic algorithm was used to optimize the drying conditions. Apples were dried at different temperatures (40, 60, and 80 °C) and at three air flow-rates (0.5, 1, and 1.5 m/s). Applying the leave-one-out cross validation methodology, simulated and experimental data were in good agreement presenting an error < 2.4 %. Quality index optimal values were found at 62.9 °C and 1.0 m/s using genetic algorithm.Centro de Investigación y Desarrollo en Criotecnología de AlimentosFacultad de Ingenierí

Supercritical CO2 extraction of bioactive compounds from radish leaves: Yield, antioxidant capacity and cytotoxicity

Supercritical Fluid Extraction by using CO2 can be employed as an alternative to conventional methods for extracting functional compounds. Overall extractions curves for extractions of bioactive compounds from radish leaves were performed using scCO2 adding ethanol as co-solvent. Yield, total phenolic compounds, total flavonoids and antioxidant capacity were determined for each extract. The best results were obtained at 35 °C/400 bar and 40 °C/400 bar, with values of total phenolics 1375 mg GAE/100 g d.m. and 1455 mg GAE/100 g d.m., respectively. Antioxidant capacity by DPPH values were 359 mg TE/100 g d.m. (35 °C/400 bar) and 403 mg TE/100 g d.m. (40 °C/400 bar). Maturation of dendritic cells was not promoted being these extracts promising and interesting sources of antioxidative and anti-inflammatory agents for future uses in the pharmaceutical and alimentary industries.Fil: Goyeneche, Rosario. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Ingeniería en Alimentos; ArgentinaFil: Fanovich, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Rodríguez Rodrígues, Christian Fernando Ariel. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Nicolao, María Celeste. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Ingeniería en Alimentos; Argentin

Effect of dehydration temperature on physico-chemical properties and antioxidant capacity of goldenberry (Physalis peruviana L.)

Consumers are health conscious in order to have a nutritious diet leading to an increase of fruits intake due to their bioactive compounds. To prolong the shelf-life of fruits, dehydration is widely used In this work, the effect of convective dehydration on physico-chemical properties, color, vitamin C, -carotene, total phenolic content (TPC), flavonoids and antioxidant capacity during dehydration of Cape gooseberry (Physalis peruviana L.) fruits in the range 50-90 ºC was investigated. Chromatic parameters (L*, a*, b*) as well as Chroma and Hue angle were affected by drying temperature, which contributed to the discoloring of the fruits during this process. TPC, flavonoids and -carotene increased at 90 ºC from 321.05-356.68 mg gallic acid 100 g-1 dm, 99.25-144.29 mg quercetin equivalents 100 g-1 of dm and 722.30-783.16 mg 100 g-1 sample, respectively. The radical scavenging activity showed higher antioxidant activity at high temperatures rather than at low temperatures. Both, vitamin C content and TPC decreased as air-drying temperature decreased. A high correlation between TPC and flavonoids with antioxidant capacity of the fruits was observed. Based on these results, this fruit is a potential candidate to develop new functional products.Fil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química; Argentina;Fil: López, Jessica. Universidad de la Serena. Departamento de Ingeniería de Alimentos; Chile;Fil: Vega Galvez, Antonio. Universidad de la Serena. Departamento de Ingeniería de Alimentos; Chile;Fil: Torres, María José. Universidad de la Serena. Departamento de Ingeniería de Alimentos; Chile;Fil: Lemus Mondaca, Roberto. Universidad de la Serena. Departamento de Ingeniería de Alimentos; Chile;Fil: Quispe Fuentes, Issis. Universidad de la Serena. Departamento de Ingeniería de Alimentos; Chile

Propriedades químicas e físicas do gel de aloe vera (Aloe barbadensis Miller) armazenado após processamento sob alta pressão hidrostática

&e aim of this study was to evaluate the in[uence of high hydrostatic pressure (150, 250, 350, 450, and 550 MPa), applied for 5 minutes, on antioxidant capacity, total phenolic content, color, Frmness, rehydration ratio, and water holding capacity of aloe vera gel stored for 60 days at 4 °C. &e analyzed properties of the pressurized gel showed signiFcant changes a\er the storage period. &e highest value of total phenolic content was found at 550 MPa. However, a decrease in the antioxidant capacity was observed for all pressurized gel samples when compared to the control sample (p < 0.05). &e smallest changes in product color were observed at pressure levels between 150 and 250 MP. &e application of high hydrostatic pressure resulted in lower gel Frmness, and the lowest value was found at 150 MPa (p < 0.05). On the other hand, the untreated sample showed a greater decrease in Frmness, indicating that high pressure processing preserves this property. &e application of high hydrostatic pressure exhibited modiFcations in the food matrix, which were evaluated in terms of rehydration ratio and water holding capacity.O objetivo deste estudo foi avaliar o efeito da aplicação de altas pressões hidrostáticas (150, 250, 350, 450 e 550 MPa) aplicadas durante 5 minutos sobre a atividade antioxidante, concentração de polifenóis totais, cor, Frmeza, taxa de reidratação e capacidade de retenção de água do gel de aloe vera armazenado durante 60 dias a 4 °C. As propriedades analisadas do gel pressurizado mostraram mudanças signiFcativas depois de armazenadas. Para pressões de 550 Mpa, registrou-se o maior aumento de polifenóis totais. No entanto, observou-se uma diminuição da capacidade antioxidante em todas as amostras, em comparação com a amostra não tratada (p < 0,05). As alterações de cor foram menores para pressões entre 150 e 250 MPa. A aplicação de altas pressões hidrostáticas diminuiu a Frmeza do gel, registrando-se o menor valor para 150 MPa (p < 0,05). Por outro lado, o tratamento sem pressão mostrou uma maior perda de Frmeza, indicando que o tratamento por altas pressões conserva esta propriedade. A aplicação de altas pressões evidenciou modiFcações da matriz do alimento, avaliadas como taxa de reidratação e capacidade de retenção de água.Fil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Vega Gálvez, Antonio. Universidad de La Serena; ChileFil: Ah Hen, Kong. Universidad Austral de Chile; ChileFil: Nuñez Mancilla, Yissleen. Universidad de La Serena; ChileFil: Tabilo Minizaga, Gipsy. Universidad del Bio Bio; ChileFil: Perez Won, Mario. Universidad de La Serena; ChileFil: Giovagnoli, Claudia. Universidad de La Serena; Chil

An artificial neural network model for prediction of quality characteristics of apples during convective dehydration

In this study, the effects of hot-air drying conditions on color, water holding capacity, and total phenolic content of dried apple were investigated using artificial neural network as an intelligent modeling system. After that, a genetic algorithm was used to optimize the drying conditions. Apples were dried at different temperatures (40, 60, and 80 °C) and at three air flow-rates (0.5, 1, and 1.5 m/s). Applying the leave-one-out cross validation methodology, simulated and experimental data were in good agreement presenting an error < 2.4 %. Quality index optimal values were found at 62.9 °C and 1.0 m/s using genetic algorithm.Centro de Investigación y Desarrollo en Criotecnología de AlimentosFacultad de Ingenierí

Drying kinetics and quality changes during drying of red pepper

A mathematical model is proposed to simulate the process of drying of individual pieces of red pepper under constant external conditions and to predict changes in some nutritional and organoleptic attributes of the product. The model was solved numerically to obtain moisture content and temperature as well as ascorbic acid and carotenoids concentration in the product as a function of time. A good agreement between predictions and experimental data at different drying temperatures was obtained. Water sorption isotherms of red pepper were determined in the range 20-50 °C and represented by two different sorption equations. Drying kinetics were represented by a diffusive model, the effective moisture diffusivity ranging from 5.01 to 8.32×10-10 m2/s with an activation energy of 23.35 kJ/mol. Degradation kinetics for ascorbic acid and total carotenoids were measured in the range 50-70 °C and modelled as first-order reactions. The rate constants increased with temperature and product moisture content. Average activation energies for carotenoids and vitamin C degradation were 50.1 and 26.9 kJ/mol, respectively. © 2007 Swiss Society of Food Science and Technology.Fil: Di Scala, Karina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Ingeniería en Alimentos; ArgentinaFil: Crapiste, Guillermo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentin