Download - Refractance Windows Monteria
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
DESHIDRATACION Y CONCENTRACION DE CREMOGENADOS DE FRUTAS TROPICALES MEDIANTE LA TECNICA NOVEDOSA DE VENTANA REFRACTIVA
DEHYDRATION AND CONCENTRATION OF TROPICAL FRUITS USIG A NOVEL
REFRACTANCE WINDOWS TECHNOLOGY
Guillermo Salamanca Grosso Es.U.T.A. (UPV) MSc (UV). PhD (UPV)
Profesor Titular
Facultad de Ciencias Departamento de Química
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Leyes de la nutrición
Raciones Energéticas desempeño físico
Carbohidratos y Grasa “Proteína”
Raciones No energéticas Indispensables para la vida
Proteína Vitaminas
Fibra Minerales
Raciones No energéticas Particulares por individuo
Edad Sexo peso talla
Primera Ley
Segunda Ley
Tercera Ley
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
VitaminasVitaminasVitaminas
LiposolublesLiposolublesLiposolubles
HidrosolublesHidrosolublesHidrosolubles
CarotenoCalciferolTocoferolFiloquinionaK (Farnoquinona, Menaiona)
CarotenoCarotenoCalciferolCalciferolTocoferolTocoferolFiloquinionaFiloquinionaK K (Farnoquinona, Menaiona)(Farnoquinona, Menaiona)
B1TiaminaB2 RiboflavinaB3 NiacinaB6 PiridoxinaB7 Ácido fólicoB12 CianocobalaminaVitamina C
BB11TiaminaTiaminaBB22 RiboflavinaRiboflavinaBB33 NiacinaNiacinaBB66 PiridoxinaPiridoxinaBB77 Ácido fólicoÁcido fólicoBB1212 CianocobalaminaCianocobalaminaVitamina CVitamina CComplejo B: Metabolismo carbohidratos,
grasas y proteínas. Piel visión, Glóbulos rojos, Crecimiento
Complejo B: Metabolismo carbohidratos, Complejo B: Metabolismo carbohidratos, grasas y proteínas. Piel visión, Glóbulos grasas y proteínas. Piel visión, Glóbulos rojos, Crecimientorojos, Crecimiento
Procesos de la visión. Metabolismo del calcioProtector de las vitaminas A y C (Antioxidante)Factor de coagulación
Procesos de la visión. Metabolismo del calcioProcesos de la visión. Metabolismo del calcioProtector de las vitaminas A y C (Antioxidante)Protector de las vitaminas A y C (Antioxidante)Factor de coagulaciónFactor de coagulación
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Función del organismo
Craplet, 1991.Alimentación y nutrición
Productos de Productos de La colmena La colmena
Conjunto de principios Conjunto de principios Nutritivos Nutritivos Proteínas. Lípidos. Glúcidos Proteínas. Lípidos. Glúcidos Agua. Electrolitos. Agua. Electrolitos. Vitaminas. Fibra. Celulosa Vitaminas. Fibra. Celulosa
Aparato digestivo Aparato digestivo
Organolépticos Organolépticos simbólicos simbólicos Conjunto de Conjunto de
caracteres caracteres
Digestión Digestión Absorción Absorción
CO CO 2 2 Agua Agua Urea Urea Creatinina Creatinina Sales minerales Sales minerales
Sistema Nervioso y órganos de los
sentidos
Nutrientes Nutrientes
No digerido No digerido
Células Células
Orina Orina
Metabolismo Metabolismo Termoregulación
Energía mecánica Renovación celular Crecimiento
Aparato respiratorio Aparato respiratorio Aire O 2
Frutas y Aporte Conjunto de principios Conjunto de principios Nutritivos Nutritivos Proteínas. Lípidos. Glúcidos Proteínas. Lípidos. Glúcidos Agua. Electrolitos. Agua. Electrolitos. Vitaminas. Fibra. Celulosa Vitaminas. Fibra. Celulosa
Aparato digestivo Aparato digestivo
Organolépticos Organolépticos simbólicos simbólicos Conjunto de Conjunto de
caracteres caracteres
Digestión Digestión Absorción Absorción
CO CO 2 2 Agua Agua Urea Urea Creatinina Creatinina Sales minerales Sales minerales
Sistema Nervioso y órganos de los
sentidos
Nutrientes Nutrientes
No digerido No digerido
Células Células
Orina Orina
Metabolismo Metabolismo Termoregulación
Energía mecánica Renovación celular Crecimiento
Aparato respiratorio Aparato respiratorio Aire O 2
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia Aspectos socioculturales
Segu
ridad
o Ins
egur
idad A
limen
taria?
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
• Las importaciones mundiales de frutas frescas y procesadas: 43 Billones de dólares
• El mercado de Estados Unidos absorbe el 30% comercio mundial de frutas.
• Las importaciones de frutas tropicales en Europa se han multiplicado en los últimos años.
• El comercio intraregional en Centroamérica representa el 3.6% de las exportaciones de frutas.
6.620´279. 595
Procesos productivos de frutas: Parte de la identificación de oportunidades comerciales y determinación de requerimientos de la demanda que alimenta un proceso de innovación tecnológica. Objetivo General: Desarrollar un sector frutícola competitivo en el mercado regional y mundial.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
El sistema productivo una cadena de valor
1 2 3
6 5 4
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia 805.000 Tn Maracuyá
Modelo alimentario
Dinámica Productiva
Tecnología
Plagas
Perdidas
I+D
Capacitación
Inasistencia
1
2
3
4
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
2007 2014 2021 2028 2030
6.620´279.595 25% Población
Edad promedio 65 Años Europa Estados Unidos
5 x Poblacion Áreas en Desarrollo
Respecto de las desarolladas 40% Edad Promedio 25 Años
Productos Premiun Not From Concentrate NFC
Mango. Mora. Maracuyá
Globalización de Mercados Tecnologías Emergentes
Consumo especializados
52 L/P.A 31 L/P.A 25 L/P.A
Consumo especializados: • Nutraceuticos • Probioticos • Productos frescos
Near water: Hipocaloricas
• 200.000.000 US China: • Jugos Naranja Manzana • Zumos tropicales desconocidos • Arazá? Copoazú? Jaboticaba?
Línea del Tiempo
1
2
3
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
2´600.000 Tn Zumo de Naranja 50% 450.000 Tn Maracuyá
Uva 120.000 Tn Mendoza
Manzana 1´100.000 Tn 44% PM
19.000 Tn Maracuyá
805.000 Tn Maracuyá
10.000 Tn
19.000 Tn
10.000 Tn
30.000 Tn
450.000 Tn
250.000 Tn
15.000 Tn
20.000 Tn
1000 Tn
Maracuyá 10.000 Tn
1000 Tn
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia Salamanca et al, 2006
C 2:F
acto
r det
erm
inan
te gr
osor
del p
erica
rpio
C1: Factores determinantes: pH; B rix; Fracción de pulpa
-3,
-2,
-1,
0,
1,
2,
3,
4,
-6, -4, -2, , 2, 4, 6, 8, 10,
Azucar
Mariquiteño
Hilacha
YulimaM. VallenatoTomy
Keitt
Sufaida LoritoVan Dyke
0 20 40 60 80
Hilacha
Mariquiteño
Yulima
Manzano vll
Van Dyke
Tomy atkins
Keiit
Sufaida
Lorito
Azúcar
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Principales razones del incremento en el consumo de frutas y hortalizas
• Actividad rentable
• Mercado en expansión
• Condiciones agroecológicas
• Posicionamiento del origen geográfico
• Oportunidades comerciales: Globalización
• Condiciones para la integración de las regiones
• Opción con futuro: Reconversión. Aéreas nuevas
• Facilidad procesos de capacitación y asistencia técnica
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Recursos principales por uso
• Salsas y Aderezos: Mora.. Tamarindo. Feijoa. Agraz. Mango
• Mesa: Anón. Papaya. Pitahaya. Zapote. Mangos. Guanábana. Feijoa. Guayabas. Chirimoyas. Piña. Mora. Uchuva. (El congelado y el deshidratado).
• Jugos: Piña. Guanábana. Maracuyá. uruba. Lulo. Feijoa. Guayaba. Tamarillo. Borojó. Mora. Mango. Papaya.
• Postres y Dulces: Agraz. Parpayuela. Icaco. Mamey. Mora. Uchuva. Tamarillo.
Frutas y usos
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
FrescasPasteurizadasEdulcoradas
Fruta con aditivos
EspesantesSacarosaDietéticos
Frutas deshidratadas
Licores De Fruta
Frutas Estructuradas
Aire calienteVacio
Osmosis
AperitivosAfrutados
Productos diversosSegún proceso
Graduaciones diferentes Brix
Jaleas Mermeladas
Bocadillos
Frutas en Almibar
Salsas
CompotasConcentrados
Pupas
Néctares
DietéticasFruta
Diferentes Formulaciones
Jarabes densosJarabes LivianosCocteles de fruta
Frutas diversasUso de espesantes
FortificadasPasterizadas
Estériles
Diferentes concentracionesAdición de Aromas
Actividad IndustrialAsociada a las frutas
Sistemas de Procesado
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia Aspectos socioculturales
Segu
ridad
o Ins
egur
idad A
limen
taria?
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Principales causas del deterioro
Factores Biológicos
Bacterias Mohos y Levaduras Parásitos az
Excesos térmicos Humedad
Luz Pp O2
Pp CO2 Pp N2
TTT PPP
Factores impuestos Condiciones de
manejo
Cambios Propiedades
Fisicoquímicas
Color. Aroma. Sabor. Textura. Consistencia
1 2
3
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Textura
Órgano
Tejido Células
Polímeros Pared celular
Niveles estructurales contribuyentes a la textura de las frutas.
Aspectos a controlar en el procesado de materias primas y desarrollo de nuevos productos.
• Actividad respiratoria.•Evolución de etileno•Incremento de la actividad enzimática •Perdida del aroma y sabor• Decoloración •Pérdida de firmeza.
Frutas Materiales vivos intensa actividad
Consideraciones Postcosecha
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Inhibiciones por efecto térmico (Calor o Frio). Las enzimas y sustratos de los productos hortofrutícolas están localizados en distintas unidades celulares. Su transferencia y actividad esta regulada.
az Inducen efectos diferenciados en frutas y sus derivados procesados. Se incrementaran de manera progresiva en el tiempo.
Enzimas de significación
Lipoxigenasas (LOX s)
Polifenoloxidasas (PPO s)
Peroxidasas (POD s)
Pectinasas (PE s)
az
• E f e c t o s s o b r e l a s características y Propiedades funcionales de las materias primas • Evolución de aromas • Perdida de la consistencia • Cambios en el color • Cambios en la textura • Deterioro de la calidad • Reducción vida útil
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Intensidad respiratoria
Estabilidad: Postcosecha estado de madurez (Intensidad respiratoria). Actividad enzimática: Los daños mecánicos y las prácticas deficientes de manejo inciden en el incremento de la actividad enzimática.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
• Cambio en los tejidos superficiales del alimento y en las células subyacentes. • Destrucción del tejido incrementa la permeabilidad y mezcla de enzimas.
Vacuolas lipídicas
Las enzimas y sustratos de los productos hortofrutícolas están localizados en distintas unidades celulares. Su transferencia y actividad esta regulada.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Lipoxigenasas ( linoleato: oxigeno oxireductasa)
LOX
LOX I
LOX II
LOX III
LOX IV LOX V LOX VI
Ácido graso + O2 = Hidroperóxido de ácido graso
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Ácido graso + O2 = Hidroperóxido de ácido graso
Acido oleico C18:1 9 Δcis-cis
3 5 7 9 18
11 13
14 16
15
Acido oleico C18:1 9 Δcis-cis
3 5 7 9 18
11 13
14 16
15
Acido Linoleico C18:2 9,12 Δcis-cis
129
9 12
15Acido linolenico C18:3 9,12,15 Δ Todo cis
LOX I LOX II LOX III
Alcalino 0 pHop =6.50
pHop =7.00
13 hidroperoxi
9 hidroperoxi
9+13 hidroperoxi
Lipoxigenasas ( linoleato: oxigeno oxireductasa)
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Ácido graso + O2 = Hidroperóxido de ácido graso
Acido Araquidonico C20:4 cis-cis
Araquidon oxigeno 5-oxidoreductasa
Araquidon oxigeno 15-oxidoreductasa
Araquidon oxigeno 12-oxidoreductasa
Araquidon oxigeno 8-oxidoreductasa 5 hidroperóxido
8 hidroperóxido
Lipoxigenasas ( linoleato: oxigeno oxireductasa)
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Acido 13 -Hidroxiperolinleico
Hidroxiperoxiliasa
Acido 12-oxo-trans-9-dodecenoico
Acido 12-oxo-trans-10-dodecenoico
Traumatin
Acido 12-oxo -fitodienoico
Acido jasmonico
Acido trans2 -dodecanoico Acido Traumático
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
ProductosHortofrutícolas
Valoracion Sistemasde Procesado
-industrialización-
Pastas/PulpasZumos/Cremogenados
Consumoen Fresco
Materias Primas Industria
CongeladoDeshidratado
Otros Sistemas de Procesado
Comercialización
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Productos generados de la transformación de las frutas frescas, susceptible de fermentación pero no fermentadas. Se obtienen por molturación, tamizado o ultrahomogenización de la parte comestible sin eliminar la fracción acuosa que constituye el zumo.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Deshidratación
Proceso de conservación que permite eliminar una gran cantidad de agua del alimento impidiendo cualquier actividad microbiana o enzimática
que deteriore el producto.
1 2
3
Eficiencia del proceso Vs Aspectos económicos La evaporación lleva asociado un gasto energético elevado.
Prolongar la vida útil de los alimentos. Disminuir el volumen de almacenamiento.
Reducir costos de transporte
Remoción de líquido de un material poroso o semiporoso.
Mecanismos difusiónales. Fenómenos de trasporte Leyes de Fick. Transferencia de calor. Sistemas de procesado
4
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Los procesos de secado se clasifican por condiciones físicas usadas para adicionar calor y extraer agua.
Deshidratación
Secaderos solares Solar drying
1
2
3
4 Secaderos de
bandeja Tray drying
Secado Atomización Spray Dryer
Liofilizado Freeze drying Lyophilisation
Cryodesiccation
5
5
6
7
Secado lecho fluidizado Fluid bed drying
Secado lecho fluidizado Fluid bed drying Ventana refractiva
Refrantance windows
Alto vacio Microondas
Radio frecuencias
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Solar drying
Drump Dryer
Tray drying
Freeze drying
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Optimización de sistemas y controles de procesdo Mantenimiento de la calidad fisicoquímica de
productos alimentarios
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Aire + Vapor de agua
Aplicación De Producto
Circulación de agua caliente
4
3
Sistema de extracción
1
2
La deshidratación mediante ventana refractiva (VR), es un nuevo concepto para el diseño de evaporadores. La energía térmica del vapor de agua es transferida por convección y radiación, al producto
No se presentan perdidas significativas de los componentes de la matriz de trabajo. Aromas & Flavor se mantiene en relacion al producto inicial.
Ti = 328ºK
TF = 330ºK
El flujo de calor desde el vapor de agua genera aumento instantáneo de la temperatura en el producto.
Abonyi, et al, 2001;Clarke, 2004. Nindo, et al, 2007Salamanca y Osorio, 2010.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
La deshidratación mediante ventana refractiva (VR), es un nuevo concepto para el diseño de evaporadores de productos procesados agroalimentarios.
Extractor
Bomba aguacaliente
Calentador de agua
Enfriadoragua
Cinta de transporte
Aire + Vapor de aguaSalida
productoAplicación producto
El agua caliente lleva asociado tres métodos de transferencia de calor: Conducción. Convección y Radiación. Las perdidas energéticas ocurren por transferencia a sus alrededores. La ventana posibilita la trasmisión de calor por radiación.
Calid
ad de
los p
rodu
ctos.
Proc
esos
efici
entes
. Re
empla
zo de
los p
roce
sos d
e con
gelac
ión
Productos de alta calidad organoleptica y funcional Superior a Spray Dryer
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Transmisión de la energía térmica del vapor de agua caliente que circula bajo el sistema y a través de una película polimerica (368ºK). Disposición del producto sobre el polimero polímero que facilita la rasferencia de calor. Vegetales. Zumos y Cremogenados de frutas se exponen en este sistema a deshidratación. Tiempo de residencia: 20 a 40 minutos en función de los componentes del producto y la complejidad de este. Energía térmica del vapor se tranfiere por convección y radiación en proporciones que dependen de la conductividad térmica (k; W/m°K) del polímero conductor.
1
2
3
4
5
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Suplementos nutricionales. Comidas preparadas. Bebidas en polvo. Cereales de desayuno. Mezclas para postres. Mezclas para sopas.
Retención de Nutrientes Alto Retención de Sabor Alto Retención Color Alto Nivel de Aditivos Bajo Recaptura de Aromas Bajo
Pures, Jugos y Cremogenados Frutas Pure de Vegetales Carne. Pescado. Huevos. Hierbas y Especias Bebidas Lácteos Cereales granos y harinas Nutracéuticos Farmacéuticos
Secado mediante ventana refractiva
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
mpin mpout
mw
Convección agua
Evaporación Condensación
El fluido caliente se expande. Áreas fría y densas descienden por efecto del calentamiento. Disipación energética. Enfriamiento aumento de la densidad.
La membrana polimerica actúa como espejo reflejando la energía infrarroja de regreso al agua.
La evaporación y la su perdida de calor asociada es refractada (bloqueada). Solo ocurre la conducción.
Convección: Se trasporta materia y energía. Diferencias de densidad.
6
4
5
2
3
Elemento calefactor 1
Conducción
Condensación
4
5
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
En el procesado el balance enérgico por calor (kW)
QS = QP + QW + QL
Calor latente de condensación Qs
En el calor latente se presentan cambios de fase
Qw(kW) = C. cedido por el agua. QW(kW) = C. transferido a la película. QL(kW) = Perdidas al entorno
1 2 3
QP
QW
QL
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
0 20 40280
300
320
340
360
Tempe
ratu
ra (°
K)
T iempo (m in)
B ano Ambiente F resa
Tiempo (min)
Temperatura (°K)
Agua
Ambiente
Producto
mpin mpout
mw
mpin mpout = Flujo de masa kg s-1
mw = tasa de evaporación kg s-1
mw = mpin [1-(Xin/Xout)]
mint = mout + mw
Capacidad del evaporador: masa de agua evaporada/hora
mint Xint = mpinXout
Mediciones de Xout posibilitan las mediciones de mw
Temp
eratu
ra ºK
0.3 1.0 mm
3 m /min
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
0 20 40280
300
320
340
360
Tempe
ratu
ra (°
K)
T iempo (m in)
B ano Ambiente F resa
Tiempo (min)
Temperatura (°K)
Agua
Ambiente
Producto
Tiempo (min)
Temp
eratu
ra ºK
λ = Calor latente de vaporizacion
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Conductividad
Parámetros físicos de interés Difusividad
Capacidad calorífica
• Trasferencia de calor • Balances de energía • Valoracion Energía
• Propiedades asociadas • Materia prima y sus cambios durante el procesado
Propiedades térmicas de los alimentos resultan de interés durante las operaciones de transformación procesado y diseño: Refrigeración. Secado y Esterilización.
Composición y Estructura
Capacidad calorífica y Calor latente fusión
Producto Cp(kJKg-1 K-1) Ac Cp(kJKg-1 K-1)Dc C. L. (kJkg-1)
Manzana 3.78 1.90 281 Fresas 3.93 1.97 302 Arándanos 3.85 1.94 291
Cp (3.47 a 4.06) kJkg-1 K-1 )
k ( 0.572 y 0.647 Wm-1°C-1)
0.134 a 0.160 mms-2
Qp (kW) = m Cp (Tf – Ti)
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
En el procesado el balance enérgico por calor (kW): QS y QW
QS = QP + QW + QL
Calor latente transferido al producto QP
Qp (kW) = m Cp (Tf – Ti) 1QP
QW
La transferencia de calor ganada por el producto está en función de la masa, la capacidad calorífica (Cp, Kj/kgºC) y la diferencia de temperatura (ΔT, ºC), al inicio y al final del proceso.
QL
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
xTTk
AQ 12 −−=
kxTT/
12 −−=RTT 12 −−=
RTΔ=
R
I
0V RVI 0=
RT
AQ Δ=
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
QS = QP + QW + QL
Calor ganado por la pelicula función de k y Qw
2 QP
QW
dxdTk
AQ −=
El calor ganado por la película está en función de la conductividad del material (k, W/m°K) y las diferencias térmicas entre el agua y la película.
QL
QW = mw λw
0.155 W/mºK
Qs = ms λs
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
mpin mpout
mw
Convección agua
QEV = QP+QW
Condensación Condensación
QEV = Calor sensible del producto =Evaporación
QEV = U A [ ] [ΔTin - Δtout]
ΔTin Δtout
Ln Coeficiente
global Área
Coeficiente global de transferencia de calor (U W/m2 ºK), que está en función de las resistencias térmicas de cada uno de los componentes del sistema
LMTD
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
QEV = U A [ ] [ΔTin - Δtout]
ΔTin Δtout
Ln
Coeficiente global
Área
A, es la unidad de área de transferencia (m2), hw y hp, son los coeficientes individuales de transferencia de calor para el producto y el agua, k, es la conductividad térmica del polímero conductor usado en el proceso.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Cp = 4.187[1-Xin(0.57-0.0018)(Tp-20))]
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Suplementos nutricionales. Comidas preparadas. Bebidas en polvo. Cereales de desayuno. Mezclas para postres. Mezclas para sopas.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
La fracción húmeda del producto en el sistema es: X=Xo en t=0. Al final se logra un producto de baja humedad.
816
Energy and operation In his work on pumpkin drying Nindo (2003) measured the moisture content of the puree on the belt of
a commercial RF unit as a function of position along the belt and hence residence time (Figure 3) He showed that with the heating water at 95ºC and a belt speed of 2.98 m/min, about 80% of the moisture was removed from the puree in the first 1/3 of the drying time and the product had almost reached its final moisture content within approximately 60% of the drying time. This drying rate shows the RW technology’s ability to utilise the heat energy during the window of opportunity when the product is moist and then to gradually shut down by self-regulation as the product moisture content decreases. During a similar experiment using a pilot plant Nindo also demonstrated the effect of using different water temperatures and the subsequent effect on drying rates (Figure 4)
Figure 3: Changes in puree moisture content during drying and residence time on the drying belt
Adapted From Nindo 2003
Figure 4: Effect of heating water temperature on moisture content and drying rate.
Kg ag
ua/K
g ss
Tiempo de secado (s)
Posición del producto en la cinta de transporte (m) Auyama: Producto seco
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
MCD TECHNOLOGIES, INC....drying at the speed of light...
Dryer REFRACTANCE WINDOW ®
Retains 94%of Vitamin C* & Natural
Color, Flavor,Aroma, Actives
*Results of Washington State University study sponsored by WashingtonTechnology Center
Our patented technologyutilizes water as the heat transfermedium to transmit energy at thespeed of light in order to dry a widevariety of products. Even delicatematerials ranging from bio-activelactobacillus to scrambled egg mixto nutraceuticals, for example, dryefficiently and with superior out-comes.
How It WorksA slurry of liquid product is
evenly applied to the top surface ofa continuous sheet of transparentplastic. This impervious conveyorbelt floats on a surface of hot water(210° F / 99° C or less).
Our proprietary process allowsinfrared energy (inherent in thecirculating water beneath the belt)to pass at the speed of light directlyinto the liquid slurry. The "window"allowing the rapid transfer of infra-red energy closes as the productloses moisture. Heat is also con-
DRYERS
ducted through the belt, which aids to evaporatemoisture in the product, especially when the productis nearly dry. Infrared energy and conducted heatpermit rapid drying at atmospheric pressure ratherthan under a vacuum.
This rapid, yet gentle process provides superiorretention of a product’s beneficial properties, includingits nutrition, flavor, color and aroma.
Environmentally ResponsibleEnergy efficient and with low water use,
Refractance Window® drying preserves air quality inand around the drying facility because little productessence is lost. In addition, the process does notgenerate exhaust dust, a significant pollution problem.
Drying RateMany factors affect drying characteristics and
rates. It is important to test-dry a product utilizing ourTest and Contract Processing services. Contact MCDto learn how we can assist you to best maintain yourproducts’ qualities.
ISO 9001:2000 Certified
MCD Technologies, Inc.2515 So Tacoma Way, Tacoma, WA 98409Tel: 1.253.476.0968 Fax: 1.253.476.0974info@mcdtechnologiesinc.comwww.mcdtechnologiesinc.com
Parametros de referencia Unidades Experimental
1 2 3 Peso Auyama fresca Kg Kg 74 141 146 Peso Auyama seca Kg Kg 16 30 31 Humedad inicial % p/p 79,4 79,6 80,1 Humedad final % p/p 4,90 4,7 5,2 Agua removida % 93,8 94,1 93,5 Tiempo de secado Minutos 64,0 97,0 86,0 Area efectiva de secado m2 17,4 17,4 17,4 Flujo de producto Kg/h 69,3 87,2 101,8 Remocion humedad Kg/h 54,3 68,8 80,4 Remocion humedad/Area Kg/h m2 3,10 3,90 4,40
Adaptado de Nindo, 2003
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
MCD TECHNOLOGIES, INC....drying at the speed of light...
Dryer REFRACTANCE WINDOW ®
Retains 94%of Vitamin C* & Natural
Color, Flavor,Aroma, Actives
*Results of Washington State University study sponsored by WashingtonTechnology Center
Our patented technologyutilizes water as the heat transfermedium to transmit energy at thespeed of light in order to dry a widevariety of products. Even delicatematerials ranging from bio-activelactobacillus to scrambled egg mixto nutraceuticals, for example, dryefficiently and with superior out-comes.
How It WorksA slurry of liquid product is
evenly applied to the top surface ofa continuous sheet of transparentplastic. This impervious conveyorbelt floats on a surface of hot water(210° F / 99° C or less).
Our proprietary process allowsinfrared energy (inherent in thecirculating water beneath the belt)to pass at the speed of light directlyinto the liquid slurry. The "window"allowing the rapid transfer of infra-red energy closes as the productloses moisture. Heat is also con-
DRYERS
ducted through the belt, which aids to evaporatemoisture in the product, especially when the productis nearly dry. Infrared energy and conducted heatpermit rapid drying at atmospheric pressure ratherthan under a vacuum.
This rapid, yet gentle process provides superiorretention of a product’s beneficial properties, includingits nutrition, flavor, color and aroma.
Environmentally ResponsibleEnergy efficient and with low water use,
Refractance Window® drying preserves air quality inand around the drying facility because little productessence is lost. In addition, the process does notgenerate exhaust dust, a significant pollution problem.
Drying RateMany factors affect drying characteristics and
rates. It is important to test-dry a product utilizing ourTest and Contract Processing services. Contact MCDto learn how we can assist you to best maintain yourproducts’ qualities.
ISO 9001:2000 Certified
MCD Technologies, Inc.2515 So Tacoma Way, Tacoma, WA 98409Tel: 1.253.476.0968 Fax: 1.253.476.0974info@mcdtechnologiesinc.comwww.mcdtechnologiesinc.com
Adaptado de Nindo, 2003
818
of quality aspects such as colour, vitamins and flavour are of such importance that pre-treatment is not always desired and able to be undertaken. This raises concerns about the ultimate safety of the dried product particularly upon reconstitution in applications where the microbial count may increase dramatically in the presence of water. Therefore a drying process that can dehydrate these products and reduce the microbial load to an acceptable level together with the retention of desirable quality attributes would represent an enhanced drying system.
Nindo (2003) investigated the effect of RW drying on the total aerobic count (APC) and also that of
three different cultures inoculated into pumpkin puree prior to drying. The results of this work are summarised in Table 3. It can be seen that the three test micro-organisms coliform, Escherichia coli and Listeria innocua were all reduced to well below the minimum detection level of <5 CFU/mL which corresponds to a microbial reduction of at least 6.1, 6.0 and 5.5 log CFU/mL respectively. The APC was also significantly reduced by 4.63 log.
Table3: Microbial counts in log CFU/mL of pumpkin puree before and after RF drying
APC Coliform Escherichia coli Listeria innocua Mean SD Mean SD Mean SD Mean SD
Control 7.17 0.12 6.78 0.09 6.73 0.14 6.14 0.11 Dried 2.54 0.26 <0.69 NA <0.69 NA <0.69 NA Log
reduction 4.63 6.09 6.04 5.45
Adapted from Nindo (2003) Colour Overall colour retention and colour change due to a range of drying techniques including RW drying
were studied by Abonyi (1999), Nindo (2003) and Abonyi (2002). Nindo found that pureed asparagus dried by RW was bright green in colour suggesting that most chlorophyll had been retained. He also noted that RW dried powder was the closest to freeze-dried in greenness. Abonyi (2002) carried out studies on carrot and strawberries. His results for the carrot trials showed that RW drying produced product closer to freeze drying than both drum and spray drying and that RW dried puree was characterised by higher L, a and B and chroma values indicating more vivid and more saturated red and yellow colours both probably due to high carotenoid content and retention. In the studies on strawberries the spray dried samples showed the greatest colour degradation. The RW product was equal to, or superior to, spray dried material when maltodextrin was added as a carrier to the strawberry puree. Table 4 shows a compilation of the results obtained
Table 4: Colour measurement comparison for drying technologies – (L* a* b*), darkness factor b* / a*, and total colour difference !E for strawberry
L* a* b* b*/a* !E Fresh No carrier With maltodextrin
36.1 45.3
25.6 27.0
19.8 22.0
0.77 0.81
0 0
Spray dried No carrier With maltodextrin
ND 77.8
ND 23.9
ND 16.8
ND 0.70
ND 34.4
RW Dried No carrier With maltodextrin
53.8 63.2
27.9 29.3
16.9 20.2
0.60 0.70
18.5 19.3
Freeze dried No carrier With maltodextrin
53.8 71.5
30.0 25.6
18.8 16.6
0.63 0.65
18.7 28.1
Adapted from Abonyi (2002)
Agentes microbianos Log (ufc/g) en Auyama antes y después del procesado mediante ventana refractiva
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
1052 JOURNAL OF FOOD SCIENCE—Vol. 67, Nr. 3, 2002
Food Engineering and Physical Properties
Product quality in Refractance Window drying . . .
solid phase micro extraction (SPME) withgas chromatography/time-of-flight massspectrometry detected several odor activestrawberry compounds in the headspaceof whole, ripe fruit. The use of SPME withGC/MS allows the measurement of odor-active aroma compounds in strawberrysamples at extremely low levels.
The objective of the present study wasto study quality retention characteristics ofRefractance Window drying system, incomparison with spray-drying, drum-dry-ing, and freeze-drying methods. The quali-ty attributes compared were color and !-carotene for carrots, and color, vitamin C,and flavor volatile content for strawberries.
Materials and Methods
Drying sample preparationFrozen strawberry purees were pur-
chased from a commercial supplier (Stahl-bush Island Farms, Inc., Corvallis, Ore.,U.S.A.). The strawberries (Fragaria annan-asa cv. Totem) were grown in the Wil-lamette Valley, Ore., U.S.A. and harvestedin June, 1998. In preparing the frozen pu-rees, strawberries were washed, inspect-ed, pureed, pasteurized (74 °C), and thencooled (3 °C) before being frozen to–20 °C. The total processing time was 20min. The strawberry puree had averagemoisture content of 93.6% (wb).
Frozen carrot purees were purchasedfrom the same supplier. Carrots (Daucvscarta L cv. Navajo) were grown in the Co-lumbia Basin, Wash., U.S.A. and harvestedin July, 1998. The processing of the carrotsincluded washing, scrubbing/peeling,blanching, pureeing, pasteurizing (85 °C),acidifying (using citric acid solution), cool-ing (2 °C), and freezing (–20 °C) The totaltime taken in carrot puree proparation was33 min. Carrot puree had average mois-ture content of 89.4% (wb). The sampleswere thawed overnight in a storage roomat 4 °C before drying tests.
Drying experimentsCarrot purees were dried by Refracta-
nce Window, freeze drying, and drum dry-ing methods. Similarly, strawberry pureeswere dried by Refractance Window drying,freeze drying, and spray drying. All testswere conducted in triplicate. The condi-tions for the drying tests were as follows:
Spray-drying. A pilot-scale spray dryer(Anhydro Attleboro Falls Mass, Copen-hagen, Denmark) was used in dryingtests. The inlet air temperature was 190 ±5 °C and the outlet air temperature 95 ±5 °C. In preliminary tests, it was foundthat strawberry purees could not be spray-
dried without adding a carrier due to itshigh sugar content. Hence, maltodextrin(DE = 10) was used as a carrier during thespray drying experiments (Hui 1992). 70%maltodextrin carrier was added to straw-berry puree and samples were dried tomoisture content of 2.3 % (wb).
Drum drying. A pilot-scale double-drum dryer was used. This dryer had 2counter-rotating drums, which had a diaof 19 cm and rotated at 0.3 rpm, giving aresidence time of 3 min. Carrot puree wasfed into the gap between the drum rolls.The drum surface temperature was main-tained at 138 °C by pressurized steam.The final moisture content of carrots was5.0% (wb).
Freeze drying. The strawberry and car-rot samples were quick-frozen at –35 °C. Afreeze dryer (Virtis Co., Gardiner, N.Y.,U.S.A.) was operated at an absolute pres-sure of 3.3 kPa. The temperature of theheating plate was 20 °C, while the con-denser temperature was –64 °C. The dry-ing time to reduce moisture content to8.2% (wb) (carrot), 3.9% (wb) (strawberrypurees with 70% maltodextrin as carrier),and 12.1% (wb) (strawberry purees with-out carrier) was 24 h.
Refractance Window drying. A pilotscale Refractance Window dryer with aneffective length of 1.83 m was used (Figure1). Air at 20 °C and 52% relative humidity(RH) was forced over the bed at an aver-age air velocity of 0.7 m/s to remove themoisture. The water temperature was95 °C while the belt speed was in therange of 0.45 to 0.58 m/min. The thicknessof the puree application was about 1 mm.Residence times of the material on thedrying bed were controlled between 3 and5 min by adjusting the belt speed. Carrotpuree was dried to 6.1 % (wb), strawberrypuree to 9.9% (wb), and strawberry pureewith maltodextrin carrier to 5.7% (wb).
After the drying tests, the productswere packed in aluminum-coated poly-ethylene bags, flushed with nitrogen, heatsealed, and stored at –20°C prior to analy-ses.
Color measurementThe color of samples (L*, a*, and b*)
was measured with a Minolta Chroma CR-200 color meter. To prepare the samplesfor color measurement, purees werepoured into a 35-mm Petri dish and care-fully covered with a Saran Wrap transpar-ent film (Dow Brands L.P., Indianapolis,Ind., U.S.A.) which was carefully pressedagainst surface to remove air bubbles.Color of the purees was measured by con-tacting the color meter with the film-cov-ered sample. Measurements were taken at5 different locations on the sample. Ateach location 5 readings were taken. Themean of 25 readings was reported. Driedsamples were ground and rehydrated tomake slurries with the same moisture con-tent as the fresh purees. Measurementswere made on the slurry following thesame procedure as described for fresh pu-rees. A darkness factor b*/a* was used toquantify possible color changes (Tulasi-das and others 1993). The hue angle, H*,and chroma C*, which are given byH* = tan–1(b*/a*) and C* = (a*2 + b*2)1/2
were also calculated.
Moisture content determinationThe sample moisture contents were de-
termined using the vacuum oven methodat 70°C and absolute pressure of 13.3 kPa(AOAC 1996). The means of 3 measure-ments are reported.
Product temperatureProduct temperature during drying
was measured with a thermometer (Ome-ga Engineering, Inc., Stamford, Conn.,U.S.A.) which used a type T thermocouplewith a response time of 0.8 s. The mea-surements were made by promptly scrap-ing off small amount of sample from thedrying belt and probing the thermal cou-ple into the sample to obtain readings.
Carotene analysisSamples were prepared from commer-
cial carrot purees following a standard pro-cedure (method 941.15, AOAC 1996) with
Table 1—Carotene losses in carrots among control and samples dried by drum,freeze, and Refractance Window† drying methods.
Total carotene alpha carotene carotene
Sample g/g solid Loss (%) g/g solid Loss (%) g/g solid Loss (%)
Control 1.77 ± 0.09†a 0.85 ± 0.04a 0.92 ± 0.05a
Drum dried 0.78 ± 0.18b 56.0 ± 1.2 0.38 ± 0.09b 55.0 ± 1.1 0.39 ± 0.08b 57.1 ± 1.3RW* dried 1.62 ± 0.33a 8.7 ± 2.0 0.79 ± 0.16a 7.4 ± 2.2 0.83± 0.17a 9.9 ± 1.8Freeze dried 1.70 ± 0.06a 4.0 ± 3.6 0.83 ± 0.03a 2.4 ± 3.7 0.87 ± 0.03a 5.4 ± 3.5Refractance WindowTM. +: average of three replicates.abcdDifferent letters in the same column indicate a significant difference (p ! 0.05)
jfsv67n3p1051-1056ms20010048-BW-wcxs.P65 5/7/2002, 2:52 PM1052
Perdidas en el contenido de carotenos En sistemas de procesado para el secado de cremogenado de zanahoria
El secado de cubos de zanahoria 60 to 70 °C en sistemas convencionales 72% y 82% de perdidas de carotenos.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
MCD TECHNOLOGIES, INC....drying at the speed of light...
Dryer REFRACTANCE WINDOW ®
Retains 94%of Vitamin C* & Natural
Color, Flavor,Aroma, Actives
*Results of Washington State University study sponsored by WashingtonTechnology Center
Our patented technologyutilizes water as the heat transfermedium to transmit energy at thespeed of light in order to dry a widevariety of products. Even delicatematerials ranging from bio-activelactobacillus to scrambled egg mixto nutraceuticals, for example, dryefficiently and with superior out-comes.
How It WorksA slurry of liquid product is
evenly applied to the top surface ofa continuous sheet of transparentplastic. This impervious conveyorbelt floats on a surface of hot water(210° F / 99° C or less).
Our proprietary process allowsinfrared energy (inherent in thecirculating water beneath the belt)to pass at the speed of light directlyinto the liquid slurry. The "window"allowing the rapid transfer of infra-red energy closes as the productloses moisture. Heat is also con-
DRYERS
ducted through the belt, which aids to evaporatemoisture in the product, especially when the productis nearly dry. Infrared energy and conducted heatpermit rapid drying at atmospheric pressure ratherthan under a vacuum.
This rapid, yet gentle process provides superiorretention of a product’s beneficial properties, includingits nutrition, flavor, color and aroma.
Environmentally ResponsibleEnergy efficient and with low water use,
Refractance Window® drying preserves air quality inand around the drying facility because little productessence is lost. In addition, the process does notgenerate exhaust dust, a significant pollution problem.
Drying RateMany factors affect drying characteristics and
rates. It is important to test-dry a product utilizing ourTest and Contract Processing services. Contact MCDto learn how we can assist you to best maintain yourproducts’ qualities.
ISO 9001:2000 Certified
MCD Technologies, Inc.2515 So Tacoma Way, Tacoma, WA 98409Tel: 1.253.476.0968 Fax: 1.253.476.0974info@mcdtechnologiesinc.comwww.mcdtechnologiesinc.com
Rápid
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spira
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perd
ida de
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Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
MCD TECHNOLOGIES, INC....drying at the speed of light...
Dryer REFRACTANCE WINDOW ®
Retains 94%of Vitamin C* & Natural
Color, Flavor,Aroma, Actives
*Results of Washington State University study sponsored by WashingtonTechnology Center
Our patented technologyutilizes water as the heat transfermedium to transmit energy at thespeed of light in order to dry a widevariety of products. Even delicatematerials ranging from bio-activelactobacillus to scrambled egg mixto nutraceuticals, for example, dryefficiently and with superior out-comes.
How It WorksA slurry of liquid product is
evenly applied to the top surface ofa continuous sheet of transparentplastic. This impervious conveyorbelt floats on a surface of hot water(210° F / 99° C or less).
Our proprietary process allowsinfrared energy (inherent in thecirculating water beneath the belt)to pass at the speed of light directlyinto the liquid slurry. The "window"allowing the rapid transfer of infra-red energy closes as the productloses moisture. Heat is also con-
DRYERS
ducted through the belt, which aids to evaporatemoisture in the product, especially when the productis nearly dry. Infrared energy and conducted heatpermit rapid drying at atmospheric pressure ratherthan under a vacuum.
This rapid, yet gentle process provides superiorretention of a product’s beneficial properties, includingits nutrition, flavor, color and aroma.
Environmentally ResponsibleEnergy efficient and with low water use,
Refractance Window® drying preserves air quality inand around the drying facility because little productessence is lost. In addition, the process does notgenerate exhaust dust, a significant pollution problem.
Drying RateMany factors affect drying characteristics and
rates. It is important to test-dry a product utilizing ourTest and Contract Processing services. Contact MCDto learn how we can assist you to best maintain yourproducts’ qualities.
ISO 9001:2000 Certified
MCD Technologies, Inc.2515 So Tacoma Way, Tacoma, WA 98409Tel: 1.253.476.0968 Fax: 1.253.476.0974info@mcdtechnologiesinc.comwww.mcdtechnologiesinc.com
Vol. 67, Nr. 3, 2002—JOURNAL OF FOOD SCIENCE 1053
Food E
ngine
ering
and P
hysic
al Pro
perti
es
Table 2—Comparison of vitamin C content of Refractance WindowTM and freezedried strawberry purees without carrier.
Treatment AA1mg/g solid AA loss(%) M.C2 wb (%)
Fresh puree 1.80 ± 0.01a 93.6 ± 0.2RW* dried 1.69 ± 0.03b 6.0 ± 1.3b 9.90 ± 0.6Freeze dried 1.68 ± 0.04b 6.4 ± 1.6b 12.1 ± 0.5*Refractance WindowTM.1Ascorbic acid. 2moisture content on a wet basis, average of 4 replicates.abDifferent letters in the same column indicate a significant difference (p 0.05).
Product quality in Refractance Window drying . . .
modifications. Upon thawing overnight atroom temperature, 5-g puree was blendedusing a Sorvall Omni-Mixer (Ivan SorvallInc., Newtown, Conn., U.S.A.) with 40 mlacetone, 60 ml hexane, and 0.1 g MgCO3for 5 min. The mixture was drawn undergentle vacuum through a 5.8 cm diameterBüchner funnel containing Whatman #4filter paper and filter aid (Celite 545, Fish-er Co., Pa., U.S.A.). The residue was placedin a separate funnel and washed with two25-ml portions of acetone, followed bywashing with 25 ml hexane. The extractwas combined with the filtrate, trans-ferred into a 250 ml separatory funnel cov-ered with aluminum foil, and kept in thedark for 1 h. The lower phase was releasedinto a flat bottom flask. The upper phasewas saponified by adding 40% methanolicKOH (5 ml). Saponification was conductedin the dark for 16 h at 22 °C. The extractwas washed of acetone with five 100-mlportions of H2O. The upper layer wastransferred to a 100-ml flask and dilutedto volume with hexane.
Samples from dried carrots were pre-pared according to method 970.64, AOAC(1996) with modifications. Analyses wereconducted using a Waters HPLC System(Waters, Milford, Mass., U.S.A.). It consist-ed of a Waters 2690 separation moduleand a Waters 996 photodiode array detec-tor. The samples were eluted through a 3!m particle size reverse phase column(100 ! 4.6 mm i.d.) (Microsorb-MVTM, Vari-
an, Walnut Creek, Calif., U.S.A.). The mo-bile phase consisted of a mixture of aceto-n i t r i t e - d i c h l o r o m e t h a n e - m e t h a n o l(85:10:5 v/v/v) plus 0.05 % ammonium ac-etate. The flowrate was 1 ml/min. Caro-tene analyses were conducted on random-ly selected samples from each dryingmethod in triplicate.
Ascorbic acid analysisThe method used for extraction of raw
samples was adapted from National Can-ners Association Research Laboratories(NCARL 1968). In titration, the volumeused to reach a permanent pink color wasdetermined from a standard curve. Analy-sis of ascorbic acid was repeated fourtimes for randomly selected samples fromeach drying method.
Flavor volatile analysis (SPMEAnalysis)
Dehydrated strawberry purees were re-hydrated at room temperature with deion-
ized water. The amount of water used toreconstitute the strawberries was calculat-ed based on the moisture content of thedried strawberries to reach a solid contentof 21.2 % (g solid/g H2O) in the mixture.The rehydrated strawberries were thenmacerated with a blender and centrifugedfor 10 min at 13,139 g and 4 °C to obtain aclear juice. For thawed strawberry purees,samples (5 g) were macerated and then di-luted in 100 ml distilled deionized water.The mixture was centrifuged to collect theclear juice.
A mixture of 0.65 g NaCl and 2 ml straw-berry homogenate were placed in a 4 mlsample vial and mixed on a stirring plate.A SPME device (Supelco, Co., Bellefonte,Pa., U.S.A.) with a fused silica fiber coatedwith 65 !m poly(dimethylsiloxane)/divin-lybezene was exposed to the headspace ofthe sample for approximately 1 h beforebeing injected into a GC. SPME injectionwas achieved by splitless injection for 2min at 200 °C into a Hewlett-Packard5890II/5970 GC/MSD equipped with aDB-1 column (J & W Scientific, 60 m ! 0.32mm i.d., 0.25-!m film thickness). Chro-matographic conditions were as describedby Mattheis and others (1991) except thetransfer line temperature and ion sourcewas held at 250 °C. The GC inlet containeda 0.75 mm SPME injection sleeve that as-sures peak sharpness, especially for theearly eluting peaks (Yang and Peppard1994). The compounds were identified bycomparing the spectra of the sample com-pounds with those contained in the Wiley-NBS library and by comparing retentionindices of sample compounds and stan-dards.
Results and Discussion
Carotene retentionThe total, "-, and #- carotene losses in
carrot samples dried by different methodsare shown in Table 1. Carotene losses inRefractance Window (RW) dried carrotsamples were slightly higher but not sig-nificantly different from that of freeze-dried samples. The carotene losses for RWdrying were 8.7% (total carotene), 7.4% ("-
Figure 2—Product temperature of carrot puree dried with the RefractanceWindow drying system at application thickness of 1 mm.
jfsv67n3p1051-1056ms20010048-BW-wcxs.P65 5/7/2002, 2:52 PM1053
Contenido de Vitamina C en fresa procesada Tecnologia mediante ventana refractiva y Liofilizada
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
1054 JOURNAL OF FOOD SCIENCE—Vol. 67, Nr. 3, 2002
Food Engineering and Physical Properties
Table 3—Color measurement results in L*a*b*, darkness factor b*/a*, chromaand hue values for carrot puree.
Treatment L* a* b* b*/a* H* C*
Fresh puree 54.3 ± 0.8d 28.7 ± 0.2b 44.0 ± 1.0a 1.53c 56.8b 52.5c
Drum dried 67.5 ± 0.6c 20.8 ± 0.4d 39.4 ± 1.7b 1.89a 62.1c 44.6a
RW dried 72.0 ± 0.3b 34.1 ± 0.5a 45.1 ± 0.8a 1.32d 52.8a 56.5d
Freeze dried 77.6 ± 0.4a 27.1 ± 1.2c 44.1 ± 0.4a 1.63b 58.5b 51.8b
L*: lightness, a*: redness, b*: blueness, C*: chroma = (a*2 + b*2)1/2, H*: Hue angle = tan–1(b*/a*).abcdDifferent letters in the same column indicate a significant difference in descending order (p ! 0.05)
Table 5—Color measurement results in L*a*b*, darkness factor b*/a*, chromaand hue values for strawberry puree without carrier.
Treatment L* a* b* b*/a* H* C
Fresh puree 36.1 ± 1.0b 25.6 ± 0.6c 19.8 ± 0.9a 0.77a 37.8a 32.4b
RW dried 53.8 ± 0.3a 27.9 ± 0.3b 16.9 ± 0.3c 0.60c 31.2c 32.6b
Freeze dried 53.8 ± 0.5a 30.0 ± 0.4a 18.8 ± 0.4b 0.63b 32.1b 35.4a
abcdDifferent letters in the same column indicate a significant difference in descending order (p ! 0.05)
Product quality in Refractance Window drying . . .
carotene), and 9.9% (!-carotene), whilecorresponding losses for freeze-dried car-rot puree were 4.0%, 2.4%, and 5.4%.Drum dried products suffered a severenutrient loss as indicated by carotene re-duction of 56.1% (total carotene), 55.0%("-carotene), and 57.1% (!-carotene). Theamount of "-carotene degradation (5.4%)in freeze-dried carrot samples was compa-rable to the 8% loss reported by Desobryand others (1997). The "-carotene contentin freeze-dried puree on a dry solid basis(1.7 mg/g solid) was close to 1.2 mg/g solidfor carrot roots documented by Durance(1999). The drum-dried carrot purees inthis study had a higher "-carotene loss(57.1%) compared to the 8% loss reportedby Desobry and others (1997). This maybe caused by the differences in the type ofdrum dryer used, operating variables se-lected, and cultivar and growing condi-tions.
Carotene degradation during dryinghas been attributed to its high sensitivityto oxidation (Desobry and others 1997). Ina drying process, the cumulative effect oftime-temperature determines the totalcarotene loss. In the absence of oxygen,formation of cis·isomers can also causedegradation of carotene (Howard and oth-ers 1999). In drum drying, the product ex-perienced severe heating after it was ap-plied on the drum wall that was heated to138 °C. When most of the water was re-moved at the falling rate period, the prod-uct temperature could reach the wall tem-perature (138 °C). As a result, drum-driedproduct had the highest carotene lossamong the methods used. In the case offreeze drying, however, sample tempera-ture was much lower. At the initial dryingperiod, when sublimation was dominant,the temperature was below 0 °C. Towardsthe end of the drying, however, producttemperature would approach the heatingplate temperature (20 °C). The near ab-sence of oxygen and low temperatures ef-fectively hindered the oxidative reactions.The slight reduction in carotene content infreeze drying might have been caused bythe formation of the cis·isomer when ex-posed to a temperature close to that of theheating plate (20 °C) for a long time(about 8 h), when drying in the secondarydrying stage (Desrosier and others 1985).RW drying of the carrot puree experiencedrelatively low temperatures (< 72 °C) (Fig-ure 2) and a short drying time (3.75 min inFigure 3). The good carotene retention inRW-dried products may be attributed to amore moderate time-temperature combi-nation compared to other drying methods,usually characterized by either high dry-
Table 4—Color measurement results in L*a*b*, darkness factor b*/a*, chromaand hue values for strawberry puree + maltodextrin.
Treatment L* a* b* b*/a* H* C*
Fresh puree 45.3 ± 1.6d 27.0 ± 1.7b 22.0 ± 1.9a 0.81a 39.2a 34.8a
Spray dried 77.8 ± 0.7a 23.9 ± 0.6c 16.8 ± 0.5c 0.70b 35.1b 29.2b
RW dried 63.2 ± 0.5c 29.3 ± 0.6a 20.2 ± 0.5b 0.70b 34.6b 35.6a
Freeze dried 71.5 ± 0.5b 25.6 ± 0.8b 16.6 ± 0.6c 0.65c 33.0c 30.5b
abcdDifferent letters in the same column indicate a significant difference in descending order (p ! 0.05)
Figure 3—Moisture content as compared with drying time for strawberry pu-ree with carrier dried with the Refractance WindowTM drying system at appli-cation thickness of ~1 mm.
jfsv67n3p1051-1056ms20010048-BW-wcxs.P65 5/7/2002, 2:52 PM1054
MCD TECHNOLOGIES, INC....drying at the speed of light...
Dryer REFRACTANCE WINDOW ®
Retains 94%of Vitamin C* & Natural
Color, Flavor,Aroma, Actives
*Results of Washington State University study sponsored by WashingtonTechnology Center
Our patented technologyutilizes water as the heat transfermedium to transmit energy at thespeed of light in order to dry a widevariety of products. Even delicatematerials ranging from bio-activelactobacillus to scrambled egg mixto nutraceuticals, for example, dryefficiently and with superior out-comes.
How It WorksA slurry of liquid product is
evenly applied to the top surface ofa continuous sheet of transparentplastic. This impervious conveyorbelt floats on a surface of hot water(210° F / 99° C or less).
Our proprietary process allowsinfrared energy (inherent in thecirculating water beneath the belt)to pass at the speed of light directlyinto the liquid slurry. The "window"allowing the rapid transfer of infra-red energy closes as the productloses moisture. Heat is also con-
DRYERS
ducted through the belt, which aids to evaporatemoisture in the product, especially when the productis nearly dry. Infrared energy and conducted heatpermit rapid drying at atmospheric pressure ratherthan under a vacuum.
This rapid, yet gentle process provides superiorretention of a product’s beneficial properties, includingits nutrition, flavor, color and aroma.
Environmentally ResponsibleEnergy efficient and with low water use,
Refractance Window® drying preserves air quality inand around the drying facility because little productessence is lost. In addition, the process does notgenerate exhaust dust, a significant pollution problem.
Drying RateMany factors affect drying characteristics and
rates. It is important to test-dry a product utilizing ourTest and Contract Processing services. Contact MCDto learn how we can assist you to best maintain yourproducts’ qualities.
ISO 9001:2000 Certified
MCD Technologies, Inc.2515 So Tacoma Way, Tacoma, WA 98409Tel: 1.253.476.0968 Fax: 1.253.476.0974info@mcdtechnologiesinc.comwww.mcdtechnologiesinc.com
Parámetros cromáticos asociados al cremogenado de fresa procesado Tecnología mediante ventana refractiva y Liofilizada
1054 JOURNAL OF FOOD SCIENCE—Vol. 67, Nr. 3, 2002
Food Engineering and Physical Properties
Table 3—Color measurement results in L*a*b*, darkness factor b*/a*, chromaand hue values for carrot puree.
Treatment L* a* b* b*/a* H* C*
Fresh puree 54.3 ± 0.8d 28.7 ± 0.2b 44.0 ± 1.0a 1.53c 56.8b 52.5c
Drum dried 67.5 ± 0.6c 20.8 ± 0.4d 39.4 ± 1.7b 1.89a 62.1c 44.6a
RW dried 72.0 ± 0.3b 34.1 ± 0.5a 45.1 ± 0.8a 1.32d 52.8a 56.5d
Freeze dried 77.6 ± 0.4a 27.1 ± 1.2c 44.1 ± 0.4a 1.63b 58.5b 51.8b
L*: lightness, a*: redness, b*: blueness, C*: chroma = (a*2 + b*2)1/2, H*: Hue angle = tan–1(b*/a*).abcdDifferent letters in the same column indicate a significant difference in descending order (p ! 0.05)
Table 5—Color measurement results in L*a*b*, darkness factor b*/a*, chromaand hue values for strawberry puree without carrier.
Treatment L* a* b* b*/a* H* C
Fresh puree 36.1 ± 1.0b 25.6 ± 0.6c 19.8 ± 0.9a 0.77a 37.8a 32.4b
RW dried 53.8 ± 0.3a 27.9 ± 0.3b 16.9 ± 0.3c 0.60c 31.2c 32.6b
Freeze dried 53.8 ± 0.5a 30.0 ± 0.4a 18.8 ± 0.4b 0.63b 32.1b 35.4a
abcdDifferent letters in the same column indicate a significant difference in descending order (p ! 0.05)
Product quality in Refractance Window drying . . .
carotene), and 9.9% (!-carotene), whilecorresponding losses for freeze-dried car-rot puree were 4.0%, 2.4%, and 5.4%.Drum dried products suffered a severenutrient loss as indicated by carotene re-duction of 56.1% (total carotene), 55.0%("-carotene), and 57.1% (!-carotene). Theamount of "-carotene degradation (5.4%)in freeze-dried carrot samples was compa-rable to the 8% loss reported by Desobryand others (1997). The "-carotene contentin freeze-dried puree on a dry solid basis(1.7 mg/g solid) was close to 1.2 mg/g solidfor carrot roots documented by Durance(1999). The drum-dried carrot purees inthis study had a higher "-carotene loss(57.1%) compared to the 8% loss reportedby Desobry and others (1997). This maybe caused by the differences in the type ofdrum dryer used, operating variables se-lected, and cultivar and growing condi-tions.
Carotene degradation during dryinghas been attributed to its high sensitivityto oxidation (Desobry and others 1997). Ina drying process, the cumulative effect oftime-temperature determines the totalcarotene loss. In the absence of oxygen,formation of cis·isomers can also causedegradation of carotene (Howard and oth-ers 1999). In drum drying, the product ex-perienced severe heating after it was ap-plied on the drum wall that was heated to138 °C. When most of the water was re-moved at the falling rate period, the prod-uct temperature could reach the wall tem-perature (138 °C). As a result, drum-driedproduct had the highest carotene lossamong the methods used. In the case offreeze drying, however, sample tempera-ture was much lower. At the initial dryingperiod, when sublimation was dominant,the temperature was below 0 °C. Towardsthe end of the drying, however, producttemperature would approach the heatingplate temperature (20 °C). The near ab-sence of oxygen and low temperatures ef-fectively hindered the oxidative reactions.The slight reduction in carotene content infreeze drying might have been caused bythe formation of the cis·isomer when ex-posed to a temperature close to that of theheating plate (20 °C) for a long time(about 8 h), when drying in the secondarydrying stage (Desrosier and others 1985).RW drying of the carrot puree experiencedrelatively low temperatures (< 72 °C) (Fig-ure 2) and a short drying time (3.75 min inFigure 3). The good carotene retention inRW-dried products may be attributed to amore moderate time-temperature combi-nation compared to other drying methods,usually characterized by either high dry-
Table 4—Color measurement results in L*a*b*, darkness factor b*/a*, chromaand hue values for strawberry puree + maltodextrin.
Treatment L* a* b* b*/a* H* C*
Fresh puree 45.3 ± 1.6d 27.0 ± 1.7b 22.0 ± 1.9a 0.81a 39.2a 34.8a
Spray dried 77.8 ± 0.7a 23.9 ± 0.6c 16.8 ± 0.5c 0.70b 35.1b 29.2b
RW dried 63.2 ± 0.5c 29.3 ± 0.6a 20.2 ± 0.5b 0.70b 34.6b 35.6a
Freeze dried 71.5 ± 0.5b 25.6 ± 0.8b 16.6 ± 0.6c 0.65c 33.0c 30.5b
abcdDifferent letters in the same column indicate a significant difference in descending order (p ! 0.05)
Figure 3—Moisture content as compared with drying time for strawberry pu-ree with carrier dried with the Refractance WindowTM drying system at appli-cation thickness of ~1 mm.
jfsv67n3p1051-1056ms20010048-BW-wcxs.P65 5/7/2002, 2:52 PM1054
Conte
nido d
e hum
edad
Kg A
gua/K
g Sóli
dos
Longitud de la banda de secado (m)
Tiempo de secado (m)
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Parámetros fisicoquímicos asociados a los cremogenados de frutas tropicales Valores de humedad inicial y final Ventana refractiva
Flavorbeefchickenpet foodclam juicepeppermintspearmintvanillacoffeewineyeast-based dough
flavoring
Fruit &VegetableFruitapricotaronia berryavocadobananablackberryblueberryborojocantaloupecherrycoconut
cranberrycurubafiggrapegrapefruitguavahuckleberrykiwilemonmangomelonnectarineorangepalmberrypapayapassion fruitpineappleplumpruneraspberrysoursopstrawberryVegetabletree tomatoartichokeasparagusbeetsbell pepper
Beveragecoffeeteacocoa mixchai
Colorannatogrape juice concentratenatural & artificial colors
Dairybioactive cultures -
kefir, lactobacilluscolostromkefirmilk (whole, skim)milk, sweetened cond.yogurtwhey
Eggwhole, white, yolkscrambled egg mixbakery wash
A Few TestedProducts
MCD TECHNOLOGIES, INC....drying at the speed of light...
Food (liquids, purees, extracts, slurries, chunky purees, including those with small seeds)
Nutraceuticalacerola cherry, algaes,aloe vera, barley grassjuice,fungi, extracts(broccoli, dandelion,echinacea, ginger,grape seed, hops,kava kava, sawpalmetto, suma,tang kuei and others),noni, papaya-green
broccolicelerycornmushroomonionpeas, greenplantainpotato, sweetpotato, whitepumpkinspinachsproutssquashtomatoyam
Herb & Spicebasilparsleypeppercornsjalapeno pepper
Meat, Fish,Poultrybeefpork
shrimpcodsalmontunachickenturkey
Starch &Cerealbarleyoatsricespecialty starches &
mixes
Othergelatin - fish, beefgelatin/sugar mixmiso - red, yellowyeast-based dough
conditioner
REFRACTANCE WINDOW ®
Pharmacalcium ascorbatecephalosporinEster-Cmagnesium ascorbatepotassium ascorbate
Chemicalcosmeticssaltreagentneon dyelaser toner
By-Productcheese plantfish processingmilk processingpotato processingyeast production
And ManyOthers . . .Call Us!
ISO 9001:2000 Certified
MCD Technologies, Inc.2515 So Tacoma Way, Tacoma, WA 98409Tel: 1.253.476.0968 Fax: 1.253.476.0974info@mcdtechnologiesinc.comwww.mcdtechnologiesinc.com
MCD TECHNOLOGIES, INC....drying at the speed of light...
The Company REFRACTANCE WINDOW ®
ISO 9001:2000 Certified
MCD Technologies, Inc.2515 So Tacoma Way, Tacoma, WA 98409Tel: 1.253.476.0968 Fax: 1.253.476.0974info@mcdtechnologiesinc.comwww.mcdtechnologiesinc.com
Company ProfileMCD Technologies, at the forefront of food
processing technology since 1989, develops state-of-the art dryers and evaporators utilizing proprietary andpatented Refractance Window® (RWTM) heat transfertechnology. In addition, MCD offers ContractProcessing Services for market samples, scale-upneeds and to demonstrate the superior qualities ofRefractance Window® dried and evaporated products.
ObjectiveMCD provides customers with technical
consulting and customized equipment to facilitateproduction of superior quality dried and evaporatedproducts, helping them maximize profits whilereducing energy use and costs.
Innovative, Patented TechnologyOur revolutionary, patented Refractance Window®
technology utilizes water as the heat transfer medium todry or concentrate a wide variety of foods, functionalfoods, nutraceuticals, pharmaceuticals, chemicals,and by-products.
Refractance Window® drying and evaporating offerexcellent results with a wide variety of products,particularly those requiring accurate, precise, lowtemperature processing.
Washington State University (WSU) studiesfunded by Washington Technology Center (WTC)have documented qualitative and energy use aspectsof Refractance Window® drying and evaporating:
Refractance Window® dried strawberry andcarrot retain similar amounts of Vitamins C and Awhen compared to freeze-dried specimens.
Refractance Window® Dryer energy efficiency isequal to the highest efficiency ever commerciallydocumented.
The Refractance Window® Evaporator is 99%efficient in heat energy transfer.Washington State University, under an SBIR
grant awarded in May 2006, is further studyingRefractance Window® drying’s superior retention ofantioxidants and other heat sensitive componentsduring gentle processing of nutraceuticals andfunctional foods.
State-of-the-Art ManufacturingMCD employs advanced engineering capabilities
to insure superior quality design and manufacture ofRefractance Window® dehydration and evaporationequipment and accessories.
Testing and Contract ProcessingMCD conducts test drying and evaporating, as
well as sample production, in its pilot facility. MCD’sproduction model dryer and evaporator are employedin contract processing for clients with special pro-cessing requirements, seasonal production, or limiteddrying needs that do not warrant purchase ofRefractance Window® equipment. Contract process-ing, sample production, and testing offer customersmaximum flexibility. We match our customers’ spe-cific requirements and specifications to our equip-ment in order to achieve the highest quality productoutcome. Our facilities are Certified Organic throughWSDA and Kosher through Orthodox Union.
Company HistoryFounded in 1989 as M.C.D. Company by Richard E.
Magoon, the inventor and patent holder of RefractanceWindow® technology, the company incorporated as MCDTechnologies Inc. in 1998. Its equipment manufacturingand food processing operations are located in Tacoma,Washington, in the beautiful Northwest.
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Relación de parámetros cromáticos para cremogenados de frutos tropicales sometidos a un proceso de secado mediante el método de ventana refractiva.
ΔE = (ΔL*+Δa*2 +Δb*2)1/2 h* = arctg [ b*/a* ] C* = [ (a*)2 + (b*)2 ]1/2
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Los tratamientos mediante ventana pueden enmarcarse en estudios de factores Empaque Producto Proceso (PPP). Temperatura Tiempo Tolerancia (TTT). Monitoreando las propiedades en el tiempo. Evaluar la mangitud y cambios de las propiedades sensorias. La retencion de aromas de los productos.
Realizar estudios cinéticos
Cinética de primer orden
C = es la propiedad del color que se mide ± Formacion o degradación de producto.
Azucares + Aminoácidos Reacciones de pardeamiento HMF´s k
C = Co± kot
C = Co exp± kt
Cinética orden cero
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
30
35
40
45
50
55
60
10 20 30 40 50
Luminancia
Tiempo (min)
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
0 10 20 30 40
b*
Tiempo (min)
0.00
5.00
10.00
15.00
20.00
25.00
0 10 20 30 40 50
a* x
b*/L
Tíempo (min)
Cinéticas de primer orden C = Co exp± kt Cambios de color Orden cero: C = Co± kot
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Secado convectivo < Spray Dryer < Liofilizados < Ventana refractiva
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
Grupo de Investigaciones Mellitopalinologicas y Propiedades Fisicoquímicas de Alimentos
Universidad del Tolima Colombia
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