Refractance Windows Monteria

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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





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



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



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


Universidad del Tolima Colombia Aspectos socioculturales

Segu

ridad

o Ins

egur

idad A

limen

taria?



• 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.



El sistema productivo una cadena de valor

1 2 3

6 5 4


Universidad del Tolima Colombia 805.000 Tn Maracuyá

Modelo alimentario

Dinámica Productiva

Tecnología

Plagas

Perdidas

I+D

Capacitación

Inasistencia

1

2

3

4



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





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


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



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



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



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


Universidad del Tolima Colombia Aspectos socioculturales

Segu

ridad

o Ins

egur

idad A

limen

taria?



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



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



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



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.



•  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.



Lipoxigenasas ( linoleato: oxigeno oxireductasa)

LOX

LOX I

LOX II

LOX III

LOX IV LOX V LOX VI

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





Acido Araquidonico C20:4 cis-cis

Araquidon oxigeno 5-oxidoreductasa



Araquidon oxigeno 8-oxidoreductasa 5 hidroperóxido

8 hidroperóxido




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



ProductosHortofrutícolas

Valoracion Sistemasde Procesado

-industrialización-

Pastas/PulpasZumos/Cremogenados

Consumoen Fresco

Materias Primas Industria

CongeladoDeshidratado

Otros Sistemas de Procesado

Comercialización



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.



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



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



Solar drying

Drump Dryer

Tray drying

Freeze drying



Optimización de sistemas y controles de procesdo Mantenimiento de la calidad fisicoquímica de

productos alimentarios



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.



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



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



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



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



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



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



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



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)



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



xTTk

AQ 12 −−=

kxTT/

12 −−=RTT 12 −−=

RTΔ=

R

I

0V RVI 0=

RT

AQ Δ=



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



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



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.



Cp = 4.187[1-Xin(0.57-0.0018)(Tp-20))]



Suplementos nutricionales. Comidas preparadas. Bebidas en polvo. Cereales de desayuno. Mezclas para postres. Mezclas para sopas.



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



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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-

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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.

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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












DRYERS









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



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.












DRYERS









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DRYERS









Vol. 67, Nr. 3, 2002—JOURNAL OF FOOD SCIENCE 1053

Food E

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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).


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.


Contenido de Vitamina C en fresa procesada Tecnologia mediante ventana refractiva y Liofilizada





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)


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.


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


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.











DRYERS









Parámetros cromáticos asociados al cremogenado de fresa procesado Tecnología mediante ventana refractiva y Liofilizada



Table 3—Color measurement results in L*a*b*, darkness factor b*/a*, chromaand hue values for carrot puree.


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



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.


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


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.


Conte

nido d

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Kg A

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Longitud de la banda de secado (m)

Tiempo de secado (m)



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

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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

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Pharmacalcium ascorbatecephalosporinEster-Cmagnesium ascorbatepotassium ascorbate

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The Company REFRACTANCE WINDOW ®



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.



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



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



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Luminancia

Tiempo (min)

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0 10 20 30 40

b*

Tiempo (min)

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a* x

b*/L

Tíempo (min)

Cinéticas de primer orden C = Co exp± kt Cambios de color Orden cero: C = Co± kot



Secado convectivo < Spray Dryer < Liofilizados < Ventana refractiva





Donde no hay abejas

…. Nace el desierto

Documents

Refractance Windows Monteria