Physical Properties of Foods and Food Processing Systems

Michael, Lewis

doi:10.1533/9781845698423

Cited by 157 publications

(110 citation statements)

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“…The obtained values for density and refractive index are in line with those reported in literature (2,3,4,16). Viscosity values were similar to those for cottonseed and olive oils and higher than those for corn, peanut and safflower oils (15,17). The measured iodine values were similar to those reported previously by Lazos (4) …”

Section: Resultssupporting

confidence: 89%

Characterization of crude and purified pumpkin seed oil.

1997

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RESUMENCaracterización de aceite de semilla de calabaza crudo y purificado.Aceite de semillas de calabaza descascarada (Cucúrbita pepo y Cucúrbita maxima) fue extraído con éter de petróleo caliente, y luego desgomado, neutralizado y decolorado consecutivamente. Las características físicas y químicas de aceites crudo y purificado fueron determinadas. La densidad, el índice de refracción, la viscosidad y el índice de peróxido no se afectaron por la purificación, mientras que se observó una disminución en la acidez, color, insaponificable, E1% ^cm 232, y estabilidad oxidativa, y un aumento en el punto de humo y de E1% -i cm 270. La purificación no afectó los perfiles de ácidos grasos y esteróles. El análisis CGL para la composición de ácidos grasos del aceite de semilla mostró que los insaturados predominantes fueron linoleico (42%) y oleico (38%), mientras que los saturados mayoritarios fueron palmítico (12,7%) y esteárico (6%). Sólo el a-tocoferol fue detectado a nivel de 126mg/kg, el cual se redujo a 78mg/kg después de la purificación. Los principales esteróles de la materia insaponificable del aceite de semilla de algodón fueron A7-22,25 -stigmastatr¡en-3(3-ol, a-spinasterol, A7.25-stigmastadienol y A^ -avenasterol, seguidos por el stigmasterol, 24-metilcolest-7-enol y A''-stigmastenol, y también se encontraron trazas de componentes menores de colesterol, brasicasterol, campesterol, sitostanol, A^-avenasterol, eritrodiol y uvaol. PALABRAS-CLAVE: Aceite de semilia de calabazaCaracterística física -Característica química -Refinación. SUMMARY Characterization of crude and purified pumpkin seed oil.Oil from hulled pumpkin seeds (Cucúrbita pepo and Cucúrbita maxima) was extracted with hot petroleum ether, and then it was degummed, neutralized and bleached, consecutively Physical and chemical characteristics of crude and purified oils were determined. Density, refractive index, viscosity and peroxide value were not affected by purification, while decreases in acidity, colour, unsaponifiable, £1% ^cm 232, and oxidative stability, and increases in smoke point and E1% icm 270 were observed. Purification did not affect the fatty acid and sterol profiles. GLC analysis for the fatty acid composition of the seed oil showed that the predominant unsaturates were linoleic (42%) and oleic (38%), while the major saturates were palmitic (12,7%) and stearic (6%). Only a-tocopherol was detected at a level of 126 mg/kg, which reduced to 78 mg/kg after purification. The main sterols of pumpkin seed oil unsaponifiable were A7.22,25^ -stigmastatrien-3(3-ol, a-spinasterol, A7,25_stigmastadienol and A^-avenasterol, followed by stigmasterol, 24-methylcholest-7-enol and A^-stigmastenol, and also trace to minor amounts of cholesterol, brassicasterol, campesterol, sitostanol, A^-avenasterol, erythrodiol and uvaol were found. KEY-WORDS:Ctiemical ctiaracteristic -Physical characteristic -Pumpkin seed oil -Refining.

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Section: Resultssupporting

confidence: 89%

Characterization of crude and purified pumpkin seed oil.

1997

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“…According to the authors, decreasing the moisture content during extrusion resulted in increased expansion and decreased density and breaking strength of extrudates. Extrusion is a process which combines several unit operations including mixing, cooking, kneading, shearing, shaping and forming (Lewis, 1987). Usually the food is compressed and worked to form a semi-solid mass.…”

Section: Introductionmentioning

confidence: 99%

“…This is then forced through a restricted opening (the die) at the discharge end of the screw. The main purpose of extrusion is to increase variety of foods in the diet by producing a range of products with different shapes, textures, colours, and flavours from basic ingredients (Lewis, 1987).…”

Section: Introductionmentioning

confidence: 99%

Optimization of Physical and Functional Properties of Sorghum-Bambara Groundnut Extrudates

Gbenyi¹,

Nkama²,

Badau³

2016

JFR

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Blends of sorghum and Bambara groundnut flour at 90:10, 80:20 and 70:30 ratios respectively, were extruded at 20%, 22.5% and 25% moisture levels and 120 o C, 140 o C and 160 o C barrel temperatures using a single-screw extruder. Response surface methodology with central composite face-centered (CCF) design was used to model the viscosity, water absorption index (WAI) water solubility index (WSI), sectional expansion index (SEI), bulk density (BD), apparent specific volume (ASV) and mass flow rate of the extrudates. , and 1.19 to 2.3 g/s respectively. The R 2 values were 0.83, 0.71, 0.55, 0.61, 0.66, 0.77 and 0.61 respectively with a non-significant lack of fit; except for viscosity. Plots of residuals against fitted values showed that residuals were randomly scattered in all cases, thus validating the empirical models for the responses. The optimum amount of Bambara groundnut flour, feed moisture and extrusion temperature were established for viscosity, WAI, SEI, BD, ASV and MFR of the extrudates. Feed moisture had the most effect on extrudates functional and physical properties followed by extrusion temperature.

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“…Propiedades físicas, termodinámicas y de transporte como densidad, capacidad calorífica, viscosidad y conductividad térmica son requeridas en diversos cálculos en ingeniería, tales como diseño de bombas, intercambiadores de calor, columnas de absorción, evaporadores, columnas de destilación, y secadores, entre otros (Lewis, 1987;Heldman y Lunn, 1992).…”

Section: Introductionunclassified

“…En algunos casos específicos y con ciertas limitaciones, el modelo puede ser "linealizado" mediante redefinición de las variables involucradas en el modelo, pero en la mayoría de las situaciones dicha linealización no es posible, sin una sobre simplificación del problema. Para las propiedades consideradas en este trabajo existen diversos modelos en la literatura pero no han sido estudiados en forma rigurosa con un modelo simple y general como el que se presenta en este estudio (Lewis, 1987).…”

Section: Introductionunclassified

Correlación de Propiedades de Aceites Vegetales y Sebo Vacuno Usando Aproximantes de Padé

Guerrero¹,

Toselli²,

Valderrama

2008

Inf. tecnol.

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ResumenSe han utilizado los aproximantes de Padé para correlacionar algunas propiedades necesarias para el diseño y modelado de intercambiadores de calor de tubo y coraza usados en procesos de elaboración de aceites vegetales y sebo vacuno y en la producción de biodiesel, entre otras aplicaciones. Los aproximantes de Padé son funciones racionales que tienen la capacidad de representar funciones complejas con un número reducido de parámetros. Se ha considerado la densidad, el calor específico, la viscosidad y la conductividad térmica de estas sustancias y se han determinado los parámetros del modelo estudiado usando datos experimentales de estas propiedades. El modelo de Padé usado muestra ser adecuado para el cálculo de las propiedades estudiadas obteniendo desviaciones similares o inferiores a otros modelos altamente no lineales. Palabras clave: aproximantes de Padé, aceites vegetales, sebo vacuno, biodiesel Correlation of Vegetable Oil and Beef Tallow Properties Using Padé Approximants AbstractPadé approximants have been used to correlate some properties needed in the modeling and design of shell and tube heat exchangers used in the production of vegetables oils, beef tallow and biodiesel. Padé approximants are rational functions that have the capacity of representing complex functions with a reduce number of parameters. The properties considered were density, specific heat, viscosity and thermal conductivity of these substances and model parameters were determined using experimental data from the literature. The proposed general Padé model shows to be adequate to estimate the properties studied, obtaining deviations similar or lower than those of other highly non-linear models.

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Physical Properties of Foods and Food Processing Systems

Cited by 157 publications

References 0 publications

Characterization of crude and purified pumpkin seed oil.

Characterization of crude and purified pumpkin seed oil.

Optimization of Physical and Functional Properties of Sorghum-Bambara Groundnut Extrudates

Correlación de Propiedades de Aceites Vegetales y Sebo Vacuno Usando Aproximantes de Padé

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