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The aim of this investigation was to evaluate the influence of certain variables of the process of deep fat frying on the lipid profile of the fat fraction of the potato type “french” (Solanum tuberosum) using palm oil. This marked the first fat fraction of both the processing type and the oil used, through the evaluation of various physicochemical parameters, using the method of AOAC and the Standard COVENIN. We identified variables that influenced the process during frying of potatoes, using an experimental design of type 3 * 22, evaluating factors such as the reuse of the matrix fat (1st, the 4th and the 8th fry), temperature (150° and 180 °C) and method of food peeling (chemical and manual), studying the content of polar compounds as an indicator of the deterioration of the fat present in the potato, finding that oil reuse and peeling method significantly influenced in a positive manner, and that the temperature has a negative influence on the absorption of polar compounds in potato chips (α: 0.05).El objetivo de la presente investigación fue evaluar la influencia de ciertas variables del proceso de fritura en profundidad sobre el perfil lipídico de la fracción grasa de la patata tipo “french” (Solanum tuberosum), empleando oleína de palma. Para ello se caracterizó inicialmente la fracción grasa tanto de la patata como de la oleína utilizada, a través de la evaluación de diferentes parámetros fisicoquímicos, empleando para ello métodos de la A.O.A.C. y las Normas COVENIN. Se identificó las variables del proceso que más influían durante la fritura de las patatas, aplicando un diseño experimental del tipo 3*22, evaluando como factores; la reutilización de la matriz grasa (1ra, 4ta y 8va fritura), la temperatura (150° y 180 °C) y tipo de pelado del alimento (químico y manual), estudiando el contenido de compuestos polares como indicador de deterioro de la grasa presente en la patata, encontrando que la reutilización y el tipo de pelado influyen significativamente de manera positiva, y que la temperatura tiene una influencia negativa en la absorción de compuestos polares en las patatas fritas (α: 0.05).

Olive oil, sunflower oil and palm olein, unused or used in repeated potato frying until the oils reached the limit of 25% of polar compounds (PC) were used. Wistar rats were fed over 28 days diets containing 8% of: olive oil, olive oil from 48 fryings, olive oil from 69 fryings (25% PC), sunflower oil, sunflower oil from 48 fryings (25% PC), palm olein and palm olein from 80 fryings (25% PC) Body weight and food intake were monitored weekly and food efficiency was calculated. At the end of the experiment the animals were sacrificed to separate the liver and calculate the hepatosomatic index. The consumption of frying oils did not modify food Intake, body weight food efficiency nor liver weight but hepatosomatic index was higher in rats consuming frying palm olein compared to unused palm olein.Se utilizaron aceites de oliva, girasol y oleína de palma, crudos o procedentes de frituras repetidas de patatas sin reposición de aceite hasta alcanzar el límite del 25% de compuestos polares (CP). Ratas Wistar se alimentaron durante 28 días con dietas que contenían un 8% de: aceite de oliva, aceite de oliva de 48 frituras, aceite de oliva de 69 frituras (25% CP), aceite de girasol, aceite de girasol de 48 frituras (25% CP), oleína de palma y oleína de palma de 80 frituras (25% CP). Peso e ingesta se controlaron semanalmente y se calculó el coeficiente de eficacia alimentaria. Al final del experimento los animales se sacrificaron para extraer los hígados y determinar el índice hepatosomático. El consumo de los aceites empleados en fritura no modificó la ingesta, peso, coeficiente de eficacia alimentaria ni el peso de los hígados, observándose únicamente un incremento del índice hepatosomático en los animales que ingirieron la oleína de palma frita frente a la cruda.

Storage studies were carried out to define the behaviour of both conventional and high oleic sunflower oils in the industrial preparation of crisps and prefried french fries. Samples of crisps and prefried french fries were stored during 6 and 21 months, respectively, and evolution of oxidation was compared with that of the more saturated fats normally used for the preparation of both products, i.e., palm olein and hydrogenated rapeseed/palm oil mixture. Total oxidation compounds, α-tocopherol content, as well as monomeric and dimeric triglycerides, were quantitated in lipids from fried products after different time periods. Results obtained for crisps at room temperature indicated that only conventional sunflower oil underwent significant oxidation after 6 months. In the case of prefried french fries, maintained at freezer temperatures, no appreciable changes were found after 21 months storage, thus indicating that both sunflower oils can be good alternatives to saturated fats.

A selected and trained descriptive sensory panel has assessed samples of crisps and French fries prepared on an industrial scale with either sunflower oil (SO) or high oleic sunflower oil (HOBO). Furthermore, crisps have been fried in these oils with or without dimethyl polysiloxane (DMPS). Reference samples were prepared using palm olein (PO) or hydrogenated rapeseed/palm oil mixture (RP). Crisps were stored at ambient temperature for six months and French fries at -20°C for 12 months. At regular intervals the samples were assessed. Crisps prepared in SO have a lower sensory quality than those prepared in PO. Frying in HOSO resulted in crips comparable with those fried in PO. The differences found in this study concerning the mouthfeel or texture were thought not to be caused by the application of different oils. The addition of DMPS did not have any positive effect on the storage quality of crisps fried in SO or HOSO. Frying of French fries in HOSO and especially in SO, in comparison with RP, resulted in a product with a typical sweet fruits odour and flavour. During storage these sensory attributes decreased in intensity. As this finding might be an artefact of this study, further research is needed.

This study evaluated some changes occurring in double fractionated (DF) palm olein during heating. DF palm olein was heated at 180°C for 60 hr (4hr/day) with no added source of water. Heated oil samples were analyzed for refractive index (Rl), viscosity, colour change, dielectric constant change (DCC), acid value (AV), peroxide value (PV), iodine value (IV) and unsaponifiable matter (UM) constituents. The results indicated that, viscosity, colour, DCC and AV gradually increased, while IV gradually decreased with increasing heating time. The study showed also that heating times correlated with increases in DCC, viscosity and AV. PV increased ca 17-fold, reached a maximum at 16 hr, then gradually decreased to remain relatively constant through the last 20 hr of heating. Chromatographic analysis illustrated that UM components changed qualitatively and quantitatively due to the heating treatment.Este estudio evaluó algunos cambios ocurridos en oleína de palma doblemente fraccionada (DF) durante el calentamiento. La oleína de palma se calentó a 180°C durante 60 horas (4 horas/día) sin adición de agua. Las muestras de aceite calentado se analizaron por: índice de refracción (IR), viscosidad, cambio de color, cambio en la constante dieléctrica (DCC), índice de acidez (AV), índice de peróxido (PV), índice de iodo (IV) y materia insaponificable (UM). Los resultados indicaron que, viscosidad, color, DCC y AV experimentan un incremento gradual, mientras que el IV disminuye con el aumento del tiempo de calentamiento. El estudio mostró también que los tiempos de calentamiento se correlacionan con los aumentos en DCC, viscosidad y AV. El índice de peróxido aumentó aproximadamente 17 veces, mostrando un máximo a las 16 horas, disminuyendo luego gradualmente y permaneciendo relativamente constante durante las últimas 20 horas de calentamiento. El análisis cromatográfico ilustró que los componentes UM cambiaron cualitativamente y cuantitativamente debido al tratamiento por calor.

Sprague-Dawley rats were fed for a total period of 8 weeks on six diets that were different in the source of their fat content. The fat content was provided either, palm oil or palm olein or corn oil or hydrogenated fat, or frying palm oil and mixture of corn oil + hydrogenated fat in the ratio (1:1). The latter was given to the control group. Animals fed these various experimental diets showed statistically significant differences in serum cholesterol and serum triglycerides content among all group. Increased HDL-cholesterol content was evident in animals fed on palm-olein and palm oil. The frying oil fed group showed lowest HDL-cholesterol content. In these experiments palm olein fed animals showed highest ratio of HDL-cholesterol to total cholesterol while the lowest ratio was shown in rats fed on frying oil. Prothrombin (PT) and activated partial thromboplastin time (PTT) showed higher values In palm oil, palm olein and corn oil diets as compared to all groups with each other.Ratas Sprague-Dawley fueron alimentadas durante un periodo total de 8 semanas con seis dietas diferentes en su contenido graso. El contenido graso fue proporcionado por aceite de palma u oleína de palma o aceite de maíz o grasa hidrogenada o aceite de palma de fritura y mezcla de aceite de maíz + grasa hidrogenada en la relación (1:1). El último fue dado al grupo de control. Los animales alimentados con las diferentes dietas experimentales mostraron diferencias significativas estadísticamente en el contenido en colesterol y triglicéridos en suero entre todos los grupos. El aumento en contenido HDL-colesterol fue evidente en animales alimentados con oleína de palma y aceite de palma. El grupo alimentado con aceite de fritura mostró el más bajo contenido en HDL-colesterol. En estos experimentos, los animales alimentados con oleína de palma mostraron la mayor relación de HDL-colesterol a colesterol total, mientras que la relación más baja fue mostrada en ratas alimentadas con aceite de fritura. El tiempo de protrombina (PT) y tromboplastina parcialmente activada (PTT) mostró valores elevados en dietas de aceite de palma, oleína de palma y aceite de maíz al comparar estos grupos con los demás.