RESUMEN
@#Palm olein (POo) has been perceived as atherogenic due to its high proportion of palmitic acid (41.2%) content. It is interesting that most of the palmitic acid of POo is located at stereospecific numbering sn-1 and sn-3 positions of the triacylglycerol (TAG) backbone. The present study aims to investigate the effects of positional distribution of fatty acids on the lipid profiles of POo or chemically interesterified palm olein (CIE POo) fed hamsters in comparison to high oleic sunflower oil (HOSO) fed hamsters. Male weanling Syrian golden hamsters (n=10 for each group), were fed diets formulated with the above oils for 12 weeks. There was no significant difference between CIE POo and HOSO groups for total cholesterol (TC). CIE POo with increased amount of palmitic acid (43.2%) at sn-2 position did not cause significant increases in TC levels compared to the HOSO group. In addition, the POo group has significantly higher high-density lipoprotein cholesterol (HDL-C) than that of the HOSO group, P = 0.011 (< 0.05) while the HOSO group has significantly lower total cholesterol (TC) levels than that of the POo group, P = 0.012 (< 0.05).
RESUMEN
Objectives: Palm olein, which is the fractionated form of palm oil, is commonly used as cooking oil in Sri Lanka. Processing of crude oil degrades α-tocopherol as does exposure to high heat during cooking. This study was aimed to determine the content and heat degradation of α-tocopherol in Sri Lankan commercially available palm olein. Method: Four different brands of Sri Lankan commercially available palm olein (100 mL) were heated to 180°C for 10 minutes. The oil was subsequently cooled and re-heated five times and assayed in duplicate. Between each cycle of re-heating oil was left in room temperature to cool for 5 hours. Fresh palm olein and the heated samples were analyzed for α-tocopherol content using reversed-phase High-pressure liquid chromatography (HPLC) (Shimadzu, Japan). Results: The mean α-tocopherol content in unheated palm olein was 3.02 ± 0.35 ppm, with no significant differences between brands. Heating Palm olein for 10 minutes resulted in 56.6% reduction in α-tocopherol compared to unheated oil. Re-heating resulted in further reduction with a 100% loss by the fourth time. Conclusion: The Sri Lankan commercially available palm olein did not provide expected α-tocopherol content, and is not a good source of dietary α-tocopherol. Further analysis is required to quantify α-tocopherol content. Since re-heating further reduced α-tocopherol levels, repeated frying during cooking is likely to result in a minimal level of α-tocopherol being provided through palm olein to the diet.
RESUMEN
En 31 comensales regulares del Comedor Universitario de la Universidad Central de Venezuela (CUUCV), en Caracas. Se observó el efecto de la sustitución del aceite de girasol que se utiliza corrientemente en la preparación de las comidas en ese comedor, por un aceite obtenido de la mezcla de aceite de girasol y oleína de palma, en la proporción 70/30 (v/v) respectivamente. Después de 40 días continuos de la sustitución no hubo cambios significativos en las concentraciones de colesterol total (CT), ni del colesterol de las lipoproteínas de baja densidad (LDL) y muy baja densidad (VLDL). La concentración del colesterol de las lipoproteínas de alta densidad (HDL) aumentó significativamente (p<0,05). Los triglicéridos (TG) del plasma aumentaron en un 30%. La resistencia a la oxidación de las LDL aumentó considerablemente (p< 0,01). Hoy se considera a esta resistencia como un factor protector de gran importancia en la prevención del inicio del proceso aterogénico. Tomando en cuenta las modificaciones favorables como el aumento de colesterol de HDL sin modificación de la LDL y el claro aumento de la resistencia a la oxidación de la LDL, se considera que la oleína de palma es un aceite vegetal que puede ser utilizado sin mayores riesgos en mezcla con otros aceites que tengan una relación linoleico/palmítico más elevada como los aceites de girasol, maíz, soja y otros.
We analyzed in 31 subjects, regular guests of the University food service of the Central University of Venezuela (UCVFS), in Caracas, the effects of replacing sunflower oil, commonly used in the preparation of meals, by a mix of sunflower oil and palm olein 70/30 (v/v) respectively. Plasma concentrations of total cholesterol, low and very low density lipoproteins were not changed after 40 days of the substitution. On the contrary, concentrations of high density lipoprotein and total triglycerides increased. The resistance to the oxidation of low-density lipoproteins increased considerably (p<0, 01). Today this resistance is considered as a protective factor of great importance in the prevention of the initiation of the atherogenic process. Taking into account the favorable modifications of HDL cholesterol and the clear increased resistance to the oxidation of LDL, we think that palm olein, mixed with other oils with a high ratio linoleic/palmític (sunflower, corn, soya an the likes), can be used as a healthy alternative in human nutrition.