Consequences of microwave heating and frying on the lipid fraction of chicken and beef hamburgers

Two types of commercial meat patties were analyzed to evaluate the effect of two applied cooking methods on the lipid fraction and the cholesterol oxidation process during heating. Microwave heating hardly modified the fatty acid profiles of both chicken and beef patties, whereas frying in olive oil increased oleic and eicosapentaenoic acids and decreased linoleic and docosahexaenoic acids in both types of products. Frying improved the omega6/omega3 fatty acids ratio in beef patties from 10.67 (raw) to 5.37 (fried). Total cholesterol oxidation product (COP) increments were 5.3-6.1-fold with microwave heating and 1.5-2.6-fold with frying. Chicken patties, raw and cooked, had a COP content twice as high as the corresponding beef ones

Evaluation of the nutritional aspects and cholesterol oxidation products of pork liver and fish patés

A comparative study between traditional patés elaborated with pork liver and fish patés (salmon, anchovy and cod) was carried out. The nutritional value and their security related to cholesterol oxidation products (COP) content were evaluated. Salmon paté showed similar fat content (24-28%) and energetic value (300Kcal/100g) to pork liver patés, whereas patés made with anchovy and cod showed less fat (13-16%) and calories (200-236 Kcal/100g). PUFA/SFA ratios were much higher in all fish patés (1.55-4.95) than in liver pork patés (0.36-0.44). No great differences were found in ω-6/ω-3 ratio between salmon and pork liver patés (11.34-18.4), being even much higher this ratio in anchovy (32.32) and cod patés (62.77). EPA and DHA supply was around 0.63 for salmon, 0.21 for anchovy and 0.07 for cod patés. Cholesterol amounts were lower in fish patés (31-37mg/100g) than in pork liver patés (77-102mg/100g). Total COP ranged 0.38-2.83ppm, without clear differences between pork liver and fish patés

Óxidos de colesterol en alimentos cocinados con presencia habitual en nuestra dieta

Cholesterol oxidation products (COPs) have shown different toxic effects and are involved in the development of atherosclerosis. These compounds can be found in animal organisms, and inconsequence in animal origin foods, and they are susceptible to be absorbed from the diet. Their formation in foods would be increased by high temperatures and the presence of oxygen, as it is a chemical oxidation process. In this paper, an estimation of the presence of COPs in different types of foods treated by different cooking technologies are shown. Also different storage conditions are studied. The analysis was carried out by gas chromatography- mass spectrometry. Both fish (salmon and shrimps) and meat (hamburgers, breast chicken, pork loin and frankfurters) showed low COPs values in raw products (0.003-0.552 mg/100 g food), increasing significantly after the application of cooking technologies (up to 0.7 mg/100 g food). Microwave treatment leaded to the highest increase of COPs in comparison to frying, grilling and roasting. Vacuum storage dramatically decreased COPs formation with regard to aerobic storage. Freezing minimized COPs formation more efficiently than refrigeration.Los productos de oxidación del colesterol (COPs) poseen demostrados efectos tóxicos y están implicados en el desarrollo de aterosclerosis. Pueden estar presentes en organismos animales y por ende, en alimentos de origen animal, siendo susceptibles de ser absorbidos a través de la dieta. Su formación en los alimentos se favorecería, al tratarse de un proceso de oxidación química, por la elevación de la temperatura y la presencia de oxígeno. En este trabajo se presenta una estimación de la presencia de COPs en diferentes tipos de alimentos cocinados mediante diferentes tecnologías culinarias y almacenados mediante distintas modalidades de conservación. El análisis se llevó a cabo por cromatografía de gases-espectrometría de masas. Tanto pescados (salmón y langostinos) como carnes (hamburguesas, pechugas de pollo, lomo y salchichas tipo frankfurt) mostraron valores bajos de COPs en crudo (0.003-0.552 mg/100 g alimento), incrementándose significativamente tras el cocinado (hasta 0.7 mg/100 g alimento). El cocinado con microondas supuso el mayor incremento de COPs en comparación con la fritura, plancha y asado. El almacenamiento a vacío disminuyó drásticamente la formación de COPs respecto al almacenamiento en aerobiosis. La congelación ralentizó más eficazmente la formación de COPs que la refrigeración

Óxidos de colesterol en langostinos frescos y congelados, crudos y a la plancha

Los óxidos de colesterol (COPs) se relacionan con diferentes efectos tóxicos entre los que destacan su implicación en los procesos de aterosclerosis. Se estudió la presencia de óxidos de colesterol en langostinos comercializados en fresco y en congelación, tanto en crudo, como sometidos a una tecnología culinaria habitual (plancha). La determinación se realizó por cromatografía de gases acoplada a espectrometría de masas (CG-EM). En los langostinos frescos se detectaron todos los COPs analizados con excepción del 7-hidroxicolesterol, presentando una cantidad total de 33,15 μg COPs/g grasa. Por el contrario, en los langostinos comercializados congelados sólo se detectaron el 7-ketocolesterol y el 7-hidroxicolesterol, dando lugar a una cantidad total de 2,38 μg COPs/g grasa. Estos resultados indican la gran efectividad de la comercialización bajo condiciones de congelación de este tipo de alimentos en cuanto a ralentizar la formación de COPs. El tratamiento culinario incrementó el contenido de COPs en ambos tipos de langostinos, alcanzando 55,43 μg COPs/g grasa en los frescos y sólo 13,06 μg COPs/g grasa en los congelados.Cholesterol oxidation products (COPs) have been related to different toxic effects, being the atherosclerotic process one of the best known. The presence of cholesterol oxides in freshly and frozenly commercialised shrimps, both raw and grilled, was studied. The determination was made by gas chromatography-mass spectrometry (GCMS). Fresh shrimps showed significant amounts of all analysed COPs, except for 7-hydroxycholesterol, accounting in total for 33.15 μg COPs/g fat. In contrast, in frozen commercialised shrimps only 7-ketocholesterol and 7-hydroxycholesterol were detected. These results point out the great effectiveness of the commercialisation of this type of products under freezing, in terms of to the minimisation of the COPs formation. The cooking method (grilling) increased the COPs content in both types of shrimps, reaching 55.43 μg COPs/g fat in fresh shrimps and only 13.06 μg COPs/g fat in frozen ones

Evaluation of the nutritional aspects and cholesterol oxidation products of pork liver and fish patés

A comparative study between traditional patés elaborated with pork liver and fish patés (salmon, anchovy and cod) was carried out. The nutritional value and their security related to cholesterol oxidation products (COP) content were evaluated. Salmon paté showed similar fat content (24-28%) and energetic value (300Kcal/100g) to pork liver patés, whereas patés made with anchovy and cod showed less fat (13-16%) and calories (200-236 Kcal/100g). PUFA/SFA ratios were much higher in all fish patés (1.55-4.95) than in liver pork patés (0.36-0.44). No great differences were found in ω-6/ω-3 ratio between salmon and pork liver patés (11.34-18.4), being even much higher this ratio in anchovy (32.32) and cod patés (62.77). EPA and DHA supply was around 0.63 for salmon, 0.21 for anchovy and 0.07 for cod patés. Cholesterol amounts were lower in fish patés (31-37mg/100g) than in pork liver patés (77-102mg/100g). Total COP ranged 0.38-2.83ppm, without clear differences between pork liver and fish patés