In deep-fat frying the food is completely surrounded by the frying fat or oil and different events occur within a few minutes: dehydration of food surface, absorption of fat, formation of flavour compounds, development of surface colour, etc Due to the drastic conditions applied during deep-frying, the frying fat also undergoes degradation Although much work has been done on modifications of used frying fats and oils under different conditions, changes in the fried substrate have been much less studied Particularly, there is minimal information on some physical and chemical aspects of the interactions between frying fats and fried foods In this paper the main changes in the frying fat due to the nature of the food fried in it as well as modifications in the food as a consequence of the fat or oil used as heat transfer medium are reviewed Fat absorption and lipid exchanges are the main physical changes involved Chemical reactions include interaction between food constituents and oxidised lipids as well as hydrolysis of frying fats due to food moisture

Interactions between fat and food during deep-frying

The effects of harvest and extraction methods on the antioxidant content (phenolics, α-tocopherol, and β-carotene) in virgin olive oil

Influence of extraction system, production year and area on Cornicabra virgin olive oil: a study of five crop seasons

Triglyceride, total and 2-position fatty acid composition of Cornicabra virgin olive oil: Comparison with other Spanish cultivars

Traditional Chinese medicine formulas for the treatment of osteoporosis: Implication for antiosteoporotic drug discovery

Separation des esters methyliques polaires et non-polaires par chromatographie sur colonne de gel de silice. La methode est une modification de celle qui est recommandee par l'IUPAC

Métodos analítícos de aplicación en grasas calentadas. I: Determinación de ésteres metílicos no alterados

In this work, the feasibility of a second centrifugation to improve the extraction of the olive paste, in the new two phases system for the extraction of virgin olive oil, has been studied. The study of its influence on the characteristics of the products and byproducts obtained has been carried out. The samples of comparative assays between the first and second centrifugation of recently obtained olive paste and between the first, with second and third centrifugation of stored olive paste has been analyzed. Therefore, a decoloration assay has been developed to study its influence on the different refination processes (physical and chemical procedures). Results obtained evidence the importance of achieving the second centrifugation with the recently obtained olive paste and under moderate temperatures. In these conditions, it is possible to obtain oils with parameters of quality and purity into the legal limits.

https://digital.csic.es/bitstream/10261/26970/1/865.pdf

Caracteristicas de los aceites de oliva de primera y segunda centrifugación

Composition of fatty acids, triacylglycerols and polar compounds of different walnut varieties (Juglans regia L.) from Tunisia.

Lipid exchange during frying of frozen prefried potatoes in high oleic sunflower oil was studied. After 15 frying operations, changes in the major food components, as well as in the fatty acid and triglyceride composition of the lipid fraction of both the food and of the frying oil, were evaluated. From analyses of the fatty acid composition, it is possible to determine the exact contribution made by both the initial food fat and of the frying oil to the lipids in the fried potatoes. Results indicate that the fat composition of fried food depends fundamentally on that of the oil used to fry, more than 90% of the fat content of the food being contributed by the oil. In addition, quantification of the triglyceride species has allowed determination of the gradual changes occurring in the fat composition of the fried food and estimation of the triglycerides that undergo significant changes in some of their acyl groups.

/pdf/intercambio-lipidico-durante-la-fritura-de-patatas-prefritas-4io1rm0pbi.pdf

Intercambio lipídico durante la fritura de patatas prefritas congeladas en aceite de girasol alto oleico

The results of a collaborative study with the participation of Governmental and Olive Oil Industry laboratories is presented. This study was carried out to determine the precision of the analytical methods used for quantifying certain components of olive oils. Samples of virgin olive oil, olive oil and residue olive oil were analysed for total sterols, sterolic composition, trans isomers from fatty acids, waxes and stigmastadienes, using the analytical methods included in the Commission Regulation EEC 2568/91 of the European Union and modifications therein, and in Document TC20/11 of the International Olive Oil Council (1993). The results have been statistically procesed according to the standard ISO 5725-1986 (E).

/pdf/determinacion-de-algunos-parametros-de-pureza-en-aceites-de-zluw9tfkdf.pdf

M. C. Pérez Camino

Papers

Métodos analítícos de aplicación en grasas calentadas. I: Determinación de ésteres metílicos no alterados

Caracteristicas de los aceites de oliva de primera y segunda centrifugación

Composition of fatty acids, triacylglycerols and polar compounds of different walnut varieties (Juglans regia L.) from Tunisia.

Intercambio lipídico durante la fritura de patatas prefritas congeladas en aceite de girasol alto oleico

Determinación de algunos parámetros de pureza en aceites de oliva. Resultados de un estudio colaborativo