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Determination of free fatty acids in cheese: comparison of two analytical methods
- FELISA CHAVARRI, MAILO VIRTO, CELIA MARTIN, ANA I. NÁJERA, ARANTZA SANTISTEBAN, LUIS J. R. BARRÓN, MERTXE DE RENOBALES
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- Journal:
- Journal of Dairy Research / Volume 64 / Issue 3 / August 1997
- Published online by Cambridge University Press:
- 01 August 1997, pp. 445-452
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- August 1997
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Two methods were compared for the determination of free fatty acids (FFA) from acetic to long-chain acids in samples with a large excess of triacylglycerols (TG) (1[ratio ]200, w/w), such as cheese and other dairy products. In method 1, after fat extraction, FFA were separated from TG by aminopropyl-bonded phase chromatography, injecting the fraction containing FFA directly into the gas chromatograph. In method 2, extracted fat was treated with tetramethylammonium hydroxide, the methyl ester derivatives being formed in the injector. Cheese samples and standard mixtures of FFA and TG in different proportions were analysed by both methods. The cheese sample contained 2·4 times more FFA when analysed by method 2 as compared with the result obtained with method 1. The composition of the standard mixtures analysed by method 1 closely reflected that of the original mixture and gave 90–100% recovery of FFA, regardless of their chain length and the ratio of FFA[ratio ]TG (1[ratio ]1 or 1[ratio ]200, w/w). The composition of samples with a FFA[ratio ]TG ratio of 1[ratio ]200 (w/v) was severely distorted (as compared with the original composition of the sample) when analysed by method 2. Varying recoveries of FFA were also obtained, the largest differences being found for the shorter-chain components. We conclude that the FFA fraction should be separated from the TG fraction before derivatization and chromatographic analysis, particularly for samples in which the FFA represent a minor fraction of the TG.
W3 - South-western Duero and Ciudad Rodrigo basins: infill and dissection of a Tertiary basin
- Edited by Peter F. Friend, University of Cambridge, Cristino J. Dabrio, Universidad Complutense, Madrid
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- Tertiary Basins of Spain
- Published online:
- 04 August 2010
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- 26 January 1996, pp 196-202
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Summary
Abstract
In the south-western sector of the intracontinental Duero Basin, the post-Hercynian sedimentary record consists of Upper Cretaceous to Quaternary terrestrial sediments. Climates shifted from tropical, with poorly defined seasons (end of Cretaceous), to Mediterranean (Neogene). Tertiary deposits are divided into three tectonostratigraphic complexes. The Late Cretaceous–Paleocene, related to the end of the Mesozoic cycle, is characterised by a well-developed weathering profile that was eroded later. The Eocene–Oligocene, formed during the morpho-structural definition of the actual basin boundaries, consists of three unconformity-bounded units related to successive tectonic events of the Alpine Orogeny; by the end of this cycle, progressive incision of the Atlantic fluvial network led to capture of the fluvial systems of the southern Duero Basin and degradation (emptying) began. The Miocene–Pliocene, related to an extensional tectonic regime, represents the spreading of exorheic conditions to the whole basin that marked a complete hydrographic reorganisation. Deposition and aggradation continued in more central areas of the basin until the end of the Neogene, coeval with degradation of the south-western corner of the Duero Basin. The coexistence resulted from differential subsidence, hinge lines (uplift zones) separating sub-basins, and the dynamics of capture processes.
Introduction
The Duero Basin has been considered as an intracratonic basin (sensu Sloss & Speed, 1974). 1974). Its north, south and east margins are moderately technically active mountain ranges, whereas the western boundary is a relatively flat Hercynian border that remained essentially passive during Cainozoic times (Fig. 1). Outcrops of Paleogene sediments occur only at the edges of the basin, whereas Neogene deposits are best represented towards the inner parts of the basin.
W2 - Alpine tectonic framework of south-western Duero basin
- Edited by Peter F. Friend, University of Cambridge, Cristino J. Dabrio, Universidad Complutense, Madrid
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- Tertiary Basins of Spain
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- 04 August 2010
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- 26 January 1996, pp 188-195
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Summary
Abstract
The tectonic activity in the south-western area of the Spanish Northern Meseta (Ciudad Rodrigo and Duero basins) during most of the Tertiary was determined by a transpressive regime that reactivated Hercynian to Late-Hercynian faults. The record of the Alpine Orogeny is complex because the sedimentary record indicates a compressive regime in the source areas coeval with the extensional to transpressive regime indicated by normal or strike-slip faults. This duality is due to the geotectonic position of this area between two compressive areas, the Cantabrian Range and the Central System, and the extensional Atlantic margin.
Introduction
The Duero basin is an intracontinental basin of cratonic type (sensu Sloss & Speed, 1974) bounded by mountain ranges that evolved relatively independently during the Tertiary (Fig. 1).
The northern border is the Cantabrian Mountains, made up of Mesozoic and Palaeozoic rocks affected by thrusts and low-angle reverse faults. Its history is related to the Alpine evolution of the Pyrenees.
The eastern border is the Iberian Range that extends between the Pyrenees and the Betics, the main Spanish compressive orogens.
The southern border is the Central System, bounded by high-angle reverse and strike-slip faults of Hercynian to Late Hercynian age, reactivated during Alpine Orogeny.
The western border is the Palaeozoic metasedimentary and igneous rocks of the western Spanish Meseta. It has a relatively passive tectonic history but was affected by the evolution of the Atlantic margin.
W6 - Lacustrine Neogene systems of the Duero Basin: evolution and controls
- Edited by Peter F. Friend, University of Cambridge, Cristino J. Dabrio, Universidad Complutense, Madrid
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- Tertiary Basins of Spain
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- 04 August 2010
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- 26 January 1996, pp 228-236
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Summary
Abstract
Vertical aggradation of Neogene fluvial and lacustrine deposits occurred until the Late Neogene in central and northern areas of the Duero Basin, coeval with river incision in the southwestern corner of the basin. The whole basin became exorheic in the Latest Neogene. We have differentiated five tectonosedimentary units (TSUs) of basinal extent, bounded by unconformities or breaks in the sedimentary record. Deposits in each TSU consist of alluvial-fan deposits in areas close to the active northern and eastern margins, and fluvial deposits along the western margin. These systems converged in the lower, subsiding areas of the basin occupied by carbonate-evaporite lacustrine systems.
Tectonics and climate controlled sedimentation. The main faults active from the Neogene to the Present reflect Late Hercynian basement fractures that were re-activated during the Alpine Orogeny, both fracturing blocks and modifying landscapes, and creating or modifying the areas of subsidence. Analysis of climatic variations during the Miocene shows that deposition of saline materials occurred in dry TSUs (1,2) and, particularly, in humid TSUs (3, 4). Climate does not seem to have been a determining factor for the formation of evaporites. However, it was a very important factor in determining both the amount of water that reached the basin and, eventually, also the extent of the lacustrine systems.
W7 - North-western Cainozoic record: present knowledge and the correlation problem
- Edited by Peter F. Friend, University of Cambridge, Cristino J. Dabrio, Universidad Complutense, Madrid
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- Tertiary Basins of Spain
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- 04 August 2010
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- 26 January 1996, pp 237-246
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Summary
Abstract
Tertiary deposits of the north-western Iberian Peninsula are heterogeneous because they occur in several morpho-structural positions as isolated and dispersed basins and outcrops. The quality of the palaeontological record is usually very poor and there are scarce data. Correlation depends on a wide range of criteria which are not always equivalent: palaeontology, mineralogy and petrology, geomorphology, tectonics and comparison with better-known and better-dated facies in regions nearby. The results lack homogeneity and there are notable discrepancies.
Introduction
Tertiary sediments of Galicia, Bierzo and the Cantabrian Range (north-western Spain) occur in small basins and isolated outcrops.
Galicia Basins
Many geographical features and the Tertiary basins of Galicia are related to fault-systems trending N–S, NNE–SSW, NE–SW, E–W and WNW NW–ESE SE (Fig. 1).
Lugo Basins
The most important outcrops of Tertiary sediments in Galicia are located in Lugo, between the central peneplain and the eastern mountains. The main basins (Terra Cha, Sarria and Monforte) are asymmetrical: Tertiary sediments rest unconformably upon Palaeozoic rocks in the west and are separated from crystalline basement (igneous rocks) by N20–30 and N50–60 faults (Fig. 2).
The sedimentary fills of the Sarria and Monforte basins, up to 200 m thick, have been divided in various stratigraphical schemes (Birot & Sole, 1954; Brell & Doval, 1974, 1979; Virgili & Brell, 1975; Martin-Serrano, 1979, 1980, 1982; del Olmo, 1986; Vergnolle, 1984, 1985, 1987, 1990) with several lithostratigraphic units which were grouped into the Monteforte Formation (Vergnolle, 1988).
W1 - The Duero Basin: a general overview
- Edited by Peter F. Friend, University of Cambridge, Cristino J. Dabrio, Universidad Complutense, Madrid
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- Tertiary Basins of Spain
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- 04 August 2010
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- 26 January 1996, pp 183-187
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Summary
Abstract
The Duero basin occupies a large area in the north-west of the Iberian Peninsula. It has an approximately quadrangular shape, and three of its four corners are the sites of distinctive sub-basins that extend outwards from the main basin. The different margins of the sub-basins and the main basin tend to have distinctive histories of tectonic and sedimentary evolution.
Introduction
The Duero Basin is the largest Cenozoic basin in Spain with a surface area of almost 50000 km2. It occupies the major part of the north-west Iberian Peninsula. High-relief mountains composed of igneous and metamorphic rocks of Paleozoic age (mainly to the south and west) and siliciclastic and carbonate rocks of Mesozoic age (mainly to the east) bound the basin (Fig. 1). These borders formed during the Alpine Orogeny and played an important role in the geodynamic evolution of the basin.
The roughly quadrangular basin extends into three relatively narrow basins protruding near the corners (Fig. 1).
– The Ciudad Rodrigo Basin, in the south-western corner, is a half-graben oriented NE–SW that penetrates south-westerly into the Hercynic Massif. Its sedimentary record consists mainly of Paleogene deposits, although no Early Paleogene deposits have been found so far.
– The Almazán Basin is a complex area that extends to the east between the Iberian Range and the Central System. It was filled by siliciclastic and carbonate sediments, along with some rare evaporites, of Paleogene and Neogene age.
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