Proceedings Volume 2010 (format .pdf) - SimpBTH

(cheese, yoghurt). This method gives useful information for establish the shelf-lifeof dairy products, being a rapid, simple and reproducible method.This method is simply and efficient for terpenes analysis.Gas chromatography coupled with mass spectrometry (GC-MS) is oftenused as an analytical method for analyzing the flavour of foods, but needs samplepreparation.Using dynamic head space-gas chromatography coupled to massspectrometry, it was found that milk collected in highland regions were richer insesquiterpenes than those collected in lowland regions [Error! Bookmark notdefined.].In the case of liquid chromatographic techniques, the stationary phaseconsists of a finely powdered solid adsorbant packed into a thin metal column andthe mobile phase consists of an eluting solvent forced through the column by a highpressure pump. The mixture to be analyzed is injected into the column andmonitored by a detector.Terpene content and profile in milk and dairy products are influenced byfeed and especially by grazed herbage. This relationship could be used todiscriminate milk or cheese originating from grazing or not grazing system and totrace the geographical origin of these products, or production site.Viallon et al. [7] have used firstly dynamic head space to extractmonoterpenes and sesquiterpenes in milk fat, and then gas chromatography toseparate these compounds collected from different cows fed successively withforage containing high and low amounts of terpenes. Their researchers have shown,on the one hand, that a modification of the plant species composition of foragesstrongly influences the proportions and quantities of monoterpenes andsesquiterpenes in milk fat and, on the other hand, that a rapid transfer of thesecompounds takes place.An array of methods can be used for carotenoid analysis. The choice isusually guided by the type of information needed. Generally, the pigment must beextracted before analysis, sometimes from a complex matrix. Therefore, efficientextraction and analytical protocols are requested.Chromatographic methods are the traditional methods to separate andquantify the carotenoids, which, structurally, are polyisoprenoid compounds.A first step is the sample extraction, a lot of solvents being widely used, such asacetone [8,9], tetrahydrofuran [10], n-hexane [11], pentane [12], ethanol [13],methanol [14], chloroform [15], and also, mixtures of solvents, such,dichlorometan : methanol (6:1, v/v) [16], acetone : petroleum ether (50:50, v/v)[17], tetrahydrofuran : methanol (1:1, v/v) [18], [19], n-hexane : toluene (5:4, v/v)[20], n-hexane : acetone (6:4, v/v) [21], 2-propanol : dichlorometan (2 :1, v/v) [22],n-hexane : ethyl acetate (85 : 15, v/v) [23].292