Naslov
Analytical criteria for purity evaluation of virgin olive oil- Application of validation and measurment unertainty for determination of stigmastadienes in vegetable oils

Autori
Petričević, Sandra ; Bogdanović, Tanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
// CEFood2008 Book of Abstracts ; The 2008 Joint Central European Congress, 4th Central European Congress on Food and 6th Croatian Congress of Food Technologists, Biotechnologists, and Nutritionists / Galić, Kata (ur.) - Zagreb : EURO-V.A.L. d.o.o, 2008, 194-194

Skup
The 2008 Joint Central European Congress, 4th Central European Congress on Food and 6th Croatian Congress of Food Technologists, Biotechnologists, and Nutritionists

Mjesto i datum
Cavtat, Hrvatska, 15.05.2008. - 17.05.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Stigmastadienes; measurment uncertainty; validation; ISO 17025

Sažetak
Among the most important performance characteristics of the chemical measurment process are those that can serve as measures of the underlying detection and quantification capabilities. These are essential for applications in research, international commerce, health, and safety. Such measures are important for planning measurments that can meet specified needs, such as the detection or quantification of a regulated level of a specified substance. Virgin olive oil has unique position among edible oils because of its delicate flavour, stability and health benefits. It is producedin restricted areas ( mainly Mediterranean countries), and it is consumed directly without purification. It is, therefore, expensive and it has always been the subject of fraud by mixing with less expensive vegetable oils and olive resiude oil or else traded as a higher grade product. Olive oil analysis is important for checking its geunuineness and assessing its purity. A reliable method for routine use in the determination of stigmastadiene (the dehydration product of β-sitosterol) in vegetable oils (COI/T.20/Doc.no.11/Rev.2, 2001), containing low concentrations of these hydrocarbons, particulary in virgin olive oils, is described. The precision of this method is very important because the legislative regulation for the content of stigmastadienes is not more than 0, 15 mg/kg. ISO 17025 contains clear statements that calibration laboratories shell have and apply procedures for the estimation of uncertainties of measurement. It also requires testing laboratoories to attempt to identify all components of uncertainty and make a reasonable estimation based on knowledge of performance of the method. The aim of this study is to evaluate a measurement uncertainty together with validation parameters for the above mentioned analytical method and to determine the lowest level of adulterant i.e. rafined oils in virgin olive oil on control (reference) samples on the matrix of olive oil from interlaboratory check tests. SMS-Food development centre, klis, has this method under the scope of accreditation. In an effort to ensure the equal quality of the results, find all the possible improvements in the obtained results as well as know better the measurment processes of the method is necessary that the laboratory is awere of uncertainty of measurment in determination of stigmastadienes. Identification and evaluation of sources of uncertainty was followed by a combined and expanded unertainty calculations. For measurment value of 0, 13 mg/kg of stigmastadienes there was determined a combined uncertainty of 0, 008 mg/kg. The eypanded uncertainty, for level of cofidence of 95 % is 0, 025 mg/kg. The greatest part in the combined uncertainty comes from the repeatability. The validation study for this capillary gas chromatography method assumes the limit of detection that is 0, 010 mg/kg and quantification limit that is 0, 020 mg/kg. Analysis of stigmastadiene content made it possible to identify adulterants at levels as low as 0, 55 w/w.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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