High performance liquid chromatography criteria for detecting sophistication with seed oils

12 High performance liquid chromatography criteria for detecting sophistication with seed oils 

The following elementary liquid chromatography (LC) elements could help to understand the method. In LC, triglycerides are separated according to equivalent carbon number (ECN). Elution order is determined by calculating ECN, normally defined as CN-2n, where CN is carbon number and n is the number of double bonds present in the triglycerides (Firestone, 1994). 

In contrast with the fatty acids, where the typical composition permits the uncovering of several types of sophistication, triglyceride molecular species do not represent straightforward data capable of discriminating olive oil from other oils. 

Flor et al. (1993) were the first to develop criteria for the authentication of olive oil based on vegetable oil HPLC data. They observed that corn, cottonseed, soyabean, sunflower and safflower oils, to mention the most important commercial products, have large peaks for LLL, LLO and LLP but generally smaller LOO and LOP peaks (abbreviations P, palmitic O, oleic S, stearic L, linoleic Ln, linolenic Po, palmitoleic). Additional typical peaks were observed LnLL peak (ca. 7%) in soyabean and LnLO peak (ca. 7%) in rapeseed oils, respectively. Other relevant compositional pictures were observed peanut oil displays a relatively small LLL peak (ca. 3.5%) but larger LLO and LLP peaks (ca. 18.2, 5.9%, respectively). 

The paper by Flor el al. (1993) was probably a stimulus for the official method in the EEC regulation 2568/91 for detecting seed oil sophistication of olive oil, defining the difference as ECN42 HPLC — ECN42. 

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