Analysis of the Lipid Component and the Sterol Ester Fraction for the Detection of Soft Wheat in Durum Wheat Flour and Pasta

Food adulteration consists of changing the original structure of a food, and so, by its definition, it is a process not admitted by law. Adulterations can not only have commercial consequences, but also hygienic and nutritional ones, and in some cases, they can cause a serious danger to public health. Therefore, it is of great interest to understand and identify the modifications that alter the original chemical composition of a food item (nutrition label). Among the food processing sectors, the pasta food chain is a fascinating production process, which finds its roots in a mixture of a few, simple ingredients; in particular, in its basic formulation to produce pasta, exclusively durum wheat mixed with water is used, while soft wheat and therefore the flour obtained from it are destined for bakeries and the confectionery industry. In this work, a procedure was developed that allows the detection of the possible presence of soft wheat in durum wheat-based products, both in the flour and after the pasta-making process. It is to point out that this adulteration is only commercial fraud and there are no consequences for people’s health. In detail, the method was based on the isolation of the lipid fraction of flours and pastas and using the gas chromatographic analysis of the sterol ester fraction, which were not altered during the pasta-making phase, because they have very high boiling points. Based on the evaluation of some specific ratios between sterol esters, it was possible to trace the percentage of soft wheat present in a mixture with durum wheat, both in flour products and pastas.