Characterization and Effect of Refining on the Oil Extracted from Durum Wheat By-Products

Abstract

Durum wheat is one of the most important cereal grains worldwide, used mostly for pasta making and bakery products. The by-products derived for the milling process, although very abundant, have only limited use. The aim of this work was to characterize the oils extracted from the by-products of debranning (DP) and milling processes (MP) of durum wheat and to follow the changes due to the refining process on the minor components. The results showed that DP had significantly higher oil content than MP, but it was characterized by a significantly lower amount of tocols. Polyunsaturated fatty acids content was similar (around 62% of total fatty acids). Consequently, a mixture of DP/MP (60/40 w/w) was chosen as a basis for further studies concerning the refining process. During refining, carotenoids almost disappeared while tocols were reduced by 24% on average. Free fatty acids, peroxide value, and oxidized triacylglycerols were significantly reduced by refining, while triacylglycerol oligopolymers were significantly higher than the crude oil. Durum wheat oil had an outstanding content of phytosterols and policosanols. Overall, the edible oil obtained from durum wheat after refining could be considered a good source of phytochemicals and could represent a valuable strategy to valorize the by-products from durum wheat mills.

The Use of Durum Wheat Oil in the Preparation of Focaccia: Effects on the Oxidative Stability and Physical and Sensorial Properties

“…Durum wheat oil, prepared as reported in Squeo et al [ 25 ], was provided by Casillo Next Food Srl (Corato, Italy). Wheat flour type 0 (Casillo Spa, Corato, Italy) (carbohydrate 72 g/100 g; proteins 11 g/100 g; fat 2 g/100 g; fiber 2 g/100 g); sunflower oil (Olearia De Santis, Bitonto, Italy); olive oil (Olearia De Santis, Bitonto, Italy); yeast ( Saccharomyces cerevisiae, Mulino Caputo, Naples, Italy); and sea salt (Atisale Spa, Margherita di Savoia, Italy) were purchased from local retailers.…”

“…The fatty acid composition of the oils used in the focaccia preparation was analyzed as described by Squeo et al [ 25 ]. A gas chromatograph (mod.…”

“…Italy is not only famous for pizza and focaccia , but also for pasta and special baked goods made of durum wheat semolina [ 20 , 21 , 22 ]. However, the milling process for obtaining semolina involves the production of by-products (bran, germ, and various middlings) [ 23 ], which should be upcycled and reintroduced into the food system to comply with the principles of a circular economy [ 24 , 25 ]. These by-products have a proven potential for oil extraction [ 25 ].…”

“…However, the milling process for obtaining semolina involves the production of by-products (bran, germ, and various middlings) [ 23 ], which should be upcycled and reintroduced into the food system to comply with the principles of a circular economy [ 24 , 25 ]. These by-products have a proven potential for oil extraction [ 25 ]. A previous study has evaluated the effect of using durum wheat oil in the preparation of biscuits [ 26 ], whose long shelf life can be affected by rancidity onset.…”

Upcycling of Agro-Food Chain By-Products to Obtain High-Value-Added Foods

“…The study showed that, despite the differences found between the samples throughout 3 weeks of refrigerated storage, buttermilk may be effectively used to produce quark cheese with suitable technological properties and good sensory features. Squeo et al [ 9 ] characterized the oils extracted from durum wheat debranning (DP) and milling (MP) by-products, to be proposed as edible oils after refining. An oil content of around 6 and 5% was found for DP and MP, respectively, both being composed of around 62% of polyunsaturated fatty acids and a rich profile of different phytochemicals.…”