Effects of microwave roasting on the yield and composition of cold pressed orange seed oils

The aim of this study was to valorize orange (Citrus sinensis) seeds, which are generated as waste. This study presents data about raw orange seed, the meal gained after cold pressing, and characterization data of the cold pressed seed oils. Furthermore, the effects of microwave roasting of the seds compared to regular roasting (control) were determined. The oil yield of orange seed cold pressing was around 52.93-62.99%. After cold pressing, 13.57-17.97% oil remained in the meal together with 20.68-25.61% protein. Hence, pressed meals could be valorized for different purposes. Except for turbidity, the color b* value, free acidity, the p-anisidine value and antioxidant capacity, there was no significant difference between the two oil samples for the measured physicochemical properties. Six different fatty acids were quantified and the major fatty acids were linoleic, palmitic and oleic acids. The fatty acid composition of the orange seed oil can be accepted as nutritionally balanced. Among the fifteen sterols quantified, beta-sitosterol was dominant (around 77-78%). Likewise, the a-tocopherol content of the samples was not significantly different. The thermal onset and peak temperatures, and enthalpies for crystallization and melting were also reported. This study showed that good quality orange seed oils can be produced by cold pressing, and the oils could be used in food and non-food applications.