Influence of heating on stability of γ-oryzanol in gluten-free ready meals

- Content of γ-oryzanol was determined in rice pasta (initially in chilled or frozen state) before and after cooking.
- Raw pasta with white rice flour had a content of 7.63 ± 2.34 mg/kg.
- Raw pasta with brown rice flour had a content of 65.60 ± 13.05 mg/kg.
- Chilled pasta with brown rice flour and cooked by microwave had the greatest content of γ-oryzanol (approx. 80 mg/kg).

Rice is a rich source of γ-oryzanol, which is a mixture of lipophilic phytosterols composed of triterpene alcohols or sterols with ferulic acid ester. In recent years the usefulness of γ-oryzanol has been especially studied and highlighted for the treatment of diseases. Therefore, given the great interest of γ-oryzanol from a nutraceutical standpoint, in this paper the effect of heating on the degradation of γ-oryzanol in rice pasta is studied, as it is a representative model of a gluten-free ready meal. The content of γ-oryzanol was determined in rice pasta (initially in chilled or frozen state) before and after cooking (in a steam pressure oven; in a conventional hot air oven; and in a microwave oven; and applying cooking times of 5 and 15 min). The results of this study show that raw pasta had a γ-oryzanol content of 7.63 ± 2.34 mg/kg if using white rice flour, and 65.60 ± 13.05 mg/kg when using brown rice flour. Chilled pasta samples prepared with brown rice flour, and cooked by microwave, had the greatest content of γ-oryzanol (approximately 80 mg/kg of rice pasta, wet basis).