Promising industrial flour processing and household applications of parboiled germinated brown rice (Khao dok mali 105)

Abstract This experiment determined the effects of various drying methods on the physicochemical properties and γ-oryzanol and tocol contents of parboiled germinated brown rice (PGBR) flour. Physicochemical properties associated with each processing technique were related to the possible applications such as crispiness, solubility, dispersability and colour of the final products. All attributes were in the acceptable range (4 out of 5). PGBR is the source of healthy flour, as it contains high γ-oryzanol and moderate tocol contents. Extrusion, drum drying and spray drying reduced the γ-oryzanol and tocol contents to 7.7, 17.2 and 26.8 mg/100 g DW for γ-oryzanol and 2.2, 23.5 and 49.9 μg/g DW for tocols, respectively. The moisture content of all end products was compiled with dried flour. The pasting temperature of drum-dried flour was compatible with the commercial product. Based on the household processing method, steaming retained the highest amount of γ-oryzanol (26.9 mg/100 g DW) and tocols (9.9 μg/g DW). This indicated that boiling and frying of PGBR flour decreased the γ-oryzanol and tocol contents. This study showed the possible applications of PGBR flour as the potential source of bioactive compounds. Therefore, a healthy product with good consumer acceptability could be achieved using PGBR flour.