Changes of phenolic-acids and vitamin E profiles on germinated rough rice (Oryza sativa L.) treated by high hydrostatic pressure

• Combined treatment of germination and HPT enhanced functionality in rough rice.
• HPT is the most important parameter for extracting vitamin E and phenolic acid.
• HPT accelerated the biosynthesis related on conversion of vitamin E and phenolic acid.
• HPT provided the useful information for utilization of germinated rough rice.

This study was performed to investigate changes in the phenolic acid and vitamin E profiles of germinated rough rice following high hydrostatic pressure treatment (HPT). Rough rice was germinated at 37 °C for two days and subjected to 0.1, 10, 30, 50, and 100 MPa pressures for 24 h. The total phenolic acid content increased from 85.37 μg/g at 0.1 MPa to 183.52 μg/g at 100 MPa. The highest gallic acid (4.29 μg/g), catechin (9.55 μg/g), p-coumaric acid (8.36 μg/g), ferulic acid (14.99 μg/g), salicylic acid (14.88 μg/g), naringin (6.18 μg/g), trans-cinnamic acid (45.23 μg/g), and kaempferol (40.95 μg/g) contents occurred in the sample treated at 100 MPa after germination. The maximum vitamin E content of about 2.56 (BG) and 4.34 mg/100 g (AG) were achieved at 30 MPa. These result suggest that a combination of HPT and germination are efficient method for enhancement of functionality in rough rice, and clarify the influence of HPT conditions on the vitamin E and phenolic acid in germination rough rice.