Total phenolic content and phytochemicals of broken landrace rice and their utilization in food products

The aim of this research was to investigate the total phenolic content and phytochemical constituents of broken landrace rice flour from the Hom Dok Hang group, Ban Khok Sa-At, Sakon Nakhon province. Four types of rice—Red Jasmine, Black Jasmine, Kam Noi, and Hom Phu Keaw—were studied. The rice samples were crushed and sifted into two grain sizes: large grains, greater than 250 µm, and small grains, less than 250 µm. The rice samples were then extracted using ethanol as the solvent. The total phenolic content was determined, and the highest quantity of total phenolic content was found in the small grains of Red Jasmine flour, measured at 69.37 ± 2.22 mg GAE g⁻¹ crude extract. For all rice types, the small grain size was found to have a higher phenolic content compared to the large grain size. The phytochemical was evaluated by qualitative analysis. It was found to contain anthraquinone, saponin, cardiac glycosides, terpenoids, flavonoids, coumarins, alkaloids, and tannins: however, steroids were not detected. Red Jasmine rice was selected as the main ingredient for product development. Kale powder and roasted black sesame powder were added to create a rice-based product targeted at menopausal women. The sensory properties of the product were evaluated, and the highest score was achieved with a recipe containing 85 g of Red Jasmine rice flour, 5 g of kale powder, and 15 g of black sesame powder. This study suggests that broken landrace rice flours are promising ingredients for food products, as they contain high levels of phytochemicals and antioxidants beneficial for health. Additionally, this approach adds value to raw materials that would otherwise be considered waste, such as broken rice, by transforming them into prototype food products. GRAPHICAL ABSTRACT HIGHLIGHTS This research provides a guideline for adding value to low-priced broken rice by transforming it into an instant rice product. This study found that rice ground into a finer size contains higher levels of important compounds, such as phenolic compounds and many phytochemicals, compared to coarsely ground rice.