Grain quality and antioxidant profiling of the top two most preferred traditional rice varieties per region in the Philippines

The Philippines is fortunate to have vast array of traditional rice varieties (TRVs) including pigmented and aromatic rice, with high demand in the domestic and international market. Recognized for their premium rice grains with excellent eating quality, most of the TRVs command higher prices compared to regular milled rice. The two most preferred TRVs in 15 regions were identified based on the Department of Agriculture's Upland Rice Development Program: Dumalengan and Mimis (CAR), 75 Days and Balatinaw (Region 1), Pinilisa and Balatinaw (Region 2), Galo and Binernal (Region 3), Inipot-ibon and Pinalawan (Region I4-A), Milagrosa and Tipak (Region 4-B), Black Rice and Red Blondie (Region 5), Malido Red and Palawan (Region V6), Kanukot and Tumindog (Region 7), Kalinayan and Baysilanon (Region 8), Ismagol and Kalingkit (Region 9), Dinorado and Speaker (Region 10), Remolitis and Perya (Region 11), Azucena and Dinorado (Region 12), Kalingkit (Black) and Gabay (ARMM). Grain quality evaluation showed that most of the preferred TRVs had good milling recoveries with intermediate amylose content (19.39-21.84%) which demonstrates good eating quality. Based on the alkali-spreading value, majority of the TRVs had intermediate gelatinization temperature (70-74 deg C), indicating shorter cooking time. For both the unpolished and polished forms, Gabay (ARMM) had the highest crude protein content while Balatinaw (Region 2) had the highest total anthocyanin content. Dinorado (Region 12) and Balatinaw (Region 2) had the highest total antioxidant activity in unpolished (9.08 Teq/g) and polished (3.33 Teq/g) form, respectively. Total phenolic content ranged from 0.39-5.54 (unpolished) and 0.14-2.7 mg gallic acid equivalent/g (polished). This study demonstrates that traditional rice varieties can be marketed at premium price due to their excellent grain quality traits and health promoting properties. With the increasing awareness on health and nutrition, these findings can also provide important inputs in the development of healthier rice.