Vitamin B contents of widely cultivating new improved rice (Oryza sativa L.) varieties of Sri Lanka

Rice is a good source of vitamin B, which is important for human nutrition and health. In Sri Lanka, rice is the dietary staple and new improved rice varieties (NIRVs) account for more than 90% of rice cultivation in Sri Lanka. However, extremely limited studies are available on the vitamin B contents of NIRVs of Sri Lanka. This study evaluated the vitamin B contents of 16 widely cultivating NIRVs in Sri Lanka. The selected rice varieties (RVs) for the present study were Bg 300, Bg 352, Bg 358, Bg 360, Bg 366, Bg 379-2, Bg 403, Bg 450, Bg 94-1, Bw 272-6b, Bw 367, At 307, At 308, At 309, At 311 and At 362. Vitamin B was extracted from whole-grain rice flour in 0.1N HCL (n=3 each) and analyzed using High-Performance Liquid Chromatography coupled with a Diode-Array Detector (HPLC-DAD). The rResults clearly showed that vitamin B contents significantly (p<0.05) varied among the studied RVs. The vitamin B₁, B₂, B₃, B₅, B₆, B₇ and B₉ contents of the tested RVs ranged from 4.3 to 31.9, 0.7 to 4.3, 15.1 to 82.9, 11.1 to 82.5, 5.7 to 13.8, 1.6 to 72.5 and 0.5 to 3.3 µg/g, respectively. The studied RVs contained more of vitamins B₁, B_3, B₅ and B₇ among the B-complex. Among the studied RVs, vitamin B₁ was significantly high in a red RV, At 311, while white RVs, namely Bg 300, Bg 352 and Bg 450, were significantly high in vitamin B₃. Interestingly, both highest vitamin B₂ and B₇ contents were also observed in Bg 300 RV while a red RV, Bw 272-6b, showed the highest vitamin B₅ content. Vitamin B₉ was only detected in the At 311, Bg 94-1, At 308, Bg 300, At 362, At 309, Bw 272-6b, Bg 450 and Bg 352 RVs and it was high in the Bg 300, Bg 352 and Bw 272-6b RVs. In conclusion, the studied NIRVs of Sri Lanka contained more of vitamin B₁, B_3, B₅ and B7 and the contents varied among the studied RVs.