Evaluation of thiamine and riboflavin in different varieties of rice grown in Kurigram district, Bangladesh.

Context: Rice is indeed a staple food in many parts of the world, including Bangladesh. This research aimed to evaluate the two essential vitamin levels in different processed rice sunned, parboiled, cooked sunned, cooked parboiled, and washed cooked rice.

Objective: The study focused on analyzing the thiamine (vitamin B) and riboflavin (vitamin B) contents in 10 different varieties of paddy samples grown in the Kurigram district of Bangladesh.

Methods: A high performance liquid chromatographic (HPLC) technique assembled with fluorescence detector was employed for these analyses. Two calibration curves were generated to analyze vitamin B and B (for thiamine the regression coefficient, r = 0.9992 and riboflavin r = 0.9989). The study demonstrated a recovery rate of 96.88 % for vitamin B and 104.24 % for vitamin B. Overall, these findings provide valuable insights into the vitamin B and B contents across different rice samples.

Results And Conclusion: The results showed that the parboiled samples had the highest thiamine content, ranging from 342.50 ± 0.3 to 673.0 ± 7.5 μg/100 g, compared to the sunned samples, which had a range of 209.5 ± 0.3 to 337.4 ± 4.3 μg/100 g. Conversely, the sunned samples had the highest riboflavin content, ranging from 26.4 ± 0.2 to 59.6 ± 0.3 μg/100 g, while the parboiled samples had a range of 3.0 ± 0.1 to 26.6 ± 0.01 μg/100 g. Additionally, it was observed that the steaming process increased the thiamine content and reduced the riboflavin content in parboiled rice samples but decreased both the thiamine and riboflavin in sunned rice samples. Another study showed a gradual decrease in the levels of both vitamins B and B in sunned, cooked sunned and washed cooked sunned rice samples.

Significance: These findings provide valuable insights into the impact of processing methods, such as parboiling and steaming, on the thiamine and riboflavin contents in rice. The results suggest that parboiled rice may be a preferable choice for individuals seeking higher thiamine content in their diet, while sunned rice may contain higher levels of riboflavin. The results shed light on the nutritional profiles of different rice varieties and highlight the potential impact of processing techniques on the vitamin content of rice.