H B Shozib
Senior Scientific Officer
Grain Quality and Nutrition, BRRI
M A Siddique
CSO
GQN, BRRI
Rice, Parboil, Minerals
Grain Quality and Nutrition Lab, BRRI, Gazipur
Quality and Nutrition
A total of 33 (Thirty three) BRRI HYV for boro season were analyzed for mineral profiling of zinc, iron, calcium and phosphorus content at the level of mgKg-1 (ppm) or gKg-1. We analyzed all samples at unparboiled milled rice condition in addition to parboiled milled rice condition for zinc and iron only at GQN laboratory, BRRI following standard protocol of AOAC for mineral content analysis by atomic absorption spectrophotometer (AAS). Varieties were BR1, BR2, BR3, BR6, BR7, BR8, BR9, BR12, BR14, BR15, BR16, BR17, BR18, BR19, BRRI dhan27, BRRI dhan28, BRRI dhan29, BRRI dhan35, BRRI dhan36, BRRI dhan45, BRRI dhan47, BRRI dhan50, BRRI dhan55, BRRI dhan58, BRRI dhan59, BRRI dhan60, BRRI dhan61, BRRI dhan63, BRRI dhan64, BRRI dhan67, BRRI dhan68, BRRI dhan69, BRRI dhan74. A specialized Satake rice mill and a rice polisher were used for milling freshly harvested rice samples. Possible source of contamination of iron were minimized by separating unit of rice mill from other sample millers of laboratory in a confined room. We used deionized water as a source of water for boiling process. An amount of 1g sample of each variety were digested in 5 mL mixture solution of HNO3 and H2O2 (4:1) in a microwave digester in 200ºC for 30 minutes. Then the digested solution were filtered through Whatmann paper-1 in 100 mL volumetric flux and volume the solution up to 100mL with de-ionized distilled water. We had used atomic absorption spectrophotometer (AAS, Shimadzu Atomic Absorption Spectrophotometer AA-6800) for measuring zinc, iron and calcium at 213.8 nm, 348.3 nm and 422.7 nm respectively. In addition, estimation of phosphorus is carried out by measuring calorimetrically the blue color formed when the sample solution is treated with ammonium molybdate and the phosphomolybdate thus formed is reduced (Yosida et al, 1976). One mL of digested sample was taken into a test tube and 2 mL HNO3 (2 N), 4 mL de-ionized water was added. Then 1 mL molybdate-vanadate solution (Ammonium molybdate solution, 5% in distilled water and Ammonium vanadate solution, 0.25% in 1 N nitric acid) and 2 mL de-ionized water was added to make the volume 10 mL. We had mixed the solution with vortex mixture and the absorbance were taken at 420 nm after 15 minutes in a spectrophotometer (V630). Rice flour NIST 1568b was used as reference material. All samples were analyzed for triplicate. Mean values (n=3) are represented in a tabular format.
BRRI Annual Report, 2015-16
Report/Proceedings