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International Journal of Pure & Applied Bioscience (IJPAB)
Year : 2018, Volume : 6, Issue : 3
First page : (159) Last page : (168)
Article doi: :

Methods of Protein Estimation and the Influence of Heat Stress on Rice Grain Protein

Sadaiah K.1, Veronica N.1, Nagendra V.1, Niharika G.1, Neeraja C. N.1, Surekha K.2, Subrahmanyam D.2, Ravindra Babu V.2 and Sanjeeva Rao D.1*
1Dept of Foods and Nutrition Professor Jayashankar Telangana State Agricultural University, Hyderabad
2Indian Institute of Rice Research, Hyderabad
*Corresponding Author E-mail:
Received: 16.09.2017  |  Revised: 22.10.2017   |  Accepted: 29.10.2017  



Rice is an important staple food crop of the world and contains 6-7 % of protein. Protein is estimated as total nitrogen content by widely accepted Kjeldhal method and converted by using an appropriate correction factor. Protein estimated by extraction buffers is superior to traditional analytical methods. Buffer containing 50 mM Tris Hcl (pH-7.5), 2 % SDS, 0.6 % 2-mercaptoethanol and 4M urea reported highest total protein in rice without mentioning incubation time and its validation. Thus an experiment was conducted to standardize the incubation time required for dissolution of sample in the above buffer. Grains from eighteen rice varieties that were cultivated under normal and high temperatures were taken for the study and were incubated for seven different time treatments viz., 0, 30, 60, 90, 120, 150 and 180 minutes and the extracted protein was quantified following Lowry method. Further, the efficiency of this buffer was compared with 1N NaOH solution and Kjeldahl method. Experimental reports indicated that incubation period does not have any impact on total protein content.  At high temperature, seven genotypes viz., GSR-328, Tellahamsa, Sita, Akdhan, Dhaniyadhan, Pantdhan-16 and GSR-330 recorded almost similar total protein content under both temperature conditions whereas less variation in protein content was observed in rest of the genotypes under normal and high temperature conditions. The other two methods yielded more protein content than the buffer and this was expected with Kjeldahl method whereas the reasons for higher protein content observed with 1N NaOH solution needs to be identified.

Key words: Heat stress, Incubation time, Kjeldahl, NaOH, Protein extraction, Rice grain

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Cite this article: Sadaiah, K., Veronica, N., Nagendra, V., Niharika, G., Neeraja, C.N., Surekha, K., Subrahmanyam, D., Ravindra Babu, V. and Sanjeeva Rao, D., Methods of Protein Estimation and the Influence of Heat Stress on Rice Grain Protein, Int. J. Pure App. Biosci.6(3): 159-168 (2018). doi: