International Journal of Agricultural Sciences

International Journal of Agricultural Sciences ISSN 2167-0447 Vol. 7 (8), pp. 1342-1349, December, 2017. © International Scholars Journals

Full Length Research Paper

Evaluation of physicochemical characteristics of rice (Oryza sativa .L.) Varieties in Ghana

Alex Tamu1*, Maxwell Darko Asante2, Richard Akromah3 and Ibrahim Soe1

1Crop Improvement Programme, Rokupr Agricultural Research Center, Rokupr - Sierra Leone Agricultural Research Institute, PMB 1313, Town Hill, Freetown, Sierra Leone.

2CSIR-Crops Research Institute, Kumasi, Ghana.

3Department of Crop and Soil Sciences, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

*Corresponding author. E-mail: tamualex1@gmail.com. Tel: +23279444496/+23288179696

Accepted 07 November, 2017

Abstract

This study evaluated grain appearance, cooking and eating qualities of 87 rice varieties. The varieties differed significantly at P > 0.001 for Grain length; volume expansion ratio, water uptake, length of blue Gel, Gel consistency, elongation ratio, alkaline spread value, gelatinization temperature and aroma. The gelatinization temperature (GT) was determined based on alkaline spreading score, and 64% of the rice varieties showed intermediate GT (70-74 ºC), 20% exhibited low GT (55-69 ºC), and only 16% of the rice varieties showed high GT above 74ºC. Hard gel consistency was observed in 71% of rice varieties evaluated, 22% recorded medium gel consistency, and only 7% of the rice varieties recorded soft gel consistency. Of the 87 test varieties, 34% were aromatic while 66% were not. Alkaline spread value had significant and positive correlation with water uptake, but gel consistency had negative correlation with volume expansion ratio. Based on the L/W ratio, 33 of the rice varieties had long slender grain type, 45 recorded medium slender grain and only 9 varieties recorded short bold grain. The characteristics of the various grain types make them suitable for different food preparations and meet the preferences of majority of consumers.

 Key words: Gelatinization temperature, gel consistency, alkaline spread value, grain appearance, elongation ratio.