A national survey of rice ( Oryza sativa L.) Grain quality in Sierra Leone II: Evaluation of physical grain quality

摘要

Rice is a very important item of food and commerce in Sierra Leone and so information on the quality of available rice grains can serve as a useful indicator for the technical status and level of competitiveness in the local rice industry. During this study an objective evaluation was conducted to measure and characterize the quality of rice grains available in the local markets of Sierra Leone. A total of 315 randomly selected rice samples from 45 markets selected from the four major cities of Sierra Leone (Makeni, Bo, Kenema and Freetown, representing urban communities from the northern, southern, eastern and western parts of the country, respectively) were evaluated. Quality evaluation involved measurement of moisture content, number of paddy (unmilled rice kernels) in 1 kg of milled rice and other quality factors normally used for the grading of milled rice. Rice samples were then graded based on criteria adapted from the Philippines Rice Grading Standards for milled rice grains. The results showed that the quality of all grain samples evaluated was generally poor, with 63.2% of the samples failing to meet the criteria set for Grade III rice quality (meaning that the quality level was worse than grade III). Quality measures obtained for imported samples appeared to be superior to that obtained for the local samples in terms of higher proportions of superior grades (grade II or better). Comparison of measures of grading factors revealed that among the four cities considered in this study, grains from Kenema were of the lowest quality. Further examination of grade limiting factors revealed that the most critical factors responsible for poor quality outcomes in grain sample were (i) the number of paddy in 1kg of milled rice and (ii) the moisture content of grains. The study provided quantitative measures of the quality status of rice grains available in Sierra Leone, as well as a means of identifying the major binding constraints to rice grain quality, in terms of the grade limiting factors. It is speculated that the low quality of rice grains observed in this study could be the result of avoidable quality defects that may be linked to an undeveloped national system for rice milling and handling.