Manual of laboratory procedures for quality evaluation of sorghum and pearl millet

Abstract

This manual is for use by scientists and technicians who screen and evaluate varieties of
\nsorghum and pearl millet for their grain quality. It is based on experience in agronomy and
\nfood technology acquired over several years in SADC/ICRISAT's Sorghum and Millet
\nImprovement Program in Zimbabwe, where there is a focus on generalized screening
\nmethods for broad grain qualities rather than detailed component analysis of a molecular
\nnature.
\nLaboratory procedures, including qualitative and quantitative methods, were compiled
\nf rom existing sources and modified in several ways for the Program's use. Quality
\nparameters were focused on grain, on primary products such as flour, meal, and malt, and
\non such secondary products as baked flour, steamed flour, and porridge. The grain and
\nthese products were evaluated using physical and chemical methods, and a database was
\ncreated to serve as an empirical reference document derived f rom field and laboratory
\nresults.
\nThe manual's first section, on grain-quality evaluation, describes rapid techniques for
\nroutine screening. The qualitative parameters used are: color, pericarp thickness, testa,
\nendosperm texture, and hardness. Quantitative parameters comprise 100-kernel weight ,
\nAgt ron readings, and moisture, floaters, dehulling loss, milling yield, size fractions, and
\nwater absorption expressed as percentages. Eight chemical methods of evaluation are
\ndescribed in the second section, among which only rapid tannin analysis forms part of
\nroutine screening tests. The last section covers product preparation and testing, wi th
\nspecific reference to bread, cookies, and porridge. And the manual ends wi th its unique
\nempirical database of 39 tables which presents grain-quality and malting test results for
\nselected lines, varieties, and hybrids of sorghum and pearl millet.