Grain and malt quality properties of some improved Nigerian sorghum varieties

Abstract

To determine their grain and malt quality properties, ten improved Nigerian sorghum varieties were subjected to several tests. The parameters that were tested included thousand corn weight, germinative energy, germinative capacity, water sensitivity, malting losses, hot and cold water extracts and free amino nitrogen (FAN). Results obtained showed variations among the sorghum varieties in most of the parameters assessed. While variety SK5912 was heaviest (40.25 g), variety Nafelen 6 had the lowest weight (22.45 g). For germinative capacity, variety KSV8 gave the highest value (97.0%), while variety ICSV400 gave the lowest value (90.5%). Variety KAT487 was the most water sensitive (5%), while four varieties simultaneously gave the lowest value. Boboje gave the lowest malting loss (13.77%), while the highest loss (37.74%) was given by White Kaura. For the extracts, variety SK5912 gave the highest value, as was the case also with FAN. Generally, there were significant differences across the different varieties of sorghum for malting loss, FAN, cold water extract and hot water extract at both p < 0.05 and p < 0.01. The results showed significant agreement with previous reports, with the key findings being that grain size mostly correlated positively with high expression of the critical malting parameters.

Changes in the Activities of Alpha and Gluco-amylases during Malting of Some Improved Nigerian Sorghum Varieties

“…As observed with germinative energy, variety SSV98001 again gave the highest value of 98% followed closely by both varieties SRNA and KSV8 with 97% while the least value of 96% was given by variety SK5912. The import of this result is that all the sorghum grain varieties used in this work showed high germinative energies and capacities of close to 100, which is a positive trait usually considered by grain buyers as it indicates that they are all alive and possess positive malting abilities [7]. The results are in agreement with previous reports for sorghum [14] but higher than those previously observed for barley [15,16].…”

“…As seen in the figure, the variety with the most weight was Sk5912 with a TKW of about 40 g, followed by KSV8 with 36.2 g, while the least was SRNA with nearly 27 g. Grain weight is often considered an important measure of grain quality. This is because higher weighted grains are believed to confer some advantages such as having less husks in addition to having higher starch content when compared to their smaller-sized counterparts [7]. Table 1 shows some preliminary malting properties of the four sorghum grain varieties used in this work.…”

“…Quantitatively and in production terms, sorghum is the world's fifth largest and most important cereal, after wheat, maize, rice and barley [7]. In most parts of Africa, sorghum is still largely a subsistence food crop helping to feed her huge and ever increasing population; however, increasingly, it is becoming the foundation for many successful food and beverage industries [8].…”

“…For instance, one of the important uses of sorghum grains presently is with respect to brewing. Although barley has historically been the oldest and most used brewing grain [10] it is essentially a temperate crop and therefore the high importation cost incurred in many tropical countries including Nigeria and many other African countries caused governments in the affected countries to compel industries to seek alternative grains as brewing raw material [7,11]. Those policy measures has resulted in the fact that today many beer brewing industries in most parts of the world are able to produce continental type beers using sorghum as the major brewing material.…”

“…The immense improvements in the developing the innate enzymes of the different sorghum varieties has played a large role in these developments. There is at present many deliberate but concerted efforts towards developing new and improved varieties of sorghum so much so that now over 10,000 varieties of it exists [7]. Because of the immense role their contents of amylases whether in their raw states or during malting process as is often required during brewing, we aimed in the present work to assess the content of α-amylase, bamylase and glucoamylase of four improved Nigerian sorghum varieties during a 4-day malting period.…”