Hardness as a modification index for malting red and white sorghum (kaffir) grains
Abstract
BACKGROUNDThis study investigated changes in the resistance to fracture of malting red and white sorghum grains using a hardness tester as another method for monitoring grain modification.RESULTSGrain hardness decreased progressively from 134.35 N and 137.29 N in malting red and white sorghums and levelled off after 120 h at 76.98 N and 69.14 N. In the red grain malts traditionally used for burukutu production, moisture content (r = −0.983), dhurrinase activity (r = −0.981), malting loss (r = −0.981), free amino nitrogen (r = −0.909) and cold water extract (r = −0.908) were better indicators of grain hardness than root length (r = −0.89). In the white sorghum malts, malting loss (r = −0.988), dhurrinase activity (r = −0.954) and diastatic activity (r = −0.936) were better indicators of grain modification than root length (r = −0.916). The soluble nitrogen ratio at the end of malting was lower in the red (0.049) compared with the white (0.0548).CONCLUSIONGrain hardness using a hand-held tester is a simple, fast and good index of modification of malting red and white sorghum grains. Oven-dried red and white sorghum malts could be considered to be well modified at hardness values/indices below 77 N/0.5730 and 72 N/0.5036, respectively.
- Publication:
-
Journal of the Science of Food and Agriculture
- Pub Date:
- March 2014
- DOI:
- 10.1002/jsfa.6331
- Bibcode:
- 2014JSFA...94..890U