Steeping time and dough fermentation affect the milling behaviour and quality of white kenkey(nsiho), a sour stiff dumpling prepared from dehulled maize grains

摘要

White Kenley is a traditional stiff dumpling produced from fermented dehulled maize grains in Ghana. The physico-chemical modifications which occur during combination of various steeping (12, 30 and 48 h) and fermentation (0 h, 12 h and 24 h) times were assessed to study the impact of these unit operations on the quality of white kenkey. Water uptake by soaked grains and the release of metabolites were followed during grains steeping and particle size distribution after milling was determined. Steeping time exceeding 24 h was required to produce a fine wet milled flour while water uptake was completed after 8-10 h. This was parallel to hydrolysis of proteins and/or hemicelluloses which occurred after 16 h. Changes in acidity and glucose content were determined in the grain after steeping and in the dough after fermentation. The texture of the kenkey was determined using a texture analyzer. Increases in acidity were higher during dough fermentation than in steeping. Stickiness of the white kenkey decreased consistently with steeping time. Principal Component Analysis showed that a combination of long steeping and short fermentation times gives white kenkey with low stickiness (and high fineness), low acidic taste and low fermented odour.