http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
malting properties of different sorghum cultivars
Malting characteristics of sixteen sorghum varieties were investigated using a standard malting procedure. Clean grain was placed in nylon bags, steeped for 20 h, treated with 2% sodium hypochlorite, and washed. Germination proceeded at 28'C and 95% relative humidity (RH) for 5 days. The wet malt was dried at 50'C for 24 h. Total dry matter loss ranged from 8-19%. Black Tx430 had the highest losses. Density decreased for all the sorghums after malting; the extent of decrease was cultivar dependent. The (X- and P-amylase activity in sorghum malts produced (x- amylase levels ranging between 25-183 U/g. Black Tx430 (183 U/g) and RTx435 (178 U/g) had the highest values. Commercial barley malt had an (X-amylase activity of 189 U/g. P-Amylase activity was low for all cultivars, ranging from 11 to 41 U/g, with BTx2752 and IS9530 having the highest values. Decrease in RVA viscosity was significantly correlated with the (x-amylase calorimetric assay (r=0.97). The RVA is a promising method to measure (X-amylase activity; it is simple, fast, and requires minimum chemicals. Sorghum diastatic power (SDU) was not significantly correlated to (x-amylase activity at SDU values below 30. Above 30 SDU, (x- amylase activity was significantly correlated to diastatic power. Dry matter loss was significantly correlated to (Alpha-amylase activity and SDU. The green malt moisture was significantly positively correlated to dry matter loss. Malts produced from College Station cultivars gave higher (X-amylase levels than those from Lubbock. P-Amylase activities ranged from 28-33 U/g in the malts regardless of growth location. A second malting procedure using jars for steeping and germination was applied to 6 cultivars, and resulted in lower dry matter losses and 0-amylase activity. Although (x-amylase levels were generally higher for the standard method, cultivars responded differently. Each cultivar may need optimum conditions to obtain the highest level of enzyme activity. Malting procedures require further control to obtain desired enzymatic levels with the least possible dry matter loss.
"Major subject: Food Science and Technology".