| Sorghum hybrids were steam flaked using a pilot plant steam flaker and a laboratory procedure. Grain conditioners, tempering, and sorghum type were evaluated for flake qualities.;A nonwaxy grain that was tempered with water and conditioners, steamed, and flaked, had decreased test weight, flaking time, and power required to process the grain, and improved flake appearance. Commercial grain conditioners provided no advantages over tempering and steaming with water only. Physico-chemical characteristics were best for flakes from grain treated with sulfurous acid and 2-mercaptoethanol.;Steam flaking properties of eight hybrids with different endosperm grown in 1993 and 1994 were compared. Waxy flakes had the best physico-chemical characteristics, most attractive appearance, and were more translucent. Flake quality decreased in order from waxy, heterowaxy, food-type, and red nonwaxy. Heterowaxy, food-type, nonwaxy, cream, yellow, and red sorghums had similar steam flaking properties. The food-type sorghums produced attractive light colored flakes. Although heterowaxy grain had significantly different flake properties than nonwaxy hybrids, many of the flake measurements remained similar.;Pasting curves, and enzymatic methods were used to differentiate among flakes. Pasting profiles revealed waxy flakes had lower pasting curves than other ground flakes. Peak viscosity decreased during flaking, and could be an indicator of extent of processing. A glucoamylase test revealed differences in hydrolysis between raw grain and flakes, but not between sorghum types. A Rapid Viscoanalyzer/;A procedure developed to simulate steam flaking in the laboratory showed that tempered grains absorbed moisture faster and produced flakes with larger diameter than nontempered grain.;Analytical results revealed no apparent advantage in using commercial conditioner. Waxy flakes had the best characteristics. Tempering of heterowaxy and food-type grains improved physico-chemical and processing characteristics of flakes suitable for use in feedlots. |
