| Summary: | Solid substrate fermentation of cooked decorticated red sorghum was run by using mould Amylomyces rouxii or Rhizopus oligosporus. The aim of the study was to investigate the mould biomass growth by glucosamine determination, and also to investigate the effects of fermentation on changes in proximate composition, pH and total titratable acidity, and in vitro starch and protein digestibility. Red sorghum was decorticated using carborundrum discs to remove the bran. Decorticated sorghum was soaked in water (1 h A. rouxii fermentation and 12 h for R. oligosporus fermentation), heated to 90 °C for 30 min, steamed for 30 min, and sterilized (121 °C, 20 menit). 50 g sterile substrate was inoculated with A. rouxii spores (2.103 spore/g substrate) or R. oligosporus (6.103 spore/g substrate) then incubated at 30 °C. Samples were taken at 0, 24, 48, 72, 120, and 168 h for A. rouxii fermentation and 0, 12, 18, 24, 30, and 36 for R. oligosporus fermentation. Glucosamine content for A. rouxii and R. oligosporus were 11.72 and 4.49 mg/g dry matter at the end of fermentation, respectively. A. rouxii hydrolyzed up to 63.4 % of initial starch and 11.4 % by R. oligosporus. There were more protein and fat loss in R. oligosporus fermentation than A. rouxii. Both of the fermentation produced acid and lowered the pH to about 3.0, but pH went up to 4.0 in the end of R. oligosporus fermentation. Mould fermentation improved in vitro starch digestibility, in A. rouxii it went up from 31.3 % to 37.9 % and down again to 11.4 % in the end of fermentation, in R. oligosporus fermentation it went up to 35.4 %. In vitro protein digestibility went up from about 35.0 % to 51.8 % and 31.7 % by A. rouxii and R. oligosporus fermentation, respectively.
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