University of Khartoum

Effect of alkaline pretreatment on protein fraction of high tannin sorghum cultivar

Effect of alkaline pretreatment on protein fraction of high tannin sorghum cultivar

Show full item record

Title: Effect of alkaline pretreatment on protein fraction of high tannin sorghum cultivar
Author: Ali, Nawal Mutasim Mohammed
Abstract: One sorghum cultivar ( Karamaka), that is high in tannin content was obtained from Kadogly Research Station .It was used to study the effect of soaking in alkali , cooking and fermentation on proximate composition, protein fraction and tannin content. Results of analysis showed that, the cultivar contained 6.01% moisture , 3.47% fat, 1.55% ash, 2.36% crude fiber, 10.40% crude protein, 76,21% carbohydrate, and 2.86% tannin. The percentage composition of the protein fractions of untreated flour was found to 11.13% albumin, 6.27% globulin, 55.35% prolamin, 20.01% glutelin and 6.33% residue. Soaking the grains of the cultivar in water, 0.05, 0.1 and 0.2% NaOH for 8h caused slight increase in crude protein, while the tannin content was significantly decreased and the reduction was 41.61, 70.28, 76.92 and 83.92% respectively . Higher drop in tannin content was observed in soaking the grains in 0.2% sodium hydroxide for 8h at room temperature. The protein fractions of soaked grains showed a significant increase for prolamin fractions reaching 59.72% compared to 55.35% (control) and the albumins fractions slightly increased. Increase in time and alkali concentration were found to cause significant reduction in tannin content and improvement in nutritive value of the cultivar . Cooking significantly reduced tannin content of the sorghum dough (control) by 29.72%, while cooking of soaked flour highly lowered tannin with maximum reduction reaching 83.92%. Cooking significantly reduced albumin and prolamin fraction but the reduction was lowed in soaked cooked samples. Fermentation significantly reduces tannin content by 68.18, 81.44 and 91.1% for untreated (control), whereas soaked fermented and germinated fermented respectively, it increased the level of albumin, prolamin fractions and the total protein content during the whole period of fermentation
URI: http://khartoumspace.uofk.edu/handle/123456789/13685
Date: 2015-06-17


Files in this item

Files Size Format View

This item appears in the following Collection(s)

Show full item record

Share

Search DSpace


Browse

My Account