functional properties of starches, physico-chemical and rheological properties of glucose syrup made from cassava and different potato varieties

Research Article
Eke- Ejiofor J
DOI: 
xxx-xxx-xxx
Subject: 
science
KeyWords: 
Functional, starches, physicochemical, glucose-syrup, Cassava, Potato
Abstract: 

The physico-chemical and rheological properties of glucose syrup from cassava and different potato varieties were determined. Starches from sweet , Irish potato and cassava were processed and hydrolyzed using 30% of rice malt per 100g starch weight for the preparation of glucose syrup. Physico-chemical properties such as moisture content, mineral ash, Total Available Carbohydrate (TAC), Total Titratable Acidity (TTA), pH and dextrose equivalent (DE) were determined while viscosity at different speeds were also determined. Sweet potato starch had the highest moisture content while Irish potato had the least (39% and 67%, respectively). The ash content showed no significant difference in value for all three samples (0.23%) as well as dextrose equivalent (in oBrix) which ranged from 24 in Irish potato to 28 in sweet potato. The pH values of all three samples were acidic with cassava recording 4.4 and potato varieties with 4.9. At 6, 12 and 30 RPM, viscosity decreased with increase in speed with sweet potato been more viscous, recording 30.46pas–1 21.34pas–1 and 12.96pas–1 respectively, while Irish potato was the least viscous recording 11.03pas–1, 7.92pas–1 and 5.38pas–1 respectively as speed in rpm increased, but at 60 rpm viscosity of samples showed inconsistency as Irish potato was more viscous (4.040 pas–1) and cassava least viscous (1.68 pas–1). Relative bulk density (g/ml) was highest in Irish potato (45.66) and lowest in cassava starch (28.45). Solubility and dispersibility (%) for the three Starches recorded no significant difference (p>0.05) with solubility ranging from 12%-14% with cassava as the lowest and Irish potato as the highest. Other functional properties of starch such as relative bulk density, swelling power, least gelation concentration (LGC) and water absorption capacity (WAC) showed significant difference (p<0.05).