Physico-Chemical Properties of Cassava Starch

✍ Scribed by Isabelle Defloor; Isabel Dehing; J. A. Delcour

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 85 KB
• Volume: 50
• Category: Article
• ISSN: 0038-9056
• DOI: 10.1002/(sici)1521-379x(199803)50:2/3<58::aid-star58>3.0.co;2-n

✦ Synopsis

2 Materials and Methods

Starch was isolated from cassava flour (60 g) obtained from roots of four genotypes (TMS 30572, TMS 81/00110, TMS 91934 and TMS 30555) grown at the International Institute of Tropical Agriculture (IITA) in Ibadan (Nigeria). More data on the planting, harvesting and processing conditions, the rainfall pattern and the maximum and minimum daily temperatures for the plant growing period are given in Defloor et al. [1][2][3]. In what follows the terms 6 MFD, 9 MFD, 12 MFD, 15 MFD, 18 MFD, 6 MFR, 9 MFR, 12 MFR, 15 MFR, and 18 MFR refer to flour produced from roots harvested 6, 9, 12, 15 and 18 months after planting in the dry and rainy season experiment respectively.

Isoamylase from Pseudomonas amylodermosa and barley b-amylase were purchased from Sigma (catalogue numbers I 2758 and A 7130, respectively), St. Louis, MO.

2.1 Isolation of cassava starch

In what follows all centrifugations were at room temperature for 15 min at 2,000 ´g. Cassava flour (60 g) was suspended in 400 ml deionised water at room temperature for 3 h and centrifuged. After removal of the top brown layer the residue was extracted again with the same quantity of water. The water-extracted residue was then treated overnight with sodium hydroxide-solution (0.05 N, 800 ml). After neutralisation with a hydrochloride solution (2.0 N), the suspension was centrifuged. The residue was suspended 5 times in 200 ml deionised water with intermediate centrifugations to remove sodium chloride. The remaining product was then suspended in 500 ml deionised water and submitted to wet sieving (50 mm) under continuous stirring of the suspension and washing with 2,000 ml water.