African Journal of Biotechnology Vol. 6 (5), pp. 569-575, 5 March 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Contribution to light transmittance modelling in starch media

Tetchi Fabrice Achille, Amani N’Guessan Georges* and Kamenan Alphonse

University of Abobo-adjamé, UFR/STA, 02 BP 801, Abidjan, Côte d’Ivoire.

*Corresponding author. E-mail: amanigeorges@yahoo.fr

Accepted 4 January, 2007

Light transmittance (%T) studies were carried out at 650 nm in several types of starch-based media such as natural tropical and non tropical starch pastes and simplified model media. With natural starch pastes (1% db), the clarity ranged from 8%T (ginger starch) to 79%T (potato starch), with intermediate values for cassava starch (47%T) and waxy maize (35%T). These values depended mainly on the spectrophotometer type, starch concentration, treatment temperature and storage time. In simplified media (treatment at 150°C, acid hydrolysis and DMSO solubilization), all paste (1% db) transmittances were improved and the maximum dispersion (using DMSO) was the main factor influencing the transmittance. In effect, the average values were classified as following: 79.5%T (DMSO) > 64.7%T (HCl 2.2 N hydrolysis) » 54.7%T (heating at 150°C) > 22.8%T (control). Thus, a model was proposed to explain that in a dilute and purified starch paste, the quasi totality of incident light passing through the media was transmitted, which made the medium clear.