Essay On Exopolysaccharide

Rheological properties of exopolysaccharide isolated from Alcaligenes faecalis B14
Varinder Kaur, M. B. Bera*, P. S. Panesar

Biotechnology Research Laboratory,
Department of Food Engineering and Technology,Sant Longowal Institute of Engineering and Technology, Longowal-148106, Punjab, India, Phone: [phone]; Fax: + 91-1672-280057

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** Corresponding Author E. mail: [e-mail] Phone: [phone]; Fax: + 91-1672-280057

ABSTRACT

Flow characteristics of exopolysaccharide produced from Alcaligenes faecalis B14 were investigated using different rheological models. The evaluation of flow behaviour of exopolysaccharide was assessed by similar

The activation energy must be overcome before the flow process occurs (Rao, 1999). To determine the activation energy at a concentration of 1% w/v and shear rate (100 s-1), the apparent viscosity were studied at different temperatures using the Arrhenius law. The effect of temperature on viscosity of exopolysaccharide was determined by using the following Arrhenius model (Macosko, 1994; Speers and Tung, 1986) η= A.e ∆E/RT ………………………………Equation (4)
By taking the logarithm of Eq. (4), a plot of log10 (η) versus 1/T should be a straight line with intercept and slope equal to log10 (A) and Ea/2.303R respectively. A Linear relationship is obtained between log10 (η) and 1/T (Fig 2) with R2 value 0.991. The values of ∆E and η0 were found to be 2.55 × 104 J/Mol and 5.487 respectively. Similarly the values of ∆E and η0 for guar gum 2.57 × 104 J/Mol; 5.4 and xanthan gum 2.18 × 104 J/Mol; 4.542 were found to be and respectively. The temperature dependency of the viscosity of Lepidium sativum seed extract (2%) at 50 s-1 has been investigated and activation energy obtained was15.59 KJ/Mol (Karazhiyan et al., 2009). Also for high acyl gellan (0.05%) at 100 s-1, the activation energy obtained was 5.42 KJ/Mol (Huang et al., 2008). In general, the higher the magnitude of activation energy, the more pronounced would be the effect of temperature on the viscosity (Mohd Nurul, et al., 1999). The xanthan gum is more stable followed by EPS from Alcaligenes sp. B14 and guar