COMPARISON GEL BEHAVIOR, RHEOLOGY PROPERTIES AND SOME PHYSICO PROPERTIES OF JELLOSE FROM SWEET AND SOUR TAMARIND VARIETIES OF THAILAND

Abstract

This research aims to comparison of Gel Behavior, Rheology Properties and some Physico Properties of Jellose from sweet (Sri Chom Phu veriety) and sour (Grà Daan variety) Tamarind seed. The molecular weight of the gellose found that sour Jellose had a molecular weight of 4×10⁵ Daltons, about 70% more than sweet Jellose, which has a molecular weight in Range <4×10⁵ Daltons, approximately 35% and Daltons in the range of 4×10⁵, approximately 49%. In terms of Water absorption index (WAI) and water solubility index (WSI) found that sweet Jellose had water absorption index (WAI) and water solubility index (WSI) more than sour Jellose with statistical significance at 95% confidence level. And the study of gel characterictic of Jellose from by a factorial experiment plan in complete random design (CRD). The factors used in the study are 2 factors. The factor one is the concentration of gellose with 3 levels as follows: 1%, 1.5% and 2%. The factor two is the pH value with 3 levels as follows: 3, 4 and 5. Found that sour gellose had higher gel strength than sweet gellose with statistical significance at 95% confidence level. Both gellose at 2% concentration at pH3 gives the highest gel strength. By increasing the concentration will increase the gel strength while the increase in pH results in a weak gel and decreased gel strength. When study the rheology properties of Jellose with rheometer. Found that the flow behavior of both gellose at 2% concentration at pH3 showed 

the flow behavior Non-newtonian pseudoplastic type and sour Jellose has a viscosity greater than sweet Jellose. And when study the viscoelastic properties of Jellose found that both Jellose have a storage modulus (G'), more than loss modulus (G") which indicates the state of elastic or the characteristics of solid-like. In terms of emulsifying properties, it showed that the emulsifying activity (EA) and emulsion stability (ES) of both Jellose showed no statistically significant difference at 95% confidence level.