Research On The Preparation Of Octenyl Succinic Anhydride Modified Canna Edulis Ker Starch And Its Properties

Canna edulis Ker is mainly planted in China’s southern provinces such as Yunnan, Guangdong, Guizhou and Guangxi. Its rhizome contains a huge amount of starch, which can be processed into native starch, vermicelli, wine and ethanol, etc. There’s no other usage and development, so developing derivatives of Canna edulis Ker starch by high-tech will increase its value and promote the development of deep processing of Canna edulis Ker.In this study, Canna edulis Ker starch was esterified by Octenyl Succinic Anhydride using aqueous slurry to optimize the reaction conditions for the product and investigate its physicochemical properties.Firstly, experiments of single factor were employed to study the effect of the concentration of starch slurry, reaction time, reaction temperature and the range of reaction pH on the DS(degree of substitution)of the product.Then response surface methodology was employed. A five-level-four-factor central composite design was given by the design-expert software version 7.0. The regression equation of the DS of product and the four factors analyzed by the software showed as follows: Y=0.012+4.275×10- 4A+5.375×10- 4B+9.883×10- 4C+1.058×10- 4D-4. 4 6 2 × 1 0- 4A B- 3. 6 1 2 × 1 0- 4A C +1. 4 3 8 × 1 0- 4A D- 4. 1 8 7 × 1 0- 4B C-1. 5 8 7 × 1 0- 4B D + 6. 3 7 5 × 1 0- 4C D- 7. 4 7 5 × 1 0- 4A2- 9.125×10- 4B2-8.137×10-4C2-5.275×10-4D2, in which Y is the DS of product, A is the concentration of starch slurry, B is reaction time, C is reaction temperature and D is the range of reaction pH. The technological optimal reaction conditions were obtained as follows: the concentration of starch slurry is 35.63%, reaction time is 3.62 h, reaction temperature is 37.77℃ and reaction pH ranges from 8.07 to 8.57. When the addition of OSA is 3%, the DS of OSA Canna edulis Ker starch obtained is 0.01213. Meanwhile, known from the ANOVA result of response surface methodology about the concentration of starch slurry, reaction time,reaction temperature on the DS of product,all of the above factors showed significantly effect, while the range of reaction pH not. The sequence of each factors’ effect on the DS of product is as follows: reaction temperature>reaction time>the concentration of starch slurry>>the range of reaction pH.Finally, the viscosity, transparency stability, freeze-thaw stability, retrogradation stability, degree of gelatinization and content of resistant starch of the product were studied. The results showed that with the increase of the DS of product, those physiochemical properties were enhanced at the same time. Also the structural characteristic of the OSA Canna edulis Ker starch was investigated by fourier transform-infrared spectroscopy and scanning electron microscopy to illustrate the existence of the esterification reaction.