| In this paper, octenyl succinic maltodextrins were synthesized from an aqueous medium using maltodextrins, which are enzymatic hydrolysis products of waxy corn starch. The investigations of influence of the esterification reaction conditions of the dextrose equivalent (DE) value of 5, 11, 18 maltodextrins on degree of substitution (DS)have been presented. Individual topics focuses on the structure and functional properties changes of maltodextrins and modifications. Octenyl succinic maltodextrin main food appliactiongs has been studied, too. This product as one of the most promising replacements for gum arabic might be suitable for use as an encapsulating material for preparing of powdered oils.The DS of the products could be controlled by the DE value of maltodextrin and the reaction conditions, such as the amount of OSA used, the concentration of the maltodextrin, the reaction temperature, the reaction time, and the reaction pH. The Design-Expert software analysis results indicated that suitable parameters for the preparation of OSA maltodextrin with DE value of 5, 11, 18 were as follows:amount of OSA 3 %, pH of reaction system8.5, 8.4 and 8.4, reaction temperature35.6℃, 35.2℃and 36.1℃, concentration of maltodextrin slurry 44.2%, 43.2% and 43.4% (in proportion to water, w/w) , reaction period4.75 h, 4.54 h and 4.63 h. The DS were 0.0204, 0.0182, 0.0165, respectively.The microstructural aspect of the enzyme hydrolysis and OSA esterificationt starch granules were observed with a scanning electron microscope(SEM) and X-ray scattering analysis. The effects verified that the two types of maltodextrins losed completely the grannular structure and crystal reign of native starch. IR spectroscopy and NMR showed some new characteristic absorption in the OSA-maltodextrin, and confirmed the persence of OSA group in occurred maltodextrin. The DS of OSA maltodextrin was calculated by 1H-NMR spectroscopy were closed to the values determined from titration.Increasing the DE value could improve the hygroscopicitiey, transparency, retrogradation, freeze-thaw stability of maltodextrin were found. However, emulsion capacity and emulsion stability were decresaed. The hygroscopicity of esterification maltodextrins could be significantly reduced with increasing DS. Esterifcation was effective in improving the retrogradation, freeze-thaw stability, emulsifying properties and intrinsic viscosity, but no significant effect on transparency were seen. Rheological properties of maltdextrin and OSA-maltodextrin showed shear thinning (pseudoplastic) behaviour. This research apply OSA-maltdextrin with DE value 11 and DS 0.018 as microcapsule wall materials by spray drying to prepare powdered oil. Spray drying process was carried out in the concurrent system at the following parameters:inlet gas temperature 180℃, outlet gas temperature 90℃, feed intensity according to temperature at the outlet. Encapsulation capacity of OSA-maltodextrin was up to 90.83%, it is greater than arabic gum and maltodextrin, which were used as reference encapsulating material. After 28 days of storage in a humid atmosphere, the encapsulating rate of OSA-maltodextrin only decreased by 3 %. Scanning electron microscopy indicated that the surface of powdered oil made from OSA-maltodextrin was comparatively integrated. On oil microencapsulation in OSA-maltodextrin gave a reasonable explanation to why OSA-maltodextrin can be more efficient than gum arabic, maltodextrin as spray drying microcapsule wall material.
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