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Double Esterification Of Waxy Maize Starch And Its Application In Powder Oil Microcapsules

Posted on:2013-04-25Degree:MasterType:Thesis
Country:ChinaCandidate:J XueFull Text:PDF
GTID:2231330374463823Subject:Food Engineering
Abstract/Summary:PDF Full Text Request
The dissertation mainly studies that the preparation order, synthetic processes,structure and basic properties of acetylation octenyl succinate waxy corn starch esters selecting acetic anhydride and octenyl succinic anhydride for double esterification with waxy corn starch as raw material and its application in vitamin E oil microencapsulation.The main results are as follows:1. Modified order of double-esterification waxy corn starchBoth acetic anhydride acetylation and octenyl succinic anhydride esterification are esterification process, so the esterification order was studied in the first place. Products were synthesized according to different orders and determined the modified success by infrared spectrum analysis of the structure of the obtained resultants. Preparation order of acetylation octenyl succinate waxy corn starch esters is acetic anhydride acetylation first and then octenyl succinic anhydride esterification with substitution (DS) as evaluation index and further validation of the emulsifying capacity and emulsion stability.2. Preparation of double-esterification waxy corn starchAccording to determined preparation order, laboratory homemade acylation starch (DS is0.0768) as raw material and single-factor and orthogonal as the experimental method were used to study the wet process preparation of acetylation octenyl succinate waxy corn starch esters,selecting initial starch slurry concentration, pH, reaction temperature and reaction time to study the influence of the DS of acetylation octenyl succinate waxy corn starch esters. Orthogonal experiments showed that the main factor is the pH value in the preparation process of acetylation Octenylsuccinate waxy corn starch esters, secondary factor is the reaction temperature and reaction time, initial concentration of starch slurry has the minimal impact and Obtain the best technological conditions are initial starch slurry concentration30%, pH8.5, reaction temperature35℃and reaction time4h under the circumstance of3%octenyl succinic anhydride addition amount.The octenyl succinic anhydride esterification DS is0.0197when prepared under the optimal parameters.3、Properties of double-esterification waxy corn starch The properties of waxy corn starch have greatly changed after being esterified by acetic anhydride and octenyl succinic anhydride. The emulsifying capacity, emulsion stability, viscosity, transparency, stability of retrogradation, freeze-thaw stability of double esterified starch has increased, and increased with the increases of DS, compared with the native starch and acetylated starch, while the pH value has dropped, and decreases with increasing DS. All these changes have something to do with the introduced acetyl, octenyl succinic anhydride and free carboxylic acid after the esterification.4、The application of double-esterification waxy corn starchExplore the double esterification waxy corn starch used as wall material and its application in vitamin E oil microencapsulation. The additive amount of double esterification waxy corn starch is30%determined by observing the apparent characters of the product and recover emulsion traits. At this additive amount,the microencapsulated powder oil’s VE oil reserves was98.8%, the encapsulation efficiency was97.87%, and the surface oil content was only1.05%. The optimal conditions of the emulsification process were determined at the same time: two-phase emulsification at60~70℃, homogenization pressure at30MPa, tow-time homogeneous. And the spray drying process parameters:inlet air temperature at190~195℃, the air temperature is90~95℃, the feed rate of15-20mL min-1, the air pressure0.10MPa. A detailed measurements and analysis of a series of properties of the microencapsulated powder oil products were done, the results show that this white powder is dry evenly, without caking, good fluidity, no strange smells, physicochemical and microbiological indicators are in line with food hygiene requirements, good solubility and dispersion. Recovery emulsion is milky white, smooth and delicate, stable, without conjunctiva and layers after standing for24hours. The surface structure of double esterification waxy corn micro-capsules was analyzed by scanning electron microscope. Photos observation showed that the microcapsules have good surface structure, the microcapsule particles were spherical, smooth and complete, no occurrence of dry surface, dense grain structure and no surface cracks, broken and leaking phenomenon, indicating that the package buried effect is good, and have good protective effects on the core material.
Keywords/Search Tags:waxy maize starch, double-esterification waxy corn starch, microencapsulation, powdered oil
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