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Non-crystalline Modification Of Waxy Corn Starch And Study On Esterification And Yacon Fruit Milk Powder

Posted on:2013-01-27Degree:MasterType:Thesis
Country:ChinaCandidate:Y Y GaoFull Text:PDF
GTID:2211330374464346Subject:Agricultural Products Processing and Storage
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Non-crystalline modification and esterification of waxy corn starch was studied in this paper. Main physical and chemical properties of octenyl succinic anhydride modified non-crystalline starch were studied. Meanwhile, a new type of Yacon (Smallanthus Sonchifolius) juice milk powder was prepared by microcapsule technology, with the soybean oil as core material, Yacon fruit juice and other materials as wall materials, and self-made non-crystalline starch ester as emulsifier in aqueous phase. The products of powdered oil were detected.1. Preparation of non-crystalline granular waxy corn starchNon-crystalline granular waxy corn starch with higher solubility and appropriate DE was prepared by acid-microwave radiation with waxy corn starch as raw material. It was determined experimentally that the amount of concentrated hydrochloric acid was0.2%, microwave power was900w, ratio between peak and empty was40s/80s (Microwave reaction was40s, and stirring it after pause80s to prevent heating too concentrated), and total reaction time was640s. The prepared non-crystalline granular waxy corn starch was DE8.5and solubility88.7%. Combining X diffraction curve, polarizing microscope, and scanning electron microscope, the change from crystal to non-crystal was confirmed.2. Preparation of octenyl succinic anhydride modified non-crystalline starchOctenyl succinic anhydride modified non-crystalline starch was prepared with self-made non-crystalline granular waxy corn starch as raw material. Taken degree of substitution (DS) as evaluation index, the optimal conditions of preparing modified starch were determined. The addition of octenyl succinic anhydride was3%, initial starch concentration was40%, reaction pH was8.5and reaction temperature was35℃. The DS of self-made octenyl succinic anhydride modified non-crystalline starch was0.0206.3. Study on physical and chemical properties of non-crystalline starch esterThe physical and chemical properties of waxy corn starch were changed by non-crystalline nodification and esterification, through the comparative study on viscosity, retrogradation, transparency, freeze-thaw stability, emulsification and emulsion stability of waxy corn native starch, non-crystalline granular starch and non-crystalline starch ester. Non-crystalline modification could reduce viscosity and increase retrogradation of native starch. But viscosity increased, retrogradation lowered after esterification. The transparency increased with DS increased. The freeze-thaw stability of non-crystalline starch ester was better than non-crystalline granular starch's and native starch's and in direct proportion to the relationship of transparency. Non-crystalline starch ester had strongger emulsifying capacity, and had good ability to stabilize oil-in-water emulsion type. With the DS increased, the emulsifying capacity and emulsion stability were enhanced.The comparison on DS, viscosity, emulsification of octenyl succinic anhydride modified non-crystalline starch and octenyl succinic anhydride modified waxy corn native starch were studied. Results showed that, esterification had greatly improved by non-crystalline modification. The DS and emulsifying capacity were enhanced.4. Application of octenyl succinic anhydride modified non-crystalline starch in Yacon juice milk powderYacon fruit was pulped and the filtrate was spray dried to Yacon fruit powder, the filter residue was made to marc powder with the fresh Yacon as raw material.0.20%citric acid was added as colour fixative. Yacon fruit powder had color of yellow and delicate texture. The content of crude fiber of the filter residue was47.84%. The Fructo-oligosaccharides contents of the products were higher.Yacon juice milk powder was prepared by microcapsule technology, with Yacon fruit juice, self-made non-crystalline starch ester and other materials as wall materials, and the soybean oil as core material. The optimum prescription was30%soybean oil,1.2%emulsifier0282,0.5%emulsifier02855,14%self-made octenyl succinic anhydride modified non-crystalline starch, stabilizers including0.5%propylene glycol alginate (PGA),0.5%sodium carboxymethyl cellulose (CMC),25%Yacon juice (calculated by solids), and the rest syrup by single factor and orthogonal experiment.The Yacon juice milk powder was creamy white. The dissolution o was stable and had Yacon aroma.The surface oil content was1.20%and the embedding efficiency was96.0%. It indicated that Yacon juice was added to the wall material of powdered oil successfully. The new kind of Yacon juice milk powder was prepared.
Keywords/Search Tags:waxy corn starch, non-crystallization, octenyl succinic anhydridemodified non-crystalline starch (OSA-MNS), Yacon, Yacon juicemilk powder, microcapsule
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