| In the study,Granular Cold Water Soluble(GCWS)waxy corn starch and porous GCWS waxy corn starch were prepared by using waxy corn starch as raw material,and the preparation conditions,starch morphologies,crystal structures,paste properties and adsorption properties of the two kinds of starches were studied.To improve the dispersibilities and adsorption properties of porous GCWS starch,the cross-linked porous GCWS waxy corn starched were prepared.Finally,GCWS waxy corn starch,porous GCWS waxy corn starch,cross-linked porous GCWS waxy corn starch were embedded by organic solvent with lemon essential oil,and the properties of embedded samples,especilly the embedding effects were compared.GCWS starches were prepared by alcohol-alkali treatment and the differences in properties of different GCWS starches with different cold water solubility were compared.The effects of alkali addition,absolute ethanol addition and reaction time on the cold water solubility of GCWS starches were studied by single factor experiments.The best cold water solubility of GCWS waxy corn starch was 97.3% whose reaction condition were: the mass ratio of starch(dry basis)to 3 mol/L NaOH was 1:4,and the mass ratio of starch(dry basis)to absolute ethanol was 1:8.5,and the reaction time was 15 min.The best cold water solubility of porous GCWS waxy corn starch was 96.4% whose reaction condition were: the mass ratio of starch(dry basis)to 3 mol/L NaOH was 1:3.5,the mass ratio of starch(dry basis)to absolute ethanol was 1:8.5,and the reaction time was 10 min.The results showed that as the addition of alkali and absolute ethanol increased,the cold water solubility of GCWS starch increased first and decreased then.The effect of reaction time on the cold water solubility was smaller than that of alkali and anhydrous ethanol.After enzyme hydrolysis,it's easier to prepare GCWS starch.SEM of GCWS starch with different cold water solubilities showed that the starches became dent-twisted,and the starch tended to flatten with the increase of cold water solubility,the Maltese Cross disappeared,and the X-ray diffraction pattern changed from an A type to an amorphous type.Turbidity,viscosity,freeze-thaw stability,oil absorption capacity decreased with the increased of cold water solubility.Pores remained on the surface of porous GCWS starch Granulars after enzymatic hydrolysis,and the oil absorption capacity increased.Cross-linked porous GCWS starch was prepared with different cross-linked starch.The study showed that the cross-linked porous GCWS starch granulars changed into a twisted depression.The higher the degree of crosslinking,the more obvious pores we can observe on the starch particles.The crystal structure changed and the Maltese Cross disappeared.The Xray diffraction pattern was an amorphous type.With the increase of cross-linking degree,the rate of oil absorption increased first and then decreased.The transparency and cold water solubility got worse.The water dispersibility of cross-linked porous GCWS starch increased with the increase of cross-linking degree..The GCWS starch,porous GCWS starch and crosslinked porous GCWS starch of the best oil absorption capacities were embedded with lemon essential oil by organic solvent.The SEM showed that there were many cracks on the surface of GCWS starch after embedding lemon essential oil.The surface of porous GCWS starch was smooth and the pores disappeared.However,there were still holes in the surface of crosslinked porous GCWS starch,and the surface was rough and uneven.The embedding rate of three embedded samples were more than 70%,among which the embedded porous GCWS starch had the best embedding effect,whose embedding rate reached 83.49%.The three kinds of starches could delay the volatilization and oxidation of lemon essential oils.All three starches dissolved quickly in cold water and released the lemon essential oils quickly. |
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