Preparation,Release Kinetics Of Aroma Compounds Complex With Corn Starch

Corn starch had the properties of easy availability and low cost,especially amylose has a hydrophilic outer surface and a hydrophobic inner core that accommodates different types of aroma compounds.Complexation of aroma or volatile compounds can improve the solubility of aroma compounds and reduce their volatility,so expand their application.It could broadened the spectrum of corn starch applications in functional food development.Carvone was nonpolar aroma compound;heptanolide and menthone were weak polar aroma compounds;linalool,heptanol and menthol were polar aroma compounds,however,they were small aroma compounds,the high volatility and low solubility limit their application.So far,the research on the ability of corn starch to form inclusion complexes with nonpolar,weak polar and polar aroma compounds is still in the blank,corn starch aroma compounds(nonpolar or weak polar aroma compounds,heptanolide,carvone and menthone;polar aroma compounds,linalool,heptanol and menthol)inclusion complexes were obtained using the co-precipitation method combined with lyophilization method.The recombination ratio,physicochemical characterization,and release experiments of the corn starch aroma compoundsinclusioncomplexes under different conditions were analyzed and compared.The main results were as follow:1.Through single factor tests,the effect of different corn starch/aroma compounds inventory ratio(10:0.6 to 10:1.0),complexe reaction temperature(30? to70?)and complexe reaction extraction temperature(30? to 70?)on the recombination ratio of corn starch-aroma compounds complexes were studied.The results showed that corn starch-carvone complex prepared under 10:0.8 inventory ratio,50? complexe reaction temperature and 60? complexe reaction extraction temperature has the optimal recombination ratio as 38.5%;corn starch-heptanolide complex prepared under 10:0.7 inventory ratio,60? complexe reaction temperature and 40? complexe reaction extraction temperature has the optimal recombination ratio as 63.3%;corn starch-menthone complex prepared under 10:0.7 inventory ratio,40? complexe reaction temperature and 60? complexe reaction extraction temperature has the optimal recombination ratio as 43.3%;corn starch-linalool complex prepared under 10:0.8 inventory ratio,50? complexe reaction temperature and 60? complexe reaction extraction temperature has the optimal recombination ratio as 86.9%;corn starch-heptanol complex prepared under 10:0.7 inventory ratio,40? complexe reaction temperature and 50? complexe reaction extractiontemperature has the optimal recombination ratio as 61.5%;corn starch-menthol complex prepared under 10:0.7 inventory ratio,50? complexe reaction temperature and 40? complexe reaction extraction temperature has the optimal recombination ratio as 51.6%.2.Basis on the single factor tests above,the optimal inclusion parameters of six corn starch aroma compounds complexes were determined by orthogonal array design experiments.The results showed that the suitable parameters of corn starch-carvone complex was 10:0.8 inventory ratio,50? complexe reaction temperature and 70?complexe reaction extraction temperature with recombination ratio as 36.9%;the suitable parameters of corn starch-heptanolide complex was 10:0.6 inventory ratio,70? complexe reaction temperature and 50? complexe reaction extraction temperature with recombination ratio as 75.6%;the suitable parameters of corn starch-menthone complex was 10:0.6 inventory ratio,50? complexe reaction temperature and 70? complexe reaction extraction temperature with recombination ratio as 43.8%;the suitable parameters of corn starch-linalool complex was 10:0.7inventory ratio,60? complexe reaction temperature and 70? complexe reaction extraction temperature with recombination ratio as 91.9%;the suitable parameters of corn starch-heptanol complex was 10:0.8 inventory ratio,40? complexe reaction temperature and 40? complexe reaction extraction temperature with recombination ratio as 67.2%;the suitable parameters of corn starch-menthol complex was 10:0.6inventory ratio,60? complexe reaction temperature and 50? complexe reaction extraction temperature with recombination ratio as 54.7%.3.The aroma compounds release curves of six corn starch complexes were studied through storage experiment.The results showed that the relative humidity(RH)and temperature has influence on the release behavior of complexes.The lower the RH or temperature,the slower the guests released from the complexes.The release kinetics of the complexes was described by the Avrami equation.The results showed that the rate of guest release was faster with both increasing RH and temperature,and the effect of temperature was stronger.The k value of corn starch-carvone complex,corn starch-heptanolide complex,corn starch-menthone complex,corn starch-linalool complex,corn starch-heptanol complex,and corn starch-menthol complex were respectively ranged from 0.0412 to 0.0683s-1,0.0300 to 0.0551s-1,0.0437 to 0.0902s-1,0.0736 to 0.1939s-1,0.0743 to 0.2054s-1and 0.0762 to0.1574s-1.This indicated that the corn starch-polar aroma compound inclusion complexes(corn starch-carvonecomplex,corn starch-heptanolide complex,corn starch-menthone complex)had higher storage stability than corn starch-nonpolar or weak polar aroma compound inclusion complexes(corn starch-linalool complex,corn starch-heptanol complex,and corn starch-menthol complex).4.Physicochemical characterization of corn starch complexes presented:(1)SEM analysis showed that gelatinized corn starch had a laminated structure with smooth surfaces.Compared to gelatinized corn starch,corn starch aroma compounds inclusion complexes displayed laminated structure and network with a certain amount of penetrated holes,the morphology changes might be a reflection of the formation of inclusion complexes;(2)DSC analysis exhibited that after encapsulating with aroma compounds,the phrase transition temperature and the enthalpy of the complexes changed,and the six complexes ranked in descending order of the thermal stability(the enthalpy)were corn starch-heptanol complex(144.63J/g),corn starch-linalool complex(96.27J/g),corn starch-menthol complex(73.97J/g),corn starch-menthone complex(65.04J/g),corn starch-heptanolide complex(57.48J/g),and corn starch-carvone complex(33.63J/g),respectively;(3)FT-IR analysis showed that,compared to gelatinized corn starch,for corn starch aroma compounds complexes,most absorption peaks of the aroma compounds were covered by gelatinized corn starch except the characteristic absorption peak of C=O around 1771cm-1,and no new absorption peaks appeared;(4)XRD analysis showed that the crystallinity percent of the gelatinized corn starch was 16.3%,however,the crystallinity percent of corn starch-carvone complex,corn starch-heptanolide complex,corn starch-menthone complex,corn starch-linalool complex,corn starch-heptanol complex,and corn starch-menthol complex were 13.7%?19.1%?21.3%?25.3%?29.0%?23.0%,respectively;(5)The CP/MAS 13 C solid state nuclear magnetic results revealed that the corn starch aroma compounds complexes possessed the chemical shift peaks of the carbon atoms of the aroma compounds,and the chemical shift peaks of the carbon atoms of corn starch moved weakly.The synthesis results indicated that the corn starch became the new phases after encapsulating with the aroma compounds,and the corn starch aroma compounds complexes were indeed formed.