| Starch is the main nutrient component in human diet,which is widely used in food and non-food fields.However,starch is limited in practical application due to its high digestibility,weak emulsification ability and easy aging.In order to improve the quality and properties of starch,type A corn starch(CS),type B potato starch(PtS)and type C pea starch(PS)were selected as raw materials in this paper.The effects of OSA modification on the microstructure and digestibility of starch were first analyzed.On this basis,emulsifying activity(EAI),emulsifying stability(ESI),the storage stability,pH stability,salt ion stability and thermal stability of OSA starch-based emulsion were further studied.Finally,the application of OSA starch based emulsion in curcumin sustained-release carrier was discussed,which would provide a new idea for the application of OSA modified starch in emulsifier.The main results are as follows:(1)The effects of OSA modification on particle size,degree of substitution(DS),amylose content and digestibility of CS,PtS and PS were systematically studied.Results showed that the average particle size of OSA modified starch increased.The DS values of OSA modified CS(CS-OSA),OSA modified PtS(PtS-OSA)and OSA modified PS(PS-OSA)in descending order was PtS-OSA>PS-OSA>CS-OSA.Amylose content decreased with the increase of OSA supplemental level.FTIR results showed that two new characteristic peaks of CS-OSA,PtS-OSA and PS-OSA appeared at 1572 cm-1 and 1726 cm-1 compared to their respective control samples,and the short-range ordered structure and double helix structure of starch were destroyed by OSA modification.DSC results showed that OSA modification significantly decreased the To,Tp,Tc and ΔH values of CS-OSA,PtS-OSA and PS-OSA compared to their respective control samples.XRD results showed that OSA modification did not affect the crystal pattern of starch.In vitro starch digestibility results showed that the content of resistant starch(RS)in CS-OSA,PtS-OSA and PS-OSA was significantly increased compared with the control.At the same OSA supplemental level,PtS-OSA showed the best anti-digestive performance.(2)The EAI,ESI,storage stability,pH stability,salt ion stability and thermal stability of CS-OSA,PtS-OSA and PS-OSA based emulsions were studied.Compared with the control,CS-OSA,PtS-OSA and PS-OSA based emulsions had better EAI and ESI values.PtS-OSA based emulsion had the highest EAI and ESI,which were 8.04 m2/g and 87.21%,respectively.Storage stability results showed that the particle size of CS-OSA,PtS-OSA and PS-OSA based emulsion increases with the increase of storage time.The changes in particle size of PtS-OSA based emulsion droplets was relatively small,and the stability was the best with a higher absolute potential.The results of pH stability showed that CS-OSA,PtS-OSA and PS-OSA based emulsion were more stable than the control at the pH 5-7.The results of salt ion stability showed that with the increase of sodium chloride concentration,the demulsification of CS-OSA,PtS-OSA and PS-OSA based emulsions was more obvious,and the particle size of CS-OSA,PtS-OSA and PS-OSA based emulsions increased.However,the absolute value of zeta potential of CS-OSA,PtS-OSA and PS-OSA based emulsions showed the opposite trend.Thermal stability results showed that the thermal stability of PtS-OSA based emulsion was stronger than CS-OSA and PS-OSA based emulsion.(3)A composite carrier system of OSA starch and curcumin was established,and the emulsion storage stability,curcumin loading effect and controlled release of curcumin in the composite carrier system were studied.Results showed that the particle size and zeta potential of OSA starch-curcumin composite carrier system did not change significantly during storage.Under the same OSA concentration,the loading effect of CS-OSA,PtS-OSA and PS-OSA based emulsion was in decreasing order of PtS-OSA>PS-OSA>CS-OSA.The simulated release results showed that CS-OSA,PtS-OSA and PS-OSA based emulsion showed certain slow release properties compared to their respective control samples.The controlled release property of PtS-OSA based emulsion on curcumin was better than that of CS-OSA and PS-OSA based emulsion. |
PDF Full Text Request