The Preparation Of Octenyl Succinic Anhydride Starch And Alginate Composite Carrier Material And Its Release Property

One of the key and basic issues to be solved in the field of health food area is to obtain oral intestinal targeting controlled release microparticals delivery system to enhance the bioavailability of the bioactive components.The small intestine is an important organ to absorb functional factors,therefore,the development of the small intestine targeted delivery system materials and their delivery systems had important value and broad application prospects.This article aimed to meet the requirements of the targeted controlled release of some biological macromolecules,using octenyl succinic anhydride starch and sodium alginate as the carrier material,the oral intestinal targeting controlled release microparticals were achieved by adjusting the degree of substitution(DS)and molecular weight of starch,as well as the ratio of OSA starch and sodium alginate,through controlling the swelling,rheological,digestion,film-forming properties and controlled release performance of the carrier materials.The octenyl succinic anhydride starch carrier materials with different substitution degree and molecular molar mass were synthesized by adjusting the mass of the octenyl succinic anhydride(OSA)and the degree of acid and heating degradation.With the increase of substitution degree and the molecular weight of starch,the content of resistant starch was rising up to 32.3%,but its degradation rate in the gastric juice was as high as 65.4%,therefore,it was necessary to reduce the degradation rate of starch films in order to put it into the application of small intestine targeted delivery system successfully.Combined the pH dependence of sodium alginate and its gel forming properties,prepared OSA starch and sodium alginate composite film,the structure of the composite film was analyzed by fourier transform infrared spectrometer,X-ray diffraction,small angle X-ray scattering instrument and the dynamic thermal mechanical analysis,the mechanical properties,swelling rate and degradation rate in the gastric juice and digestion performance of composite film were also investigated.The crystal shape of blend film changed compared with starch,with the adding of sodium alginate,the interactions between the sodium alginate and starch were stronger,the ordering degree of aggregation improved,the Ca2+ with sodium alginate formed tight structure by electrostatic forces,with the increasing of substitution degree of starch,there formed more microcrystalline structures.For OSA starch with larger molecular weight,the double helix structures were relatively more stable with higher crystallinity,and the corresponding content of resistant starch was more;DMA results showed that with the adding of sodium alginate,the interactions between the sodium alginate and starch were stronger,causing the movement friction of the molecular chain segment improved,the glass transition temperature and the initial storage modulus increased.OSA starch with appropriate Mw had larger glass transition temperature and initial storage modulus due to the higher degree of crystallinity of its composite film.With the increase of the content of sodium alginate,the degradation rate of composite film decreased in gastric juice,moreover,the swelling rate and degradation rate of the films crosslinked with Ca2+ were greatly reduced;And with the increase of the content of sodium alginate,the resistant component of composite film increased greatly;With the increase substitution degree of OSA starch,there formed more V-shaped crystallization,as a result,the resistant component of the component film increased,the composite film of OSA starch with larger molecular weight had higher degree of crystallinity,its corresponding resistant component was more.Furthermore,the OSA starch and sodium alginate film coating microparticals were produced by aqueous fluidized bed film coating technology,using OSA starch and sodium alginate as carrier film coating materials,natto kinase as model function.As the increasing of sodium alginate and the molecular weight of OSA starch,the viscosity and the gel rate of compositeing system increased,while with the increase of substitution degree of OSA starch,the viscosity of compositeing system decreased.With the increasing of sodium alginate,the release of natto kinase decreased gradually,the release of natto kinase in simulated gastrointestinal juice within 2h reduced to 41.7% by controlling the ratio of OSA starch and sodium alginate.As the the molecular weight of starch increasing,the release of natto kinase reduced slightly.The substitution degree of starch had little influence on the release of natto kinase.Microparticals crosslinked with 0.2mol/L Ca2+ had a slower releasing speed,the result indicated that the delivery system possessed better small intestine targeting property.This research focused on the key problems about the preparation of the targeting controlled delivery carrier materials and the establishment of polysaccharide composite film coated microparticals through controlling the substitution degree and the molecular weight of starch,as well as the ratios of OSA starch and sodium alginate.And the sodium alginate composite film structures were characterized,the rheological properties of composite system were studied.Thus,they provided basic data and theory basis for designing high performance of OSA starch and sodium alginate oral controlled-release carrier systems.