Abstract:

Sorghum polyphenols， as a natural active ingredient， have many potential health benefits. Through microcapsule embedding technology， the stability and efficacy of sorghum polyphenols can be improved. The study targets sorghum polyphenols as the active ingredient， uses sodium alginate solution to prepare sorghum polyphenol microcapsules， and conducts single factor orthogonal experiments， thermogravimetric analysis， and determination of sorghum polyphenol release rate. Through single factor investigation and orthogonal test combination， it is found that when the mass fraction of calcium chloride is 2.5%， the mass fraction of sodium alginate is 2.25%， the mass fraction of sorghum polyphenols is 0.3%， the embedding time is 0.5 h， and the mass fraction of chitosan is 1.5%， the embedding rate of microcapsules could reach 87.19%. The results show that polyphenols are the most important factor affecting the embedding rate， followed by chitosan， while sodium alginate， calcium chloride， and embedding time has relatively small effect. The microcapsules prepared under the optimal combination conditions have a tighter embedding structure and good embedding effect. The release time of microcapsules in intestinal fluid is shorter and more efficient than in gastric fluid， with a maximum release rate of 83.16%. This rapid release can effectively prevent changes in sorghum polyphenols during the release process in the body and improve the utilization rate of active substances by the human body. The microencapsulation of sorghum polyphenols can provide scientific basis for the deep processing and subsequent property research of sorghum.

Key words: Sorghum, Polyphenols, Microcapsules, Orthogonal method