Study On The Stability And Microencapsulation Of Hawthorn Extract

Hawthorn contains many kinds of chemical composition with physiological activation, and combines food value and medical value together. It is a kind of plant which has a long history in China. In this paper, the stability of hawthorn extract in different storage conditions and microencapsulation technology was investigated.Firstly, major active components from hawthorn extract had been quantitated, and antioxidant activity of hawthorn extract had been evaluated in vitro. Detected by UV-spectrophotometry, the content of proanthocyanidins was59.77%, the average degree of polymerization of proanthocyanidins was2.29, both using catechin as comparison sample. To quantify Procyanidin B2and Epicatechin present in hawthorn extract, a HPLC method was developed. It was showed that the contents of these two compounds were19.43%and15.26%, respectively. The extract had a strong reducing capacity, total antioxidant activity, scavenging effects on DPPH·,·OH and·O2-, inhibiting role on liposome peroxidation.Secondly, the stability and antioxidant activity of hawthorn extract in different storage conditions had been investigated. Results showed that hawthorn extract was sensitive to heat, light and oxygen, and was stable under acid condition. The extract was severely destroyed when Fe3+, Cu2+or Fe2+was added, and was a little affected when the medium added Mn2+or Al3+, so the extract should avoid Fe3+, Cu2+, Fe2+, Mn2+and Al3+. Food additive ascorbic acid, citric acid and sodium bisulfite could protect the extract. Moreover, there was a positive correlation between content and antioxidant activity of hawthorn extract.Finally, the effect of different wall-materials had been compared, and experimental conditions of hawthorn extract microcapsule according to the orthogonal experimental design had been optimized. The optimum microencapsulation conditions were as follows: microencapsulation temperature was30℃; microencapsulation time was1h; the ratio of core-sub stance to wall-material was3:7(W:W), and the content of arabic gum was40%(W/W); the percent of EDTA-2Na in the whole materials was0.02%(W/W), and the content of the slurry was25%(W/V). According to the optimum conditions, the content of proanthocyanidins in microcapsule was16.11%.Detected by high performance liquid chromatography (HPLC), major components of core-sub stance in microcapsules were not changed or destroyed during microencapsulation; Observed by scanning electron micrographs (SEM), microcapsules were complete. The results of experiments also showed the stability of hawthorn extract was increased.