Study On Extraction Of Polyphenol Compounds From Pomegranate

In recent years, studies show that the reason for a variety of diseases,such as human aging, cancer are related to oxygen free radicals. Because the security of synthetic antioxidants was under suspicion, people began to pay attention to natural and safe antioxidants. Ellagic acid has a strong free radicals scavenging capacity, which has an excellent prospect in natural antioxidants application on food, daily chemical and polymer synthesis. When reasercher were looking for new a source of ellagic acid, pomegranate extract was increasingly receivied attention and affection for its high resistance to oxidation.China is the largest producer of pomegranate, where many different varieties of pomegranate were. So china has cultivated a rich resource for preparation of ellagic acid in pomegranate. In this dissertation, the method of preparation of ellagic acid from pomegranate husk and pomegranate leaf was studied. We established the production process of ellagic acid from pomegranate leaf. On the basis of the mechanism that pomegranate husk tannins could transform to ellagic acid, the production process of ellagic acid using pomegranate husk as raw material was established.1. Production process of ellagic acid from pomegranate leaf as follow: The powder of pomegranate leaf was hydrolyzed by 5% H2SO4 at 110℃for 8 hours.Then 44.7g of ellagic acid at 27% purity from 100 g pomegranate leaf was obtained. After alkali and acid treatment in proper order,11.7g of ellagic acid at 88% purity was yielded.2. Production process of ellagic acid from pomegranate hust was as follow: The powder of pomegranate husk was hydrolyzed by 3% H2SO4 at 110℃for 13 hours. Then 36.6g of ellagic acid at 23.7% purity from 100 g pomegranate husk was obtained. After an alkali and acid treatment,8.7g of ellagic acid at 83% purity was yielded.3. After comparing several methods for removing crystal water, we established the method as follows:The lOg powder of ellagic acid was added 300mL methanol at 65℃for 1hours. Then 8.7g of ellagic acid at 97.8% purity was obtained.4. A novel HPLC method was developed for analyzing the content of ellagic acid, which eliminated the influence of acid to the response of UV detector. This method had a good separation effect and was simple and timesaving.