The Physicochemical Properties And Biological Activity Of Pingguoli Pectin

With the research and development of functional polysaccharides, pectin as a soluble dietary fiber was paid more and more attention. Different kinds of materials had used to extract pectin but less reporting on the pectin which extracted from Pingguoli. In this article the changes of pectin substances in the Pingguoli during the growth period were studied, so to establish the best location and extracted times of pectin then the pectin was extracted by acid method from Pingguoli. The physicochemical properties such as purity,degree of esterification and intrinsic viscosity et. and the retardation index of pectin on glucose and taurocholic acid movement were determined respectively. In order to development a new resource to extract pectin and provide ingredients for functional food so that these could improve the utilization of Pingguoli and contribute to economic benefits. The research showed that:The yield of alcohol-insoluble solids in the peels and flesh had maximum at 50 days after full bloom during the growth period and then decrease with the mature of fruits. The yield of alcohol-insoluble solids in the peel was higher than the flesh's.The content of total pectin in the peels and flesh of alcohol-insoluble solid and peels of fruit were higher at fruit expanding process and then declined gradually but it was highest in the flesh at 50 days after full bloom during the growth period. The content of pectin in the peels was higher than the flesh.The content of sodium hydroxide soluble pectin was the main component among four pectin components in the young fruit; however the content of hydrochloric acid soluble pectin was higher than sodium hydroxide soluble pectin in the mature fruit. The rates of water-soluble pectin and ammonium oxalate soluble pectin were almost lower during the growth period.The purity of Pingguoli pear pectin with precipitation method after acid hydrolysis could reach more than 70%. The color was light brown in the early stage and was white in the mature period. The intrinsic viscosity and molecular of pectin in the mature stage were 4.32dL/g and 69,6000, they were higher than the pectin in the early stage, however the pectin in the early stage and mature were both high-methoxyl (HM),then the pectin in the early stage was HM slow gel pectin and was the HM rapid gel pectin in the mature periodThe retard absorption of Pingguoli to glucose and taurocholic acid could keep four hours and twenty four hours respectively, however at one hour and eight hour had obviously effect on the retard absorption of glucose and taurocholic acid.