Preparation And Application Of Hawthorn Pectin And Its Galacturonic Acid

As a kind of acidic macromolecular polysaccharide,pectin has a complex structure and a variety of functions.It plays an important role in the field of food and medicine.The polygalacturonic acid of oligosaccharides could be obtained from pectin by different ways of degradation,which have physiological and biological activities.Hawthorn is rich in pectin,as the biggest producing area of hawthorn,Hebei Hawthorn not only yields large,but also rich in varieties.The study of Hawthorn pectin oligosaccharides is an effective way to widen the processing range and increase the added value of hawthorn.In this paper,taking the Hawthorn from Yanshan area as raw material,we studied the extraction,physical and chemical indexes and of pectin,the hydrolysis conditions of pectinase and the separation,analysis and preliminary application of polygalacturonic acid.The main results are detailed as follows:1.In this paper,the monosaccharide composition,the content of pectin methyl,the degree of esterification and the content of pectin acid of 9 varieties of Hawthorn were compared.The results showed that Haw Pectin was acidic polysaccharide.The main component of pectin is galacturonic acid,and hawthorn pectin were of high methoxyl pectin.The result of HPLC analysis of pectin composition shows that,big Venus Hawthorn pectin was composed of six monosaccharide components,namely,rhamnose,Arabia sugar,galactose,glucose,galacturonic acid,glucuronic acid.The content ratio of each component was 2.69︰30.7︰3.2︰0.67︰53.61︰9.12.Through the analysis of the yield and methoxy content,Pectin acid,screening Dawang hawthorn as further experimental varieties,to provide the basis for the next stage of haw pectin.2.Based on the temperature,time,solid-liquid ratio,extraction pH of single factor and orthogonal experiment,the optimal extraction conditions of Hawthorn pectin polysaccharide were obtained,extraction temperature 70,extraction time 70 min,solid-liquid ratio 1︰35(W/V),pH 2.5.Under these conditions,the extraction rate of Haw pectin was 5.04%.The application of pectin in hawthorn jelly,screening the pectin content of 0.9%,can significantly improve the taste of hawthorn jelly and reducing the sugar content of hawthorn jelly.3.Pectin acid,which prepared by the de-esterification reaction of haw pectin,enzymatic hydrolysis for 1 h at 45 ℃ and pH 4.5 conditions.Polygalacturonic acid mixture obtained from the reaction was separated and prepared by anion exchange resin.Selected of polygalacturonic acid with high antioxidant capacity by DPPH and reducing power as the determination index.ESI-MS analysis was performed to analysis the mixture and ascertained polygalacturonic acid with the degree of polymerization of 3,4,5,7,9.The results showed that when the amount of 0.2% was added,the galacturonic acid oligosaccharide could effectively retard the growth of lactic acid bacteria.Under the storage environment of 30 ℃,the results show that the acidity of yogurt with 0.2% pectin at the seventh day is equivalent to the acidity of contrast yogurt at the fifth day.And it can obviously prolong the shelf life of yogurt.