Preparation Of Hawthorn Pectin Oligosaccharide And Its Antibacterial Activity

This paper mainly studied the extraction method and main components of pectin in hawthorn.And to explored the conditions of the enzyme solution to produced the oligosaccharides and separated it.Finally researched bacteriostasis of oligosaccharides and its preservation effect of food.The main results are as follows:First of all,the hawthorn was taken from chengde,hebei province in 2016.Compared the different extraction method to extract the hawthorn pectin obtain ion exchange extraction method is more suitable for hawthorn pectin compounds in the extract.The yield of pectin was the index,The experiment factors were used to extract the temperature of resin,Using single factor test and response surface test,Ion exchange was optimized extraction optimum process of extracting pectin compounds are as follows:solid-to-liquid ratio 1 : 26.68g/mL,extraction temperature 89.90 ℃,resin dosage 0.76 g,extracting time120 min.Under the condition,the yield of pectin compound was 5.135%,and the extraction rate was 92.87%.Useing D101 Resin dosage 1.0g,extract pH2.0,water bath oscillation temperature 35 ℃,decolorization time 9h,the decolorization rate is 84.58%,and the retention rate of pectin is 82.86%.A mathod of a liquid phase chromatography to analyze the monosaccharide composition was established.The samples of hawthorn pectin were detected by liquid phase detection,Its monosaccharides are made up of mannose,rhamnose,galactose and arabinose,The mole ratio is 1.34:2.06:5.45:1;The esterification of pectin was 66.43%,The ash content was 5.42% and the moisture content was 2.7%.Subsequently,the effects of enzymatic hydrolysis conditions on the oligosaccharide polymerization were investigated.Using single factor experiment,the enzymatic hydrolysis temperature,enzymatic hydrolysis and enzymatic hydrolysis were investigated.The optimal enzymatic hydrolysis conditions for enzyme solution temperature 50 ℃,120 min,enzymolysis time with enzyme quantity is 1g/L.Subsequently,D201 anion exchange column was compared with the glucan gel G-50 column to analyze the sepetation effects of pectin oligosaccharide.The results showed that the separation effect of glucan gel g-50 was better,and 4 kinds of oligosaccharides with the polymerization degree 2-5 was seperated.Finally,researched the influence of the ratio of the expansion agent,the chromogenic agent and the color temperature on the TLC.Eventually determine the detection of sugar by TLC was the best condition is an agent for n-butyl alcohol: acetic acid: water = 2:1:1,chromogenic agent for methanol: sulfuric acid = 95:5,the temperature is 120℃,The results showed that the polymerization degree was 2-5.Thirdly,the antibacterial properties of pectin oligosaccharide were studied,The antibacterial properties of bacillus subtilis,e.coli,staphylococcus aureus,saccharom yces cerevisiae and lactobacillus were determined.In this experiment,the antibacteria l effect of oligosaccharides with different polymerization degree was determined,an d the antibacterial ability of pectin oligosaccharide was detected by antibacterial rin g and minimum inhibitory concentration;The stability of oligosaccharide inhibition was detected by different treatment conditions;The bacteriostatic mechanism was st udied by measuring the growth curve,morphology,conductivity and leakage of con tents.The results showed that:The average polymerization degree was 3,and the ant ibacterial effect was the most significant,The antibacterial effects of e.coli,bacillussubtilis and staphylococcus aureus were the most significant,The antibacterial effec ts of e.coli,bacillus subtilis and staphylococcus aureus were the most significant.T he antibacterial activity of pectin oligosaccharides was stable under different treatm ent conditions.The antibacterial activity of pectin oligosaccharides was stable under different treatment conditions.It can be found that with the increase of the concentr ation of pectin oligosaccharide,the relative conductivity of the bacterial suspensionincreases rapidly,It showed that the membrane permeability of bacteria was affecte d,and the increase of nucleic acid and protein content indicated that the membran e integrity was destroyed,It is indicated that the oligosaccharides can cause the bact erial cell to rupture,causing the material leakage of the substance,affecting its me tabolic activity,and eventually leading to the apoptosis of the bacteria.Finally,we studied the effect of oligosaccharide of hawthorn as natural preservative on the bread,and made fresh coating of strawberry.The effect of antisepsis preservation was studied.The results showed that pectin oligosaccharides could effectively inhibit the growth and reproduction of mold,bacteria and other microorganisms in bread production,Mildew and mycelium on the bread surface were delayed from day 5 to day9,Mold,total bacteria and so on exceeded GB7099–2003 bacterial count from 3 days to 9days,Effectively prolongs the shelf life of bread.Evaluation of sensory attributes in 1-9days.Adding pectin oligosaccharide group bread was significantly better in appearance,flavor and degree of corruption than without pectin oligosaccharide bread;The time of strawberry mildew in strawberry was significantly delayed compared with that in thecontrol group,In the 1-9 days of physical and chemical properties,the treatment of strawberries was significantly superior to the control group in the index of weightloss,Vc,soluble sugar,titration and soluble solids.The results showed that pectin oligosaccharides had a great prospect in the food industry as a natural food preservative.