Study On The Extraction And Purification Technology Of Pectin In Seed-using Watermelon

Pectin is based on the ProtoPectin, Peetinicacid and PectiePectin forms widely distributedpolysaccharide macromolecular compounds in plant fruits, roots, stems, leaves, is a hydrophilic gum. Thebasic composition of pectin backbone molecule is D-galacturonic acid. There are a number of naturalneutral sugars such as rhamnose, xylose, galactose, Arabia sugar, glucose, also exists in the pectin. Pectinhas good emulsification, thickening, stability and gelation, not only widely used in the food industry,butalso is the essential industrial medicine, cosmetics, printing and dyeing and other accessories. Seed-usedwatermelon as an agricultural waste in production in Xinjiang Province and in the northwest of China haslot of production, extracting pectin, make full use of seed melon has a broad market prospect, and cansolve the problem of environmental pollution caused by waste, waste, increase the added value of seedmelon pomace。The results show that:1、Seed-used watermelon crushing is appropriate size in the mesh60mesh; Seed-used watermelonenzyme by using method of waste water blanching, time to5minutes is appropriate.2、Through single factor and orthogonal experiment, acid treatment conditions, to get the bestextraction process was: extracting temperature was90℃, pH value1.5, extraction time2.5h, the ratio ofmaterial to liquid (W:V) for1:15, pectin yield is19.7%. Through microwave treatment effects ofconditions of single factor and orthogonal experiments, the pH value is1.5, extraction time4min, ratio ofsolid to liquid (W:V) is1:15, the microwave power was400W, the average yield was21.7%. The singlefactor and orthogonal test by ultrasonic treatment conditions, pH value is1.5, extraction time35min, ratioof solid to liquid (W:V) as1:20, ultrasonic power was450W, the average yield was17.3%, the microwaveextraction of pectin, pectin yield is the biggest, and the extraction time is greatly shortened, so themicrowave assisted extraction of pectin.3、 The optimum process conditions for seed melon pericarp pectin liquid activated carbondecolorization: activate carbon dosage was2.0g/100mL, pectin solution pH value was6, thedecolorization temperature is50℃, adsorption time is40min.. The optimum process conditions for resindecolorization: on the column temperature was60℃, flow rate of200mL/h. Protein by TCA method forremoving pectin can remove63.2%of the protein, Soluble sugar by dialysis method for removing pectinsolution effect significantly, can remove95.6%of the soluble sugar.4、The seed melon pericarp pectin separation process was studied, the concentration ratio, dosage ofethanol and pectin solution pH value effect on pectin yield. According to the single factor experiment theoptimum concentration for1/4, ethanol dosage is2times the volume of concentrated pectin, pectinsolution pH value is about3.5.5、Tthe loss on drying of seed melon pectin was5.95%, the total ash content is4.6%, pH is2.83, thedegree of esterification was36, galacturonic acid was78.3%, the arsenic content of0.017mg/kg, the leadcontent was0.34mg/kg, with QB2484-2000and GB/T5009.11-2003, GB/T5009.12-2003requirements; determine the seed melon pericarp pectin intrinsic viscosity [η]=0.2756m3/kg through viscosity method,pectin viscosity average molecular weight of M η=89172.9; seed melon pectin was dark brown, slightlydarker than the standard pectin; solubility acidity effect; thermal stability and acid resistance are better;pectin viscosity decreases with increasing temperature, and increased with the pectin concentration and theincrease of concentration of sucrose, and decreases with calcium chloride, sodium chloride andconcentration of citric acid.