Study On Extracting Technology And Physicochemical Properties Of Pectin From Chili

Pectin is a polymer molecular weight belongs to the derivatives of carbohydrates in chemical classification, molecular weight between50,000-300,000, the basic component unit is D-pyranoid galacturonic acid. Because of good emulsification, thickening, stability and gelation effect, pectin has been widely used in food, medicine, cosmetic, textile, printing, dyeing, metallurgy, tobacco industry, etc.In our country capsicum is not only an important economic crops but also a kind of effective industrial raw materials, with chili industrial develepment unceasing, part of the process will produce capsicum residue, it can be used to reduc waste of resources and avoid large chili waste pollution.The pectin preparation process and physicochemical properties of the chili residual which already extracted capsanthin, and the results are as follows:Using hydrochloric acid as extraction agent with microwave-assisted,through single factor and orthogonal test to get the optimum technological conditions to extract pectin.The optional extraction conditions are that the microwave power is450W,microwave time is9min,the ratio of solid to liquid is1:30and the pH of solution is1.5,the total yield of pectin is12.1%. The extraction solution need decolor preliminarily to purify, get the best conditions for carbon decoloring:the decoloring temperature is70℃, the dosage of activated carbon is0.3g, the decoloring time is60min, the decolouring ratio is54.4%and the pectin is14.3%lost.After decoloring to removing impurity,the best technological condition is every100mL extract to use salt8mL, the pH is6.5, the salting-out temperature is65℃and the salting-out time is40min, the total yield of pectin is10.8%, galacturonic acid content is73.1%.Using aluminum sulfate as precipitation agent,the optimal conditions of desalination is each4g pectin in250mL desalting liquid which content is60%alcohol+3%hydrochloride+37%water solution, fully mixing30min.The chili pectin is high methoxyl pectin(HMP) and the degree of esterification (DE)is71.2%.Base catalysed de-esterification produce low methoxyl pectin(LMP), the optimum conditions is the temperature is10℃, time is60min, pH is9, DE is48.3%and galacturonic acid content is69.4%. The method for detect of chili high ester pectin and low ester pectin is FCC and GB about gel, moisture, ash, metal elements, galacturonic acid content and results meet the requirements.To investigate physicochemical properties of the chili high ester pectin and low ester pectin include the solubility, viscosity, emulsification and emulsion stability, gelatin,electron microscope etc, found that the solubility and viscosity of low ester pectin has a certain extent reduced, and emulsification emulsion stability has been improved.