Research On Extraction Technique Of Pectin And L-Citrulline From Seed Melon

The seed melon is uesed to melon seeds.Most of rinds and pulps of melon are wasted,leading to resource waste and environmental pollution.by extracting of the pectin and L-citrulline due to its abundant natural ingredient it is important to realize the waste utilization of seed melon.In this experiment,seed-melon pulp was used as test material to study the technics of extraction,separation and purification of pectin,and membrane separation and concentration technics of L-citrulline.The application provided reference for the equipment selection and parameter determination in industrial production of extracting L-citrulline.The main results were as follows(1)The effects of ionic liquid types,iquid ratio,ultrasonic time,ultrasonic power and ultrasonic temperature on the galacturonic acid content of the extracted pectin.The optimum were investigted using ionio liquid as extractant of seed melon extraction conditions were as follows:ionic liquid([Bmim]C1)concentration was 1 mol/L,solid-liquid ratio was 1:20(g/mL),ultrasonic power was 300 W,ultrasonic time was 40 min,extraction temperature was 70?.In this conditions,the pectin galacturonic acid content was 82.89%(2)The effects of macroporous resin types,pH value,temperature,flow rate,and the amount of processing on decolorization of pectin were studyied.Results show that HZ-801 resin had better decolorizing effect on pectin extractant and the loss rate of extractant was low.The optimum conditions that maximing elimination of pigment by HZ-801 resin were found as temperature of 30?,flow rate of 3 BV/h,solution processing amount of 4 BV,upper column pH value of 4.0.The decolorizing rate of pectin extractant was 81.65%(3)Pectin destainer was was dried using spray drying technology.The effects of feeding rate,feeding temperature and destainer mass concentration on the decoloration of pectin were studied.The prepared conditions were as follows:the flow rate was 25 mL/min,the feeding temperature was 190 C,the destainer mass concentration was 0.6,and the pectin quality was in accordance with national standard GB2553-2010.(4)Use ultrafiltration membrane to remove impurity of L-citrulline extracting solution,decolourize of nanofiltration and condense the reverse osmosis membrane.The protein removal rate in the L-citrulline extracting solution extracted by ultrafiltration membrane was 95.77%,the pectin removal rate is 95.37%;nanofiltration decoloration technology's pH was 2.0 and temperature was 20?,pressure 1.0 Mpa,screening decolorizing rate was 82%under the conditions of nanofiltration and decolorization.The reverse osmosis membrane can concentrate L-citrulline extract 8.3 times(5)The scale-up experiment of L-citrulline extraction was carried out on the basis of test 2.81 g L-citrulline can be extracted from a kilogram seed melon pulp,and the purity was 83.87%.The analysis of technical economy provides theoretical basis and technical support for the application of processing and extraction technology of seed melon by-products.