Research On Series Extraction Technique Of Valuable Elements From Orange Peels

Some deeply processed products of orange peel such as yellow pigment, pectin , hesperidins and dietary fiber have high application value in chemical food industry. Through the methods of anhydrous ethanol soaking , alkali solution dissolution ,salts adsorption ,hydrogen peroxide the de-coloration, the orange pigment, hesperidins, pectin, dietary fiber were extracted. The technical condition as well as the content of each substance were studied and discussed .First of all , detailed studies of extracting separating and purifying yellow pigment are carried out in this paper .Compared by the effect of 4 methods such as immersing ,solvent refluxing technique , microwave and ultrasound technique ,it is found that with microwave radiation technique the obtained rate of orange peeling pigment is higher than immersing or solvent refluxing technique. Optimal parameters of extracting yellow pigment by immersing are respectively got through orthogonal experiment. The results show that the optimal condition of immersing technique are :the ratio of 90% ethanol to orange peel weight 1:4, orange peel is immersed at 30℃ for 3 time and amounted to 6h. Then, the effects of pH , light and reagent on the physical and chemical performance of pigment are also discussed.Secondly, a method is studied on extracted citrus hesperidins from orange peel after extracted pigment. The results of the study indicate that the optimum technological condition are solid-liquid ratio 1:15, under 75℃, 3h of extracting and pH 4, the total extraction yield was 5.8%.In the same time, the antimicrobial activity of hesperidins are studied .The results show that hesperidins can effectively inhibit the growth of food pollutant bacteria.What's more , we studied the extracting and purifying technology about pectin using orange peel after extracted pigment and hesperidins as the raw material .It involved the following aspects: choosing the optimal acidulous reagent, determining the optimal parameters of extracting technology of pectin , attempting the experiment of pectin de-coloration and purification. At the above condition, influence of process parameters , such as variety and dosage of salts, the pH ,salting out time and temperature on the pectin were carried out .The result shows: the optimal parameters of pectin extracted by acid are: 90℃, pH 2.0, 2.0h,the ratio of raw material and water 1:13. The optimal condition of salting out is: the ratio of mixed salt 2:1, salting out time 1.5h, pH 3.8 and temperature 80℃.The colure of the pectin by salting out...