Study On The Extraction, Toxicology And Antioxidant Activities Of Dietary Fiber From Citrus Sinensis Osbeck Cv. Jincheng Peel

People are fond of citrus fruits,which are aromatic,delicious,and have high nutritional value.Apart from the rich juice,sweet and sour,Citrus also have rich sugars,organic acids,minerals,cellulose,amino acids and vitamins,especially higher vitamin C content than other fruits.Citrus peel is widely used as functional food and pharmaceutical raw materials,which has good development prospects.However,as a food additive,the security issues of dietary fiber from Citrus peel have drawn people's special attentions.The study will select the best way to extraction of dietary fiber from Citrus sinensis Osbeck cv.Jincheng peel by enzymatic.And it also will make toxicological evaluation of the safety for dieary fiber from Citrus sinensis Osbeck cv. Jincheng peel and study on the antioxidantnt activites of dietary fiber from Citrus sinensis Osbeck cv.Jincheng peel by radical assay systems.The study will provide a theoretical basis for the safty and functional effect of dieary fiber from Citrus peel.The main tasks and conclusions of the papers are as follows:1.The orthogonal test L₉(3⁴) was performed to determine the optimal extracting conditions as follow:the time was 2h,the temperature was 50℃,mixed enzyme addition was 0.2%and the pH value was 7.5.The TDF content of products was 69.08%and the SDF content was 20.73%.The swelling capacity of products was 9.02ml/g and the water holding capacity of it was 11.09g/g.2.The savenging effect of Citrus sinensis Osbeck cv.Jincheng peel DF was studied by free radical assay systems,which included hydroxyl radical system,superoxide radical system and DPPH system.The results showed that Citrus sinensis Osbeck cv.Jincheng peel DF exhibit reducing power.In superroxide radical assay system,free radical scavenging ratio was as high as 46.28%,lower than 50%,which means its savenging effect in this free syetem is not strong while IC₅₀ of V_C in this system was 37.43μg/ml.Its IC₅₀ in hydroxyl radical assay system was 3.27mg/ml while IC₅₀ of V_C in this system was 97.63μg/ml.In DPPH system,its IC₅₀ was 5.66mg/ml while IC₅₀ of V_C in this system was 14.43μg/ml.It was proved that Citrus sinensis Osbeck cv.Jincheng peel DF exhibit reducing power and had the scavnenging effect on free radical compared with V_C in these systems.3.In order to assess the food safety of the Citrus sinensis Osbeck cv.Jincheng peel DF,the acute toxicity test,micronucleus test of marrow cells as well as chromosome aberration test and 30 days feeding test were carried out ro judge the acute toxicity,genetic toxicity,embryo toxicity and general toxicity according to the methods of our country for toxicological assessment on food safety.The results showed that the LD₅₀ for Citrus sinensis Osbeck cv.Jincheng peel DF was more than 15g/kg,belonging to nontoxic level;there was no obvious toxicity,side-effect and dose dependently,and genetic toxicity,teratogenicity effect and mutabginicity wasn't observed with range of high dose.Therefore,the Citrus sinensis Osbeck cv.Jincheng peel DF was an edible and safe food without obvious signs of toxicity to trial animals in according with the demands of procedures and methods for toxicological assessment on food safety.