【作者】 李燮昕；

【导师】 蒲彪；

【作者基本信息】 四川农业大学 ， 农产品加工及贮藏工程， 2009， 硕士

【摘要】 柑橘,是我国南方主产水果之一,因甜酸多汁,清香爽口,风味醇厚,营养丰富,深受人们喜爱。柑橘皮渣因富含水分、纤维素、木质素、微量元素以及多种生理活性成分,可作为功能食品基料和药品原料而具有广阔的应用和开发前景。但是,柑橘皮渣膳食纤维作为一种食品添加剂,它的安全性问题,一直受到人们的广泛关注和高度重视。本试验旨在选择锦橙果皮膳食纤维的最佳提取方法、研究锦橙皮膳食纤维的抗氧化活性,并对其进行安全性毒理学评价,为柑橘皮渣膳食纤维保健品开发的安全性提供实验依据。主要研究结果如下:1.采用L₉（3⁴）正交试验设计法,研究了锦橙皮膳食纤维的复合酶法提取工艺条件,筛选出最佳工艺条件为:酶解时间为1.5h、酶解温度为50℃、加酶量为0.2%、pH为7.5。所提取的锦橙皮膳食纤维总膳食纤维含量为69.08%,水溶性膳食纤维含量为20.73%,溶胀性和持水力分别是9.02mL/g、11.09g/g。2.对于提取锦橙皮膳食纤维的还原能力及其在·OH、O₂^-·、DPPH·体系中清除自由基的活性进行了研究。结果表明:锦橙皮膳食纤维具有一定的还原能力。在O₂^-·体系中,锦橙皮膳食纤维在本试验测定范围其最高清除率为46.28%,低于50%,无法计算IC₅₀,即表明其对O₂^-·清除能力饺弱(V_c的IC₅₀=37.43μg/ml);在·OH体系中,锦橙皮膳食纤维的IC₅₀为3.27mg/ml(V_c的IC₅₀=97.63μg/ml);在DPPH·体系中,锦橙皮膳食纤维的IC₅₀为5.66mg/ml(V_c的IC₅₀=14.43μg/ml)。在各自由基体系中,与V_c这一阳性参照物比较,证明锦橙皮膳食纤维具有一定的还原能力,对该三种自由基有一定的清除能力。3.按照我国GB15193.1-2003《食品安全性毒理学评价程序》进行了小鼠急性毒性试验、小鼠骨髓细胞微核试验、小鼠睾丸染色体畸变试验和大鼠30d短期喂养试验,分别研究了锦橙皮膳食纤维的急性毒性、遗传毒性和亚急性毒性。结果表明,锦橙皮膳食纤维对小鼠半数致死剂量(LD₅₀)大于15g/kg,属于无毒级,在最大剂量范围内未产生明显的毒副作用,且无剂量反应关系,未观察到遗传毒性,也未显示致畸和致突变性。锦橙皮膳食纤维的毒性试验未显示毒性作用,符合《食品安全性毒理学评价程序》的要求,可认为用于人体食用安全可靠。更多还原

【Abstract】 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.更多还原