Detoxification Of Jatropha Curcas Seed Cake By Hydrogen Peroxide Oxidation

Jatropha curcas, commonly known as physic nut, belongs to the Jatropha genus and Euphorbiaceae family. Its seed is rich with oil which can be used for producing biodiesel. Now, there are large scale cultivation base in southwest of China. Jatropha curcas seed cake (JSC) is a massive by-production as the production of biodiesel. But, as phorbol esters is the main toxic composition in JSC, its utilization as protein live-stock feed is restricted. In order to develop the seed cake for food or live-stock resource, phorbol esters have to be removed for detoxification of JSC. The research contents can be summarized as follows.(1) Determining if phorbol esters existed in seed cake by HPLC determining. According to the property of phorbol esters which can be easily oxidized, we used H2O2to oxidize phorbol esters in JSC and studied the effect of time, temperature, pH, H2O2concentration and H2O2-JSC ratio(m/m) on phorbol esters content in JSC.(2) Estimated the nutritious compositions, fatty acids compositions and amino acids compositions in JSC and detoxified products, for valuing the possibility of detoxified products as live-stock.(3) Acute oral toxicity test of ethanol extract of JSC and detoxified products in mice, and feeding broiler chicken which diets contained JSC or detoxified products, were used to valuing the toxicity of JSC and detoxified products, determined if the detoxification was successful.The results were showed as follows.(1) Determining phorbol esters existed in seed cake by locating, distinguishing and determining peaks on HPLC chromatogram, and the content was0.52mg/g. Under the optimizing condition, H2O2-JSC ratio (m/m) of0.6and15%H202was added, adjusted the paste pH=8.0, placed in an oven at60℃for8h. By verifying the optimizing condition, there was not any peaks of phorbol esters on HPLC chromatogram by HPLC determining, so phorbol esters were complete degration.(2) JSC is rich nutritious compositions. The nutritious compositions of detoxified products were decreased by H2O2oxidizing. Unsaturated fatty acids of JSC and detoxified products were oleic acid and linoleic acid. Unsaturated fatty acids of detoxified products was less than JSC. Both of levels of total essential amino acids in protein of JSC and detoxified products were higher than sunflower seed cke. Quality of detoxified products reaches the standard of the secondary feeding sunflower seed cke on GB10377-89.(3) No obvious toxic presented in mice by ethanol extract of detoxified products, LD50is greater than22.58g/kg body mass, judging non-toxic level。 LD50and95%confidence limits of ethanol extract of JSC for mice is2710mg/kg body mass and2000～3690mg/kg body mass, judging low toxic leve. No significant abnormal changes, signs, activity, body mass increaseing and organs mass at ethanol extract of detoxified products studied. Broiler chicken which diets contained25%or50%detoxified products were not dead during28days feeding, but their body mass increasing is slower than control group of bean cake. And broiler chicken which diets contained25%JSC were dead during7days feeding.