Study And Application On Process Optimization Of Extracting Orange Pectin And Fermentation Production Of Biological Feed By The Residue Of It

Dregs of orange peel is a kind of by-product when manufactured, which is high-yield, abundant in pectin and lots of nutrient substance, difficult to be degraded. With the development of crop farming and processing industry of orange, massive dregs of orange peel generated. We can extract pectin by microbiological fermentation and the residue could be used to produce biology feed, to keep environmentally sound and elevate added value of the dregs. To sum up, this paper mainly do a research of several aspects below:1、This paper shows how to extract pectin from the dregs by water extraction and microbiological fermentation and optimize the extraction conditions. Result shows the optimum process conditions:so lid-to-liquid ratio 1:20, extraction duration60min, extraction 60℃, extraction ratio can reach 13.2% under these conditions. The optimum process conditions of microbiological fermentation:inoculum concentration10%, fermentation duration40h、 fermentation 36℃, pH7.0, nitrogen source urea, additive amount 1%, extraction ratio can reach 21.5% under these conditions.2、Optimizing the process conditions of ethanol precipitation method and salting out method (iron trichloride), measuring several index of pectin. Result shows the optimum process conditions of ethanol precipitation method:ethanol concentration75%, temperature under45℃, precipitation duration 60min; salting out method:saturated iron trichloride solution10%, temperature60℃, precipitation duration 60min. pH, ash content, loss on drying rate, hydrochloric acid insoluble matter, the total galacturonic acid of the pectin extracted all reach the national standards. Besides, measuring result of degree esterification shows, the pectin extracted is high-esterified pectin.3、Producing biological feed by residue of orange extracted. Ensuring the optimum ratio of the compound strains and fermentation conditions by single factor and orthogonal experiment, crude protein content viewed as the index. Result shows, the optimum ratio of the compound strains is 2:2:1(Candida tropicalis:Trichoderma:Bacillus subtilis), optimum fermentation conditions:temperature 30℃duration48h、 inoculum concentration 2%、 moisture content50%, nitrogen urea, inoculum concentration1%. Crude protein content can reach the peak. Dairy cattle feeding experiment shows, compared with pure beneficiated burden material, feed with a part of remarkably fermentation products can advance milk crop and keep the protein content of milk.