Recycled Utilization Of The Crop Processing Wastes Of Both Corn And Potato

Nowdays corn and potato production is more than 100 million annually in China respectively, They are not only major crops, but also are important industrial raw materials. Corn germ meal is the waste of the oil extracting processing, corn gluten meal and potato wastes are by-product of starchy processing.The first aim of this study was to extract protein from corn germ meal and corn gluten meal, and then obtained peptide by hydrolysis. Moreover, corn gluten meal was also utilized as raw material to extract zeaxanthin. The second purpose of this research was to gain protease inhibitors from potato starch processing waste waters. Besides, potato starch processing residues was fermented to put out feeds completely. The main results of these experiments were as follows:(1) Utilization of corn germ meal to isolate corn germ proteins. The mono-factor design was carried out to determine the effects of isolation methods:factors such as pH, liquid-solid ratio, temperature and extracting time having a major impact were optimized by orthogonal method. The results showed that for the high-temp meal's optimized conditions were as following:pH 9.0, liquid-solid ratio of 10, temperature 60℃and extracting time 120min. For the low-temp meal, the conditions were almost the same as that for high-temp meal except extracting time, which was just 90min. Two corn germ protein yields were 5.14% and 9.29% respectively.(2) Response surface methodology was applied to optimize the extraction conditions of zein and zeaxanthin synchronously from corn gluten meal. The optimal conditions of extraction were as follows:extracted with 82.5% ethanol for 6h at 60℃. Under these conditions, the measured yields of zein and zeaxanthin were 30.87% and 0.20404%o respectly, which were closed to the predicted values of 30.44% and 0.19952%o. The purity of zeaxanthin was 41.22% confirmed by HPLC.(3) The method of composite enzyme digestion was used to produce peptide and micro-peptide from corn protein. Corn germ protein was digested by alcalase for 3h first, following by trysin for more 4h. Zein was hydrolyzed by alcalase for 3h and following neutrase for more 3h. Two hydrolysis rates were 29.9% and 25.7%. The final samples were characterized by MS.(4) Potato protease inhibitors had been extracted from the wastewater of potato starch processing based on a series of protein separation methods and the inhibition rate was 77.27%. Besides, the COD, total suger, total protein were decreased 58.12%,27.36%,56.54% respectively, after an array of methods such as PI sedimentation, heating, centrifugalization, active carbon adsorption and so on. The improved method successfully turned potato starch processing residue into feeds by three kinds of microorganism. The yield of reducing total sugar, total protein and total phosphorus reached to 13.15%, 28.685%,0.04%.