Studies On Microbial Transformation Of Orange Peels To Produce Kojic Acid And Comprehensive Utilization

The year output of citrus fruit in china is over 10 million ton. The giganticcitrus fruit utilize industry bring tremendous by-products inevitably. In general, theprocess of citrus fruit utilize have 50% wastes ,which conclude orangs peels andresidues. If these wastes cannot be used appropriately, there are not only aboudantresources waste every year, but also take lumbersome pressure to environmentsecurity. In fact, the orange peel is rich in nourition for microbio to use, and thebioflavonoid,fiber,pectic also can be comprehensive used.There are those woks and main results of our study include:1.The method of strains screen set up was used to filtrate a strain which canuse hesperidin as Carbon resource, According to screening model, the strain H-10was selected from over 20 different soils around citrus trees and rotted orange peels.2. The products of fermentatiom was examined by the method of thin layerchromatogram. It can be seen: the mark of hesperidin was vanished gradually, and anew red mark was seen, we called it A product. For the aim of produce A product,we got the optimized condition: orange peel powder 7.5%(W/V), the pH was nature,20% medium, 25℃,180rpm shaking for 5d.3. The A product was separated by the combinative method of extraction andrepeated crystal, The combinative method of HPLC,NMR and IR was used toidentify the A product. Then the following statistic were got:¹H NMR (D₂O)d:8.0168(-O-CH=), 6.5082(-CH=), 4.4405(-CH₂-); O¹³C NMR (D₂O)d: 176.7(-CO-),168.5 (C-4), 144.6 (C-OH), 142.1 (C-1), 110.6 (C-3), 59.9(-CH₂-).IR: 1074,1472,1582,1659,1691,2924, 3177 cm^-1. Summarized and analyed these results,we gotthe conclusion that the A product was kojic acid. Though spectrophotometer method,the kojic acid produce rate was about 0.23%. The ability of antibacterial was stronger after microbial fermentation.4. The content of total bioflavonoid had a large change after microbialfermentation. Used the spore to ferment, the content of total bioflavonoid wasincrease by 56.5%, used the liquid seeds to ferment, the content of total bioflavonoidwas increase by 76.9%.5. The orange peel powder used to be as the dietary fiber. Water holdingcapacity and expansion capacity were known as important character of dietary fiber.After microbial fermentation, the water holding capacity of it was increased by84.7%, and expansion capacity 17%.This research provide a new approach of exploiting and utilizing resource oforange peels, on one side,it can produce the kojic acid,on the other, the microbialfermentation supply a new way to Comprehensive utilization.