Navel Orange Slag Extraction Technology And Determination Method Of Total Flavonoids In Research

The citrus production of china has reached20million tons in2007, ranking second in the world.50million tons of waste biomass was generated from the juice process every year. However, the utilization of the waste biomass is very low, a small part of them was used as animal feed; most of them was discarded or buried as waste, which caused both serious waste of natural resources, and also lead to the pollution of the environment at a certain degree. Currently, Ganzhou city has the largest growing area of navel orange in the world, and the annual output ranked the third. In2010, the growing area of Ganzhou city’s navel orange reached160acres and production exceeded110million tons. It can be expected that the growing area of Ganzhou city’s navel orange will be improved to300acres, and the total production will reach above200million tons in2015.It should be noted that the flavonoid is rich in waste biomass of citrus, and this type of flavonoid has stronger anticancer activity than other plant-derived flavonoids, so the extraction of flavonoid from the waste biomass of citrus has aroused great interest in the world and has became a research hotspot and focus for the current citrus deep processing. At the same time, this also can be considered as the reusing of resources, so it has brought new hope to the main producing areas of navel orange in the development of the utilization of waste biomass. The researchers of USA have used the flavonoid in the functional food development successfully from the considering its strong antioxidant effects, and has been sold in the global sales.In order to take full advantage of the waste-citrus residue from the agricultural production and processing, the optimization of the experimental conditions for the extraction of flavonoids from citrus residue was researched in this study. The ultrasonic wave-assisted extraction technique was used to continual extract flavonoids from citrus residue, and the content of citrus flavonoid in different extraction methods was determined by the using of rutin as standard sample. In the present study, four factors were examined by using an orthogonal [L9(3)4] test design, including the concentration of ethanol, extraction temperature, ratio of waste-citrus residue to extracting solution and pH of the extraction solution. Results shown that the influence on the mean extraction yields of the compounds decreases in the order:A>C>D>B according to the R values, and the optimum experiment scheme is A2B2C3D3In other words, the maximum yield of the flavonid was obtained when the concentration of ethanol was60%, the extraction time was60min, ratio of waste-citrus residue to extracting solution was1:25, and the pH of buffer solution was4. A regression model was established from experimental data. It shown that the optimized extraction conditions for maximum yield of total flavonoids were:the concentration of ethanol was61.84%, ratio of waste-citrus residue to extracting solution was1:25, the pH of buffer solution was4, and the extraction time was58.57min, and an extraction ratio of6.0412%for the flavonoid can be attached. The difference between the predicted value6.6735%and the experimental result6.0412%of the extraction ratio of flavonoid is less, indicating this obtained regression model can predict the extraction yield of total flavonoids in citrus residue well. Therefore, the optimized extraction conditions for the citrus residue were found with a small number of experiments. This also indicated that the ultrasonic method can be better applied to extract flavonoid from navel orange residue. Then the using of cation exchange resin and macroporous resin for the purification of the flavonoids that were extracted from navel orange residue was preliminary studied, and obtained several types of flavonoids. The characterization of these extracted compound’s structures was made from the determination of physical and chemical properties and spectral data for compounds, and identified it as hesperidin.This method can be used for industrial-scale extraction of flavonoids from orange residue and acted as the health care drugs for the people’s health. The comprehensive utilization of orange residue not only improved the utilization efficiency of raw materials, thus lowering production costs, but also greatly enhanced the economic value and economic benefits for the processing of orange, thus providing an effective way for the comprehensive utilization of orange residue.