The Flavonoids Of Onion And Its In The Production Of Functional Foods In The Study

It is necessary to study and develop new functional foods in order to satisfy people's aspiration for health and longevity. China is abundant in onion resource,which is world-famous for its anti-oxidation,free radical scavenging,reducing blood lipid and other. aspects.Therefore,onion has tremendous development potential,and It's ensured that the onion will certainly bring new. broad prospects to this field.High performance liquid chromatography (HPLC) was applied to study the Flavonoids in onion bulb in this paper. This study is of important applications.For example, it can not only deal with the pollution problems of onion's skin but also promote the Favonoids functions.The extraction methods of Favonoids in onion is significant to the production of functional foods.An appropriate extraction method can directly affect the function of onion. This product is economical, environment friendly and convenient,and it can supply more important information for the industrialized production of plant functional foods. Three extraction methods of Flavonoids were discussed in the third part: Water extraction, soxhlet extraction, enzymatic- assisted ultrasonic method.The innovative points of water extraction were:with traditional mechanical pressing abandoned,the sample was extracted by hot water,for short time,low temperature and without organic solvent,no need for additional water.This method can provide the value theoretical basis for economizing the production cost,reducing the energy consumption and enhance the industrialized production.The advantages of Soxhlet extraction were:short time,low temperature,stable extract,extraction solvent of alcohol,no pollution, suitable conditions for fermentation of acetic acid bacteria, and no need for additional alcohol.This method has been used for onion vinegar adequately.The innovative points of enzymatic-assisted ultrasonic method were: It is a compound method for extraction, enzymolysis and alcohol extraction are two main processes,which can supply "natural" materials for the production onion dry red wine of high quality.The results obtained through the above methods are following:1.Study on Flavonoids in onion.The result showed that the concentration of Flavonoids in red onion was higher than yellow onion,and the lowest was white onion.The concentration of Flavonoids in the same onion was higher in skin (to 42872.6 mg/Kg) than the edible part, Where the amount of external scale leaves was higher than internal scale leaves.2.Three methods,water extraction, Soxhlet extraction, and Enzymatic- assisted Ultrasonic can be used to extract the Flavonoids in onion. The optimal parameters of water extraction were:material to water ratio 1:6, extraction temperature 60℃,extraction time 2h, and the concentration of onion Flavonoids reached 1018.73 mg/Kg(±6.93 mg/Kg).The optimal conditions of Soxhlet extraction were:extraction temperature 50℃, extraction time 4h,the concentration of alcohol 80%(v/v),with concentration of Flavonoids 16870mg/Kg. The optimal conditions of enzymatic- assisted ultrasonic method were following:cellulase 0.5mg/g, pH 4.5, enzyme treating temperature 40℃,enzyme treating time 150 min. After enzymolysis,70%(v/v) alcohol was used for further extraction, for 15min, with concentration of Flavonoids above to 7528.6mg/Kg. The process conditions and stability of onion beverage,onion vinegar and onion dry red wine were also studied in this paper, which can provide theoretical basis and reference for industrialized production of onion.