Extraction And Analysis Of Onion Oleoresin And Preparation Of Microcapsule

Onion is a medical and edible plant. It is an important flavoring that commands universal application as seasonings and flavorings in the food industry with the development of snacks and prepared foods. Furthermore, onion is used in folk therapy because of its biologically active sulphur compounds. In recent years, the general public has exhibited increased awareness of health-promoting functional foods.The goal of this work was to determine the optimal conditions of extraction for producing oleoresin with the highest yield and the best quality. Essential analysis and microcapsule preparation were carried out in the paper to make some breakthrough on the exploitation and utilization of onion oleoresin.Several main parts of this paper were summarized as follows:3. Solvent extraction and solid phase extraction of onion oleoresin With the oil yield as the evaluation index, the technology of extracting of onion oleoresin was studied. The effects of crushing degree, enzyme digestion condition, drying condition, extracting solvent, extracting method were investigated. An appropriate procedure of extracting onion oleoresin was established. The oil yield was 2.12%.Solid phase extraction with polystyrene as stationary phase, ethanol as mobile phase was studied. The effects of onion serous Ph, activation and capacity of the extracting column, the volume of mobile phase were investigated.Silica gel-thermosensitive hydrogel particles have been prepared and its application on stationary phases in chromatography have been evaluated.2. Sulphur concentration of onion oleoresin was determined by titration. The volatile compounds of extracted onion oleoresin were separated by gas chromatograph. The extracts of solid phase extraction were estimated by gas chromatography-mass spectrometry (GC-MS).Sulphur content of onion oleoresin was quantitatively determined by titration with bromimetry.