The Composition Analysis Of Domestic Olive Oil And The Extraction And Detection Of Polar Phenols Component

Extra virgin olive oil is directly squeezed from olive fruit without heating and refining process, which contains a lot of nutrients, including unsaturated fatty acids and active ingredients. Now the polar phenolics in extra virgin olive oil are widely used in food, pharmaceutical, cosmetic and skin care fields because of its special effects on scavenging free radicals, anti-oxidation, anti-aging, regulating blood lipids, lowering cholesterol, anti-cancer disorders. In this study, we analyzed the physicochemical indexes, material composition and fatty acid composition of domestic extra virgin olive oil, and found the results of the analysis were within the scopes of the national standard. Then we researched the relationship of olive oil quality and the changes of flavor components in extra virgin olive oil stored at room temperature and high temperature. At last, we established the extraction and detection methods of polar phenolic compounds in homemade olive oil and analyzed the major polyphenol materials in olive oil, and conclued the optimization of the extraction conditions of total polar phenol based on the experimental results.The physicochemical indexes of oil samples were within the scopes of the national standards, and the samples were clear with good diaphaneity and high quality. There were eight fatty acids in olive oil according to the gas chromatography. Fatty acid contents were calculated by area normalization method, respectively, saturated fatty acids was16.57%, monounsaturated fatty acids was70.07%, polyunsaturated fatty acids was 13.36%, and Oleic acid reached 68.41%.The peroxide value increased from the initial 6.09 mmol / kg to 23.91mmol/ kg after stori ng at room temperature away from light for 90 d, the anisidine value was basically unchanged,peroxide value was only sensitive for the characterization of storage at room temperature or a lower temperature oxidation stability of oil within a certain time. Whereas, it couldn’t be the i ndicator of the degree in lipid oxidation under hot, especially the frying temperature. The dete ction of characterizing the change could be done through both detections of secondary peroxid ase and flavor components.With the comparison of two extraction methods of polar polyphenols in olive oil, liquid-liquid extraction method had better reproducibility, and was simple and easy to implement, and what’s more, it could meet large samples’ extraction. The total phenolic content of olive oil were measured with three common methods, and we also compared the stability, reproducibility, precision and recovery rate of three detection methods. The results showed that the determination of total phenols in olive oil using Folin-Ciocalteus colorimetry not only met the determination of polarity total polyphenol content in olive oil, but also had better reproducibility(RSD% to 0.23%) and recovery rate(93.3%). We determined chlorogenic acid and ellagic acid in olive oil by HPLC method and the standard sample corresponding method, and found that there were maybe 4-hydroxyacetophenone aldehyde, 3,4-dihydroxyphenyl acetic acid in olive oil by silane gas chromatography- mass spectrometry. By analyzing the GC- MS total ion chromatogram of polyphenols, we detected a dozen unknown oleuropein derivatives samples.The total polyphenol was extracted by liquid-liquid extraction and the content in olive oil was determined by using the Folin-Ciocalteau colorimetry, meanwhile the extraction process was optimized. Methanol, ethanol, acetone were mixed with distilled water for the extraction of olive polyphenols so that the best extraction solvent could be determined. On the basis of si ngle factor experiments, selected volume fraction of 60% methanol solvent, the solvent and oi l samples than 2mL / g, shocking time 60 min, extracted 3 times as an relative ideal single fact or in the extraction of total polyphenol in olive oil. On the basis of the single factor extraction tests, the extraction conditions for total polyphenol polar in olive oil were optimized by the re sponse surface experiments. The results showed that the best processes of extraction were: the volume fraction of solvent 52.4%, extraction time 58.22 min, extraction times 2.7, the radio of solvent and oil samples 1.98 mL / g, under these conditions, the total phenols in olive oil extra ction theoretical value was 11.99 mg / kg.