Study On Extraction,Separation And Analytical Method Of Components In Grapefruit

Grapefruit belonging to Rutaceae is a fruit whose leave is always green, it is alsoknown as pomelo, zhuluan, shaddock etc. Grapefruit has the glorious cultivationhistory in our country. It is widely planted in the south of our country such asGuangdong, Guangxi, Fujian, Taiwan etc. Its a medicine of high value. It has variousbenefits such as helping the stomach digestion, curing cough and enlivening the body.In recent studies, it is found that the meat of grapefruit included extremely richvitamin C as well as parainsulin, therefore it could cut down the blood sugar,cholesterol, lose weight etc. The flesh of the grapefruit can be eaten raw and it canalso be process into preserved food besides that the peel contains essential oil,naringin, pectin etc, which are of great medicinal value. The grapefruit also containsmany other kinds of biological activity materials.Having referred to the academic publication on grapefruit during the lastdecade, several parts including the extraction techology of the oils and fats of the seedof grapefruit, determinating the components of fatty acids, investigating differentfactors leading to the stability of the oils and fats, examination of trace elements indifferent parts of the grapefruit by inductively coupled plasma-atomic emissionspectrometry and isolation and identification an active compound limonin by somemodem analytical technologys have been studied systematically in this paper, mainresearch results as follows:1. Seed oil of grapefruit was studied by Soxhlet extraction and SFE-CO₂ extraction,respectively. The effects of different conditions on the seed oil of grapefruit extractionwere explored and the fatty acids in the extracted oil were analyzed using GC. Theresults showed that the oil contained abundant fatty acids, the main fatty acids werelinolenic acid, linoleic acid, oleic acid, palmitic acid and stearic acid. Their relativecontents were more than 90ï¼…, and the composition of fatty acids in grapefruit seedoil was not influenced by different extraction methods.2. POV was used to evaluate the stability of grapefruit seed oil. Effects of temperature and light on grapefruit seed oil were tested. TBHQ, BHT, PG, Tea polyphenol andmixed antioxidant were tested for their antioxidation properties in grapefruit seed oilby Schaal oven storage (63±0.5℃), respectively. The better antioxidant was obtainedand the composition of fatty acid of grapefruit seed oil put in different conditions wasdetermined by GC. The results showed that the grapefruit seed oil was affectedremarkably by the light, specially by the ultraviolet ray when the oil was irradiateddirectly under it, the antioxidation properties of several kind of antioxidants ingrapefruit seed oil was: TBHQ+CA＞TBHQ＞BHT＞Tea polyphenol＞PG, and the seedoil was preserved well under the low temperature condition.3. A method of simultaneous determination of trace elements in grapefruit wasdeveloped by using inductively coupled plasma-atomic emission spectrometrytogether with HNO₃-HClO₄ digestion. The contents of fifteen kinds of elements B, Ba,Ca, Cu, Zn, Mg, Sr, Mn, Fe, Na, Be, Pb, Bi, Cd and As were determined in four partsof flesh, scarfskin, endodermis and seed which were collected from Guangdong,Guangxi and Ganzhou. The relative standard deviations of all these elements in thismethod were between 0.22% and 5.54%, and the recovery rates were between 87.0%and 115.0ï¼…. The measuring method was proved to be simple, rapid, reliable, andhighly sensitive. In addition, determination of these fifteen elements can be carriedout at the same time, which could meet the requests of actual sample analysis. Theexperimental results showed that some beneficial elements to human such as Ca, Mg,Fe, Zn, Mn, Cu and Na in grapefruit were abundant, while some comparativelyharmful elements (Be, Pb, Bi, Cd and As) were not detected. Regional differences andpartial differences obviously exist in the concentrations of one or more trace elementsin grapefruit.4. A compound limonin was isolated from seed of grapefruit after removing fat,extracting by acetone and crystallizing by dichlormethane and avantin. It's structurewas identified by IR, LC-ESI- MS, NMR spectra and element analyze.