| The subcritical extraction and nanoemulsion preparation of Cumin seed oil was studied in this paper inorder to improve yield, solubility and stability of Cumin oil, so far as to work out some problems about thedeep processing of low level, less variety and low appendant value. With extraction rate of Cumin oil andcontent of Cumin aldehyde as indicators, and with supercritical and solvent extraction as control, theoptimal extracting technological parameter were obtained. Then the formula of Cumin oil nanoemulsionwas analyzed and optimized, also the technical parameters of high pressure homogenization on it werereached. Afterwards, the stability of Cumin oil nanoemulsion was evaluated under high speedcentrifugation, strong light and different temperature.In addition, its antimicrobial activity wastested.Thereby a suitable preparation route of Cumin oil nanoemulsion was screened out.The results are asfollows:(1) With Cumin seed produced in Turpan of Xinjiang as raw material and extraction ratio as index,theoptimum conditions of subcritical extraction of Cumin oil was determined by through single factor andorthogonal design: particle size of material40mesh, bulk density65g/L, the temperature of extraction50℃and the extraction time90min were obtained by both single factor and Orthogonal test. The extractingratio had been validated as97.3%.(2) Compared with supercritical CO2extraction, the operating pressure range is far lower, which is0.4-0.6MPa compared with35-50MPa in supercritical extraction, and also equipment costs fell sharply.Compared with solvent extraction, the extraction time in subcritical extraction under2hours is just onethird of that in the former, in addition, energy consumption fell sharply, and without solvent residualproblems. Cumin-aldehyde is one of the most important fragrant and active ingredients in Cumin. thecontent of Cumin aldehyde in cumin oil by the subcritical extraction was20.00μg/ml,which is2.27timesas amount as that by.solvent extraction. Therefore, subcritical extraction had certain practical value andwas worthy developed in preparation of Cumin oil in cost, energy consumption and product quality ascompared with supercritical extraction and solvent extraction.(3) The optimum formula of Cumin oil Nanoemulsion was w(MS PG2000)=12%,w(MCT Neobee105)=2%,w(Cumin oil)=10%, w(ultrapure water)=76%.High pressure homogeneous parameters forCumin oil nanoemulsionn is100MPa and10cycles. The The prepared nanoemulsion was the type ofoil-in-water and the drop size averaged180-300nm with a polydispersity index concentrated under0.35.(4)The stability of nanoemulsion is an important indicator for quality evaluation. The samples wereplaced30days respectively at strong light(4000Lx),room temperature,low temperature(-4℃) or hightemperature(60℃), the percentage of cumin aldehyde were determined periodically.The results showedthat Cumin oil nano-emulsion had good thermal stability,because Cumin aldehyde content was not changed significantly in different temperature, and no stratification or breaking phenomenon occurred byhigh-speed centrifugation.But it was sensitive to light and should stored in dark place, because Cuminaldehyde was slightly decreased7.14%and14.75%by stored for15d and30d respectively.(5)In the three kinds of foodborne pathogens, the Cumin oil nanoemulsion has shown certaininhibitory effect against Listeria monocytogenes, and the minimum inhibitory concentration(MIC) was0.4%(v/v), just1/5of bulk Cumin oil, which indicated that the form of nanoemulsion would help reducethe molecular size and increase its solubility of cumin oil, improved antibacterial activity of cumin oil, thusimproving the antibacterial activity of cumin oil... |
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