| Kiwi fruit contains essential many minerals and vitamins, and also contains 17 kinds of free amino acids, especially the VC, very rich, in addition, kiwi fruit contains Butanoic acid ethyl ester,Methyl butyrate,Hexanal,aromatic aldehydes, etc, which constitutes the kiwi is a unique scent flavor. Kiwi on health care can treat maldigestion and vitamin deficiency, hepatitis, respiratory diseases. It is not only to reduce blood cholesterol and triglyceride in the function of prevention scurvy, atherosclerosis and coronary heart disease, hypertension, have special effect. To control scurvy, atherosclerosis and coronary heart disease, hypertension, Kiwi fruit has special effect, and with blood and lipid peroxidation, removing oxygen free radicals, inhibitting tumor cells, improving the immune function of pharmacological activities. Kiwi fruit juice, if it was kept on dringking,can reduce serum and malondialdehyde (MDA) content of erythrocyte and improve the body immunoglobulins leels, have apparent anti-cancer and anti-fatigue effect, therefore the development of natural healthy kiwi fruit juice has broad prospects for development, it also has the good economic efficiency and the social efficiency. Based on literature at home and abroad, a new strains of kiwifruit"chosen-815"was chosen as the raw material, the juice was prepared from kiwi fruit by the new technology of freezing wall-breaking centrifugal separation method, and the kiwi fruit juice was clarified on the use of chitosan , the two kinds of process optimization were explored. The aroma samples of kiwi fruit juice were extracted by the method of solid-phase microextraction which was prepared by the traditional and new technology of extracting juice ,then they were analyzed on the method of GC/MS.The main contains as follows:(1) After reading lots of literatures,the study of kiwi fruit juice were reviewed, including the research status and existing problemsthe of kiwi fruit juice, VC and color protection technology of the kiwi fruit juice,the technology of kiwi juice clarification, the concentrated process technology of kiwi fruit juice and kiwi fruit aroma compositions of research progress were discussed and discussed respectively. The characteristics of various process was repaired and the kiwi fruit aroma compositions of the sample preparation techniques were analyzed and compared. Finally the development trend of kiwi fruit juice is discussed. (2) Through the freezing test of the kiwi slice, Kiwi slice freezing point and the shortest time of refrigeration were determined: freezing point was for -2.1 Celsius,the shortest time of kiwi slice reaching -18 Celsius was for 4 hours and nine minutes.(3) In this paper,according to the principle of slow-freezing and cell wall-breaking,the juice was prepared from kiwi fruit by the new technology of freezing wall-breaking centrifugal separation method, By the new technology of freezing wall-breaking and centrifugal separation process parameters of a single factor experiment and the orthogonal experimental analysis based on orthogonal test, the result showed that the production of the new technology juice were obviously superior to the production of traditional juice in the juice yield, VC, light transmittance and colour and luster.Take the best technology for:sliced thickness was 0.6cm, after freezing slice in -14 degrees Celsius for 10 hours,they were taken 30 minutes to defrost in water at room temperature, after adding centrifuge thaw in 3000r/min centrifugal in 20 minutes, the juice was filtered with 100 mesh cloth filter.(4) To explore the kiwi fruit juice, chitosan clarification of the dosage of chitosan, temperature and time on the single factor experiment was studied and analysized. The orthogonal experimental analysis was based on orthogonal test.The result showed: On the raw kiwifruit juice and clarified kiwifruit juice, the content of total sugar, total acids, VC, soluble solids,total polyphenol changed light.Transmittance of kiwifruit juice greatly improved and achieved 95.9%. The content of protein is 76.54% less than that of the raw kiwifruit juice. The optimum technological conditions of clarifying the juice by chitosan is for: dose of chitosan additives was for 0.4g/L,the clarifying conditions was at 40 Celsius, 60min. Chitosan clarification comparised with membrane separation clarification on the basis of the optimum technological conditions of clarifying the juice,the research showed that the membrane separation clarification in transmittance and removing protein is better than chitosan clarification, but the chitosan clarification in reducing VC and total polyphenol material loss was superior to the membrane separation, and took less time.(5) The aroma compositions was preliminary explored in the use of solid-phase microextr- action and gas chromatography mass spectrometry which was of kiwi fruit and traditional techniques and new technology of sample preparation of kiwi fruit juice, the results showed that: the common aroma of the kiwi fruit and four kinds of juice compositions were:Ethanol,ethylacetate,2-Hexenal,Phenol, 2,6-bis(1,1-dimethyle thyl)-4- methyl-,L-(-)-Menthol,Butanoic acid,ethyl esteretc.The six substance is mainly composed of kiwi fruit aroma.This explained that the juice of new technology and traditional technology were basically maintained kiwi fruit aroma.The mutual aroma compositions, of which the raw kiwifruit juice,kiwifruit juice of freezing wall-breaking centrifugal separation and clarified kiwifruit juice were obtained,were that : Ethanol, Ethyl acetate, 2-Hexenal, Phenol, 2,6-bis(1,1-dimethyle thyl)-4-methyl-,L-(-)-Menthol, Butanoic acid, ethyl ester,2-Hexen-1-ol,(E),trans-Caryophyllene,l-Limonene.The mutual aroma compo- sitions,of which the raw kiwifruit juice,the juice and clarified juice with the traditional process,were that:Ethanol,ethylacetate,2-Hexenal,Pheno,2,6-bis (1,1-dimethyl ethyl)-4- methyl-,L-(-)-Menthol,Butanoic acid,ethyl ester.It was seen that:Compared with the aroma of the raw kiwifruit juice, the extracting juice and clarified juice with the traditional process only retained the above six types of aroma substances,while the juice and clarified juice with new technology had more than mutual six components,they still retained three raw fruit aroma compositions of 2-Hexen-1-ol,(E),trans-Caryophyllene, l-Limonene.So the new technology can be better to keep their raw fruit aroma compositions. |
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