| Vacuum extraction is a novel technology, which is combined a vacuum systemwith conventional extractor. Under the vacuum condition, the solvent could boil atlow temperature, which prevented the change of heat sensitive components. And, theboiling status could promote extraction of active compounds. The advantages ofvacuum extraction are lower temperature, high product yields, fast processing time,low impurity content, clarified extract, low energy consumption and so on. This studyintroduced the development and application of vacuum extraction technology. Salviamiltiorrhiza Bge., Polygonum cuspidatum Sieb.et Zucc and Curcuma longa L. werestudied by the vacuum extraction. In order to investigate the advantages of vacuumextraction, we compared the extraction effect (rates of active ingredients, protein,soluble sugar, extract yield, light transmittance and DPPH free radical scavenging rate)of vacuum extraction with heat reflux extraction, ultrasonic extraction and diffusionextraction.Salvia miltiorrhiza Bge. is the dried root and rhizome, and it is commonly usedas Chinese herbal medicine and health food material. Salvianolic acid B is the majorwater-soluble active ingredients, with a strong inoxidizability and a variety of featuresto protect the brain and heart, anti-fibrotic and anti-tumor. Salvianolic acid B issensitive to temperature, which is easily decomposed into tanshinol or othersubstances under high temperature and high pressure. This study compared theextraction rates of salvianolic acid B, protein, soluble sugar and extract yield, lighttransmittance, DPPH free radical scavenging rate of extracts from Salvia miltiorrhizaBge. by vacuum extraction with heat reflux extraction, ultrasonic extraction anddiffusion extraction. The optimum conditions of vacuum extraction were ethanolconcentration50%, ratio of solid to liquid1:10, vacuum degree of0.07MPa, temperature50℃, extraction time1.0hour. Using the same extraction agents, therates of salvianolic acid B and DPPH free radical scavenging rate were equivalentcompared with vacuum extraction and heat reflux extraction. At the same time, theextraction rate of salvianolic acid B, DPPH free radical scavenging rate, the extractyield, contents of protein and soluble sugar of extracts by vacuum extraction werehigher than that by ultrasonic extraction and warm immersion. And the extract yield,contents of protein and soluble sugar of extracts by vacuum extraction were lowerthan that by heat reflux extraction. In view of the higher rate of salvianolic acid B, theclearer extract and the less impurity.vacuum extraction of Salvia miltiorrhiza Bge.isbetter than conventional extraction.The dried root and rhizome of Polygonum cuspidatum Sieb.et Zucc have theeffect alleviating rheumatism, remove blood stasis, and stimulate the menstrual flow.Resveratrol is one of major functional components, which can reduce tissue and organdamage caused by a variety of factors, protect the liver, hypolipemic and anti-lipidperoxidation.The optimal conditions of vacuum extraction were ethanol concentration70%, ratio of solid to liquid1:10, vacuum degree of0.07MPa, temperature of50℃and extraction time of1hour. Compared with heat reflux and ultrasonic extractionmethods, vacuum extraction has higher resveratrol yield, transmittance, DPPH radicalscavenging rate and lower extract yield, lower content of protein, soluble sugar andother impurities. The results showed that it is superior to other extract methods.Curcuma longa L.is commonly recognized as a pharmaceutical/food resource.The major active constituents of Curcuma longa L. are naphtha and curcuminoids.Curcumin, demethoxycurcumin and bisdemethoxycurcumin, which are classified tocurcuminoids, are the major active components of Curcuma longa L. In the study,weevaluate the effects of three factors on the extraction yields of curcuminoids underdifferent solvents, extraction time and solid/liquid ratio. The optimal extractionconditions of vacuum extraction were: ethanol concentration70%, ratio of solid toliquid1:15, vacuum degree of0.07MPa, temperature50℃, extraction time1.0hour.Under the optimized conditions, the extraction yields of curcuminoids are3.48%. Inorder to compare vacuum extraction with other extraction methods, the content of curcuminoids, protein, and soluble sugar, transmittance, yield rate of dry extract andDPPH free radical scavenging rate were tested. The result showed that the content ofcurcuminoids and the antioxidant activity of extract by vacuum extraction were higherthan other methods. However, the content of protein, and soluble sugar were similarwith ultrasonic extraction and warm immersion but lower than heat reflux extraction.Under the vacuum condition, the boiling status could promote extraction of activecompounds. Furthermore, the microstructures of sample were not destroyed, whichcould prevent the macromolecule dissolution. In a word, the traditional medicinecontaining heat sensitive constituents was suitable for extracting with vacuumextraction.This article describes the study of vacuum extraction in different edible plantresources Salvia miltiorrhiza Bge., Polygonum cuspidatum Sieb.et Zucc,Curcumalonga L. were selected. The optimum extraction parameters were obtained throughoptimizing the process parameters of vacuum extraction. The experiment alsocompared vacuum extraction with traditional extraction methods. This study provedthe advantages of vacuum extraction no isolation of the active ingredient (especiallythe heat-sensitive components), and provides a theoretical basis for the applicationand technical support. |
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