| With the development of artificial cultivation technology of Cordyceps sinensis,the fermented C.sinensis powder as the most important substitute of natural C.sinensis has gradually been recognized and widely used.The fermented C.sinensis powder that produced through extraction and separation of medical strains from C.sinensis by artificial fermentation.At present,the technology of liquid deep fermentation has been inclined to mature,and this technology can be used to produce C.sinensis on a large scale,which is more in line with the production requirements of modern industrialization.Under the background of scarcer and scarcer wild C.sinensis resources and higher and higher market demand,the production cost of C.sinensis powder was greatly reduced by using liquid deep fermentation technology,and the output of raw materials of C.sinensis powder was expanded to meet the market demand.The main research contents include the following aspects:1.Optimization of fermentation conditions and amplification fermentation technology of C.sinensis strainThe C.sinensis used in this paper is a strain isolated from wild C.sinensis in Qinghai.In the early stage,the related basic studies such as plate activation,liquid culture and active ingredients were carried out.In this study,the high-yield capacity of C.sinensis under different culture conditions was investigated.In the medium of small shaking flask,the selection of magnesium salt types,the dosage of magnesium salt,the rotation speed,the culture temperature,the inoculation amount,the culture time and other culture conditions were optimized.The optimized culture conditions of C.sinensis were tested by using 100 L fermenter to enlarge the culture.The results showed that magnesium salt had a certain effect on the growth and flavor of C.sinensis.Magnesium hydrogen phosphate was selected to replace magnesium salt,the dosage of magnesium salt was changed to 0.4 g/L,the culture temperature was 26 ℃,the fermentation speed was 130 rpm,the inoculation amount was 2%,and the culture time was 8 days.Shaking flask bacteria had the best growth state in the small test.After the fermentation tank debugging,the fermentation process of C.sinensis before and after the optimization was compared,the fermentation time was shortened by 7 days,the yield of C.sinensis powder was increased from 200 g/50 L to 584.21g/50 L at the highest,and the process was relatively stable in the process of repeated fermentation.2.Study on drying processing technology of fermented C.sinensisDrying is one of the key technologies to ensure the quality of storage and preparation.Electric heating blast oven is used to stimulate the generation of volatile flavor substances of C.sinensis powder in the way of heating while drying,which is conducive to presenting a good impression and feeling to consumers.The drying temperature and drying time of the same batch of C.sinensis mycelium were determined by using the drying aging and cordyceps pink degree as the evaluation criteria.The results show that the drying temperature is 55 ℃ and the color condition is the best.However,the current drying technology and equipment are updated quickly.Due to the experimental time and conditions,the subsequent research should further explore the effects of different drying technologies on the main active components and flavor substances of fermented C.sinensis powder.3.Study on antioxidant and immune activity of Cordyceps PolysaccharideThe single factor and orthogonal experiments were used to optimize the extraction conditions of Cordyceps polysaccharide by hot water extraction.The results showed that the highest polysaccharide content was obtained under the conditions of 1.5 h extraction time,65 ℃ extraction temperature and 1:95solid-liquid ratio.Four kinds of polysaccharide samples were obtained from C.sinensis mycelium and fermentation broth by water extraction and alcohol precipitation,Sevege method and activated carbon method.The results of infrared spectrum analysis of Cordyceps polysaccharide showed that the polysaccharide samples were mainly pyranose ring,and its monosaccharide may be composed of glucose,mannose,galactose,etc.The antioxidant results of the four polysaccharides samples showed that compared with the positive control,they all showed better antioxidant and immune activity.Both crude polysaccharide samples could significantly promote the proliferation of RAW 264.7 macrophages.In the activity of promoting NO production,the polysaccharides from fermentation broth were superior to intracellular polysaccharides,and there was a significant difference with LPS group(p < 0.001).4.Study on quality evaluation of fermented C.sinensis powderIn this study,the internal quality of fermented C.sinensis powder was studied through character observation,TLC identification,water content,total ash content,acid-insoluble ash content and water-soluble extract,so as to provide data reference for quality evaluation of fermented C.sinensis powder.The results of TLC identification showed that the fermented C.sinensis powder produced by this strain was rich in a variety of active substances.The content of some active components was determined,and it was found that polysaccharide and nucleoside were the most important components in the fermented C.sinensis powder.The contents of polysaccharide reached 73.10%,uridine and adenosine reached 2.6766 mg/g and1.6383 mg/g in nucleoside components.In the existing quality standards of C.sinensis and related preparations,the total ash percentage of fermented C.sinensis powder was between 5.21-5.86%,the moisture content was between 1.5-1.8%,and the adenosine content was 1.6383 mg/g,which reached the pharmacopoeia standard. |
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