| Huangjing(Polygonatum sibiricum Red.)is a perennial herb with the same source of medicine and food,which has a medicinal history of more than 2000 years in our country.At present,Huangjing is also one of the important traditional bulk medicinal materials,and the annual dosage of medicine is increasing year by year.However,the use of raw Huangjing is easy to make people feel numb and painful,and even stimulate the throat.If the raw Huangjing juice touches the human skin,it will make people feel itchy and painful.Therefore,in order to eliminate the adverse side effects,the raw Huangjing is usually processed before being used in medicine.At present,there are still many problems in the research of Chinese medicine steaming,in which the inconsistent processing technology and the different process parameters are main problems,resulting in uncontrollable quality and affecting the clinical efficacy of traditional Chinese medicine.This study focused on the nine-steam-nine-bask processing of Huangjing produced in Weihai,and comprehensively analyzed the changes of various physical and chemical properties of Huangjing in the process of nine-steam-nine-bask,which provided guidance for the establishment of a standardized Huangjing nine-steam-nine-bask processing method.Based on the above research background,this study used Huangjing from Weihai as a raw material to prepare multi-steamed Huangjing processed products,and explored the changes of Huangjing’s sensory characteristics,and the content of polysaccharides,saponins,5-Hydroxymethylfurfural(5-HMF)during processing.The volatile chemical compositions of Huangjing processed products were analyzed by gas chromatography-mass spectrometry.In view of the good biological activity of Polygonatum sibiricum polysaccharide,this paper further used orthogonal method and response surface method to optimize the extraction process of Polygonatum sibiricum polysaccharides,and finally the monosaccharide composition and antioxidant activity of polysaccharides were determined.The specific research contents are as follows.First of all,the preparation of Huangjing processed products,and the changes of its sensory characteristics were investigated.As the steaming proceeds,the surface color and cross-section color of the processed products gradually deepened,and gradually changed from yellow to black,the sense of tingling tongue also changed from nothing,and the sweetness gradually changed from light to sweet.The content of extracts decreased with the increase of steaming times,the content of polysaccharide first gradually decreased with the increase of steaming times,and basically stable by the third steaming.The content of reducing sugar,total saponins and 5-HMF increased with the increase of steaming times.The GC-MS analysis of the volatile chemical composition of the processed products showed that the compound types were different during different steaming times.Not only the production of new ingredients,but also the disappearance of the original ingredients and the proportion of each ingredient exhibited changed.The PCA analysis showed that the samples of processed products were relatively concentrated in the main component space,indicating that their chemical composition and proportion were closely related and had a certain characteristic,while the processed products were far away from the raw Huangjing in main component space,indicating that the chemical composition of Huangiing had changed significantly after steaming.The orthogonal method was used to optimize the hot water extraction of Polygonatum sibiricum polysaccharide,the optimal process conditions of hot water extraction method were:material-liquid ratio was 1:20,extraction temperature was60 ~oC,extraction time was 3 h,extraction number was 3 times,under this conditions,the extraction yield of Polygonatum sibiricum polysaccharide was 13.85%;After the optimization of response surface,the optimal extraction process conditions of Polygonatum sibiricum polysaccharide by ultrasonic assisted extraction method were:material-liquid ratio was 1:30,ultrasonic power was 300W,ultrasonic temperature was 70 ~oC,ultrasonic time was 50 min,under this process condition,the extraction yield of Polygonatum sibiricum polysaccharide was 13.62%;Comparing the two methods,it was found that the hot water extraction method used for extracting polysaccharides from Huangjing had a higher polysaccharide extraction yield.The monosaccharide composition of Polygonatum sibiricum polysaccharide was determined,the results showed that the polysaccharide composition of raw products were Man,Glc,Gal,Ara,and the percentages of the four monosaccharides were52.47%,36.84%,7.32%,3.37%respectively.After steaming,the monosaccharide composition of Polygonatum sibiricum polysaccharide had changed,with the increase of steaming times,the content of Man continued to decrease,from the initial 52.4%to18.86%at the ninth steaming;The content of Glc decreased in the first two steaming time,but as the steaming proceeds,its content continued to increase,the highest was52.2%at the ninth steaming time.As the steaming proceeds,the content of Gal and Ara increased relatively,and the increase of Gal content was relatively large.The DPPH method and the ABTS method were used to detect the antioxidant activity of Polygonatum sibiricum polysaccharide,the results showed that the polysaccharides of Huangjing had certain scavenging ability to these two free radicals,but their scavenging abiliity was lower than Vc’s scavenge abiliity.After steaming,the anti-oxidant activity of the polysaccharide of Huangjing was slightly higher than that of the raw product,but the steaming time did not have too much influence on the anti-oxidative activity of polysaccharide,and it only showed a slight increase. |
