Effects Of Different Preparation Processes On Quality Characteristics And Composition Changes Of Black Ginseng

American ginseng（Panax quinquefolium L.）,is a herbaceous plant of the ginseng genus.It is both medicinal and edible.The main edible part is the root.Panax quinquefolium tastes sweet and slightly bitter,slightly cool in nature,has the effects of clearing away heat,replenishing qi,nourishing qi and nourishing yin,and has the effects of lowering blood sugar and blood lipids,improving immunity,alleviating fatigue,etc.,and has certain anti-proliferative effects on tumor cells.Ginsenoside is considered to be the most important active ingredient in Panax quinquefolium,and its composition and content are different from ginseng.Related studies in recent years have found that the chemical composition of Panax quinquefolium will change after processing.The conventional ginsenosides Rg₁,Rb₁,Re,etc.in American ginseng will be converted into rare polar ginsenosides Rh₁,Rg₂,Rg₅,etc.At the same time,processing will also change the type and content of polysaccharides and amino acids in Panax quinquefolium.Studies have shown that black ginseng are rich in rare saponins.At present,the research on the processing method of Panax quinquefolium is relatively limited.The research on black ginseng is mainly the traditional nine steaming and nine drying.This method will cause the loss of nutrients such as saponins.Therefore,this article explores a new method of processing black ginseng,namely constant temperature and humidity method.Finally,the physical and chemical indexes and pharmacological activity of Panax quinquefolium products before and after processing were analyzed and researched to provide a new way of thinking for the processing of black ginseng.The research content of this article is mainly divided into the following four parts:1.The first chapter summarizes the nutritional value,pharmacological activity and processing status of Panax quinquefolium.The Maillard reaction plays a role in the participation of Panax quinquefolium.The chemical composition and pharmacological activity of Panax quinquefolium before and after processing were discussed.At the same time,the reaction mechanism and experimental methods of the antioxidant activity of Panax quinquefolium are briefly described.2.The second chapter makes a study on the changes of physical and chemical characteristics during the black participation process.Five temperature gradients of 60^oC,70 ^oC,80 ^oC,90 ^oC,and 100 ^oC are set,and the processing method of constant temperature and humidity is adopted to process Panax quinquefolium.According to the physical state and sensory traits of Panax quinquefolium after treatment,the temperature of black participation was preliminarily selected.The physical and chemical indexes of black ginseng samples processed at different temperatures and times were analyzed.The main conclusions are as follows:the chromaticity of black ginseng is positively correlated with the processing temperature and time.The highest values of chromaticity at 60^oC,70^oC,80^oC,and 90^oC are 26.27,25.4,26.93,and27.79,respectively.The p H of black ginseng is negatively correlated with processing temperature and processing time.The p H of black ginseng samples can reach as low as 3.36,3.56,4.01,4.18 at 60^oC,70^oC,80^oC,and 90^oC.The reducing sugar content of black ginseng showed a trend of increasing first and then decreasing with processing temperature and processing time.The content of reducing sugar in white ginseng and red ginseng was lower.The reduction of black ginseng samples at 60^oC,70 ^oC,80 ^oC,90 ^oC The sugar content can reach up to 324.53,298.05,295.04 and236.7 mg/g.The content of amino acids in black ginseng is negatively correlated with processing temperature and processing time.The total amount of amino acids in white ginseng is 10.43%,but after processing it is reduced to 4-5%.3.In chapter 3,the main chemical components of black ginseng（ginsenoside and5-HMF）obtained by different temperature and time treatments are tested and analyzed.The change trend of conventional saponins is negatively correlated with processing temperature and time,and the change trend of rare ginsenosides increases first and then decreases.The ginsenosides with higher content after conversion are mainly 20（S）-Rg₃,20（R）-Rg₃,Rk₁and Rg₅,and as the processing time increases,the rare saponins will further decompose and show a downward trend.The content of5-HMF is positively correlated with processing temperature and processing time.Neither white ginseng nor red ginseng contains 5-HMF.The 5-HMF content of black ginseng samples at 60 ^oC,70 ^oC,80 ^oC,and 90 ^oC can reach 3.486,3.407,3.169,and12.593 mg/g.4.In chapter 4,the antioxidant activity of different black ginseng samples was tested and analyzed,proving that the antioxidant capacity of black ginseng is positively correlated with the processing time.After processing,the antioxidant activity of black ginseng is increased 2-8 times than that of white ginseng.The DPPH free radical scavenging IC₅₀of white ginseng was 18.75 mg/m L,and the DPPH scavenging IC₅₀value of black ginseng processed at 60^oC was reduced to 2.38mg/m L.The DPPH scavenging IC₅₀value of black ginseng processed at 70 ^oC was reduced to 4.31 mg/m L.The DPPH removal IC₅₀value of black ginseng processed at80^oC was reduced to 5.36 mg/m L.The DPPH removal IC₅₀value of black ginseng processed at 90 ^oC was reduced to 4.51 mg/m L.By comparing the best antioxidant activity of black ginseng treated by different processing techniques,we found that as the temperature rises to a certain extent,the antioxidant activity of black ginseng will instead increase,the reason may be that the temperature is too high,dilute ginsenoside The degradation products and Maillard reaction products also have a certain antioxidant capacity,both of which further enhance the antioxidant capacity of black ginseng.