Studies On The Extraction And Application Of Polyphenols From Ginseng Leaves

Panax ginseng is a perennial herbaceous plant of the genus Panax in Acanthopanax family.It originated in China and abounds in the Changbai Mountains in Northeast China.It has high nutritional and medicinal value and is called"king of all herbs".Ginseng leaves are the leaves of acanthopanax,which are rich in polyphenols.They have many functions,such as enhancing immunity,anti-fatigue,anti-oxidation,anti-aging and so on.At present,ginseng leaves are mainly used in the production of medicine and health products,but there are still problems such as low utilization rate of raw materials and serious waste of resources.As a kind of ginseng resource that can be fully developed and utilized,ginseng leaf has a broad development prospect.In this paper,the polyphenols in ginseng leaves were extracted by low temperature plasma assisted double enzyme method,and the activity of polyphenols in ginseng leaves was analyzed.Finally,a kind of functional low sugar milk yoghurt product was developed by adding ginseng leaf polyphenols into the milk,which is of great significance to improve the comprehensive utilization rate of ginseng leaf resources and the added value of the product.1.In order to improve the yield of total polyphenols and total flavonoids in ginseng leaves,on the basis of single-factor experiments,orthogonal experimental design was applied to optimize the process conditions for extracting total polyphenols and total flavonoids from ginseng leaves by double-enzyme method(mass ratio of cellulase and pectinase is 1:2).The order of influence of each factor on the yield of total polyphenols and total flavonoids are as follows:enzymolysis temperature>enzymolysis pH>double enzymes addition amount>enzymolysis time,enzymolysis pH>double-enzyme addition amount>enzymolysis time>enzymolysis temperature;The optimal conditions for extraction of total polyphenols were as follows:the addition of double enzymes was 15 U/mL,the enzymolysis pH was 5.0,the enzymolysis temperature was50?,the enzymolysis time was 90 min,and the total polyphenol yield was(840.81±5.45)mg/100g;The optimal conditions for extracting total flavonoids were as follows:the addition of double enzymes was 25 U/mL,the enzymolysis pH value was4.5,the enzymolysis temperature was 50?,the enzymolysis time was 120 min,and the yield of total flavonoids was(348.56±2.10)mg/100g.2.In order to further improve the yield of total polyphenols and flavonoids in ginseng leaves,on the basis of the optimal extraction conditions of double enzyme method,response surface design was applied to optimize the extraction process of total polyphenols and flavonoids by low temperature plasma assisted double enzyme method.The conditions of extracting total polyphenols in ginseng leaves were obtained as follows:discharge power 280 W,treatment time 65 s,quality of ginseng leaves 2.00 g.The best extraction conditions of total flavonoids were:300 W of discharge power,60s of treatment time,2.00 g of ginseng leaves,(883.77±7.63)mg/100g of total polyphenols and(498.24±7.29)mg/100g of total flavonoids.3.HPD-600 macroporous resin was used to purify the polyphenols in ginseng leaves.The purity of polyphenols in ginseng leaves increased from 23.3%to 54.62%,which was 2.34 times higher than that before.It indicated that HPD-600 macroporous resin had a good purification effect on polyphenols in ginseng leaves.4.The components of polyphenols from leaves of Panax ginseng before and after purification were analyzed by UV-Vis spectrum scanning in the wavelength range of200~800 nm.The results showed that the polyphenols of ginseng leaves before and after purification had similar structure with flavonoids.V_C was used as the positive control to study the antioxidant activity of ginseng leaf polyphenol purification.When the concentration of ginseng leaf polyphenol purification was 2.0 mg/mL,the ABTS free radical scavenging rate reached 69.17%,indicating that ginseng leaf polyphenol has certain antioxidant activity.5.18 polyphenol monomers in red ginseng root,white ginseng root,ginseng stem,ginseng leaf,ginseng flower and ginseng whisker were detected by HPLC.The results showed that 18 phenolic compounds were separated within 35 min,with good repeatability(relative standard deviation(RSD)?3.49%),high precision(RSD?3.02%),good stability(RSD?2.58%)and reliable recovery(average recovery rate84%–99%,RSD?5%).The contents of 18 polyphenol monomers in different parts of Chinese ginseng were significantly different(P<0.05),and the contents of maltol and catechin were higher.The total polyphenols in different parts of Chinee ginseng significantly differ from them(P<0.05).6.Using goat milk as raw material,the effects of ginseng leaf polyphenol,mogroside,inulin and mixed starter(the volume ratio of Lactobacillus plantarum,Lactobacillus rhamnosus,Lactobacillus acidophilus and Bifidobacterium lactis is1:2:1:1)on the quality of functional low sugar goat milk yoghurt were studied by single factor test and orthogonal test.The optimum technological scheme was determined as follows:2%of siraitia grosvenori glycoside,2%of inulin,4%of mixed fermentation agent and 0.05%of ginseng leaf polyphenol extract.