| Acer ginnala Maxim is a common garden plant in northern China due to its bright and beautiful leaves and fruits.It contains various active substances such as polyphenols,flavonoids,and volatile oils,among which the content of gallic acid is as high as about 20%.It also has good antioxidant,anti-tumor,antibacterial and other effects,and has high medicinal value.However,as an ornamental tree species,it is often not valued by people,resulting in the lack of reasonable and scientific development and application of resources.This article takes A.ginnala as the research object and conducts seasonal dynamic analysis on the content of gallic acid in its leaves,fruits,and branches.Based on this,the extraction process,antioxidant activity,and microcapsule preparation of gallic acid in A.ginnala leaves were studied,providing reference and guidance for the development and utilization of gallic acid in A.ginnala and the application of gallic acid microcapsules in the field of food and cosmetics.The main experimental results are as follows:In the study of the yield of gallic acid from different parts of A.ginnala,the highest to lowest yield of gallic acid was found in leaves,fruits,and branches.The yield of gallic acid from tea maple leaves was 20.39±0.34%and reached its highest value in July.The yield of gallic acid from tea maple fruit was 11.76±0.25%and reached its highest value in August.The yield of gallic acid from tea maple branches was the lowest at 7.21±0.18%and reached its peak in June.The tannin enzyme coupled ultrasound microwave synergistic extraction of gallic acid from tea maple leaves was used,and the optimal extraction process was determined using single factor experiments and response surface methodology.The optimal extraction process parameters for gallic acid are:extraction time 39.60 minutes,tannase addition 4.33%,solid-liquid ratio 1:61.64 g/m L,microwave power 520.48 W.Under these conditions,the yield of gallic acid is 26.25±0.41%.After adjusting the optimal extraction parameters of tannase coupled ultrasound microwave synergistic extraction method and comparing it with other extraction methods,the yield of gallic acid was higher than other extraction methods.It has been confirmed that the tannase coupled ultrasound microwave synergistic extraction method can effectively improve the yield of gallic acid in tea maple leaves,and the purity of gallic acid after purification can reach over 90%.The antioxidant activity of gallic acid from A.ginnala leaves in vitro and in vivo was studied respectively.Gallic acid and V_Cwere the main objects of the antioxidant study in vitro.Through the comparison of the scavenging capacity of DPPH and ABTS,the scavenging capacity of hydroxyl radical and the reduction capacity of iron atoms,the experimental results showed that the antioxidant activity of gallic acid in vitro was higher than that of V_C,with strong antioxidant activity.In vivo antioxidant research,mice were used as experimental objects to establish an alcoholic liver injury model,and the mice were treated with gallic acid.The activities of superoxide dismutase(SOD),catalase(CAT),reduced glutathione(GSH-PX)and the content of propylene glycol(MDA)in serum and liver tissue of mice were detected.The results showed that the MDA content in the serum of the medium and high dose groups of gallic acid was lower than that of the model group,while the CAT,SOD,GSH-PX activity was higher than that of the model group.The MDA content in the middle and high dose groups of gallic acid in the liver tissue of mice is lower than that of the model group,and CAT,SOD,GSH-PThe content of gallic acid in leaves,fruits,and branches of A.ginnala reached its peak in July,August,and June,respectively.Using the yield of gallic acid from A.ginnala leaves as an evaluation index,the optimal extraction process was determined used single factor experiments and response surface methodology.The optimal extraction process parameters for gallic acid are:extraction time 39.60 min,tannase addition 4.33%,solid-liquid ratio 1:61.64 g/m L,microwave power 520.48 W.Under these conditions,the yield of gallic acid is 26.25±0.41%.After adjusting the optimal extraction parameters of tannase coupled ultrasound microwave co extraction method,compared with other extraction methods,the yield of gallic acid was higher than other extraction methods.After purification,the purity of gallic acid reaches over 90%.The antioxidant activity of gallic acid from A.ginnala leaves was studied in vitro and in vivo,respectively.The antioxidant activity in vitro was mainly studied with V_Cand A.ginnala leaves as research objects.By comparing the scavenging ability of DPPH and ABTS,hydroxyl radical scavenging ability,and iron atom reduction ability,the experimental results showed that the antioxidant activity of gallic acid from A.ginnala leaves in vitro was higher than that of V_C,which had strong antioxidant activity.In vivo antioxidant research,mice were used as experimental objects to establish a model of alcoholic liver injury in mice,and mice were treated with gallic acid from A.ginnala leaves.The activities of superoxide dismutase(SOD),catalase(CAT),reduced glutathione(GSH-PX),and propylene glycol(MDA)in serum and liver tissue of mice were measured.The results showed that the MDA concentration in serum of the middle and high dose groups of gallic acid from A.ginnala leaves was lower than that of the model group,and the activities of CAT,SOD,GSH-PX were higher than those of the model group.The concentration of MDA in the liver tissue of mice in the medium and high dose groups was lower than that in the model group,while the activities of CAT,SOD,GSH-PX were higher than those in the model group.Gallic acid microcapsules were prepared using arabic gum and maltodextrin as composite wall materials.The optimal preparation conditions obtained through single factor optimization experiments were as follows:wall to wall ratio 1:1,core to wall ratio 1:8,wall mass fraction35%,homogenization time 8 minutes,and the embedding rate obtained under these optimal conditions was 79.36%.The microcapsules of gallic acid were analyzed by a series of characterization methods such as laser particle size analyzer,scanning electron microscopy,infrared spectroscopy,X-ray diffraction,differential scanningcalorimetry,and thermogravimetric analysis.The results showed that gallic acid was successfully embedded in the wall material.The stability and in vitro release rate of gallic acid raw material and microcapsules were studied.The results showed that in the light stability experiment,with the increase of light time,the retention rate of gallic acid microcapsules was better than that of the raw material itself.In the temperature stability experiment,the retention rate of gallic acid microcapsules is higher than that of gallic acid raw materials at the same temperature.In the storage stability experiment,after a month of storage,the retention rate of gallic acid raw material was only48.3%,while the retention rate of gallic acid microcapsules was as high as 89%.In vitro release rates of gallic acid microcapsules in artificial gastric juice and artificial intestinal juice at 12 hours were 72.2%and 81.65%,respectively,3.54 and 3.48 times higher than those of raw materials.This indicates that the stability and in vitro release rate of microcapsules made of gallic acid have been improved. |
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