| Cistanche tubulosa(Schrenk)R.Wight)is widely distributed in the desert areas of Northwest China and is an important "food and drug homologous" raw material.Cistanche tubulosa polyphenols have antioxidant,anti-aging,hypoglycemic and other biological activities.Based on the quality analysis of Cistanche tubulosa and the innovative extraction and identification of polyphenols,the polyphenol liposomes of Cistanche tubulosa were constructed.The main conclusions are as follows:(1)Comparative study on nutrition and bioactivity of wild and cultivated Cistanche tubulosa.The contents of crude fat,crude ash,soluble sugar and unsaturated fatty acid in wild Cistanche tubulosa were significantly higher than those in cultivated Cistanche tubulosa;The contents of protein,saturated fatty acids,amino acids,total polyphenols,total flavonoids and total triterpenes in cultivated Cistanche tubulosa were significantly higher than those in wild Cistanche tubulosa.The ethanol extract of Cistanche tubulosa has stronger scavenging ability of DPPH and ABTS free radicals(IC50 values are 0.549 and 0.473 mg/m L respectively).When the concentration is higher than 0.726 mg/m L,α-The inhibitory activity of glucosidase was higher than that of wild species(the inhibition rate was 41.5%).(2)Optimization of ultrasonic-assisted extraction of polyphenols from Cistanche tubulosa with deep eutectic solvent and its bioactivity.The deep eutectic solvent was prepared with proline glycerol(molar ratio 1:1).The optimal extraction process of polyphenols from Cistanche tubulosa by ultrasonic-assisted deep eutectic solvent was optimized by response surface methodology: ultrasonic temperature 40℃,water content 39.9%,solid-liquid ratio1:45.3 g/m L and extraction time 28 min.under these conditions,the yield of polyphenols was 37.76 mg/g.Furthermore,the second-order kinetic model of ultrasonic-assisted extraction of polyphenols from Cistanche tubulosa was established.The crude polyphenol extract of Cistanche tubulosa has a strong scavenging ability for DPPH radical,ABTS radical,superoxide radical and hydroxyl radical,and the corresponding IC50 values are 0.875 mg/m L,0.501 mg/m L,11.291 mg/m L and 60.196 mg/m L respectively(3)Construction of Cistanche tubulosa polyphenol liposomes.Using soybean lecithin as raw material,Cistanche tubulosa polyphenol liposomes were prepared by ethanol injection method.The results showed that the preparation process of Cistanche tubulosa polyphenol liposome was as follows: the addition amount of cholesterol was 80 mg,the addition amount of Cistanche tubulosa polyphenol extract was 20 mg,and the addition amount of soybean lecithin was 400 mg.The Cistanche tubulosa polyphenol liposome(TPC-Lip)was prepared by uniformly injecting 40 m L ultrapure water after dissolving in 20 m L of absolute ethanol.The physicochemical properties of Cistanche tubulosa polyphenol liposome(TPC-Lip),chitosan modified TPC-Lip(CH-TPC-Lip)and pectin chitosan modified TPC-Lip(P-CH-TPC-Lip)were further constructed and compared.The results showed ththe at TPC-Lip was successfully modified by positively charged chitosan through electrostatic adsorption,and pectin was further added.The negatively charged pectin was successfully wrapped outside chitosan.After polymer modification,the particle size increased significantly and the zeta potential changed significantly.In vitro release model showed that liposomes a had sustained-release effect,and the stability of CH-TPCLip and P-CH-TPC-Lip were significantly higher than TPC-Lip.In conclusion,in this paper,ultrasonic-assisted low eutectic solvent was used to extract Cistanche tubulosa polyphenols,and different types of polyphenol liposomes were constructed,and their physicochemical properties and sustained-release properties were compared,to provide a theoretical basis for the steady-state and industrial application of Cistanche tubulosa polyphenols. |
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