Lonicera Caerulea L.seed Oil Microcapsules Preparation And Evaluation Of Lipid-lowering And Antioxidant Activities

Lonicera caerulea L.seeds are often discarded as a by-product of processing,and their full utilization would help to increase the economic value of Lonicera caerulea L.The seed oil of Lonicera caerulea L.contains a large amount of unsaturated fatty acids,including conjugated linoleic acid,which has been shown to have excellent biological activity.Therefore,Lonicera caerulea L.seed oil is a functional plant seed oil with high nutritional value.However,due to the unstable physicochemical properties of such lipophilic compounds,Lonicera caerulea L.seed oil is susceptible to oxidation and rancidity due to the disturbance of external adverse factors,resulting in the impairment of the original active ingredients of the seed oil,which affects the promotion of Lonicera caerulea L.seed oil.Microencapsulation of the seed oil can significantly reduce the oxidation rate and protect the effective active ingredients,and the photothermal stability and bioavailability of the seed oil can be enhanced.In this paper,the seed oil of Lonicera caerulea L.was extracted with ultrasound-assisted ethanol,and the microencapsulation of Lonicera caerulea L.seed oil was prepared using ultrasound-assisted molecular embedding method,and its physicochemical properties and biological activity were also determined.The main research results are as follows:（1）The processes of ultrasound-assisted ethanol extraction of Lonicera caerulea L.seed oil and ultrasound-assisted molecular embedding for the preparation of Lonicera caerulea L.seed oil microcapsules were optimized using response surface analysis,respectively.Among them,the best extraction process conditions were obtained with the oil yield as the evaluation index,the material-liquid ratio of 1:22 g/m L,the ultrasonic temperature of 42℃,the ultrasonic power of 395 W,and the ultrasonic time of 39 min,and the best oil yield of 39.15±0.24%was obtained.Hydroxypropyl-β-cyclodextrin was used as wall material and Lonicera caerulea L.seed oil as core material,taking the embedding rate as the evaluation index,the best preparation process of seed oil microcapsules was obtained as the wall concentration 6:1m L/mg,wall-core ratio 5:1 g/g,embedding time 63 min,and embedding temperature 59℃,at which the best embedding rate was 70.34±0.13%and the best yield was 75.28±0.39%.（2）The results of the basic physicochemical properties of the microcapsules showed that the water content of the microcapsules was 1.43±0.09%,the solubility was 98.62±0.31%,the resting angle was 34.65±0.28°,the density was 0.68±0.03 g/cm,and the average particle size was 216.21±5.32 nm observed that the microcapsules of Lonicera caerulea L.seed oil had a compact structure without gaps and an irregular block structure.The formation of microcapsule inclusion was further confirmed from the spectroscopic point of view by the characterization of UV-Vis,FTIR,XRD and ¹H NMR spectra;in addition,thermogravimetric（TG）and differential thermal（DSC）analyses proved that the thermal stability of the microencapsulated Lonicera caerulea L.seed oil was significantly enhanced.（3）The determination of the retention rate of core material of Lonicera caerulea L.seed oil microcapsules under different storage environments showed that the storage condition of4℃could significantly slow down the release of core material,and the light-proof and dry environment was also more favorable for the storage of Lonicera caerulea L.seed oil microcapsules.The determination of peroxide value and conjugated diene value of Lonicera caerulea L.seed oil microcapsules showed that the formation of seed oil microcapsules could effectively slow down the oxidation rate of the core material in unfavorable environments such as temperature,oxygen and light,and the seed oil microcapsules had good oxidative stability.The analysis of the fatty acid composition of seed oil microcapsules by gas phase mass spectrometry showed that the microencapsulation treatment had little effect on the fatty acids of seed oil,and the relative content of unsaturated fatty acids in microcapsules was 71.109%.In vitro release simulation experiments showed that Lonicera caerulea L.seed oil microcapsules could release a small amount of core material in gastric juice,and the core material continued to be released after entering intestinal juice.（4）The results of the in vitro biological activity study on Lonicera caerulea L.seed oil microcapsules showed that the seed oil microcapsules were free from 0-80μg/m L range.The seed oil microcapsules could reverse the lipid accumulation caused by Na OL in a dose-dependent manner,and also had the ability to regulate TC/TG,HDL-C/LDL-C,ALT/AST levels in the NAFLD model of Hep G2 cells,which could accelerate lipid metabolism and reduce hepatocyte damage.Seed oil microcapsules alleviated the decrease in cell viability caused by H₂O₂ and significantly decreased the level of ROS within the oxidative stress model with increasing concentrations.In summary,this study rationalized the use of Lonicera caerulea L.by-product resources,optimized the extraction process of Lonicera caerulea L.seed oil,and established a new method for the preparation of seed oil microcapsules by ultrasound-molecular embedding.The microcapsules prepared by this method are safe and non-toxic,rich in polyunsaturated fatty acids such as conjugated linoleic acid and have good oxidative stability,and also have in vitro hypolipidemic and antioxidant biological activities.This study reduced the oil loss of Lonicera caerulea L.,and laid the foundation for the deep development and industrialization of Lonicera caerulea L.seed oil in multiple fields.