Study On Masking The Bitterness Of Quercetin By Polysaccharide Modified Liposomes

Quercetin is a natural active substance of flavonoids,widely present in plants such as jujube,sophora japonica,hawthorn,and mulberry leaves,with a wide range of sources and broad application prospects.Quercetin is easily oxidized under light and heat conditions,and has a strong bitter taste,which limits its application in the food industry.Embedding is a simple and effective method that can mask the bitterness while improving the stability of quercetin.In this paper,a thin film dispersion method was used to prepare quercetin loaded liposomes,and polysaccharide modified liposome was established to deliver quercetin.This not only achieved the masking of quercetin’s bitterness,but also improved the stability of the liposomes.At the same time,the application of this system to functional gelatin candy meets the requirements of modern food safety,nutrition,and health,expanding the application of quercetin in the food industry.The main research contents of this paper are as follows:(1)Preparation optimization and characterization of quercetin liposomesQuercetin nanoliposomes were prepared by thin film dispersion method.The optimized lipid preparation conditions were as follows: lecithin 150 mg,mass ratio of lecithin to quercetin 20:1,mass ratio of lecithin to cholesterol 6:1,ultrasound time 15 minutes.At this time,the entrapment efficiency of quercetin liposomes was 79.05±1.91%,particle size was 74.57±0.18 nm,PDI was0.28±0.0036,Zeta potential was-12.23±1.07 mV.Through TEM observation,it can be seen that the liposomes have uniform size distribution and mainly spherical morphology.Compared to quercetin,liposome encapsulation increased its phase transition temperature from 110 ℃ to 156 ℃,and improved its thermal stability.In addition,after liposome embedding,the DPPH free radical scavenging rate of quercetin increased by about 40%,and its antioxidant activity increased.(2)Bitter masking of quercetin by liposomes modified with different polysaccharidesIn this chapter,three different polysaccharides(carrageenan,pectin,and trehalose)were used to modify quercetin nanoliposomes and investigate their masking effects on quercetin’s bitterness.The sensory evaluation results showed that when the concentration of quercetin was 0.15 mg/m L,the sensory bitterness of quercetin suspension was 7.3±0.3,with a strong bitter taste.After liposome embedding,the sensory bitterness decreased to 1.8±0.2,and after polysaccharide modification,the sensory bitterness decreased to 0,almost completely masking the bitterness of quercetin.This was because polysaccharide modification inhibited the release of quercetin and controlled its diffusion to the taste buds,thereby reducing bitterness perception.The electronic tongue results showed that the modification of high viscosity carrageenan had the strongest bitterness masking effect,reducing the bitterness of quercetin liposomes from 10 mV to 7 mV.Polysaccharides bind to liposomes mainly through hydrophobic forces,hydrogen bonds,and electrostatic interactions.The hydrogen bond binding between polysaccharides and liposomes increased the order of the accumulation of the intramolecular chains of lipids,and the rigidity of the liposomes became stronger.More hydrogen bonds were generated between carrageenan with higher charges and the liposomes.The results provided theoretical support for polysaccharide modified nanoliposomes as effective carriers of quercetin.(3)Study on the stability of quercetin in polysaccharide modified liposomesThe effect of polysaccharide modification on the fluidity of liposomes was investigated using fluorescence probe technology.After modifying liposomes with carrageenan,pectin,and trehalose,the polarity of the microenvironment where the ANS probe and pyrene probe were decreased.The fluorescence results of pyrene showed that with the addition of polysaccharides,the number of hydrophobic regions formed in the solution increased,and the rigidity of liposomes increased.At the same time,polysaccharide modification enhanced the anti-surfactant ability of liposomes.In addition,liposomes modified with polysaccharides still had good temperature stability,salt particle stability,and pH stability.When the pH value was 6.0,the particle size and PDI of liposomes decreased.The tight combination of polysaccharides and nanoliposomes effectively reduced the propagation rate of lateral diffusion and oxidation reactions within the membrane,and protected the antioxidant activity of quercetin.Trehalose modification had the strongest inhibitory effect on lipid peroxidation(71.04±0.59%),followed by pectin liposomes(56.07±1.84%)and carrageenan liposomes(55.37±0.13%).The results provided a scientific basis for the application of polysaccharide modified quercetin liposomes in food.(4)Study on the preparation process of quercetin liposome gelatin candyThe functional gelatin candy was prepared with gelatin content of 16%,xylitol content of40%,citric acid content of 0.8%,and quercetin lyophilized samples in different systems.The results showed that the gelatin candy modified with carrageenan liposomes had higher hardness,viscosity and elasticity.This was mainly due to the formation of intramolecular hydrogen bonds between hydrophilic carrageenan and gelatin,and the reduction of system water activity promoted the formation of gel molecular network,thus having higher hardness and viscoelasticity.At the same time,the introduction of quercetin can improve the reducing ability of gelatin candy,and the gelatin candy prepared by adding polysaccharide modified liposome still retains strong antioxidant activity.Compared with QQ sugar on the market,the elasticity,hardness,chewability and taste of carrageenan modified liposome gelatin candy are better to meet the quality requirements.