| The total planting area and yield of citrus in China are ranked first and second in the world,it became one pillar industriy which support the rural economy in our country.Citrus processing is often accompanied with 30%-50%by-products,so effectively improving its comprehensive utilization rate has become an urgent problem in citrus industry.?-carotene is an important fat-soluble pigment in Citrus Peel,which has many functions,such as anti-oxidation,lowering blood lipid and enhancing immunity,therefore,the recovery of?-carotene has become an important measure to improve the comprehensive utilization rate and economic added value.However,the biological activity of?-carotene is easily affected by light,temperature and oxygen content,and its application is limited in practical production.The objective was to explore the extraction of?-carotene by ultrasonic assisted organic solvent extraction,and optimized the process of microcapsule preparation by complex coagulation,In order to provide reference for the comprehensive utilization of orange peel by-products and the industrial application of?-carotene microcapsules.The main findings are as follows:?1?A single factor experiment was used to determine the extraction rate of?-carotene in citrus peel residue under different material-liquid ratio,extraction time and temperature.On the basis of single factor experiment,the extraction process of?-carotene was optimized by L9?34?orthogonal experiment.The results showed that the primary and secondary relationship of influencing factors were extraction temperature>extraction time>material-liquid ratio,comprehensive economic factors,and the final optimization scheme was material-liquid ratio 1:10,time 15 min,temperature 35?.?-the extraction amount of carotene was 28.00mg/kg,and the purity reached 92.10%in this condition.?2?The effects of different pH on the charged property and turbidity of microencapsulated wall material system,and the effect of different proportion of gelatin/CMC ratio on the emulsifying activity of the polymer were studied.The results showed that the potential of gelatin solution,CMC solution and gelatin/CMC?9:1?solution decreased gradually with the increase of pH.The gelatin/CMC?9:1?mixed solution system achieved positive and negative charge equilibrium?electrostatic charge 0?at pH 4.5 and the polymer had high yield.Emulsification activity of gelatin-CMC complex increased first and then decreased with the increase of the ratio,and the emulsification activity index reached maximum value at the ratio of 10:1.?3?With different wall material concentration,average velocity,curing agent addition,pH and oil phase as the investigation factors,a single factor experiment was used to study the effect of different conditions on the embedding rate of?-carotene microcapsules.The results showed that the best extraction process was as follows:pH 4.65,wall material concentration 0.91%,homogenization speed 8804.05 rpm?curing agent 25?g,and chosee corn oil as phase,and the embedding rate could reach to 87.50%in this technology.?-carotene microcapsules prepared under optimal process conditions:embedding rate86.21%,yield 84.31%,moisture content 8.72%,density 0.72 g/cm3,angle of repose 35.60,particle size 31.29?m,heap density 897,It has good dispersibility in water,slight smell of?-carotene,orange powder and loose particles..Microencapsulated?-carotene was embedded in dense and stable cystic wall,the tolerance to air,temperature and light was significantly improved.Meanwhile,the stable structure of microcapsules could protect?-carotene from release in simulated gastric juice.Its bioavailability can reach 70%in the simulated intestinal fluid for 4 hours,which was not different from the control group?P>0.05?.Add?-carotene microcapsules to cookies,the results showed that there were no significant differences in hardness N,brittleness,elasticity,cohesion,stickiness and chewiness between the two groups?P>0.05?,but there were significant differences in color between the two groups. |
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