| Mango is a fragrant tropical fruit mainly grown in Baise,Guangxi.This article used the pulp,peel and leaves of five mangoes,Tainong,Royal Concubine,Red Ivory,Jinhuang,and Guiqi as raw materials.To carry out mango volatile components analysis,mango leaf volatile oil extraction,purification and identification,mango leaf volatile oil microencapsulation preparation and basic quality index analysis.The research in this thesis has practical significance and theoretical reference for promoting the comprehensive utilization,improving quality and efficiency of Guangxi mango industry.The specific research content and results are as follows:Using headspace solid-phase microextraction method to extract,GC-MS technology identification,qualitative and quantitative volatile components of 15 samples,and compare the differences of different species and different tissue parts,a total of 137 components were detected,there are 63 unique ingredients in total.Experiments have shown that 1-methyl-4-(1-methylethylene)-cyclohexene is a common volatile component in the flesh of the five varieties,and the difference in characteristic aromas preferred by consumers is reflected in Tainong 3-carene(5.36%),Royal β-Ocilene(13.29%),Red Ivory α-Pinene(4.00%)and 3-Carene(3.66%),Jinhuang 3-Carene(14.18%),Guiqi β-Ocilene Ene(78.88%)and α-pinene(2.98%).The peel does not contain volatile components,and the content of other types is increased compared to the content of pulp olefins.The fruit leaves contain five components: α-pinene,camphene,β-pinene,γ-terpinene,and caryophyllene,and the content of olefins is high,but there are some differences in their main components.Cinnamomum vulgare has24.87% enhanced aroma the role of esters.The types and relative contents of volatile components in different parts of the same species are significantly different.For example,red ivory contains 8 kinds of ingredients,7 kinds of pulp,11 kinds of peels,and 12 kinds of leaves.Principal component analysis shows that olefins are the most important aroma contributors in mangoes,and olefins are based on 1(3)-methyl-4(6)-(1-methylethylene)-cyclohexene,β-Ocimene,α-pinene and 3-carene are the main aroma components.The volatile oil extraction device using the solvent n-hexane layer collects the mango leaf crude oil with special aroma,and analyzes the extraction solvent,distillation temperature,distillation time,and material-to-liquid ratio of four factors that affect the extraction rate.The best process combination for extracting mango leaf volatile oil is: material-to-liquid ratio 1:9,soaking time30 min,distillation temperature 300℃,distillation time 2.5h,extraction solvent n-hexane layer,the extraction rate is about 0.20% under these conditions.In the process of molecular distillation,keep the scraping speed 300r/min,the cold trap temperature(liquid nitrogen cooling),and the feed flow rate(2 drops/s)unchanged,by adjusting the three variable parameters of the condenser temperature,vacuum degree and evaporator temperature,It is concluded that the separation effect of each component is ideal under the conditions of one-time molecular distillation where the condenser temperature is-15 ℃,the vacuum degree is 40-50 Pa,and the evaporator temperature is 45 ℃.Set the condenser temperature to-15 ℃,the vacuum degree to 150～160 Pa,and the evaporator temperature to carry out the second molecular distillation of the heavy components at 35 ℃.The total intermediate component mixture is the purified mango leaf volatile oil.Its main component is terpene(C10H16,C15H24)compounds and the purification rate is 87.01 %.Gum arabic,maltodextrin and β-cyclodextrin are used as composite wall materials,and mango leaf volatile oil is used as core material to prepare the microcapsules by spray drying.Through single factor experiment and response surface experiment design,the order of the degree of influence of each factor on the embedding rate of volatile oil microcapsules is determined in the order of core wall material ratio> composite wall material ratio> solid content,wall material ratio and core wall ratio interact The embedding rate has the most significant impact.The best process conditions are: the wall material ratio(gum arabic: β-cyclodextrin: maltodextrin)is 10:6.3:3.7,the core-wall material ratio is1:7.58,and the solid content is 20.46 %.Under these conditions,the embedding rate of mango leaf volatile oil microcapsules can reach 92.08 %,which is close to the theoretical value(92.45 %),and the model design is reasonable.The microcapsule product has small and uniform particles and has a certain degree of flowability.It is light yellow and has a faint mango fragrance.The product has a large bulk density(0.486 g/cm3),high solubility(88.82 %),and low water content(2.14 %),At the same time,it has very good slow-release properties.The volatilization rate is only 3.20 % when heated for 10 hours,which is 96.07 % lower than the unembedded product.The average particle size of the product is 1757.33 nm in the micron level,which meets the requirements of general production for the particle size of microcapsules,and the absolute value of the Zeta potential(-31.50 m V)is greater than 30 m V under the condition of p H6.The particles are mutually repellent,the suspension is stable,and has good dispersion.Sex.Scanning electron microscopy results show that the surface of the product is relatively round,with full particles and no cracks.Therefore,the microencapsulated products of mango leaf volatile oil have good quality.This study shows that mango leaves are rich in volatile substances and have great development potential.Among them,mango leaf essential oil microcapsules made from Jinhuang mango leaves are of good quality and have application promotion value. |
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