Research On The Preparation And Application In Food Field Of Perilla Oil Microcapsule

Perilla frutescens is also called red Sue, Sue seed, sweet Sue, belonging to labiataeperilla annual herb. It is traditional medicinal plants in our country. It has a long history andare widely cultivated. Perilla seeds are rich in oil, the content of α-linolenic acid in perillaoil ranges from54%to64%. α-linolenic acid can be converted to the EPA(eicosapentaenoic acid) and DHA (docosahexaenoic acid) in the body. It is potential onnutrition, health and development value, Long-term consumption can play an importantrole in regulating metabolism, prevention and treatment on cardiovascular andhyperlipidemia disease. However, as much as90%of unsaturated fatty acids in perilla oilare oxidizable, light and heat sensitive, that make the shelf can not meet the expected result.Microencapsulation is an efficiency method that can use special coating materialsembedding liquid oil to stable and free-flowing solid powder, which is also used in all kindsof food as food additive because of its facilitate storage and transportation.This project includes four parts:(1) The microcapsule of perilla oil was prepared by spray-drying andfreeze-drying technology by using the starch octenylsuccinate as the wall material.The best technological conditions were achieved by carrying out the research onsolid content, the mass ratio of core material and wall material, homogenization time,homogenization rate and emulsification temperature. The optimization preparationconditions were as follows: solid content30%, the mass ratio of core material andwall material1:4(m/m), homogenization time2min, homogenization rate16000r/minand emulsification temperature50℃。The effects of microencapsulation methods onencapsulation efficiency, storage stability, sensory evaluation, and the configurationof surface were studied comparatively. The microcapsules encapsulation efficiency(MEE) of perilla oil can reach at98.86%by spray-drying preparation, can reach at76.24%by freeze-drying preparation. Spray-dried microcapsules appeared regularspherical, good fluidity, fine texture, easy to dissolve; smooth surface and densestructure so as to reduce the chance of contact with the outside world,slow down theoxidation rate, prolong storage period. However, freeze-dried microcapsules wereporous, showing irregular lumps, poor mobility and high moisture content. It wasconcluded that the properties of powdered oil produced by spray-drying precededthose produced by freeze-drying, and the starch octenylsuccinate was suitable forpreparation of spray-drying microencapsulated perilla oil with respect to long-termstorage. (2) Encapsulation of perilla oil using soybean protein isolate(SPI) and sodiumalginate(SA) as wall materials by complex coacervation technique was investigated. Theinfluence of the amount of emulsifier, homogeneous time, homogeneous rate, ratio of wallmaterials, the mass ratio of core material and wall material on the properties ofmicrocapsules were determined. The optimization preparation condition were as follows:the amount of emulsifier0.1%, homogeneous rate1000r/min, homogeneous time1min,coacervation pH3.5, wall material content4%, the mass ratio of core material and wallmaterial1:1, the mass of soybean protein isolate and sodium alginate4:1. Andencapsulation efficiency, solubility and storage stability and other properties werestudied comparatively prepared by spray-drying and freeze-drying. The results showthat encapsulation of perilla oil prepared with freeze-drying reflects higherencapsulation efficiency and high stability. And the glucose was chosen as curingagent instead of toxic chemical reagent glutaraldehyde so as to offer theoretical basis forthe application in food field.(3) The quality of cold-squeezed and hot-squeezed perilla oils was comparativelyevaluated by measuring contents of free fatty acids and total fatty acids. The measurementresults of free fatty acid in perilla oils show that free fatty acid content of hot-squeezedperilla oil (1.53mg/g) is significantly higher than that of cold-squeezed perilla oil (0.54mg/g). Through acid hydrolysis, the glycerol esters in perilla oils were converted into freefatty acids. Each fatty acid in two kinds of perilla oils was qualitatively and quantitativelydetermined by reversed phase high performance liquid chromatography with evaporativelight scattering detector (HPLC-ELSD) and the gradient elution mode. The results showthat, fatty acid compositions of perilla oils are the same including linolenic acid, linoleicacid, oleic acid, palmitic acid, and stearic acid. However, the difference of the content ofeach fatty acid is larger. The contents of linolenic and linoleic acids in cold-squeezed oil aresignificantly higher, and of oleic acid and palmitic acid are relatively low than those ofhot-squeezed oil. The content of five fatty acids is up to95.09%in cold-squeezed oil and87.89%in hot-squeezed oil. The recoveries of five fatty acids are99.70%~101.11%, andRSDs are between0.44%~3.66%.(4) Perilla oil powder grease instead of part of milk powder as additive was used in icecream, bread and cookies, and the products were compared with traditional products andones added liquid perilla oil. Then sensory evaluation, chromatism, texture, special flavorand so on were analyzed comparatively. Results showed that powder oil with gooddispersion and mobility can mingle with raw materials succinctly and evenly, improved the production and storage efficiency, thus nutritious and health food were achieved.