Effect Of Wall Materials On The Physical Properties Of The Microcapsules And Carrier Mixed Behaviour

Microcapsule technology is widely used in the food industry, such as the preparation of functional powder oils, microcapsule of essence, microcapsule of nutrients, microcapsules of food additive, etc.Microcapsules are generally mix with food carriers to product fortified foods,and the uniformity of premix distribution is an important index of fortified foods. Physical properties of mixture are the key factors influencing the mixing effect, and the wall material is the main component of microcapsule capsule shell, rheological characteristics of wall material influence physical properties of microcapsule, research rheological properties of wall material have great significance.In this issue,soybean protein isolated(SPI),carboxymethyl cellulose(CMC),gum arabic(AG), octenyl succinate anhydrate(OSA) and gelatin(GEL) as the wall model, peanut oil as the core material, through the method of spray drying granulation, exploring the effect of rheological characteristics of wall materials on the physical properties of microcapsules and the effect of physical properties of microcapsule to dynamic behavior of mixed with carrier.The apparent viscosity?dynamic modulus?loss factor and stress-deformation characteristics of five kinds of wall material such as soybean protein isolated(SPI), carboxymethyl cellulose(CMC),gum arabic(AG),octenyl succinate anhydrate(OSA) and gelatin(GEL) under the same consistency conditions was studied by use TA Discovery-DHR. The results showed that the five kinds of wall material were all pseudo-plastic fluid in aqueous solution. The apparent viscosity decreased with the shearing rate increase and the apparent viscosity order was SPI<CMC<GEL<OSA<AG. GEL?OSA?AG has higher storage and loss modulus which has higher viscosity. On the contrary, SPI?CMC has lower storage modulus and loss modulus. The loss factor is higher than other wall material which viscosity is higher, such as OSA,the loss factor is smaller than other wall material which elastic is higher such as GEL.SPI,CMC is more likely to occur deformation than AG, OSA, GEL.The preparation of the same consistency gum arabic(AG), soybean protein isolated(SPI),octenyl succinate anhydrate(OSA),carboxymethyl cellulose(CMC) and gelatin(GEL) wall material paste were studies, research the effects of creep time 75 s,150s,300 s,and 600 s, the creep stress 1, 6, 10, 20 Pa(500, 1000, 2000, 5000 Pa GEL), and the condition of 25 ?,50 ?add malt dextrin(MD) impact on creep-recovery characteristics of wall materials by use TA Discovery-DHR.Results: Creep curves were fitted to the Burgers model, fitting R2 > 0.9046.The maximum creep compliance increase and recovery rates decrease with creep time increase. The recovery rates of GEL?OSA and AG decrease significantly with creep time increase, SPI and CMC show the good recovery; As for GEL and AG which storage modulus is greater than the loss modulus, the main recovery is instant reply in the recovery phase. OSA recovery is poor which storage modulus is less than the loss modulus.Creep stress of 1, 6, 10 Pa, the SPI,CMC Jcmax increases with stress increases, the AG Jcmax decreases with stress increases, and when the stress is 20 Pa, SPI,AG, CMC section elastic structure damage, Jc0, Jc1, Jcmax increases significantly, ?0 and recovery rates fall rapidly, the OSA,GEL Jcmax?Jc0?Jc1 increases with stress increases and have corresponding reply in recovery phase,elastic structure not damage;Add malt dextrin(MD) to wall material under the condition of 25 ?, SPI, CMC, GEL Jc0, Jc1, Jcmax are increases, CMC, GEL Jr0, Jr1 are increases,the recovery rate of GEL from 11.92% to 34.45%,and AG?OSA Jc0?Jc1?Jcmax are decreases,?0 is increases, the viscosity of OSA from 5.37×103Pa.s to 12.79×103Pa.s, Jr0?Jr1 are increases,the recovery rate of AG from 2.59%to 15.98%;Add the MD to wall material under the condition of 50 ?, the viscosity of AG?OSA?SPI increase one times,Jc0?Jc1??c?Jcmax of AG?OSA?SPI are decreases, Jr0, Jr1, ?r reduce obviously and response rates decline in recovery phase, the recovery rate of OSA from 18.69%to 5.13%,and CMC Jr0?Jr1??r?Jrmax are increases and recovery rate from 30.01%to 61.59%,the viscosity of GEL from 292.86×103Pa.s to 64.32×103Pa.s and Jc0, Jc1, ?c, Jcmax are increases, Jr0?Jr1??r decreases rapidly,the recovery rate of GEL from 18.27%to 1.46%.The physical properties of microcapsules is different with different wall,solids content is higher in emulsion then preparation of microcapsules with lower moisture content, bulk density is larger. The preparation of microcapsule moisture content increases, friction coefficient?rest angle and density increases with add malt dextrin to wall material. With SPI and CMC as wall material of microcapsules kinetic friction coefficient is smaller, with SPI, AG as wall material of microcapsules rest angle is smaller;Under the condition of 25 ?, add the MD to the OSA, AG enhanced ability to resist deformation of wall material, surface preparation of microcapsule sag was improved, with OSA + MD as wall material of microcapsule particle the sleek, because deformation resistance of SPI,GEL decreases, microcapsule apparent sag seriously;Apparent structure compact microcapsule embedding effect is good.Mixing process of microcapsule and carrier were simulated by use 3D discrete element method(DEM) to studied the effects of particle size ratio(food carrier:enhancer particle) bulk density,friction coefficient and speed of mixer shaft on mixing effect.The results show that the smaller bulk density and friction coefficient of particle more conducive to blending;The speed greater of shaft, the better of mixing effect;If particles size differences, mixing effect easily appear statified phenomenon as mixing time go on, is not conducive to mix.The simulation test results are basically consistent with actual situation, can provide a reference for practical production.