| Ethyl cellulose(EC)is the only polymer gelling agent that can be directly dissolved in the oil phase.Methylcellulose(MC)is the only polymer food colloid with thermoreversible gelling properties.Candelilla wax(CDW)is a type of vegetable wax that contains long-chain fatty acids,fatty alcohols and esters.Each of the above three gels has its specificity.This paper compared the gel properties and oxidation characteristics of the gelled oils prepared by these three gels,and analyzed the physical and chemical properties of the microencapsulated products prepared by the three oil gels.Using rheological properties,oil retention,microstructure,texture properties,infrared spectroscopy and X-ray diffraction as evaluation indicators to compare and research on the gel properties of EC,MC,and CDW oil gels.It could be seen that with the increase of EC and CDW,the number of crystals in the gel oil increased,which made the network structure more stable,the viscosity and hardness values increased,and the grease loss rate decreased.The maximum hardness value of fish oil gel was 1360.78 g when the EC addition amount was 10%,and the corresponding grease loss rate was the lowest 17.74%.The maximum hardness value of fish oil gel was 1446.81 g when the CDW addition amount was 7%,and the corresponding oil loss rate was the lowest 18.29%.The gel properties of MC oil gel did not change significantly with the increased in the amount of addition.When the added amount of MC was 0.6%,the fish oil gel had a maximum hardness of 1169.33 g,and the lowest oil loss rate was 3.24%.Infrared spectroscopy showed that EC and MC mainly constructed gel networks through intermolecular or intramolecular hydrogen bonds of polysaccharides,while CDW mainly relied on van der Waals interaction between crystals to form a three-dimensional network structure to wrap liquid grease.Combining the evaluation indexes of gel properties,it could be known that the stability of the oil gel formed by the three gelling agents was MC>EC>CDW.Comparing and researching on the oxidation characteristics of EC,MC and CDW oil gels with different additions.Based on the evaluation indexes of acid value,peroxide value,anisidine value and malondialdehyde value,the optimal addition amount of the three gelling agents was determined to be 6%,0.6%,and 6%,respectively.EC,MC and CDW all showed different degrees of inhibition on oil oxidation.When EC was added at 6%,fish oil gel had the lowest peroxide value of 9.53mmol/kg,which was 19.5% lower than the blank control group;when CDW was added at 6%,fish oil gel had the lowest peroxide value of 11.93mmol/kg,which was 20.8% lower than the blank control group;when MC was added at 0.6%,the fish oil gel had the lowest peroxide value of 141.53 mmol/g,which was 23.7% lower than the blank control group.Although the oxidation degree of MC oil gel was greater than that of EC and CDW oil gels,the peroxide value of MC oil gel had a greater decrease compared with the blank control group,indicating that MC could significantly reduce the oxidation of oil inside the gel and inhibited the oxidation of oil.Comparing and researching on the physical and chemical properties of EC,MC,CDW microencapsulated fish oil with different additions.Based on the evaluation index of emulsion viscosity,emulsion particle size distribution,embedding rate,thermal stability,microstructure,and peroxide value,the optimal addition amounts of the three gelling agents were determined to be 2%,0.7%,and 6%,respectively.And EC had better physical and chemical properties than the microencapsulated fish oil obtained from MC and CDW.The microcapsule embedding rate coild reach 90.00% when the addition amount was 2%,and the degradation degree of microcapsule raw materials under high temperature was76.22%.Combining indicators such as particle size distribution,embedding rate and peroxide value,it could be seen that the physical and chemical properties of microencapsulated fish oil prepared by the three gels ware EC>CDW>MC. |
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