| Comminuted meat products are favored by more and more consumers because of the unique flavor and rich nutrition.However,in the actual production and processing,the emulsified meat emulsion system often has many unstable problems such as out of water and oil,which affects the final quality of product.This topic is based on the solid particle emulsifier which stabilizes the Pickering emulsion after hydrophobic modification of rice starch.and to the research object of myofibrillar protein which to investigate the characteristics of Pickering emulsion and the effect of hydrophobic modified starch granule on the properties of myofibrillar emulsions,and finally investigate the effect of Pickering emulsion on the properties of protein gels.The main results are as follows:1.Modified starch granules had emulsifying ability which were obtained by esterification reaction of octenyl succinic anhydride with rice starch.Infrared spectroscopy showed a carbonyl stretching vibration peak near 1242cm-1,1222cm-1,which indicated that the ester group replaced the hydroxyl group on the starch molecule successfully and with a degree of substitution of 0.019,which was consistent with the degree of substitution in food application;The X ray diffraction and microstructure of starch granules indicated that the esterification reaction occurs on the hydroxyl group in the amorphous region of the starch molecule,which had no obvious effect on the crystallization zone of the starch,and the modified starch granule still maintained the particle morphology of the original starch.The hydrophobically modified starch granules remain intact and could be used as materials for subsequent experiments.2.Tween 80 and modified starch granules were used as emulsifiers to prepare traditional small molecule emulsion and Pickering emulsion respectively.The characteristics of the two emulsions were compared with the emulsion stability analyzer test,and found that the particle migration rate of Pickering emulsion during centrifugal instability was significantly lower than that of traditional small molecule emulsion,which indicated that the stability of Pickering emulsion was significantly better than traditional small molecule emulsion,and the stability and emulsifier concentration were positive.Microstructure could find that unlike traditional small molecule emulsions,as the concentration of emulsifier increased,the oil-water interfacial tension was reduced.Pickering emulsion was the adsorption of particles at the oil-water interface to form a dense interface film to prevent droplets.Aggregation between them to stabilize the emulsion;analysis of the rheological properties of the emulsion indicated that the Pickering emulsion had a high viscosity and elastic modulus,which was beneficial to delay the aggregation between the droplets.The results showed that the Pickering emulsion prepared by solid particles had better stability and application prospect than traditional small molecule emulsion.3.In order to improve the stability of the myofibrillar emulsion,the modified starch granules were added to the myofibrillar protein emulsion to investigate the effect on the properties of the protein emulsion.The addition of modified starch granules could significantly improve the stability and emulsifying activity of the protein emulsion,and thestability and emulsifying activity were reached the highest value at the added amount of 1%;meanwhile,as the concentration of the modified starch granule increases,the protein emulsion large droplets had a tendency to transform into small droplets,and the average particle size was also significantly reduced(P<0.05).The electrostatic interaction between the negative ion group and the myofibrillar protein in the modified starch could significantly reduce the potential of the protein emulsion(P<0.05),from-28.1 mV to-52.3 mV.At the same time,the modified starch granules and myofibrillar proteins had certain competitive effects in the emulsion system,and the interface protein content was reduced.The stability of the myofibrillar emulsion was significantly improved4.Finally,the effect of Pickelin emulsion prepared from modified starch on the properties of myofibrillar gel was investigated.After the Pickering emulsion prepared by hydrophobically modified starch was added to the myofibrillar protein solution to form composite gel,the water holding capacity of the protein gel was increased from 28.5%to 61.2%,the water content of the non-flowable water increased significantly(P<0.05),and the water retention was improved.;the strength of gel was also increased from 0.28 N to 0.66 N,which indicated that enhanced the texture of the gel;and the presence of modified starch granules in the Pickering emulsion was also increased the elasticity modulus of the gel system;and the addition of Pickering emulsion also reduced the degree of oxidation of the protein gel to some extent.The results showed that the addition of the Pickering emulsion formed by the modified starch could improve the performance of the composite protein gel. |
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