| Pickering emulsion, as a new kind of emulsion, based on stabilization by solid particles instead of traditional surfactants, has a great potential in food processing, with lots of advantages, such as strong stability, minor dosage, low cost, and good safety. And the use of food borne particles as an emulsifier has important application value in food, medicine,cosmetics and other fields.In this paper, we use Flammulina velutipes as raw materials to preparation emulsion which was stabilized by nanoparticles. And the emulsion was added into the sausage to replace the fat, and the effect of the emulsion on the properties of sausage was studied.First, after continuous alkali treatment, grinding, cleaning and high pressure homogenization treatment, we got nanometer level of Flammulina velutipes polysaccharide nanoparticles (FVPN), and analyse composition of the polysaccharides. With FVPN as emulsifier, The Pickering emulsifying properties of FVPN were studied with the FVPN:palm oil (70:30, v:v) emulsion as modle, and the mixture was treated with supersonic to prepare Pickering emulsions. After all, emulsifying properties under different concentrations of emulsifying properties were studied, including emulsifying volume,emulsion droplets particle size, sugar residues, rheological properties and stratification stability. Results showed that polysaccharides mainly composed of glucose and glucosamine; concentration had a significant effect on the emulsification effect, along with the increase of concentration, the volume of emulsified oil also increased, reaching the maximum at a concentration of 0.2% and remained unchanged; emulsion particle size increaseed first and then decreases; aqueous polysaccharide residue amount is consistent with particle size change; Emulsion viscosity decrease with the concentration increase, and G’ and G" increased with polysaccharide concentration increase. The higher is the concentration of polysaccharide, the smaller are the stratification rate and the stratification coefficient of emulsion,and the more stable of the emulsion.Secondly, the emulsifying properties of the emulsions with the same FVPN concentration were studied under different conditions, including the addition of different concentrations of NaCl, and changing pH conditions. The results showed that the addition of a certain concentration of NaCl has a positive effect on the emulsion, the specific performance showed in the smaller particle size of emulsion, less residual amount of polysaccharide.While the addition of NaCl concentration over a certain range (> 2.0wt%), the emulsification effect became poor. In addition, the emulsion droplets size did not change significantly in different pH, indicating that the emulsion has a relatively good emulsifying effect in the larger pH range.Finally, we added the emulsion prepared by FVPN and palm oil as fat simulants to sausages to substitute part of animal fat in the sausages, to produce healthier meat products.The effects of emulsion on moisture content, texture properties, cooking loss rate were studied, and the microstructure was observed by scanning electron microscopy, and the distribution of fat in sausage was observed by confocal laser scanning microscope. The emulsions were centrifugated to change the distribution of liquid droplets in the emulsion,and then added to the sausage, compared the difference between centrifuge and no centrifuge group. The results showed that with increasing of the ratio of emulsion, the moisture content of the sausage increased from 53.24% increased to 64.85%, cooking loss rate reduced from 18.87% to 8.63%; pH change was not significant in the range of 6.3 to 6.6; Adding less than 20% of the emulsion can improve the sausage elasticity; at the same time, the addition of emulsion can make sausage structure more closely. After centrifugation, the distribution of oil droplets was changed. Compared with the no centrifugal group, the water content of the sausage was decreased, the cooking loss rate increased, and the fat distribution was uniformity.In summary, FVPN can be a new type of food emulsifier, and can be used as a potential high dietary fiber ingredient used in the development of functional meat products. |
