Effects Of Psyllium Husk Powder On The Gel And Emulsification Properties Of Myofibrillar Protein

In order to improve the quality and yield of meat emulsion products,hydrophilic colloid additives such as xanthan gum and carrageenan are often added,which is a common method to improve its quality.With the continuous enhancement of consumers' health and nutrition concepts,products with green labels such as natural and additive-free have gradually become the first choice.Psyllium husk(PH)was listed as a new food resource in the 2014 Announcement No.10 of the National Health and Family Planning Commission.The dietary fiber content in PH is more than 80%,and it is mainly used as a dietary fiber supplement and animal feed.The dietary fiber in the PH is mainly arabinoxylan.The polysaccharides in PH have good thickening,water absorption and gel properties,and can be used as a substitute for traditional colloids in food.Applying PH to the production of meat products can not only play the role of emulsification,thickening,gelling,etc.,but also increase the dietary fiber content.However,there is little information available in literature about the use of PH for meat emulsion quality improvement and mechanism research.Myofibrillar protein(MP)is the most important protein in muscle protein.The gel and emulsifying properties of MP play a key role in the water and oil retention and texture properties of meat products.In this study,starting from the practical application of PH in meat patties,based on the protein-polysaccharide interaction,the influence of different PH additions on the properties of MP gel and emulsification and its mechanism were explored.The specific research content and main conclusions are as follows:(1)Performed steady-state and dynamic rheological tests on PH gel with different concentrations to understand its processing characteristics.The results showed that PH could form a weak gel and was a pseudoplastic fluid with low thixotropy.It had high viscosity and could be used for food thickening.The rheological properties of PH gel were affected by different processing conditions: The higher the concentration,the higher the modulus value and the stronger the gel performance;the pseudoplasticity of the fluid increased slightly under alkaline conditions;PH gel had better thermal stability in the temperature range of 5-85 ?;the introduction of salt ions increased the structural stability of the PH gels.(2)Pork and PH were used as raw materials to make pork patties.The effects of different PH additions on the cooking loss,water and oil retention and sensory quality of meatloaf were explored.The results showed that when the PH addition was 0.5%-1%(w/w),the water and oil retention of the meat emulsion were significantly improved,the cooking loss was greatly reduced,so the yield was increased.When the amount of PH was increased to 2%-3%(w/w),the oil retention of meat patties decreased,the texture characteristics decreased,but the viscosity increased which made it easy to shape.(3)Extracted MP from pork to study the effect of different PH additions(0.1%-3%,w/v)on the properties of MP gel and the interaction mechanism.The results showed that the addition of PH improved the gel properties of MP gels,and significantly increased the hardness,water holding capability and viscosity of the gels.At low additions(0.1%-1%,w/v),PH promoted the structure expansion and interaction of the proteins,the MP gel network was filled,and the gel system formed a dense network structure,which effectively improved the performance of the MP gel.The hardness,water holding capacity and viscosity of the gels were improved.With 2%(w/v)PH addition,the water holding capacity and gel strength of the composite gel were nearly doubled compared with the pure MP gel,and the viscosity was increased by about six times.The system formed a complex interpenetrating gel network,showing the best gel performance.Compared with the medium and low addition,high PH addition(3%,w/v)caused the performance of MP/PH composite gel to deteriorate,but it was still better than pure MP gel.Excessive PH hindered the formation of a continuous network of MP,resulting in deterioration of gel properties such as gel strength and water retention capacity.(4)The MP/PH mixtrue with different PH content(0.1%-0.8%,w/v)was used as emulsifier to prepare oil-in-water emulsion.Under the conditions of standing,centrifugation,heating,freeze-thawing,the stability of the emulsion increased with the increasing PH content.However,the microstructure,interface viscoelasticity,interface adsorption behavior,static contact angle,and rheological analysis results showed that under different PH concentration,the emulsion stability mechanism was different.At low PH concentration(0.1%,w/v),PH promoted MP aggregation and adsorption to the oilwater interface,thereby stabilizing the emulsion.As the amount increased(0.3%-0.5%,w/v),PH further promoted the aggregation of MP,the hydrophilicity of emulsifier increased,and the interface adsorption rate and adsorption capacity of MP decreased.When the addition amount was increased to 0.8%(w/v),the viscosity of the continuous phase was obviously increased,thereby hindering the diffusion of MP in the continuous phase,and obviously inhibiting the adsorption of MP at the interface.However,due to the increase of the viscoelasticity of the continuous phase,the oil droplets were also not easy to diffuse in the continuous phase,and were easier to disperse into small droplets and not easy to aggregate,so as to achieve a stabilizing effect.