Study On The Stability And Gel Properties Of Mung Bean Protein-based Liquid Egg Replacer

Eggs play a vital role in the food system due to their excellent emulsifying,gelling and foaming properties.However,due to the health risks such as high cholesterol and allergenicity,as well as the increased demand for vegetarianism and sustainable development,the consumption of traditional egg products is limited.It has led to an increased interest in finding suitable egg replacers.Mung bean protein has become an alternative protein source due to its low beany flavor,high health efficacy and better gel property than other bean proteins.In this study,mung bean protein was used as the main raw material to prepare for the O/W emulsion system with a high protein-content（pH 7,protein content 8%,w/w）.This study systematically investigated the effects of pH-shifting,the addition of calcium ions,TG-crosslinking,and different oil phases on the stability and thermal gel properties of mung bean protein-based emulsion system.The main conclusions were as follows:Firstly,the effects of pH-shifting and Ca²⁺concentration on the stability and thermal gel properties of mung bean protein-based emulsion system were studied.The results showed that due to the partial expansion of protein structure caused by pH-shifting,BMBP exposed more action sites,thereby significantly improved the protein solubility（20%increase）and emulsifying activity（50%increase）.The pH-shifting reduced the sensitivity of BMBP to calcium ion concentration.The emulsion prepared by pH-shifting treated mung bean protein（BMBP）remained stable after 5 days of storage at 25°C without phase separation.After heat-induced at 95°C,under the condition of 10 m M Ca²⁺,the stable emulsion droplets wrapped by BMBP have stronger filling ability thus the gel strength of emulsion gel prepared by BMBP was 80%increased than control.The water holding capacity was increased from 71.4%to98.8%and the proportion of bound water was increased.The results showed that pH-shifting combined with 10 m M Ca²⁺could maintain a good balance between stability and thermal gelation of the BMBP-based emulsification system.Subsequently,under the condition of 10 m M Ca²⁺,the effects of pH-shifting,TG-crosslinking and two different oil phases（canola oil and coconut oil）on the freeze-thaw stability of emulsions were investigated.The results showed that the freeze-thaw stability of BMBP emulsion was higher than that of NBMP emulsion,which was mainly manifested in lower flocculation and coalescence rate.The apparent viscosity of BMBP emulsion was significantly higher than that of NMBP emulsion（canola oil-base:increased by 6.3 times;coconut oil-base:increased by 4.0 times）,and the difference of viscosity（canola oil-base:increased by 1.7 times;coconut oil-base:increased by 0.4 times）between the two groups was greatly reduced by freeze-thaw process,which reduced the viscosity of BMBP emulsion to a suitable dumping range.The results of creaming index indicated that the stability of NMBP in canola oil-based emulsion was higher than that of coconut oil-based emulsion,and TG-crosslinking further aggravated this phenomenon.For BMBP-based emulsions,the effects of two oil phases and TG-crosslinking on the emulsion freeze-thaw stability were not significant,which could be attributed to that the stable interfacial film in BMBP emulsion could resist the influence of oil phase and water phase crystallization.The effect of TG-crosslinking on the gel strength of BMBP-based emulsion gels（canola oil-base:increased by 80%;coconut oil-base:increased by 30%）was better than that of NMBP-based emulsion gels（canola oil-base:increased by 30%;coconut oil-base:increased by 10%）.Finally,the mung bean protein-based liquid egg replacer was applied to egg tart system,and its application effect was evaluated by the appearance,texture and water holding capacity.The results showed that 80μmol/g（protein basis）curcumin could maintain the optimum appearance color,shear viscosity and gel strength of mung bean protein-based liquid egg replacer.The egg tart prepared from BMBP-based liquid egg replacer was closest to the egg-based sample in terms of the sensory evaluation results and texture indexes such as hardness,elasticity,viscosity and cohesion,while these of egg tart prepared by NMBP-based liquid egg replacer were lower than those of egg-based samples.From the perspective of texture properties and sensory evaluation,the NMBP-based liquid egg replacer could partially replace eggs,while the BMBP-based liquid egg replacer could achieve the completely replacement of eggs.In summary,this study provided a new idea for improving the stability and thermal gel properties of mung bean protein-based O/W emulsion system with high protein content,and also lays a theoretical foundation for better expansion of mung bean protein-based liquid egg replacer in food industry.