Study On The Application And Stability Mechanism Of Tamarind Gum In Set Yogurt

As a natural neutral hydrophilic polysaccharide extracted from Tamarindus indica L,tamarind gum has been used as thickening and stabilizing agent.It was added to the set yogurt to solve the problem of texture destruction and whey separation of the set yoghurt.In this research,the effects of lactic acid,sucrose,and casein on the properties of tamarind were investigated.The effects of tamarind gum on the sensory,pH,viscosity,water holding capacity and texture properties of set yogurt stability during cold storage were studied.The application effects of different amounts of tamarind gum in set yoghurt were studied.Finally,the interaction and stability mechanism of coagulated yoghurt with tamarind gum was explained.The main findings of the paper are as follows:(1)The effects of lactic acid and sucrose on the viscosity,apparent viscosity and particle size of tamarind gum were measured,which confirmed the characteristics of tamarind gum with good acid and heat resistance;the addition of sucrose could increase the apparent viscosity and particle size of tamarind gum.(2)By analyzing the particle size,DSC,FTIR,and SEM of tamarind gum,casein,and the mixtures of tamarind gum and casein,the results showed that the lamellar tamarind gum adsorbs to the surface of casein by steric hindrance,thereby forming a mutually enveloping complex and increasing the formation of its networked three-dimensional spatial structure,thereby stabilizing the system.(3)In the storage time,the proper amount of tamarind gum could delay the acidification process of yoghurt,increase the viscosity of yoghurt,and the water holding capacity and overall acceptance of yoghurt system could increase significantly.The firmness,viscosity,stickiness and chewiness of yogurt were enhanced.(4)The results of rheological properties,low-field NMR spectroscopy,particle size,and CLSM showed that the elastic modulus(G')and viscosity modulus(G'')of set yogurt both increased first and then decreased with the addition of tamarind gum,and the maximum was 0.03%.It indicated that the proper amount of tamarind gum was more beneficial to stabilize the three-dimensional network structure of the yogurt system.Tamarind gum binds more whey through hydrogen bonds,reducing the amount of free water in the system and protecting the casein from steric hindrance.The number of cavities in the yogurt microstructure with tamarind was higher,and the larger whey pore interfered with the continuity of the network structure.The casein-centered gel can then hold more moisture,forming a tighter cluster of casein proteins,and the protein structure is tighter,resulting in a more stable three-dimensional network of yoghurt systems.