Effect Of Different Treatment And Additive On The Stability Of Coconut Milk

Coconut milk is an natural oil-in-water emulsion,and has better nutrition value,like all emulsions,coconut milk is unstable and readily separates into cream and serum layers,which is suspected to be the consequence of the composition and properties of coconut milk.As an important food ingredient,the key problem is improving the stability of coconut milk.In the process,the mechanization about how the treatment on coconut meat,the additive and the mechanical treatment affect the stability of coconut milk is rarely reported.Thus exploring the mechanization is essential,which also provide theory basis for production of coconut milk.The main contents of this study are the following:(1)Heating increased the average droplet size of coconut milk.Freezing decreased the average droplet size of the emulsion to a minimum of 7.67 ?m.High-speed shearing increased the average droplet size of the emulsion to a maximum of 10.29 ?m.The creaming index of the emulsion squeezed from coconut meat that underwent freezing treatment was 35.10%,which was the minimum value.Thus,freezing treatment on coconut meat could induce the size of the emulsion droplets and improve the stability of the emulsions.(2)The stability is the best and the interfacial tension is the minimum when the HLB of the compound emulsifier is 8.(3)The coconut oil droplet size is between 300 and 400 nm,and the PDI(polydisper dispersion index)is between 0.3 and 0.5 while the concentration of compound emulsifier(GMS-SE)is between 0.15%and 0.45%,which indicates that the mean size of coconut oil droplets are smaller and their distribution are homogeneous;The ?-potential is between-39 and-42 mV while the concentration of compound emulsifier(GMS-SE)is between 0.25%and 0.45%,which indicates a bigger repulsive force among coconut oil droplets and a better stability of coconut milk;the interfacial tension is the minimum,16 mN/m,when the concentration of compound emulsifier(GMS-SE)is 0.35%and 0.45%.According to the creaming index,the creaming index is mininum while the concentration of compound emulsifier(GMS-SE)is between 0.35%and 0.45%,which shows that the stability of coconut milk is good.(4)The coconut oil droplet size is between 200 and 300 nm,and the PDI(polydisper dispersion index)is between 0.2 and 0.4 while the concentration of sodium caseinate is between 0.3%and 0.8%,the ?-potential is between-31.56 mV and-38.56 mV while the concentration of sodium caseinate is between 0.2%and 0.6%,the ?-potential is-41.23 and-46.23,while the concentration of sodium caseinate is 0.7%and 0.8%,respectively.The interfacial tension(IFT)is between 9 and 11 mN/m while the concentration of sodium caseinate is between 0.4%and 0.6%.According the creaming index,the creaming index is 2.14%and when the concentration of sodium caseinate is between 0.4%and 0.8%,which shows that the stability of coconut milk is good.All of the data shows that the coconut oil droplet size is smaller and homogeneous distribution,the ?potential is larger,the creaming index is smaller and the stability is better.(5)With the increasing of the concentration of CMC,the viscosity and droplet size of coconut milk were on the rise,but the stability were decreasing.The viscosity of coconut milk is between 1 and 1.75 mPa · s,and rise more slowly,which close to the viscosity of water.The viscosity raised much faster when the concentration of CMC is between 0.4%and 1%.The viscosity are 2.3.3?15?4.45.5.75 mPa·s with the increasing of the concentration of CMC.The droplet size is the minimum,0.34?m,when the concentration is 0.04%,and there is no stratification before the forth day.The droplet size of coconut milk is 1.5 ?m,when the concentration of CMC exceed 0.2%,with the time extension,the stability of coconut milk destroyed completely.