Study On Extraction,Separation,Purification And Stability Of Cocoa Pigment From Cocoa Shell

Cocoa husks are waste from chocolate production,and it is important to reduce resource waste and develop a technical route for cocoa colors applied to the food industry.In this paper,using cocoa husk as raw material,the extraction conditions,separation and purification methods and stability are started,and the results are as follows:Extraction conditions of cocoa pigment:(1)The conditions for removing pectin in cocoa shell by acid extraction alcohol precipitation method in subcritical state: 1 mol/L HCl solution,feed-liquid ratio 1:15,extraction time 50 minutes,and the removal amount of pectin in cocoa shell under this condition was 30 g/100 g cocoa shell.(2)Conditions for extracting cocoa pigment in subcritical state: 0.25 mol/L Na OH solution,material-liquid ratio 1:10,extraction time 50 minutes,the color value of cocoa pigment reaches about 30.(3)The same batch of cocoa shell can be extracted twice in the subcritical state to obtain97% cocoa pigment..Purification of large-hole resin adsorption method:(1)The XAD-16 large-hole resin is more suitable for the separation and purification of pitch through static and dynamic adsorption and resolution experiments,but the pigment concentration obtained is low and cannot meet the needs of industrialized production.(2)Use D113-FC weakly acidic cation to exchange resin static adsorption removal of salt ions in the pitch pigment solution to neutralize the p H of the extract.Purification of cocoa pigment by membrane separation method:(1)Microfiltration-nanofiltration combined method separates and purifies cocoa pigment,and with the progress of nanofiltration,the color value of cocoa pigment gradually increases to about 70.(2)Subsequent dialysis method was used to continue to separate and purify cocoa pigment,and with the increase of dialysis times,the color price of cocoa pigment continued to increase to about 110-120.Stability of cocoa pigment:(1)Cocoa pigment solution is extremely unstable under acidic conditions(p H <6.0)and gradually fades to light yellow.(2)The structure is destroyed in a high temperature environment and the concentration of cocoa pigment is reduced.(3)Cocoa pigment solution is unstable under light conditions,and attention should be paid to storing it in the dark.(4)Avoid storing in aluminum,copper,and iron containers when storing.(5)Cocoa pigment solution has a certain tolerance to oxidants and poor stability in VC solution.(6)Sugar food additives have a fixing effect on cocoa pigment,but acid food additives cannot be added to cocoa pigment solution because the solution is acidic and cocoa pigment is unstable.