Study Of Color Protection And Emulsion Stability On Coconut Milk Under Vacuum Concentrated

Coconut is a main cash crop of Hainan Province which has provided important support for local economy. Consumers are fond of coconut food for its full range of nutrients. It is made from fresh coconut. Therefore, hot weather causes browning and delamination problems in the storage and transportation. In this paper, preparation of concentrated coconut milk under vacuum are selected. After that, comprehensive analyses of the Browning are made. By adding inhibitors and emulsifiers, prepare coconut milk product which has a better stable quality.The results are as follows:1the optimizative results of vacuum concentrated coconut milk production processFresh ripe coconut meatâ†'Peeled, Juicer and filtrationâ†'Vacuum Concentrated:the degree of vacuum0.095MPa, concentrated at55℃to a moisture content of about30%â†'Emulsification:60～75℃â†'High Pressure Homogenization:first pressure40MPa, second pressure15MPa,10minâ†'Hot fillingâ†'Sterilization:112℃,10min.2the results of concentrated coconut milk browning analysis(1) Comparison coconut milk from Malaysia, Indonesia and Hainan, the color of Indonesia’s is not suitable to prepare concentrated coconut milk. After being storaged under room temperature0d,15d,30d, distribution of PPO or POD in different parts of the coconut:testa> white copra with testa> white copra. The more time, the higher PPO and POD activity increase. Therefore, it is nessary to make it peeled as much as possible and used timely.(2) In the production process, the PPO and POD activity continuously reduce, and nearly reach zero after sterilization. So the enzymatic browning has little effect on the color change in the storage of concentrated coconut milk.(3) Before storage, the browning index of coconut milk is only0.10±0.01. The main ingredients are as follows:total acid0.32±0.02g/100ml, total sugar13.11±1.03g/100ml, sugar7.53±0.41g/100ml, free amino acids2.02±0.19mg/ml, total phenols892.31±52.43mg/L and Vc is zero. The result shows browning during storage is not due to crack of Vc.(4) Measure the mainly composition changes of concentrated coconut milk in4℃,25℃,37℃,50℃every other week. The total phenolic content slightly reduced, while the total sugar and free amino acids significantly decreased. It is found the higher temperature, the faster decline. While the other ingredients nearly remained unchanged.In conclusion, the browning of concentrated coconut milk is Maillard reaction dominated. 3results of color fixative effect on concentrated coconut milkExperiments investigation during storage at37℃.The Common color fixative EDTA-2Na, Vc, sodium bisulfite and citric acid, Vb-Na are used to search for better browning inhibition of concentrated coconut milk. EDTA-2Na, citric acid, Vb-Na are selected to design response surface experimental. The best combination is EDTA-2Na0.01%, citric acid,0.176%, Vb-Na0.040%, the browning inhibition rate is63.31%.4the study results of vacuum concentrated coconut milk emulsion stabilityThrough concentrated coconut milk emulsifier compound selected, the optimal combination of emulsifiers obtained:monoglycerides0.15%,0.10%sucrose ester, sodium caseinate0.09%, span600.06%.Concentrated coconut milk is an important raw material of coconut products. Used in candy, cookies or beverage industry, the quality, flavor and taste are improved apparently. Thus it is aviliable for long term use. This is significant for the development of coconut industry.