As in the case of the single strength frozen coconut milk, a small amount of citric acid is added to the milk before putting it through the pasteurizer. Pasteurization is carried out at the same conditions, but instead of passing the hot coconut milk through the cooling Votator, it is fed directly from the heating votator into the vacuum evaporator. The falling film evaporator and the vacuum kettle have been successfully used in the concentration of the coconut milk. Concentration operations with both equipment have been carried out at a temperature ranging from 90o to 96oF.
When using the vacuum kettle in concentrating coconut milk it has been found that the heating jacket of the kettle should be heated with hot water at 210oF. If steam is used the concentrated coconut milk becomes brown.
When the desired concentration is reached, the concentrated coconut milk is canned and placed in the blast freezer from which it is moved into the -10oF storage.
Fourfold coconut milk concentrates prepared in the falling film evaporator and prepared in the vacuum kettle have been found to be equally stable in storage. No difference in flavor has been detected between the 2 products, immediately after preparation or after storage in the -10oF freezer for a year.
The coconut milk obtained from the speed basket centrifuge, which is already free of suspended coconut pulp particles, is fed to a high speed continuous centrifuge. This separator can be of any of the three types used industrially; pressure feed totally enclosed low pressure discharge; or gravity feed and atmospheric pressure discharge.
Pilot plant work carried out with a westfalia model IW A-205, which is a gravity feed and atmospheric pressure discharge separator, produced a cream of varying fat content. Feeding the separator with 40 to 60 gal of coconut milk gave a water extract with a fat content of 0.08 to 0.14% and a coconut milk cream with a fat content of 65.0 to 52.0%, respectively. In order to obtain a water extract of about 0.03% fat, the feed should be maintained at 30 gal per hr which gives a coconut milk cream of about 75% fat.
In the high speed centrifugation of the coconut milk the speed of the centrifuge and the feed of the milk should be coordinated so that the emulsion isn’t broken during the operation. Excessive speed at a fixed feed or a very low feed at a moderate speed breaks the emulsion, resulting in a separation of the coconut oil from the rest of the liquid. In pilot plant runs, it was found that high or very low temperature treatments given to the coconut milk before the centrifugation process caused oil separation from the rest of the liquid.
Packaging of the coconut cream is done immediately after it leaves the separator. For consumers and remanufacturing purposes the coconut milk cream has been standardized at a fat content of 75%. The canned coconut milk cream is frozen in a blast freezer and later moved to the storage at-10F, where the shelf-life is more than 1 yr.
Coconut milk cream has been used with remarkable success in the preparation of bakery products and “ice cream” (reitz 1954), where the fat content of the products prepared has been totally supplied by the coconut milk cream.