Cocoa is a commodity used as an ingredient in many food products as well as in chocolate manufacturing. Variations in the raw materials and processing steps creates cocoa and chocolate of varying properties.
Quality is a key driver in the cocoa processing and chocolate manufacturing industries, both as payment criteria as well as final product quality control.
In the process, cocoa beans are roasted in an oven and undergo a winnowing process, where the shells are removed. The resulting de-shelled beans, called nibs, are ground into cocoa liquor, which at slightly elevated temperatures is a thick liquid. Two potential processes can be undertaken with the cocoa liquor. In one process, the cocoa liquor is pressed into cocoa butter and pressed cake. The pressed cake can be ground into cocoa powder. In the other process, sugar, cocoa butter, and milk powder or other ingredients are added to the cocoa liquor to produce chocolate.
At every step in the process, there is a necessity to make analytical measurements. Incoming cocoa beans can be analyzed for moisture to determine the quality. Moisture can be measured during the roasting process to determine when the process is complete. The nibs can be analyzed for moisture and fat content to predict the quality of the resulting cocoa liquor. The cocoa liquor, which is sold by fat content, can be analyzed for fat and moisture to optimize the process.
After the cocoa liquor is pressed, the resulting cocoa butter can be analyzed for free fatty acids and iodine value. These properties relate to the melting characteristics of the butter. The other by-products of the pressing of cocoa liquor, cake and cocoa powder can be analyzed for moisture and fat. Since cocoa powder is routinely sold based on its fat content, it is critical to have accurate and timely measurements to optimize the process.
Finally, finished chocolate can be analyzed for fat, moisture and sugar to verify that the product is to nutritional and quality specifications.
NIR analysis has been used for many years for rapid analytical measurements at all stages in the cocoa processing and chocolate manufacturing processes. The measurements described above can be made in 30 seconds at-line in the plant. Timely, accurate analytica data ensures efficient production, optimal yield and high quality end-products, all adding profit to the bottom line.