Improvement of cocoa powder and butter quality
1992
Thuy, Minh Nguyen
Study was conducted to investigate the effects of roasting duration (30, 40, 50 minutes), types of alkali (Na2CO3 and K2CO3) with concentration (0.3 to 2 %), types of emulsifier (Polysorbate, Sorbitane monostearate, two types of Lecithin) from 0.25 to 0.7 % on the quality of cocoa powder. The effects of bleaching materials (activated carbon, Fuller's earth and their combination) was also studied. The results showed that high roast temperature and the longer time gave a poor quality in term of color and flavor. Potassium Carbonate at 0.3 % gave ideal color of cocoa powder. The effects of four different types of emulsifiers and cocoa butter contents were investigated. Optimum levels for every emulsifier was determined. It was found that overrun, emulsion stability and viscosity of whipped mixture increased with higher levels of emulsifiers and cocoa butter contents. The free fatty acid and unsaponifiable matter were reduced from 1.50 and 0.46 % to 0.04 and 0.18 %, respectively. Refining losses of cocoa butter varied from 7 to 13 % during neutralization. Storage of raw, neutralized and bleached cocoa butter for 65 days at ambient temperature showed a slight rise in color and free fatty acid content with neutralized and bleached oil.
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