Cocoa Powder > Composition > Physical Properties

Physical Properties of Cocoa Powder

There are several physical properties of cocoa powder that are important to both the consumer and food manufacturers (1). The pH and color of cocoa powders are important characteristics and can vary significantly depending on the source of cocoa beans and how they are processed.  Natural cocoa powders have lower pH and a characteristic light brown color while alkalized cocoa powders have higher pH and darker colors that range from dark brown to brownish red to dark red to black.

The ability to produce cocoa powders that are either darker in color, including dark red or even black, have important uses in the food industry.  The dark color of alkalized cocoa powder yields a rich dark brown color to cakes, cookies, and brownies that are desirable.  The milder flavor of alkalized cocoa powder also provides a unique and desirable taste for certain products.  In particular, alkalized cocoa has less sourness (acidity) and lower bitterness than untreated, natural cocoa powder.  Another advantage of alkalized cocoa powder is its increased solubility in certain beverage applications.

pH 
The pH of cocoa powder is a measure of the degree of acidity or alkalinity on a 14 point scale.  A value of pH 7 is neutral, while values less than pH 7 are acidic and values above pH 7 are alkaline.  In a scientific study published by Miller et. al. in 2008(2), the pH of natural and alkalized powders was measured.  Light brown natural powders ranged from pH 5.4-5.8.  Lightly alkalized, darker brown cocoa powders had values ranging from pH 6.8-7.2.  Moderately alkalized dark brown and brownish-red powders had pH values in the range of 7.2-7.5 and heavily alkalized dark red and black powders had pH values ranging from 7.6-8.1.  All of these pH values for cocoa powders are within safe and acceptable ranges for food products and for cocoa powders in particular.

Color
One way to objectively measure the degree of lightness or darkness of cocoa powder is by using the Hunter “L” scale value where a high value represents lighter colors and a lower value represents darker colors.  In a study published by Miller et.al. in 2008 (2), the Hunter “L” values for natural cocoa powders ranged from 38-41 exhibiting light brown colors.  In contrast, alkalized cocoa powders had “L” values ranging from 16-35 depending on the degree of alkalization. The colors for these alkalized cocoa powders ranged from medium brown and brownish red at the higher end of the ‘L” scale to dark red and black at the low end of the scale. 

Nutrition
Cocoa powder is nothing more than a cocoa bean seed with most of the fat removed.  It, therefore, contains a wide variety of plant nutrients necessary for the seed to grow.  The nutritional content of cocoa powder can be found in the [Nutritional] section of this website.