Food Chemistry

966 21 Coffee, Tea, Cocoa

and porous cell structure of the cocoa mass. Co-
coa so treated is often incorrectly designated as
“soluble cocoa” – the process does not increase
solubility. Finally, the cocoa is disintegrated with
fine roller mills. The “alkalized” cocoa generally
contains 52–58% cocoa butter, up to 5% ash and
up to 7% alkalized mass or liquor.

21.3.2.7 Production of Cocoa Powder
by Cocoa Mass Pressing

To convert the cocoa mass/liquor into cocoa
powder, the cocoa fat (54% of nib weight on
the average) has to be reduced by pressing,
usually by means of a hydraulic, mechanical or,
preferentially, horizontally-run expeller press at
a pressure of 400–500 bar and a temperature of
90–100◦C. To remove the contaminating cell de-
bris, the hot cocoa butter is passed through a filter
press, then molded and cooled. The bulk of the
cocoa butter produced is used in chocolate manu-
facturing. The “stone hard” cocoa press cake,
with a residual fat content of 10–24%, is dis-
integrated by a cook breaker, i. e. rollers with
intermashing teeth. It is then ground in a peg mill
and separated into a fine and a coarse fraction by
an air sifter, the coarse fraction being recycled
and milled repeatedly. Cocoa powders are divided
according to the extent of defatting into lightly
defatted powder, with 20–22% residual cocoa
butter, and extensively-defatted powder, which
contains less than 20% but more than 10% butter.
Lightly defatted powder is darker in color and
milder in flavor. Cocoa powder is widely used
in the manufacture of other products, e. g., cake
fillings, icings, pudding powders, ice creams and
cocoa (chocolate) beverages.

21.3.3 Chocolate

21.3.3.1 Introduction

Switzerland has the highest per capita consump-
tion of chocolate at 10.2 kg (2004), followed by
Norway (9.2), Belgium (9.1), Germany (9.0), Ire-
land (8.8), Great Britain (8.8). The consumption
of chocolate is low in Italy (3.5), Greece (2.5),
Japan (1.8), Spain (1.6) and Brazil (1.0).

Chocolates were originally made directly from

cocoa nibs by grinding them in the presence of

sugar. Chocolate is now made from nonalkalized

cocoa liquor by incorporating sucrose, cocoa

butter, aroma or flavoring substances and, oc-

casionally, other constituents (milk ingredients,

nuts, coffee paste, etc.). The ingredients are

mixed, refined, thoroughly conched and, finally,

the chocolate mass is molded. To obtain a highly

aromatic, structurally homogeneous and stable

form and a product which “melts in the mouth”,

a set of chocolate processing steps is required, as

described below.

21.3.3.2 Chocolate Production

21.3.3.2.1 Mixing

Mixing is a processing step by which ingredients

such as cocoa liquor, high grade crystalline

sucrose, cocoa butter and, for milk chocolate,

milk powder are brought together in a mixer

(“melangeur”) or paster. A homogeneous,

coarse chocolate paste is formed after intense

mixing.

21.3.3.2.2 Refining

The refining step is performed by single or multi-

ple refining rollers which disintegrate the choco-

late paste into a smooth-textured mass made up of

much finer particles. The rollers are hollow and

can be adjusted to the desired temperature by wa-

ter cooling. The refined end-product has a particle

size of less than 30 to 40 μm. Its fat content should

be 23–28%.

21.3.3.2.3 Conching

The refined chocolate mass is dry and powdery

at room temperature and has a harsh, sour

flavor. It is ripened before further processing

by keeping it in warm chambers at 45–50◦C

for about 24 h. Ripening imparts a doughy

consistency to the chocolate and it may be

used for the production of baking or other

commercial chocolates. An additional conching