3.2.5. Foreign matter

The presence of foreign matter will also affect the yield of edible material and hence reduce the value of the cocoa to the chocolate manufacturer, and may also affect the flavour and be a source of contamination to the product. 

Foreign matter in this case may be divided into two types, one that has no commercial value to the manufacturer and the other that has only a reduced value (known as “Residue” or Cocoa Related Matter).

3.2.5a Foreign matter with no commercial value

The type of foreign matter which has no value to the manufacturer consists of material that is (a) not cocoa-related, e.g. sticks, stones etc., which can damage the manufacturer’s machinery; or (b) cocoa-related but has no commercial value, e.g. placenta, pod husk and flat or shrivelled beans which contain very little nib etc., which can be detrimental to the flavour as well as reducing the yield of edible material.
 

3.2.5.b Cocoa residue including broken beans and fragments

Cocoa residue consists of broken beans and fragments of beans and shell. Some bean breakage is inevitable during shipping and storage, although from normal production the amount seldom exceeds 2%. 

The process of moving the cocoa in bulk form may generate more broken beans and fragments if not properly managed (e.g. limiting free fall, mechanical damage etc.). Higher levels can result in greater amounts of nibs and fragments being removed by bean cleaners with corresponding loss of edible material. 

There are two main areas of concern to the manufacturer. The first is that cocoa nibs of broken beans and fragments are likely to have a higher FFA content than whole beans, due to higher rates of lipolysis because of the greater surface area exposed to oxygen, and a higher likelihood of their being affected by mould. 

Moreover, the FFA content of butter from broken beans will continue to rise during storage and therefore cocoa beans containing high levels of broken beans and fragments cannot be stored for any appreciable period. 

The second area of concern is that broken beans and fragments are not easily processed as the effectiveness and consistency of the roasting process depends directly on the homogeneous size of the nibs. 

This difficulty also occurs with bean clusters – see Section 3.2.7.