Glossary and Abbreviations - Unido

taken on the relative benefits of employing a larger number of workers or buying machinery
to do a particular.
Raw materials
Having decided how much product to make, a processor needs to calculate how much crop
to buy. This depends on the likely levels of wastage and losses during the process. Losses
arise from peeling, from substandard roots that are thrown away during sorting or from low
quality or spoiled product. Typical losses are shown in Table 3.1, but it is important that
processors measure these in their own process so that accurate figures can be used in the
calculations.
Table 3.1. Typical peeling losses during the preparation of root crops
Root crop Typical peeling losses (%)
Cassava
Coco-yam
Irish potato
Sweet potato
Yam
10-20
10-20
5-15
15-30
15-30
(Source: Fellows, P., Midway Technology Ltd, Bonsall, UK )
Table 3.2. Typical losses during processing of root crops.
(*does not include moisture loss)
Stages in a Process
Typical Losses
Washing
Sorting
Peeling
Slicing/dicing
Drying *
Packaging
Rejected packs
0-5
5-50
10-20
5-10
5-20
0-10
0-5
(Source: Fellows, P., Midway Technology Ltd, Bonsall, UK)
The amount of usable food after raw materials are prepared for processing is known as the
‘yield’, and is calculated as follows:
Yield (%) = weight of raw material actually used in the process
x 100
weight of raw material that is bought
The true cost of raw materials depends on the yield and can be calculated as below:
True raw material cost = (Supplier cost/yield) x 100
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