Reducing Postharvest Losses
In the OIC Member Countries
66
Table 26: Causes of PHLs reported for roots and tubers and per step of postharvest.
Postharvest step Cassava Sweet potato
Sorting  Discount for Broken roots
 Rejection of Rotten roots
 Theft
 Rejection of Rotten
roots
Transportation  Breakage
 Breakdown of vehicle; poor road infrastructure
 Broken roots
 Pilferage (theft)
 Weight/quality loss
 Damage due to
moving
 Moulding due to
humidity
Washing  Discarded pulp  Discarded pulp
Peeling  Discarded peels
 Over peeling
 Inefficient hand peeling
 Discarded peels
Grating/Rasping/Chipping/C
rushing
 Waste liquid from grating/rasping/crushing
 Inefficient rasping
Centrifuging  Waste Liquid from centrifuging
Soaking & Fermentation  Waste starch washed away or over-soaking Mouldy cassava
from fermentation
 Over fermentation (too many days) reduces starch content
Dewatering/pressing  Waste liquid from pressing containing Starch residue
Sieving  Waste of fibre
Blanching/Steaming/Boiling  Loss in nutrients  Loss in nutrients
Drying  Loss as dust
 Inefficient drying (taking too long)
 Loss as dust
 Loss in nutrients
Milling/Grinding  Loss as dust
Packaging  Poor packaging material
 Quality deterioration
Storage  Loss due to moisture
 Loss in value from Insect infestation
 Loss due to
moisture
Note: No comments were reported for potato
Broken and rotten roots at sorting have to be discounted. During transportation, a number of
uncertainties due to the poor road infrastructure may delay supply and cause physical damage.
During processing, peeling are a main loss and over peeling can cause unnecessary losses.
Inefficiency of processing operations (peeling, grating, dewatering, and drying) can cause
additional losses in quantities but also in nutrients. Packaging and storage are also key
operations where losses occur due to quality deterioration of the roots and tubers. In order to
mitigate those losses, suggestions were made by the respondents .
Table 27: Mitigation of PHLs reported for roots and tubers and per step of postharvest
Postharvest step Cassava Sweet potato
Transportation  Policies to support improvement in
road infrastructures
 Reduce sack sizes, better roads
 Better packaging. Proper cover to prevent
roots from rain. Better roads.
Peeling  Improved peeling technologies be
promoted
 Peeling machine
 Select cassava with white thin skin
 More efficient peeling practice. Awareness
raising in the improved procedures.
Grating/Rasping/Chipping
/Crushing
 Mechanised systems
Dewatering/pressing  Better and more even pressing
 Improved technologies for
dewatering