Potato defects are physical, physiological or pathological faults in tubers, including hollow heart, black spot, scab, greening, rot and growth cracks, and they matter in trade because defect tolerances determine whether a lot is accepted for a given grade or end use.
In trade practice
At intake, QA teams conduct visual and cut-sample inspections against defined tolerance tables, recording defect type and percentage by weight. Processing plants apply additional sorting lines to remove defective tubers before cutting or blanching, since some defects such as greening indicate elevated glycoalkaloid levels that affect food safety. Buyers of frozen potato products often require pre-shipment inspection reports from the raw material stage. A common error is applying table-potato defect tolerances to processing lots, which have different acceptance criteria.
In a specification
A specification should list each defect category, state the maximum permitted percentage for each, and reference the applicable grading standard or buyer-defined tolerance table that governs acceptance at intake.