ASTA colour value is a spectrophotometric measure of the carotenoid pigment intensity in paprika and related spices, expressed on a scale defined by the American Spice Trade Association, and used as a standard quality index in trade specifications.
In trade practice
The test extracts pigments in acetone and measures absorbance at a defined wavelength; the result is converted to an ASTA unit figure using a standard formula. Buyers specify a minimum ASTA value in purchase contracts, and suppliers provide the result on the certificate of analysis from an accredited laboratory. Higher values indicate deeper red colour and are associated with premium grades. Fading during storage due to light exposure or high temperature is a common cause of non-conformance on arrival, making packaging and storage conditions critical.
In a specification
A paprika specification states the minimum ASTA colour value, the test method version, and whether the limit applies to the product as packed or after a defined storage period.