Proof of authenticity of pure instant coffee

摘要

An HPLC method with refractometric detection was worked out for the determination of the limiting contents of marker saccharides (free mannitol and total glucose and xylose)used for the proof of authenticity of pure instant coffee.This method,even though more laborious,yields results comparable with those obtained by the HPAE-PAD method and is intended mainly for those laboratories where the current HPLC technique with refractometric detection is presently used for saccharide analysis.The survey ofmarket supply showed that instant coffee imported in bulk and subsequently packaged in the Czech Republic is most frequently aduterated-only one out of 7 samples examined contained authentic coffee.On the other hand,only one out of 10 samples of instant coffee imported in original packaging did not meet the authenticity criteria.The samples of instant coffee by domestic producers indicated that one producer placed on the market an adulterated product,whereas the other brand is authentic coffee.