LAUSR

BACKGROUND Organoleptic properties and positive health effect on consumers both justify the importance of determining apple juice authenticity with respect to retail and wholesale trade networks worldwide. RESULTS Adulteration of apple juice through dilution with water, as well as with ascorbic acid, has been determined. It has been demonstrated that polarization curves of a platinum electrode in apple juice are useful for undeclared antioxidant determination, as a result of the movement of the polarization curve to the left, by 200 mV, when ascorbic acid was added. A difference between the equivalent electrical conductivity of suspended solids of undiluted and diluted (1:1) juices has been substantiated as a new quantitative criterion for determining adulteration through dilution. The criterion values range from 0.030 to 0.034 S m-1 for juices of different apple varieties. Gas chromatography-mass spectrometry results have shown the presence of (E)-2-hexenal and n-hexanal in all juices tested obtained from different apple varieties. CONCLUSION A new conductometric method for the determination of diluted apple juices has been substantiated. It has been established that the volt-ampere method is useful for the investigation of undeclared ascorbic acid. © 2018 Society of Chemical Industry.