Structural identification of compounds for use in the detection of juice-to-juice debasing between apple and pear juices

•4-O-p-Coumarylquinic acid was identified as a fingerprint phenolic in apple juice.•Isorhamnetin-3-O-rutinoside was identified as a fingerprint phenolic in pear juice.•Abscisic acid was identified as an additional fingerprint compound in pear juice.•Chromatographic differences were found between production regions in pear juice.

The ability to detect the undeclared addition of a juice of lesser economic value to one of higher value (juice-to-juice debasing) is a particular concern between apple and pear juices due to similarities in their major carbohydrate/polyol profiles. Fingerprint compounds for the detection of this type of adulteration were identified in both commercial apple and pear juices by HPLC-PDA, were isolated chromatographically, and structurally identified by LC-MS/MS. The apple juice fingerprint was identified as 4-O-p-coumarylquinic acid and two pear compounds as isorhamnetin-3-O-rutinoside and abscisic acid. Additionally, the HPLC-PDA profile of pear juices in combination with pear fingerprint compounds including arbutin could be used to identify samples originating from China versus those from other geographical locations.