Detection of sugar addition to citrus juices by capillary GC

✍ Scribed by Cornil, Vera ;Ooghe, Wilfried ;Sandra, Pat

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 322 KB
• Volume: 18
• Category: Article
• ISSN: 0935-6304
• DOI: 10.1002/jhrc.1240180504

✦ Synopsis

A method is described for the detection of citrus juices adulterated by addition of industrial sugar products. The oligosaccharides maltotriose (DP3) and maltotctraose (DP4), both of which are absent from the natural sugar profile of citrus fruits, serve as markers. The sample preparation method includes clean-up on a solid phase ODS cartridge, fractionation of DP3 and DP4 carbohydrates by LC on aminopropyl silica gel, and derivatization of the collected sugars to form the oxime-trimethylsilyl derivatives. Capillary GC analysis is performed on a 30 m x 0.32 mm i.d. polydimethylsiloxane fused silica column applying cool on-column injection and BID detection. The detection limit for maltotriose and maltotetraose is about 1 mg 1-' . Several orange and grapefruit juices were evaluated on their authenticity. Adulteration with crystalline sugar products cannot be detected with the described procedure.