Lactulose (4-O-β-D-galactopyranosyl-D-fruc- tose), formed from lactose (4-O-β-D-galactopyranosyl-D- glucose) by the Lobry de Bruyn–Alberda van Ekenstein rearrangement during severe heat treatments, is considered a useful indicator of heat-induced modifications in milk. Its chromatographic determination in milk is particularly troublesome due to the concomitant presence of a lactose amount two orders of magnitude larger than the lactulose amount and to a similar retention time of the two compounds. In this work, four HPLC methods have been compared with the aim to develop a more accurate analytical procedure to determine lactulose in milk, together with lactose. The developed method is based on a Carrez precipitation followed by a HPLC separation on two in-series amino-based columns, using CH3CN:H2O 75:25 (v:v) as the mobile phase at 1 ml/min flow rate and a refractive index as the detector. The linearity test for the quantitation of lactulose has been carried out over the range 0.060–1.006 mg/ml, the limit of detection, is 0.013 mg/ml (256 ng injected) and the limit of quantita- tion is 0.028 mg/ml (556 ng injected). The proposed method, simple, cheap and time-saving, allows an accurate lactulose–lactose separation, with conventional HPLC equipment.
|Autori:||Manzi, P.;Pizzoferrato, L.|
|Data di pubblicazione:||2013|
|Titolo:||HPLC Determination of Lactulose in Heat Treated Milk|
|Rivista:||FOOD AND BIOPROCESS TECHNOLOGY|
|Appare nelle tipologie:||1.1 Articolo in rivista|
File in questo prodotto:
|2013 HPLC Determination of Lactulose in Heat Treated Milk.pdf||Post-print||Nessuna licenza||Administrator Richiedi una copia|