he aim of this work was to characterize lactose-hydrolyzed milk during its industrial development and to monitor chemical changes during storage. Glucose, galactose and lactose were quantified and evaluated by a high-performance anion-exchange chromatographic method coupled with pulsed amperometric detection. A HPLC method was proposed for the determination of epsylon-N-2-furoylmethyl-L-lysine (furosine) in acid hydrolyzed of milk samples. Furosine content was chosen as a molecular marker to evaluate the initial steps of Maillard reaction involved during UHT (Ultra High Temperature) thermal processing and storage of milk. Furthermore, variations of the protein fractions in milk samples were evaluated by protein fingerprints with Matrix Assisted Laser Desorption Ionization-time of fligth (MALDI-tof) mass spectrometry
Nel presente lavoro sono stati analizzati alcuni parametri analitici in campioni di latte UHT, a ridotto contenuto in lattosio (delattosato), al fine di caratterizzare il prodotto durante la messa a punto del processo di idrolisi enzimatica e risanamento termico UHT. Inoltre, sono state verificate eventuali variazioni della qualita' del prodotto durante la sua shelf-life. I parametri presi in considerazione sono stati i seguenti: frazione glucidica (glucosio, galattosio e lattosio), furosina (epsilon-N-2-furoilmetil-L-lisina) e frazione proteica. Glucosio, galattosio e lattosio sono stati determinati quantitativamente impiegando un sistema HPLC a scambio anionico forte con rivelatore amperometrico pulsato. Per valutare lo step iniziale della reazione di Maillard e' stato determinato il contenuto di furosina. L'analisi di tale composto e' stata eseguita mediante HPLC, utilizzando un sistema isocratico a fase inversa, impiegando una colonna con diametro interno da 2,0 mm (narrow bore). La denaturazione delle proteine e' stata valutata mediante spettrometria di massa (MALDI-tof). I dati ottenuti sono stati confrontati analizzando analoghi prodotti reperibili in commercio
Chracterization of UHT low-lactose milk by innovative analytical methods
Isabella Nicoletti;
2001
Abstract
he aim of this work was to characterize lactose-hydrolyzed milk during its industrial development and to monitor chemical changes during storage. Glucose, galactose and lactose were quantified and evaluated by a high-performance anion-exchange chromatographic method coupled with pulsed amperometric detection. A HPLC method was proposed for the determination of epsylon-N-2-furoylmethyl-L-lysine (furosine) in acid hydrolyzed of milk samples. Furosine content was chosen as a molecular marker to evaluate the initial steps of Maillard reaction involved during UHT (Ultra High Temperature) thermal processing and storage of milk. Furthermore, variations of the protein fractions in milk samples were evaluated by protein fingerprints with Matrix Assisted Laser Desorption Ionization-time of fligth (MALDI-tof) mass spectrometryI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
