Microwave hydrolysis for the rapid analysis of furosine in foods

A microwave procedure for the rapid preparation of hydrolysates for furosine determination has been developed. Hydrolysis was performed in liquid-phase with 8N HCl in sealed vessels using a microwave oven. The amounts of furosine in pasta, milk and cheese samples, determined by HPLC after applying different microwave hydrolysis programmes, were compared with those obtained using traditional hydrolysis (time: 23 h; temperature: 110 degrees C; HCl concentration: 8N). The microwave programme characterised by three irradiation stages (1(st)= 50 degrees C, 2 min; 2(nd)= 100 degrees C, 5 min; 3(rd)= 155 degrees C, 10 min) gave the best correlation with traditional hydrolysis (r=0.999, P less than or equal to 0.001). The standardised microwave hydrolysis programme presented in this paper can remarkably reduce hydrolysis time from 23 hours to less than 30 minutes without losing the accuracy and precision of the traditional method.