QUALITY PROFILE OF SPANISH AND GERMAN UHT MILK

UHT-milk samples were drawn in 2 enterprises respectively in Spain and the FRG and examined analytically and sensorially at the Institute fo r Process Engineering of the Federal Dairy Research Centre, Kiel, and only analytically at the Instituto del Frio, Madrid. During sampling t he operation of the UHT-plants was controlled and the temperature-time relations measured. On the basis of the temperature-time curves deter mined the sterilization values (F(L) - for lactulose formation, F(m) - for destruction of B. steathermophilus and F(O)- for destruction of C l. botulinum) were calculated and compared with the admmissible limit sterilization values. Except for the direct UHT plant, all others were found to be very close to the prescribed limit values. The analytical examinations of lactulose formation and proteolytic activity during s torage at 20, 30 and 40-degrees-C showed an increase in lactulose conc entration in all milks, a marked increase in enzyme activity, however, only as far as the Spanish samples were concerned. When determining t he proteolytic enzyme activity a direct comparability of the results b etween the enzymatic and the HPLC method could not be established. The sensorial changes of the milks were examined according to profile ana lysis. Although the intensity of flavour and the kind of flavour were found to be rather varying from sample to sample, the Spanish milks we re, on average, worse scored as regards quality.