HEAT-RESISTANCE OF BYSSOCHLAMYS-NIVEA, BYSSOCHLAMYS-FULVA AND NEOSARTORYA-FISCHERI ISOLATED FROM CANNED TOMATO PASTE

Cultures of heat resistant molds (20) were isolated from spoiled canne d tomato paste in order to estimate the pasteurization efficiency appl ied to commercially canned products. Ascospores of nine strains grown on mall extract agar for 30 days at 30 degrees C, survived heating at 85 degrees C for 20 min when initial numbers were near 10(5)/mL. Of th ese heat resistant strains were identified: two Byssochlamys nivea, th ree Byssochlamys fulva and four Neosartorya fischeri strains. Ascospor es of all cultures were more heat resistant in tomato juice than in ph osphate buffer. Thermal death rate curves were nonlogarithmic but appr oached logarithmic death rates at higher temperatures. The thermal des truction time for 1 log(10) at 90 degrees C was 1.5 min for a Byssochl amys nivea strain, 8.1 min for a Byssochlamys fulva strain and 4.4 to 6.6 min for Neosartorya fischeri strains.