P. Kotzekidou, HEAT-RESISTANCE OF BYSSOCHLAMYS-NIVEA, BYSSOCHLAMYS-FULVA AND NEOSARTORYA-FISCHERI ISOLATED FROM CANNED TOMATO PASTE, Journal of food science, 62(2), 1997, pp. 410
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.