Behaviour of Neosartorya fischeri Ascospores in pineapple juice

ABSTRACT

For heat-resistance derterminations, a Neosartorya fischeri ascospore suspension, obtained at three different conditions of temperature (20, 30 and 35ºC) and age (1, 2 and 3 months), was heat treated in pineapple juice with three different ratio conditions. The 1/k (min) values obtained were statistically analysed through the software Statisitca 6.0. At 80ºC, when there was a level change in the ratio factor from a lower (10) to a higher one (38), the thermal resistance (1/k) increased in approximately 41 per cent. The increase of the ascospore production age and temperature caused an increase on the thermal resistance approximately equal to 28 per cent and 14 per cent, respectively. Throufh the results, it could be concluded that N. fischeri presented lower thermal resistance for heating mediums with lower ratio values, or rather, the increase of the soluble solids concentration caused an increase of its thermal resistance. It was also observed that the ascospore production age and temperature increased significantly the thermal resistance of this mould in pineapple juice.