BEHAVIOUR OF Neosartorya fischeri ASCOSPORES IN PINEAPPLE JUICE

Abstract

For heat-resistance determinations, a Neosartorya fischeri ascospore suspension, obtained at three different conditions of temperature (20, 30 and 35°C) 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 statisticatically analysed through the software Statistica 6.0. At 80°C, 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%. The increase of the ascospore production age and temperature caused an increase on the thermal resistance approximately equal to 28% and 14%, respectively. Through 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.