THERMAL-RESISTANCE OF BACILLUS-STEAROTHERMOPHILUS SPORES HEATED IN ACIDIFIED MUSHROOM EXTRACT

The thermal resistance of Bacillus stearothermophilus spores was studi ed in bidistilled water as the reference medium, mushroom extract and acidified mushroom extract. Citric acid and glucono-delta-lactone were used as acidulants. Results indicated that mushroom extract affects t he heat resistance of spores; D values were lower than for those in bi distilled water. The pH effect was lower with higher treatment tempera tures. Acidification reduced the thermal resistance of spores, the red uction being similar for both types of acidulants, and in general it a lso had the effect of increasing the z values. it has been confirmed t hat acidification of the canned mushrooms could actually help to contr ol the thermophilic spoilage. This acidification could also be obtaine d by the use of glucono-delta-lactone, which has been shown to be as e ffective as citric acid in reducing the heat resistance of spores