Prediction of hot-fill-air-cool sterilization processes for tomato paste in glass jars

Abstract

A mathematical model to predict heat transfer and integrated sterilization values during the hot-fill process of double concentrated tomato paste in glass jars was developed. The model was capable of predicting satisfactorily the time-temperature relationships during the air-cooling process following the hot-fill process. Integrated sterilization values after hot-filling were calculated as a function of the retention time. A hot-filling temperature of 85°C was not adequate to sterilize properly this product for any of the jar sizes studied and for the initial and final population levels established, for the target microorganism employed ( B. coagulans). Hot-filling temperatures of at least 94, 92 and 90°C are recommended for jar sizes of 200, 500 and 4000 cm 3, respectively. As jar size increased, the hot-filling temperature and the retention time required to achieve the desired integrated sterilization value decreased. Larger retention times were obtained as the hot-filling temperatures decreased.