Resumen de Investigation of a tunnel pasteurizer for �Nocellara del Belice� table olives processed according to the �Castelvetrano method�
Pietro Catania, M. Alleri, A. Martorana, Luca Settanni, G. Moschetti, Mariangela Vallone
The influence of pasteurization temperature and time of treatment on the flesh firmness and the evolution of microbial communities was studied for table olives Cv. Nocellara del Belice, packed in glass jars and processed with a tunnel pasteurizer. The experiment was first carried out on the laboratory level in order to select the optimal combination of pasteurization time/temperature so as to obtain the proper balance between the consistency of the pulp and the microbiological quality of the final product. Pasteurization at industrial scale was then carried out in a tunnel pasteurizer applying the treatment at 75 °C for 8 min in the thermal center of the jars. Besides flesh firmness and microbial evolutions, the pH, total titratable acidity (TTA) and color were evaluated for the table olives during storage at 6, 12 and 15 months from packing. The table olives showed a high stability and acceptable flesh firmness for the entire period under observation. Specifically, olive pulp texture decreased during the storage period, but the softening was most evident in the deeper layers of the pulp. The results indicated that the storage period should not exceed 6 months. Although the hygiene is preserved, after this period the firmness might not be acceptable to consumers.
