Modelling of the electron range for use of E-beam treatment for boned dry-cured hams sanitation

Abstract

The heterogeneity of the dry-cured ham size and the fat layer thickness can compromise the electron range throughout the piece and, therefore, the E-beam treatment effectiveness to guarantee its microbiological and sensory quality. The present work aimed to model the electron range in boned dry-cured ham according to the mentioned factors. For that, a dose mapping was carried out applying 2 kGy in experimental blocks manufactured with different thicknesses of lard and/or lean ham. The model, that explains 99.2% of the dose distribution variability, consisted in both a two-phase linear and a modified Gompertz functions. According to the model, the thicker the subcutaneous fat layer, the greater the electron range. The model estimated that the two-face treatment at 2 kGy on hams with a 10-mm external fat layer would be sufficient to sanitize the area of highest risk of contamination during deboning process. Industrial relevance: The export of deboned dry-cured ham to countries such as the USA and China requires the absence of Listeria monocytogenes in 25 g of product. The E-beam treatment at doses between 2 and 3 kGy provides to achieve this objective without product quality losses. The model developed in this work allows to predict the absorbed dose according to the piece size and the thickness of the subcutaneous fat layer. The results show that the distribution of the absorbed dose after bilateral treatment with 2 kGy is more uniform when the thickness of the piece is approximately 80 mm and the thickness of the fat layer is 10–30 mm. The model also makes it possible to quantify the optimal thickness of the specimen when the subcutaneous fat layer is <10 mm or >30 mm