[Effect of the position of the container in the retention of nutrients in food models heated by natural convection].

The existence of statistically significant differences in the nutrient retention of products heated by natural convection in cylindrical containers of equal size when thermally processed in vertical and horizontal position was studied. The thiamine retention was found to be significantly greater for containers placed in vertical position. A modification to the model proposed by Barreiro (4) for the prediction of nutrient retention during thermal processing of vertically placed canned model systems heated by natural convection was also developed to adapt it to containers processed in a horizontal position. To achieve this goal, an equivalent characteristic length was found for the vertically placed containers, and several changes were introduced. The modified model was then evaluated through ten experiments with different thermal processing parameters. The theoretical thiamine retention values predicted by the model wee compared with the experimental retention. In all cases they were within the 99% confidence interval of the experimental values. This demonstrated that the modified model can accurately predict nutrient retention during thermal processing of products packed in cylindrical containers, and placed in horizontal position.