X-ray absorptiometry for non-destructive monitoring of the salt uptake in bone-in raw hams during salting

- X-ray inspectors can predict salt uptake of hams during the salting process.
- Only one incident energy is needed to predict accurately enough salt content in hams.
- Salt, water and fat contents of the hams do not affect salt content prediction error.
- Salt uptake variability can be reduced by adapting the salting process.
- Salting process is adapted according to the predicted salt content by X-ray.

Salt uptake variability in dry-cured ham batches is a problem for the dry-cured ham industry because part of the hams have either an excess or a lack of salt and therefore are more prone to sensory defects. The aim of this study was to evaluate the feasibility of an X-ray inspector for a non-destructive, on line determination of the salt uptake in entire bone-in hams during the salting procedure. Moreover, its usefulness in combination with a modified salting procedure to reduce the salt content and within batch variability was evaluated in an industrial case study. Predictive models for salt content, accurate enough for classification purposes (RMSEV = 0.210−0.257%), were developed using only one X-ray energy (50 kV). The use of an X-ray inspector in combination with slight modifications of the process allowed the reduction of the average salt content a 13.75% and 26.67% and a within-batch standard deviation from 0.45% to 0.21% or 0.26% depending on the reduced target salt content.