Application of the magnetic induction technique for the non-destructive assessment of salt gain after the salting process of Parma ham

- A single frequency magnetic induction (MI) system was used to test salt gain in bone-in ham after the salting step.
- Effect of salted ham traits on system performance was assessed.
- Predictive models (MLR analysis) of the salt content, were validated.
- MI can be considered a feasible technique to predict salt uptake of hams after the salting phase.

The fast and non-destructive inspection of salt uptake after the salting phase of dry-cured ham process still remains a goal to allow the optimization of the salting process.This work aims to show the capability of a single frequency, magnetic induction (MI) system, to predict salt (NaCl) content of whole hams after the salting stage. MI system is based on the measurement of the perturbation caused by an alternating excitation magnetic field on a conductive sample; the perturbation is typically detected by measuring the current induced in a suitable receiver coil. One hundred and fifty-nine hams were scanned by the MI scanner before and after the salting phase. Hams were dissected, separated into muscle and fat parts, and analysed for salt content (potentiometric method). Predictive models (multi-linear regression analysis) of the salt gain in hams were developed, based on output signals generated by the MI system. The model including independent variables given by scanning ham when raw and after the salting, achieved the best accuracy (R2 = 0.89; RMSEC = 0.19%). It was concluded that variations in electrical conductivity originated by different salt content and revealed by magnetic induction have potential application to predict the salt content inside entire bone-in hams after salting process.