Non-invasive ultrasonic technology for continuous monitoring of pork loin and ham dry salting

Abstract

Online ultrasound measurements were taken using pulse-echo mode in loins (Longissimus dorsi) and hams at different salting times (up to 30days). From the time-domain ultrasonic wave, the time of flight (TOF) was computed as well as its variation between two signals (ΔTOF). A progressive decrease in TOF during dry salting was found, which was linked to the salt gain, water loss and the reduction in sample thickness. Predictive models based on the ultrasonic parameters (ΔTOF and initial time of flight, TOF) correctly classified 85% of the loins and 90% of the hams into 3 groups of salt content (low/medium/high). The results obtained confirm that the use of the ultrasonic pulse-echo technique is of great potential in the non-destructive monitoring of dry salting in pork loins and hams, as well as in the prediction of the salt gain for classification purposes.

Application of non-invasive technologies in dry-cured ham: An overview

“…Until now, commented results are obtained using the through-transmission mode, namely a method in which two transducers are connected directly at both sides of the sample (De Prados et al, 2017). That is the reason why it can be very difficult to introduce this mode of application in certain stages of the dry-cured ham process.…”

“…However, the pulse-echo mode allows to simplify its implementation in the process, considering that only one transducer is positioned in the sample, working as emitter and transducer at the same time (Awad et al, 2012). Traditionally, this mode has been applied for the detection of defects in metallic materials, although its use for the characterization of components in food has been recently investigated (De Prados et al, 2017). By measuring the Time of Flight variation (ΔTOF) of the pulse-echo mode it is possible to monitor the salting process in hams with a mean thickness of 15.7 cm (De Prados et al, 2017), showing a high ΔTOF reduction at few hours after the beginning of the salting (De Prados et al, 2016).…”

“…Traditionally, this mode has been applied for the detection of defects in metallic materials, although its use for the characterization of components in food has been recently investigated (De Prados et al, 2017). By measuring the Time of Flight variation (ΔTOF) of the pulse-echo mode it is possible to monitor the salting process in hams with a mean thickness of 15.7 cm (De Prados et al, 2017), showing a high ΔTOF reduction at few hours after the beginning of the salting (De Prados et al, 2016). Additionally, the salt prediction model could be improved by the addition of fat and water gain information (De Prados et al, 2017).…”

Monitoring microstructural changes and moisture distribution of dry‐cured pork: a combined confocal laser scanning microscopy and hyperspectral imaging study

“…During dry‐curing, salt crystals must first dissolve and be absorbed into the meat matrix to effect water removal. However, various factors, including meat chemical characteristics, fat content, and age, have a remarkable impact on NaCl uptake during dry‐curing, 56 which will invariably affect water expulsion. Thus, to achieve maximum moisture loss, the meat product may have to be cured for an extended period.…”

Investigation into crystal size effect on sodium chloride uptake and water activity of pork meat using hyperspectral imaging

“…Graiver, Pinotti, Califano, and Zaritzky () have also provided mathematical relations governing the uptake of curing salts in pork meat. Factors including meat chemical characteristics, fat content, pH, age, and species among others have been identified to influence NaCl uptake during curing (de Prados, Garcia‐Perez, & Benedito, ; Vestergaard, Andersen, & Adler‐Nissen, ). Another study (Quilaqueo & Aguilera, ) also identified salt morphological characteristics, specifically size and shape as important factors that influence salt crystal dissolution and uptake, and concluded these may be important variables to consider in the drive to achieving sodium reduction while maintaining the overall quality and acceptability of foods.…”