Ultrasound for Meat Processing: Effects of Salt Reduction and Storage on Meat Quality Parameters

Meat samples (Longissimus dorsi) were processed using an ultrasonic (US) probe system (20 kHz) and a US bath (33 kHz), in brine solutions of 15% NaCl or NaCl/KCl. Selected quality parameters, namely hardness (Warner–Bratzler shear force, WBSF), secondary lipid oxidation products (thiobarbituric acid reactive substances, TBARs) and total colour difference (TCD) were analysed at day 0 and day 60. Inoculated E. coli and L. innocua cells, total viable counts and lactic acid bacteria were also monitored for 60 days on meat stored at 4 and 10 °C. US brining could achieve a 25% sodium reduction in a shorter processing time. No changes were observed for WBSF and TBARs values; noticeable colour differences (ΔΕ > 5) were measured in US-treated samples at the end of storage. Whilst no differences were observed in the levels of inoculated and spoilage bacteria on the meat surface, a significant reduction in E. coli in the brine subjected to US treatment indicates the potential of US as a hurdle technology to prevent cross contamination during meat processing. These results suggest that US processing, in combination with KCl, could assist current sodium reduction strategies improving processing time. In addition, the potential effects for decontamination of brining tanks increasing the shelf-life of the brine and preventing processing losses are highlighted.