Pressure-heat treatment of meat: Changes in myofibrillar proteins and ultrastructure

Gelation of barramundi (Lates calcarifer) minced muscle as affected by pressure and thermal treatments at low salt concentration

BACKGROUND

Barramundi minced muscle with salt 10 g kg^-1 and 20 g kg^-1 added is gelled by different combinations of pressurisation (300, 400 and 500 MPa at 4 °C for 10 min), cooking (0.1 MPa, 90 °C for 30 min) and setting (0.1 MPa, 50 °C for 2 h) to improve mechanical properties of barramundi gels and reduce salt added to barramundi gels.

RESULTS

At the low salt concentration of 10 g kg^-1 , pressurisation prior to cooking (P-C) treatment induced barramundi gels with comparable mechanical properties and water-holding capacity to those of conventional heat induced (HI) gels with 20 g kg^-1 added salt. At salt concentration of 20 g kg^-1 , pressurisation prior to setting (P-S) and P-C gels exhibited higher mechanical properties and water-holding capacity as compared to HI gels. Scanning electron microscopy images showed a smooth and dense microstructure of P-C and P-S gels whereas the microstructure of HI gels is rough and less compact.

CONCLUSIONS

P-C treatment can reduce salt concentration added to barramundi gels to 10 g kg^-1 . P-S and P-C treatment can result in higher mechanical and functional properties of barramundi gels at conventional salt concentration (20 g kg^-1 ) as compared to HI gels. © 2017 Society of Chemical Industry.

Volatile compounds in fresh meats subjected to high pressure processing: Effect of the packaging material

The effect of high pressure treatment (400MPa, 10min at 12°C) on the volatile profile of minced beef and chicken breast, packaged with or without aluminum foil in a multilayer polymeric bag, was investigated. The analysis of the volatile fraction was carried out by dynamic headspace extraction coupled to gas chromatography-mass spectrometry. Pressurization produced significant changes in the levels of some volatile compounds presumably coming from microbial activity. Some alcohols and aldehydes decreased, while other compounds, such as 2,3-butanedione and 2-butanone, were more abundant in high pressure processed meats. A significant migration of compounds from the plastic material was observed, mainly branched-chain alkanes and benzene compounds. Two functions built by the principal component analysis explained a high percentage of the variance and could be used to separate the samples into four distinct groups, according to high pressure treatment and packaging material.

Effects of pressurization on structure, water distribution, and sensory attributes of cured ham: can pressurization reduce the crucial sodium content?

This study investigated the replacement of tumbling (intermittent vacuum tumbling for 6 h) with pressure treatment (7 MPa for 4 s) in the production of a cured ham product with the aim of elucidating if the pressure treatment could reduce the amount of salt added to obtain a satisfactory product. Confocal laser scanning microscopy (CLSM) revealed a pressure-induced loosening of the meat structure, and proton nuclear magnetic resonance (NMR) relaxometry revealed that this structural modification of the meat had an impact on water properties and water distribution in both cooked and cooked/fried products. Three salt levels (0.6, 1.1, and 1.7% w/w) were investigated, and sensory profiling revealed that the pressured-cooked meat obtained a significantly higher juiciness score at low and medium salt levels. In addition, sensory profiling assessments revealed that at the lowest salt concentration the pressured product was perceived to be saltier compared with the tumbled product; however, the difference was not significant and was absent upon frying. In contrast, in sensory time intensity analysis the maximum intensity and the total salt taste were significantly higher in the pressured samples at the low and medium salt levels in the cooked samples. In conclusion, the present study showed strong evidence that the structure and biophysical characteristics of cured ham is altered by pressurization and suggested that pressurization may reduce the critical amount of salt required in a ham product.