Effect of ultrasound on proteolysis and the formation of volatile compounds in dry fermented sausages.

Ultrasound (US) is an emerging technology capable of affecting enzymes and microorganisms, leading to the release of amino acids and the formation of volatile compounds. The effect of different exposure times (0, 3, 6, and 9 min) of US (25 kHz, 128 W) on the proteolysis and volatile compounds of dry fermented sausages during processing (day 0 and 28) and storage (day 1 and 120) was investigated. Lower alanine, glycine, valine, leucine, proline, methionine, and tyrosine levels were observed at the beginning of manufacture for the sample subjected to 9 min of US (p < 0.05) when compared to the control. During the storage period, the samples subjected to US exposure for 3 and 6 min exhibited higher free amino acid levels. A greater formation of hexanal, pentanal, and hexanol was observed in the US-treated samples when compared to the control (p < 0.05), as well as other derivatives from the oxidation reactions during the storage. The use of US (25 kHz and 128 W) in the manufacture of dry fermented sausages can affect the proteolysis and the formation of compounds derived from lipid oxidation during the storage.

Application of electrolyzed water for improving pork meat quality.

The microbiological and oxidative qualities of pork loin sprayed with different types (slightly acidic, acidic and basic) and combinations of electrolyzed water (EWs) were evaluated. The EWs were applied at two temperatures (18° and 30°C) and pressures (30 and 45psi) and the volume corresponded to approximately 10% water commonly used in carcass washing. EW after spraying exhibited a chlorine concentration between 15 and 25ppm. The application of acidic EW (AEW) alone or in combination with basic EW (BEW) decreased (P<0.05) the microbial counts shortly after spraying. In addition, the combination of BEW+AEW (30psi) reduced the mesophilic and psychrotrophic bacteria counts throughout the refrigerated storage (P<0.05). The EWs did not increase the lipid oxidation of the samples. On the other hand, a high protein oxidation was observed in the samples sprayed with AEW and slightly acidic EW (SAEW), while BEW was effective to reduce the oxidation reactions. Therefore, the results showed that the combination BEW+AEW may be a viable alternative to reduce the volume of water used at slaughter and to improve the microbiological quality of pork meat.