Ultrasound and slightly acid electrolyzed water application: An efficient combination to reduce the bacterial counts of chicken breast during pre-chilling.

Pre-chilling leads to a temperature decline of the pre-rigor muscle of poultry carcasses, and a reduction of the initial bacterial load may occur. Both ultrasound (US) and slightly acidic electrolyzed water (SAEW) have been used alone in the meat industry for the manufacture of emulsions, pasteurization, and prevention of bacteria growth. However, the impact of the combination of these technologies during the pre-chilling of chicken carcasses has not been evaluated. In this study, breast chicken cylinders (CBCs) were pre-chilled for 10 min at 10 °C using SAEW and different US frequencies (25 and 130 kHz). The microbiological characteristics, lipid and protein oxidation, shear force, and anaerobic glycolysis were evaluated. The US + SAEW combination led to an effective reduction (P < 0.05) of enterobacteria, mesophilic bacteria, lactic acid bacteria, and psychrotrophic bacteria, while the lipid and protein oxidation, shear force, anaerobic glycolysis, and muscle structure were not affected (P > 0.05). Therefore, the combination of these technologies may be promising in the pre-chilling stage of chicken carcasses.

Application of ultrasound in chicken breast during chilling by immersion promotes a fast and uniform cooling.

The initial objective of the study was to evaluate different operation modes (sweep and normal) and frequencies (25 and 130 kHz) of ultrasound in pre-chilling of breast chicken cylinders (BCC) immersed in water at 10 °C during 10 min. The second objective was to study the effect of the immersion time (5, 10, 15, 20, and 30 min) using the best operation mode and frequency obtained in the pre-chilling of the BCC in water at 10 °C. Pre-chilling was evaluated in both stages by infrared thermography, and the percentages of water absorption were determined in the second stage. The application of US at 130 kHz and normal operation mode provided a reduction of temperature on the surface of BBC higher (≈19.6%) than untreated samples. Also, compared to control, the US-treated samples in these conditions presented a more uniform cooling rate (≈22.3%) and higher water absorption (≈113%).

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.