EFFECT OF HIGH HYDROSTATIC PRESSURE TREATMENT IN NATIVE MICROBIOTA AND QUALITY OF FRESH CHICKEN FILLETS

Chicken is one of the most widely consumed meat products worldwide, however, raw chicken provides favorable conditions for the growth of spoilage microorganisms, which significantly reduces its shelf life. In this context, poultry industry is continuously seeking technologies to improve product safety and quality. In this sense, high hydrostatic pressure (HHP), involving the application of pressures between 200 and 700 MPa, represents an alternative for food preservation without significantly affection of sensory properties.

The aim of this study was to evaluate the effect of HHP treatment on microbiological and quality parameters in fresh chicken fillets. Samples were obtained from a poultry distributor and vacuum-packed prior to treatment at 400 MPa, 500 MPa and 600 MPa for 10, 5 and 3 minutes, respectively. Subsequently, microbiological parameters (aerobic mesophilic bacteria - AMB, total coliforms - TC, and psychrotrophs - PS) and quality attributes (color: L*, a*, b*, ΔE, Texture profile analysis and pH) were evaluated.

In control samples populations were 6.06, 3.47 and 5.05 log CFU/g for AMB, TC and PS respectively. In treated samples no growth was detected for all microbial groups independently of the tested conditions. Considering this results, treatment could induce shelf-life increase in the product. Lightness (L*) significantly increased from 55.27 to 77-78 in treated samples, possibly due to enhanced light scattering associated with the aggregation of denatured proteins on the surface. The overall color change (ΔE) ranged from 20.50 to 21.47, indicating differences perceptible to consumers. Additionally, slight pH increase was observed (5.93-6.08) in treated samples compared to control (5.77) likely due to structural changes and possible formation of basic compounds. Finally, texture analysis showed an increase in hardness, gumminess and chewiness, particularly at 500 and 600 MPa, probably due to greater protein denaturation and aggregation. In contrast, treatment all treatments decreased sample resilience and adhesiveness without differences among them.

In conclusion, although HHP treatment improves product safety, it induces significant changes in quality that may influence consumer acceptance.