## 1 Introduction  
Quality is an interdisciplinary term, and its perception depends on what it concerns and by whom it is assessed. One can perceive quality from the following perspectives: objective--focused on the quality of the product, process, control; and subjective--customer oriented. When keen to satisfy food quality attributes, it is important to consider customer requirements and expectations. Food processing facilities wishing to maintain high product quality should focus on continuous improvement and search for reasons for deviations from the planned results in the existing production system to take actions aimed at minimizingnegative effects and maximizing the use of emerging opportunities [1]. Polish poultry production, which has maintained its leading position among European Union countries since 2014, engages in such activities. The Polish poultry industry has set several strategic goals to achieve by 2024. These goals include maintaining a high level of poultry consumption in Poland by building values such as quality, safety, and sustainable production of meat and poultry products. Moreover, scientific research and development work are conducted to improve the quality of poultry meat [2].  
The process of stunning poultry is the first and most important technological process, which, while ensuring humane behavior during slaughter (depriving the birds of consciousness and feeling until bleeding), determines the good quality of meat and carcasses. The most popular method in Poland and most countries in the world is the method of electric stunning in a water bath [3; 4; 5]. It is often criticized due to animal welfare during slaughter and reduced meat quality, which generates large economic losses. To ensure the effective stunning of poultry, the legislative document developed [6] strictly indicates defined doses of electric current, characterized by a range of frequency and intensity values. To achieve effective stunning in 90% of chickens, the minimum current per animal was determined: at frequency (f) < 200 Hz--100 mA; at f = 200-400 Hz--150 mA; and at f > 400 to 1500 Hz--200 mA. In practice, however, it turned out that the variants of electrical parameters suggested in the current Regulation (much higher than before the entry into force of this Regulation) do not allow maintaining high quality standards and cause more hemorrhages in fillets [7; 8; 9]. Meat defects in the form of hemorrhages are noticeable, especially on the inside of fillets sold both loosely and in packages, so they significantly reduce their culinary and technological usefulness, reduce customer purchasing decisions, and lower the market price of meat [10; 11]. The results of own research on the effects of using own-construction devices for stunning poultry compared to commercial devices (Dutch and Danish companies), most often used in poultry plants, showed that the current parameters used [12; 13] allow for an increase of approx. 50% of the production of high-quality fillets without hemorrhages and with uniform color [14; 15], which also meet the expectations of Polish consumers [10]. The availability of devices for electrically stunning poultry on the domestic market and their use by Polish plants inspired the authors to continue the research problem with a broader scope of analysis and evaluation.  
The aim of the research was to determine the possibility of managing the quality of chicken meat, fresh and refrigerated, using two stunning devices--own-construction and a commercial one from a Polish company (control). These possibilities were determined on the basis of instrumental assessment of technological parameters (pH, tenderness, color, cooking loss) and visual features (hemorrhages, defects) of meat, as well as Profit statistical analysis, which constitutes measurable evidence for producers to take actions to improve the production process and meat quality.