Ultrasound-assisted Plasma-activated Water for Bacterial Inactivation in Poultry Industry

Abstract

Normally, the slaughtering process in the poultry industry always uses chlorine solution to reduce pathogenic bacteria. However, use of chlorine in the food industry has some adverse effects, such as cross-contamination, low-efficiency sterilization, and other human health concerns because of which the industry tries to avoid usage of chlorine and other chemical substances in the production line. Currently, plasma technology is being broadly investigated to be employed for bacteria inactivation as a substitute technique for chlorine solution processing. One category of plasma technology, called plasma-activated water (PAW), has shown promising results as regards bacterial inactivation without using the chemical substance. Thus, PAW could be considered as a clean technology which has been widely applied in medical, agricultural, and food industries. This study applied PAW from arc liquid discharge in combination with ultrasound to inactivate Escherichia coli and Staphylococcus aureus on fresh raw chicken meat. The results show that the combined technique can reduce E. coli and S. aureus in 4 mm muscle chicken thickness by 1.51 log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> CFU/ml and 0.85 log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> CFU/ml, respectively, while individual treatment with ultrasound can reduce E. coli and S. aureus by only 0.25 log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> CFU/ml. At the same time, it was found that plasma-activated water alone could reduce E. coli and S. aureus by 0.74 log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> CFU/ml and 0.68 log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> CFU/ml, respectively. Furthermore, the physicochemical properties of PAW, including pH, electrical conductivity (EC), oxidation reduction potential (ORP), OH radical, and hydrogen peroxide (H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), were also investigated.