Effects of the Plasma-Activated Water on the Quality and Preservation of Fresh-Cut Lettuce

CHAMORRO, JUAN CAMILO; DENOYA, GABRIELA INÉS; SANTAMARÍA, BRENDA; FINA, BRENDA; FERREYRA, MATÍAS; CEJAS, EZEQUIEL; RODRÍGUEZ, ANABEL; VAUDAGNA, SERGIO RAMÓN; PREVOSTO, LEANDRO

IEEE TRANSACTIONS ON PLASMA SCIENCE

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Año: 2023 p. 1 - 11

0093-3813

The effect of the application of plasma activated water (PAW) on the quality and preservation of fresh–cut lettuce is reported in this paper. PAW was produced by using a liquid–cathode air discharge. The average (bulk) water temperature was kept at ~ 22°C during the activation procedure and stored at 4 °C up to 5 days. The pH value, electrical conductivity and concentrations of H2O2 and NO3– in liquid at day 1 was 2.81, 1492 μS/cm and 77.8 and 223.4 mg/L respectively, with slight variations over the whole storage time. No measurable amounts of NO2– were found. Twenty pieces of lettuce leaves were washed for 1 and 5 min in 1 L of PAW stored for 1 and 5 days. PAW treatments were compared to tap water treatments. The lettuce samples were stored at 4 °C and analyzed on days 1, 3 and 7. The chromatic parameters results suggest that PAW treatments significantly reduce the degradation of lettuce chlorophyll from day 3 of refrigerated storage. The lettuce firmness was not significantly modified. The microbiological results of aerobic mesophilic, enterobacteriaceae and psychrotrophs populations shown that lettuce treated with PAW after three days of storage exhibited the strongest inactivation efficiency. Psychrotrophs counts were maintained up to 7 days. Similar inactivation efficiencies were found regardless the PAW storage time. PAW treatments also favored both the antioxidant capacity FRAP, ABTS and DPPH, as well as the total phenolic contents of lettuce at the day 7 of storage.