Evaluation of lettuce (Lactuca sativa L.) in aquaponic system in terms of food safety

Abstract

We determined the number of coliform bacteria, Escherichia coli, yeast, and molds that may occur in the system, and the quality of lettuce grown in aquaponics for consumers from sensory, colour, and texture points of view. The amount of yeast and mold in the plant growing medium (hydroton) and water was 4.67 log CFU/cm2 and 2.25 log CFU/mL at the end of the six-week experiment, respectively. The number of coliform bacteria and E. coli in the growing medium and in the system water was found to be 2.57 log CFU/cm2 and 3.46 log CFU/mL for coliform, 0.75 log CFU/cm2 0.31 log CFU/mL for E. coli, respectively. Organisms that pose a risk to food safety, accumulate in the culture media. After the harvest, lettuce cultured in the aquaponic system (AP) was compared with the lettuce cultured in soil (SC). According to the results, AP lettuce was found to have darker colors (Lightness: 56.4 AP, 49.09 SC, p<0.05), harder (Hardness: 209.3 AP, 153.7 SC, p<0.05), and slightly appetizing (Sensory analysis overall liking: 8.4 AP, 7.7 SC) than SC. In conclution, aquaponic systems are much more preferable in terms of sensory quality and consumer preferences than soil-based production systems.