Chemical, Microbiological, Color and Textural Changes in Nile Tilapia (Oreochromis niloticus) Fillets Sterilized by Ozonated Water Pretreatment During Frozen Storage

To assess the impact of ozonated water pretreatment on fish quality, Nile tilapia fillets were sterilized by 4.5 mg/L ozone-containing water for 30 min and stored at -181C for 180 days. Untreated fillets were used as controls. Quality changes during storage were assessed by chemical, microbiological analysis, color and texture measurements in both groups. The results showed that the pH did not significantly differ in both groups at various time points during storage and did not exhibit a significant correlation with the microbiological data, which reflects the changes in quality during frozen storage. Malondialdehyde content and K-values increased in the control and ozone-treated fillets samples after 180 days of frozen storage. Ozonated water treatment had antimicrobial, bleaching and textural quality enhancement effects on tilapia fillets processing. In conclusion, the tilapia fillets quality can be improved partly and shelf life can be extended well after ozonated water pretreatment. Practical ApplicationsWe assessed quality during storage in Nile tilapia fillets after ozonated water treatment. Ozonated water treatment improves the quality and extends the shelf life of the fish. Hardness, gumminess, springiness and chewiness were enhanced by pretreatment. This study is of interest to the aquatic food industry and the consumers.