CHEMICAL, MICROBIOLOGICAL, COLOR AND TEXTURAL CHANGES IN NILE TILAPIA (OREOCHROMIS NILOTICUS) FILLETS STERILIZED BY OZONATED WATER PRETREATMENT DURING FROZEN STORAGE

摘要

To assess the impact of ozonated water pretreatment on fish quality, Nile tilapiarnfillets were sterilized by 4.5 mg/L ozone-containing water for 30 min and storedrnat 21861C for 180 days. Untreated fillets were used as controls. Quality changesrnduring storage were assessed by chemical, microbiological analysis, color and texturernmeasurements in both groups. The results showed that the pH did not significantlyrndiffer in both groups at various time points during storage and did notrnexhibit a significant correlation with the microbiological data, which reflects thernchanges in quality during frozen storage. Malondialdehyde content and K-valuesrnincreased in the control and ozone-treated fillets samples after 180 days of frozenrnstorage. Ozonated water treatment had antimicrobial, bleaching and texturalrnquality enhancement effects on tilapia fillets processing. In conclusion, the tilapiarnfillets quality can be improved partly and shelf life can be extended well after ozonatedrnwater pretreatment.