Improvement the Shelf Life of Tilapia Fillets Stored at Chilling Condition

Abstract

The main purpose of this investigation was to study the effect of immersing fillets of Nile Tilapia (Orechromis niloticus)in 1% acetic acid and storage under standard conditions (80% CO2: 20% N2) at a temperature of 2°C on their shelf life.Fillets samples were divided into four groups, Group 1 (G1): the fillets immersed in sterilized distilled water for 2 minutesand packaged in Polyamide/ Polyethylene (PA/PE) bags. Group 2 (G2): the fillets immersed in sterilized distilled waterand stored under standard conditions. Group 3 (G3): the fillets immersed in 1% acetic acid for 2 minutes and packaged inPA/PE bags. Group 4 (G4): the fillets immersed in 1% acetic acid and stored under standard conditions. All sampleswere stored at a temperature of 2°C for 21 days and analyzed at the beginning of the experiment and after 7, 14 and 21days of storage. Results of the study showed that the organoleptic properties of tilapia fillets dropped by the extension ofthe cold storage time to 21 days. The average values of Thiobarbituric acid-reactive substances (TBARS) in the G1, G2,G3 and G4 are 9.23, 2.56, 8.07 and 0.98 at day 21 of the cold storage at a temperature of 2 °C, respectively. Tilapia filletskept under CO2-enriched atmosphere had lower total volatile base nitrogen (TVB-N) than those stored in air where theaverage values were 19.9, 15.93, 18.97, 15.93 mg/100g in G1, G2, G3 and G4, respectively at the end of the storageperiod. The results also showed that the total viable count (TVC) remained at permitted in G4 as the average number was6.14 ± 0.05 × 103 after 21 days of storage at a temperature of 2 °C, while in G1, G2 and G3 were 7.53 ± 0.06 × 106, 7.63± 0.11 × 105 and 5.30 ± 0.09 × 106 respectively. Thus, the results indicated that the tilapia fillet immersion in 1% aceticacid and storage under standard conditions that have been applied in our study contributed to the extension of the validityperiod for tilapia fillet for a longer period of cold storage of up to 21 days