Shelf-life Extension Strategies of Skipjack Tuna (Katsuwonus pelamis) Using Sodium Acetate and Vacuum Packaging at Chilled Storage

Abstract

Skipjack tuna (Katsuwonus pelamis) is highly perishable under chilled storage, creating a need for preservation approaches that maintain product quality and extend shelf life. This study evaluated the effect of sodium acetate treatment combined with vacuum packaging on skipjack tuna chunks stored under chilled conditions. Fresh tuna were processed into 3–4 cm chunks and divided into three treatments: untreated vacuum-packed control (T1), 1% sodium acetate-treated vacuum-packed samples (T2), and 2% sodium acetate-treated vacuum-packed samples (T3). Samples were stored at 0–4°C and evaluated at 4-day intervals for biochemical, microbiological, physical, and sensory quality characteristics over 24 days. The untreated vacuum-packed control remained acceptable for up to 16 days, while treatment with 1% sodium acetate extended acceptability to 20 days. The 2% sodium acetate treatment showed the longest shelf life, with acceptability extending to 24 days. Across storage, the 2% treatment generally showed better retention of the measured physical, biochemical, and microbiological quality attributes than the other treatments. Changes were assessed through pH, trimethylamine nitrogen, total volatile base nitrogen, peroxide value, total plate count, colour, drip loss, hardness, and springiness. Overall, the findings indicate that sodium acetate treatment, particularly at 2%, in combination with vacuum packaging can delay quality deterioration of skipjack tuna chunks during chilled storage.