Effects of eco-friendly cold packs on the quality of vacuum-packed mackerel fillets during room temperature distribution

In this study, we evaluated the effectiveness of commercial cold packs (CC) and 3AC-developed cold packs (3AC) in expanded polystyrene containers (EPS+CC and EPS+3AC, respectively) for maintaining the freshness of -vacuum-packed mackerel (Scomber japonicus) during distribution in EPS boxes. Temperature monitoring showed that EPS+3AC packaging maintained slightly lower temperatures (by over 1° C) than EPS+CC during 4–16 h of storage. The pH of both groups gradually increased over 72 h, with significant differences observed between 0 h and 72 h. The total volatile basic nitrogen content in EPS+CC exceeded the acceptable limit (≥ 35 mg/100 g) after 36 h, whereas EPS+3AC showed a slower increase. Odor intensity increased with storage time, with higher values observed in EPS+CC than in EPS+3AC at 72 h. Total aerobic bacteria counts exceeded 6 log CFU/g earlier in EPS+CC than in EPS+3AC. Overall, EPS+3AC packaging delayed quality deterioration and extended the freshness-related shelf-life indicators of vacuum-packed mackerel under the tested conditions.