Chilled bulk storage of gutted hake (Merluccius merluccius L.) in CO2 and O2 enriched controlled atmospheres

This work compares hake gutted whole and placed in boxes in ice under controlled atmospheres (CA) with four different gas mixtures: M1 CO2/O2/N2(%) (60/15/25), M3 (40/40/20), M4 (60/40/0) and M5 (40/60/0) and hake in air for 33 days of storage. The storage chamber temperature was 0 ± 1°C. Biochemical analyses [pH, total volatile basic nitrogen (TVB-N), trimethylamine nitrogen (TMA-N) and thiobarbituric acid (TBA index) and sensory analyses (inspection and tasting)] were carried out to study the quality of the hake. The hake, kept under controlled atmospheres, did not exceed the limits for acceptability of 35 mg/100 g and 12 mg/100 g of TVB-N and TMA-N, respectively, throughout the storage period, and the TBA values remained lower than the recommended limits of 14 mg of malonaldehyde/100 g. Chemical results accorded with the tasters who did not detect any off-odour in the samples, and the M4C lots stored under 60/40/0 (CO2/O2/N2%) was rated the best. However, this result did not accord with the inspection or pH by which all the lots were rejected at day 25 of storage. Despite this, the atmosphere system for preservation of chilled hake could be used safely and effectively on fishing boats to extend the shelf life of this species, and was better than conventional storage in ice. © 2001 Elsevier Science Ltd. All rights reserved.