Application of Quality Index Method (QIM) Scheme and Effects of Short-Time Temperature Abuse in Shelf Life Study of Fresh Water Arctic Char (Salvelinus alpinus)

ABSTRACT

Farmed arctic char were divided into two groups after slaughtering. One group (T1) was stored in ice up to 18 d and the other (T2) was stored at 18°C for 24 h (temperature increased from 3°C up to 12°C), then iced and stored up to 18 d. Changes during storage were observed with sensory evaluation using the Quality Index Method (QIM) and Quantitative Descriptive Analysis (QDA), total viable counts (TVC), and hydrogen sulphide (H₂S)-producing bacteria. A high correlation between Quality Index (QI) and storage time in ice was found. Storage time could be predicted within ± 1.3 d. The maximum shelf life, determined with QDA and microbial counts, was 17 and 15 d, respectively, for iced (T1) and temperature-abused (T2) arctic char. At the end of shelf life, TVC was 10⁵–10⁶ CFU/g in the flesh of both groups, with H₂S producing bacteria constituting a higher proportion of TVC in T2.

KEYWORDS:

• Arctic char
• sensory evaluation
• shelf life
• temperature abuse

This work was carried out at the Icelandic Fisheries Laboratories (IFL)/MATÍS as part of the United Nations University Fisheries Training Programme. The authors are greatly indebted to Asa Thorkelsdottir for her guidance in sample preparation, all the sensory panellists at IFL/MATÍS, and Dr. Tumi Tomasson, Programme Director, Mr. Thor Asgeirsson, Deputy Programme Director, and Mrs. Sigridur Ingvarsdóttir, Programme Officer of UNU-FTP for their valuable guidance, discussions, and support during the study.

Notes

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