Title: Development and application of quality index method (QIM) in quality determination and shelf life study of Red fish fillets: The effect of bleeding, superchilling and packaging in modified atmosphere

Effective quality control management by fish processing industries and fish inspection demands fast and reliable freshness evaluation methods such as Quality Index Method (QIM). The aim of the study was to develop a QIM scheme for deskinned redfish fillets and evaluate it in a shelf life study of air (A) and Modified Atmosphere Packaged (MAP): 40% CO2 and 60% NO2 (M1) and 40% CO2 and 60% Ar (M2) redfish fillets. Gas compositions for the MAP were identified in a preliminary study. The effects of gas mixture, bleeding, and storage temperature on the shelf life and quality parameters were evaluated during superchilled (-0.5°C; day 0- 6) and chilled (2°C; day 7-16) storage. The changes during storage time were assessed by measuring drip, sensory evaluation of raw fillets using QIM and of cooked fillets using Torry-scheme and Quantitative Descriptive Analysis (QDA), and total viable microbial counts (TVC). The results of the shelf life study showed no significant difference in quality changes between the MAP fillets (M1 and M2). However, difference in MAP compared to the air packaging was found significant for all the analysis. Maximum storage time was 11 days for A and 14 days for MAP (M1 and M2) in superchilled storage. Quality index (QI) scores were around 8 for all the sample groups at sensory rejection point evaluated by Torry scheme. This implied that the developed QIM scheme would be applicable for evaluation of MAP as well as air packaged fillets.