Influence of the Technological Cycle «Fixing» on the Quality Characteristics of Pollock Fillets (Theragra Chalcogramma)

Abstract

Pollock (Theragra chalcogramma) remains one of the main fishing objects in the far Eastern region. The most popular product on both the domestic and international markets is fillet, when it is frozen it can be used to produce a wide range of finished products. The main technology for obtaining iced fillet consists of its production in a fixed or loose form. A man conducts the operation «fixed fillet» immediately after filleting fresh fish by irrigation or immersion in a cold 10 % solution of table salt. The research purpose was to determine changes in the quality characteristics of fixed and unfixed Pollock fillets during cold storage. The research object was refrigerated fixed and unfixed fillet of Pollock stored at a temperature below minus 18 degrees for up to 26 weeks. During storage the authors run organoleptic assessment on refrigerated, defrosted fillets after the cooking test. The results are the following: after 6 weeks of storage the organoleptic quality indicators are quite stable for all types of fillets; after 14 weeks there is a 40 % decrease in the overall score for the fixed fillet; moreover, there are the main changes in the samples after cooking for the most significant organoleptic indicators: color, taste, smell, consistency. After 14 weeks of storage the quality indicators of loose fillets remained almost unchanged. By the 14th week of storage the freshness value coefficient of the fixed fillet increases almost 3 times (from 14.8 to 40.0), i.e. a man can consume the fish only after mandatory cooking. The study identified that the operation of fixing fillet preserved the fillet block integrity, giving greater mechanical strength to the fillets, reducing the tissue juice loss, but it is inferior in organoleptic parameters to the loose fillet during storage reducing its shelf life. According to the experiment results, the researchers recommend a storage period for fixed frozen fillet of Pollock – up to 5 months, for loose fillet – up to 7 months without considering packaging materials.