Combined Blast and Contact cooling — Effects on physiochemical characteristics of fresh haddock (Melanogrammus aeglefinus) fillets
Skaginn hf. hefur einkaleyfi á nýrri vinnslutækni við vinnslu ferskra og frystra flaka sem byggist á svonefndri roðkælingu fyrir roðflettingu. Tilgangur þessa rannsóknarverkefnis var að bera saman flakavinnslu með roðkælingu og hefðbundna flakavinnslu. Í verkefninu eru borin saman annars vegar fersk flök og roðkæld flök með tillit til nýtingar, gæða og geymsluþols. Tvær tilraunir voru framkvæmdar, annars vegar tilraun I þar sem vatnsheldni, gæði, suðunýting og útlit voru skoðuð, og hins vegar tilraun II þar sem þessir sömu þættir voru skoðaðir auk þess sem skoðuð var áhrif roðkælingar á aukið geymsluþol ferskrar og frosinnar ýsu. Tilraunirnar voru framkvæmdar hjá Festi ehf. í Hafnarfirði. Meginniðurstöður þessara rannsókna sýndu að flakavinnsla með roðkælingu hefur fleiri kosti en hin hefðbundna flakavinnsla. Roðkælingin gefur hærri nýtingu og verðmætari afurðir með lengra geymsluþol. Aukið geymsluþol fersks fisks gefur aukinn möguleika á útflutningi sem er mjög mikilvægt fyrir fiskiðnaðinn.
The aim of the project was to compare a new processing technique, CBC, with traditional processing of haddock fillets. In the latter the fillets go through the process without additional refrigeration. In the new processing technique, CBC, the fillets, after filleting and pre-trimming, go through pre-cooler/fluid-ice followed by CBC super-chilling. Two trials were performed, a preliminary experiment (I) and a main experiment (II). In the preliminary experiment (I), water holding capacity, quality and cooking yield were examined. In the main experiment (II) these same factors were examined, in addition to the superchilling effect on extended shelf-life of fresh and frozen haddock fillets. After the pre-cooler step, the fillets gained weight with yields of 101.6% to 102.7%. After the CBC super-chilling the fillets had final yields of 100.3% to 101.2%. After skinning, the fillets without refrigeration (traditional processing) lost most weight. The highest value of cooking yield was obtained in CBC super-chilled fillets with skin. Skinless traditional and CBC super-chilled fillets showed similar cooking yield (P>0.05). CBC super-chilling increased the total yield of the fillets. The difference between the traditional fillets and the super-chilled fillets was significant. The appearance of the CBC super-chilled fillets was much better and with less gaping than the traditional fillets. The traditional fillets had more ragged outlines, and the ratio of cut-offs after fine-trimming was therefore higher for the traditional fillets than the CBC super-chilled fillets. Appearance of the traditional fillets showed a little yellow tinge which increased during the storage time. The CBC super-chilled fillets had a whiter and more “fresh” appearance and were therefore more attractive. Examination of total bacterial count, and amount of TMA and TVN showed that the CBC super-chilling process can extend the shelf life of fresh haddock fillets.