The suitability of using sunflower and rapeseed oils, and water as media for the canning of smoked fillets from Atlantic mackerel (Scomber scombrus) caught during feeding migration was investigated. Physicochemical and sensory changes were evaluated after one month of storage at room temperature. The aqueous medium in the cans led to significantly higher water content and lower salt content than when sunflower or rapeseed oil was used, indicating that while additional water was absorbed by the fillets, salt was leached due to the cook-out effect during sterilization and storage. Using sunflower oil, regardless of the ratio, resulted in better retention of the traditional and desired smoky odour and -flavour, and preserved the juicy and tender texture of the fillets better than when rapeseed oil was used. Fillets canned in water exhibited a significantly lower salty flavour and fat-in-mouth attribute than those canned in vegetable oils. While there were only minor differences in the overall sensory parameters among treatments, the variation in salty flavour and fat-in-mouth feeling are crucial due to their significant impact on consumer acceptance. Therefore, using water as a medium is suggested as a favourable option for canning deep-skinned and smoked fillets from well-fed Atlantic mackerel.
Merki: Hot-smoking
Tengiliður
Sigurjón Arason
Yfirverkfræðingur
sigurjon.arason@matis.is
Effect of brining and frozen storage on physicochemical properties of well-fed Atlantic mackerel (Scomber scombrus) intended for hot smoking and canning
Makríll (Scomber scombrus) er tiltölulega ný nytjategund við strendur Íslands. Þar sem makríll er feitur fiskur með stutt geymsluþol, krefst hann því hámörkunar á geymsluaðstæðum og vinnsluferlum. Í þessu verkefni voru breytingar á efna- og eðliseiginleikum við hitameðhöndlun á söltuðum og ósöltuðum makríl rannsakaðar. Fyrir vinnslu var fiskurinn geymdur í 6, 9 og 12 mánuði við -18 °C og -25 °C með það fyrir augum að kanna hversu vel íslenskur frosinn makríll hentar sem hráefni í niðursoðnar og heitreyktar vörur. Til þess að athuga þau áhrif sem hitameðhöndlun hefur á vinnslueiginleika makríls voru sýnin hituð upp í 75 °C (til að herma eftir reykingu) og 90 °C (til að herma eftir niðursuðu). Langvarandi geymsla í frosti hafði neikvæð áhrif á hráefnið vegna aukinnar þránunar og var fiskurinn sem geymdur var við -18 °C með marktækt lakari gæði samanborið við fisk sem geymdur var við -25 °C fyrir vinnslu. Niðurstöðurnar sýndu að afurð hituð að 75 °C hafði hærra vatnsinnihald, hærri vatnsheldni og hærri nýtingu og var auk þess meyrari samanborið við afurð hitaða að 90 °C. Á heildina litið þá gefa niðurstöðurnar til kynna að feitur sumarmarkíll gæti hentað vel til vinnslu á niðursoðnum og heitreyktum afurðum.
Atlantic Mackerel (Scomber scombrus) is a novel species in Iceland and as a fatty fish with a short shelf-life it requires optimization of storage and processing conditions. Physicochemical changes of brined and un-brined mackerel were analysed during frozen storage (6, 9, 12 months) at -18 °C vs. -25 °C with the aim of investigating the suitability of using well-fed frozen mackerel as raw material for canned and hot-smoked products. Heat treatments to a core temperature of 90 °C (representing canning) and 75°C (representing hot-smoking) were applied. Prolonged frozen storage showed negative effects on the raw material prior to heat processing due to an increased level of lipid oxidation, where fish stored at -18 °C was of significantly poorer quality than fish stored at -25 °C. Moreover, the results indicated that heat treatment resulting in a core temperature of 75 °C showed higher water content, liquid holding capacity, heating yield as well as lower maximum shear force of texture compared to mackerel heated to a core temperature of 90 °C. Overall, analyses indicated that the fatty summer mackerel was well suitable for production of canned and hot-smoked products.