Tengiliður
Kolbrún Sveinsdóttir
Verkefnastjóri
kolbrun.sveinsdottir@matis.is
Þessi skýrsla er lokuð / This report is closed.
Merki: Quality
Tengiliður
Kolbrún Sveinsdóttir
Verkefnastjóri
kolbrun.sveinsdottir@matis.is
Þessi skýrsla er lokuð / This report is closed.
Skoða skýrslu
Tengiliður
Kolbrún Sveinsdóttir
Verkefnastjóri
kolbrun.sveinsdottir@matis.is
Þessi skýrsla er lokuð / This report is closed.
Skoða skýrslu
Tengiliður
Kolbrún Sveinsdóttir
Verkefnastjóri
kolbrun.sveinsdottir@matis.is
Þessi skýrsla er lokuð / This report is closed.
Skoða skýrslu
Tengiliður
Kolbrún Sveinsdóttir
Verkefnastjóri
kolbrun.sveinsdottir@matis.is
Þessi skýrsla er lokuð / This report is closed.
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Tengiliður
Aðalheiður Ólafsdóttir
Skynmatsstjóri
adalheiduro@matis.is
In the Norwegian oceanic fleet, whitefish onboard processing creates a great amount of rest raw materials. Cod heads are nutritious and a good source for production of high-quality marine peptides. Frozen cod heads, captured by trawl or longline, were evaluated based on the lightness and redness in the neck cut to compare the quality in heads from the different fishing gears. The heads were subjected to enzymatic hydrolysis. The hydrolysates have been chemically and sensory characterized. There was no significant difference in quality or chemical and sensory characteristics based on type of fishing gear. The resulting hydrolysates were of high quality, although moderately bitter. The study demonstrates that frozen cod heads from the oceanic fleet can be an excellent source of high-quality proteins for human consumption.
Tengiliður
Sigurjón Arason
Yfirverkfræðingur
sigurjon.arason@matis.is
Hámörkun gæða frosinna karfaafurða / Quality optimization of frozen redfish products
The aim of the study was twofold. Firstly, to explore the influence of time and temperature during frozen storage on lipid deterioration of red fish. That was done by comparing the effect of temperature fluctuation and abuse during frozen storage, as can be expected during transportation, on the physicochemical characteristics and lipid stability of redfish fillets. Secondly, to investigate the effect of 4 days postcatch and 9 days postcatch, and seasonal variation on the quality and storage stability of frozen red fish.
Storage temperature and storage time affected the physical- and chemical properties in redfish, e.g free fatty acids, TBARS and TVB-N. Season of capture affected both the nutritional value and stability of golden redfish. The light muscle of fish caught in November was richer in EPA and DHA than in the fish caught in June. The fish caught in November was also more unstable through frozen storage, due to a more unsaturated nature of the fatty acids present, indicating that special care needs to be applied during handling and treatment of golden redfish caught at this time. The light muscle had a higher nutritional value than the dark muscle and is a good nutritional source for human consumption. However, the dark muscle was prone to lipid oxidation which may have a negative influence on the more valuable light muscle. So there seems to be need to separate them.
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Tengiliður
Guðmundur Stefánsson
Fagsviðsstjóri
gudmundur.stefansson@matis.is
Holding of Sea Urchins and Scallops in a RAS Transport System
Trials were carried out at Matís on holding live sea urchins and scallops in a RAS system developed by Technion, Israel, which not only recirculates the water, but additionally controls the pH and removes toxic ammonia. The aim of the trials was to test the feasibility of holding sea urchins and scallops alive in the RAS system for 10 days at 4°C, with at least 90% survival. The project was funded by EIT food, and the participants were Technion and Matís.
The survival of sea urchins held in the RAS system at 4°C was high during the first five days. Eight days from catch the survival was only 80%, after 12 days about 50% and after 15 days, 10%. Sea urchins, packed in the standard way of transporting live urchins (in polystyrene boxes at 4°C) were at similar quality as the RAS stored sea urchins, five days from catch and the roe was still edible at eight days from catch. All the urchins in the polystyrene boxes were dead after 12 days storage and the roe inedible.
Scallops had a high survival when held in the RAS system or about 89% after 24-days at 4°C.
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Tengiliður
Sigurjón Arason
Yfirverkfræðingur
sigurjon.arason@matis.is
The effects of food container depth and coverage on the quality of superchilled rainbow trout
Ferskur eldisfiskur er almennt slægður og pakkað í frauðplastkassa með ís fyrir útflutning í kæligámum. Í ljósi þess að mikil þróun hefur átt sér stað hvað varðar ofurkælingu og jákvæð áhrif hennar á gæði fiskafurða, þá hafa aðrar hagkvæmari og umhverfisvænni pökkunarlausnir verið skoðaðar, þar á meðal einangruð matvælaker. Meginmarkmið verkefnisins var að meta áhrif mismunandi pökkunaraðferða á gæði fersks regnbogasilungs. Slægðum fisk með haus var pakkað í frauðplastkassa og einangruð ker af mismunandi dýpt (29-60 cm). Auk samanburðar á misdjúpum kerum, þá voru mismunandi útfærslur við lokun á kerum einnig skoðaðar. Fylgst var með tilraunafiskum efst og neðst í hverju keri. Kerin voru geymd í hitastýrðu umhverfi við um -1 °C og gerðar mælingar eftir 8 og 13 daga frá pökkun. Sá fiskur sem pakkað var í frauðplastkassa var ýmist ofurkældur fyrir pökkun eða kældur á hefðbundinn hátt með ís. Það var gert til að meta áhrif ofurkælingar á ferskan regnbogasilung. Til að meta gæði regnbogasilungsins var fylgst með örveruvexti, áferð og losi í flökum. Niðurstöðurnar sýndu að þær pökkunarlausnir sem skoðaðar voru í verkefninu höfðu tiltölulega lítil áhrif á heildarörverufjölda, en ekki reyndist marktækur munur á milli tilraunahópa við lok geymslutímabilsins. Almennt var lítill sem enginn munur á milli hópa m.t.t. áferðar og loss í flökum. Aftur á móti sýndu niðurstöðurnar að nauðsynlegt er að loka kerunum, en tegund loks hafði ekki marktæk áhrif. Ofurkæling fyrir pökkun hafði marktæk áhrif á los. Fiskur sem var kældur á hefðbundinn hátt og pakkað í frauðplastkassa með ís hafði marktækt meira los samanborið við þegar hann var ofurkældur og pakkað í ker eða frauðplastkassa án íss. Niðurstöðurnar sýna að ekki er marktækur munur á milli frauðplastkassa og kera af mismunandi dýpt miðað við þær gæðabreytur sem skoðaðar voru í þessu verkefni. Þær gefa því til kynna að flutningur á ofurkældum regnbogasilungi í kerum er raunhæfur möguleiki m.t.t. stöðuguleika hráefnisins og afurðargæða.
The overall aim of the study was to explore the effects of different packaging solutions on the quality of fresh rainbow trout. Different packaging methods included expanded polystyrene boxes (EPS), insulated food containers of 29 to 60 cm depth with various combination of covers. Each container was split up into two groups, top- and bottom layer. Both fish chilled on ice and superchilled fish were considered. Microbial growth and sensory characteristics (fillet gaping, softness and elasticity) were used to evaluate the quality of the rainbow trout fillets after 8 and 13 days of storage at around -1 °C. The different packaging solutions had no effects on the microbial quality of the fish. Moreover, no listeria activity was detected. Sensory evaluation showed minor differences between containers of different depths and/or EPS boxes, as well as between top and bottom layers. However, the presence of cover proved to be of great importance, but the type of cover turned out to be not relevant. The effects of superchilling before packaging on fillet gaping was evident in present study since fish packed in EPS box with ice resulted in more gaping than superchilled fish packed in EPS boxes and/or containers without ice.
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Tengiliður
Sigurjón Arason
Yfirverkfræðingur
sigurjon.arason@matis.is
The effects of insulated tub depth on the quality of iced Atlantic cod / Áhrif dýptar einangraðra kera á gæði ísaðs þorsks
Markmið verkefnisins var að rannsaka gæði þorsks sem hafði verið slægður einum degi eftir veiði, ísaður og pakkað í 12 mismunandi stór ker, 4×250 L, 4×460 L og 4×660 L. Fylgst var með tilraunafiskum efst og neðst í hverju keri. Kerin voru geymd í hitastýrðu umhverfi við 1 °C og gerðar mælingar eftir 6, 10, 13 og 15 daga frá pökkun. Til að meta gæði þorsksins var notast við vatnstap í kerum eftir geymslu, vinnslunýtingu og skynmat. Niðurstöður sýndu að vatnstap var mest í 660 L keri og minnst í 250 L keri. Enginn munur var á vinnslunýtingu. Í öllum tilfellum var minna los í botni kers miðað við toppinn, líklega vegna mismunandi stærðar fiska í toppi og botni. Enginn munur var á niðurstöðum úr mati með gæðastuðulsaðferð (QIM) milli kera en þeir skynmatsskalar sem til eru ná ekki til þeirra eiginleika sem greinilegur munur sást á. Mikill munur sást á fiskum í topplagi og fiskum í botnlagi í öllum tilvikum, en ísför og marin flök voru fyrirferðameiri á botnfiskum. Í framhaldi tilraunarinnar verður í áframhaldandi rannsóknum á gæðum ísaðs og ofurkælds fisks í mismunandi stórum kerum hannaður nýr skynmatsskali sem tekur á þessum þáttum, þ.e. förum eftir ís og marskemmdum í flökum.
The aim of this project was to examine the quality difference of Atlantic cod that had been iced and packed into 12 different sized food containers (tubs), 4×250 L, 4×460 L and 4×660 L. Each tub was split up into two groups, top-and bottom layer. Drip loss, processing yield, and sensory evaluation were used to evaluate the quality of the cod. The results showed that the greatest drip loss was in the 660 L tub, and the least in the 250 L tub. There was no difference in processing yield. Sensory evaluation showed no difference between tubs, except that the fillets from fish in the bottom layer of all containers had less gaping than fillets from the top layer of fish, most likely due to size differences of top-and bottom layer fish. No current sensory evaluation scales account for different amounts of ice marks and crushed fillets that was detected between fish in the top-and bottom layer of the tubs. The results of this project will be used in continuing research of iced and superchilled fish in different sized containers to develop a new sensory scale that will account for these qualities.