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Greinar eftir starfsmenn Matís í vísindaritum

11.10.2010

Nú eru aðgengilegar rafrænar útgáfur af tveimur greinum sem birtast í Journal of Food Engineering og Food Chemistry (sjá tengla neðar á síðunni). 

Greinarnar lúta báðar að saltfiskverkun.  Fyrri greinin fjallar um áhrif af mismunandi pækilstyrk á þyngdarbreytingar þorskvöðva og upptöku salts við pæklun.  Seinni greinin fjallar um áhrif mismunandi söltunaraðferða á afmyndun próteina og hvernig tengja má niðurstöður við breytileika í nýtingu afurða.

Greinarnar eru afrakstur doktorsverkefna sem unnin hafa verið að stærstum hluta hjá Matís, þ.e. verkefni Minh Van Nguyen sem stundar nám við Háskóla Íslands og verkefni Kristínar Önnu Þórarinsdóttur sem lokið hefur námi frá Háskólann í Lundi Svíþjóð. 

Verkefnin voru styrkt af AVS (R042-05), Rannís (R051364005) og Nordic Innovation Centre Fund (04252).  Auk þess hefur Sjávarútvegsskóli Háskóla Sameinuðu Þjóðanna (United Nations University-Fisheries Training Programme) styrkt Minh Van Nguyen til námsins og  Nordic Marine Academy (NMA) nám Kristínar Önnu Þórarinsdóttur.

Helstu upplýsingar um greinarnar, auk útdráttar er að finna hér að neðan.  Nöfn þeirra höfunda sem starfa á Matís eru undirstrikuð.  Nánari upplýsingar veitir Kristín Anna Þórarinsdóttir, fagstjóri hjá Matís (tölvupóstfang: kristin.anna.thorarinsdottir(hja)matis.is). 

Minh Van Nguyen, Sigurjon Arason, Kristin Anna Thorarinsdottir, Gudjon Thorkelsson, Agusta Gudmundsdottir.  2010.  Influence of salt concentration on the salting kinetics of cod loin (Gadus morhua) during brine salting.  Journal of Food Engineering, Volume 100, Issue 2, 225-231

Abstract
The influence of different salt concentrations of 6%, 15%, 18% and 24% (w/w) on mass transfer of water and salt during brine salting of cod loins was studied. An increase in salt concentration accelerated water exudation and salt diffusion in the cod loins. Weight gain of the cod loins increased with decreasing salt concentration and the cod loins in the 6% brine had the highest process yield. The salting kinetic parameter values for total and water weight changes decreased with increasing salt concentration. Inversely, higher salting kinetic parameter values for salt weight changes were observed for higher brine concentrations. The samples brined at 18% and 24% had identical effective diffusion coefficients and the highest effective diffusion value was found in the cod loins brined at 15%.

doi:10.1016/j.foodchem.2010.09.109 

Kristin Anna Thorarinsdottir, Sigurjon Arason, Sjofn Sigurgisladottir, Thora Valsdottir, Eva Tornberg.  2011.  Effects of different pre-salting methods on protein aggregation during heavy salting of cod fillets.  Food Chemistry, Volume 124, Issue 1, Pages 7-14.

Abstract
The use of injection and brining as the first step in heavy salting of cod increases weight yields of the products through both salting and rehydration, compared to other pre-salting methods, like brining only and pickling. This is interesting since salt content of the muscle exceeds 20% NaCl, in all procedures. Therefore, the dissimilarities in yield were presumed to depend on the degree of protein denaturation and aggregation as influenced by the different salting procedures. This hypothesis was studied and confirmed with the aid of SDS–PAGE and DSC-analysis. Higher water retention of injected products was explained by stronger salting-in effects on proteins during pre-salting, reducing aggregation of muscle proteins during the dry salting step. The degree of protein aggregation during salting increased in the following order with regard to the different pre-salting methods: injection and brining < brining < pickling. These effects were still observed after rehydration. Furthermore, differences in denaturation/aggregation were assigned to both myosin and collagen.

doi:10.1016/j.foodchem.2010.05.095


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