Low salt brining of pre-rigor filleted farmed cod (Gadus morhua L.) and the effects on different quality parameters

Computed X-ray tomography (CT) was used to determine NaCl, water, and protein levels in dried salted cod. Cod fillets were salted and dried, and CT was conducted several times during the process. Also, homogenized cod samples with a chemical composition covering the typical composition of cod during salting and drying were produced, and CT scanned. Chemical composition of fillet and model samples was predicted from CT images acquired at 80, 110, and 130 kV. The best average prediction errors (RMSECV) obtained for homogenized samples were 0.6% NaCl, 1.3% water, and 1.5% protein; all explained variances were R2= 0.99 or above. The best RMSECVs and explained variances for cod fillet samples were 0.9% NaCl (R2= 0.96), 0.8% water (R2= 0.99), and 1.4% protein (R2= 0.79). Combining CT values from 2 or 3 voltages gave the best predictions except when predicting salt in cod fillet, where 1 voltage was sufficient.

Section: Resultsmentioning

confidence: 72%

Nondestructive Analysis of Salt, Water, and Protein in Dried Salted Cod using Computed Tomography

Håseth

Høy

Egelandsdal

et al. 2009

“…It is possible that samples injected with brine prerigor lose some of the injected salt with drip during the rigor process, resulting in an insignificant difference in salt content of the unbrined and brine injected prerigor farmed and wild cod samples. This is supported by the study of Larsen and others (2008) who showed that brining of prerigor filleted farmed cod resulted in increased rigor contraction, reduced fillet gaping, and less force needed to pull out pin bones with increasing salt concentration in the brine. The freezing process did not seem to have a significant effect on the water or salt contents of any of the samples, compared to the fresh samples on day 1 or 6.…”

Section: Resultsmentioning

confidence: 68%

Process Control of Lightly Salted Wild and Farmed Atlantic Cod (Gadus morhua) by Brine Injection, Brining, and Freezing—A Low Field NMR Study

Guðjónsdóttir

Gunnlaugsson²,

Finnbogadóttir³

et al. 2010

The aim of this study was to use low-field nuclear magnetic resonance (NMR) and traditional chemical methods to investigate the physical and chemical differences in wild and farmed cod processed pre- and postrigor, and how these properties were affected by brine injection, brining, and freezing. In prerigor processed farmed or wild cod, brine injections followed by brining for 2 d, with brine concentrations up to 5.5% and 4%, respectively, were not sufficient to reach a muscle salt concentration of 2% as aimed for, while wild cod processed postrigor had sufficient salt uptake after the same processing. Low-field NMR gave valuable information about the differences in the muscle structure between wild and farmed cod as well as the state of the water in the muscle during brine injection, brining, and during rigor tension. Low-field NMR is, therefore, a valuable tool that can be used to optimize the salting and storing processes of lightly salted cod products from both wild and farmed cod. For farmed cod to be used in the production of lightly salted products further research is needed. Practical Application: Optimal processing of lightly salted cod products is important to the fish industry, due to an increasing market for this product in southern Europe. Farmed cod, which is seen as a potential steady raw material source for this production, differs considerably from its wild counterparts by having other chemical and physical muscle properties, such as lower water content and lower pH. With the processing procedures used today the farmed cod can, therefore, only be used in some of the products, where wild cod is currently used as raw material. It is, therefore, important that the processing of these products is optimized with regard to these differences in the raw material. This study gives a valuable contribution to further studies about optimal combinations of brine injections, brining, and freezing of pre- and postrigor processed farmed compared to wild cod.

“…A substantial and instant contraction on the caudal‐cranial axis in pre‐rigor injection salted salmon fillets have been reported previously (Birkeland and others 2007; Akse and others 2008). Lauritzsen and others (2004) and Larsen and others (2008) have suggested that supply of salt to a fillet in a pre‐rigor state increases the depletion of available energy in the muscle and thus induce a rapid rigor contraction. During the 4 d storage after pre‐rigor filleting these fillets had already finished the shrinking, though far more slowly compared to the instant contraction of the pre‐rigor brine injected fillets.…”

Section: Resultsmentioning

confidence: 99%

Study of the Quality Characteristics in Cold‐Smoked Salmon (Salmo Salar) Originating from Pre‐ or Post‐Rigor Raw Material

Birkeland¹,

Akse²

2010

Improved slaughtering procedures in the salmon industry have caused a delayed onset of rigor mortis and, thus, a potential for pre-rigor secondary processing. The aim of this study was to investigate the effect of rigor status at time of processing on quality traits color, texture, sensory, microbiological, in injection salted, and cold-smoked Atlantic salmon (Salmo salar). Injection of pre-rigor fillets caused a significant (P<0.001) contraction (-7.9%± 0.9%) on the caudal-cranial axis. No significant differences in instrumental color (a*, b*, C*, or h*), texture (hardness), or sensory traits (aroma, color, taste, and texture) were observed between pre- or post-rigor processed fillets; however, post-rigor (1477 ± 38 g) fillets had a significant (P>0.05) higher fracturability than pre-rigor fillets (1369 ± 71 g). Pre-rigor fillets were significantly (P<0.01) lighter, L*, (39.7 ± 1.0) than post-rigor fillets (37.8 ± 0.8) and had significantly lower (P<0.05) aerobic plate count (APC), 1.4 ± 0.4 log CFU/g against 2.6 ± 0.6 log CFU/g, and psychrotrophic count (PC), 2.1 ± 0.2 log CFU/g against 3.0 ± 0.5 log CFU/g, than post-rigor processed fillets. This study showed that similar quality characteristics can be obtained in cold-smoked products processed either pre- or post-rigor when using suitable injection salting protocols and smoking techniques.