Kristin Anna Thorarinsdottir

Changes in myofibrillar proteins during processing of salted cod (Gadus morhua) as determined by electrophoresis and differential scanning calorimetry

The effects of salt-curing, drying and rehydration on muscle proteins in cod (Gadus morhua) were studied during the processing of heavily salted cod or “bacalhau”. The aim was to observe conformational stability and possible degradation or denaturation, with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and differential scanning calorimetry (DSC). The salting process significantly decreased the heat stabilities of both myosin and actin. The decrease in water content during dry-salting did shift the transition temperatures slightly back to higher temperatures. The results, from the SDS-PAGE, showed that the myosin heavy chain (MHC) was cleaved into smaller sub fragments in the salting process with the two heavy meromyosin fractions (HMM S1 and S2) and the light meromyosin (LLM) fraction being the most abundant. Actin was less affected than myosin.

Flavor and quality characteristics of salted and desalted cod (Gadus morhua) produced by different salting methods.

Flavor characterization and quality of salt-cured and desalted cod (Gadus morhua) products was studied using sensory analysis and gas chromatography techniques. The products were produced in Iceland using two different processing methods (filleting and splitting) and three different salting procedures, i.e., the old single-step kench salting or a multistep procedure, and presalting (injection and brine salting or only brine salting), which was followed by kench salting. The main difference observed was between fillets and split fish, where the split fish was darker and had stronger flavor characteristics. Comparison of different salting procedures showed that the use of presalting improved the appearance of the salted products, which can be described as increased lightness and reduced yellowness of the products. In the same products, the intensity of curing flavors was milder, as described by sensory analysis and key aroma compounds. Derivatives from lipid and protein degradation contribute to the characteristic flavor of the salted products.

The Effects of Presalting Methods from Injection to Pickling, on the Yields of Heavily Salted Cod (Gadus morhua)

The production of heavy-salted cod (Bacalao) has changed from being a single-step process (kench) salting to a multistep procedure varying between producers and countries. Presalting by injection, brining, or pickling is increasingly applied prior to pile (dry) salting. This article describes the effects of different presalting methods (injection and brining, brining only, and pickling) on yield and chemical composition of salted cod fillets, in comparison to a single-kench salting step. The procedures used influenced the weight yields and chemical composition of the products. Injection was significantly different from other methods in increasing weight yields throughout brining, dry salting, and rehydration. The yield of nitrogenous compounds tended to be lower for injected and brine-salted fillets, mainly due to higher losses of nonprotein nitrogen. Practical Application: Salting procedures for cod have changed rapidly in recent years. Injection is increasingly used as a presalting method. It has been suggested to have strong effects on weight yields of salted cod products. This article describes the effects of injection on weight yields on products in salted, rehydrated, and cooked stage.

Effects of Different Temperatures on Storage Quality of Heavily Salted Cod (Gadus morhua)

The aim of this study was to compare the effects of different storage temperatures (+2°C, -4°C, -12°C, -18°C and -24°C) and time (0, 1, 3 and 6 weeks) on the quality of heavily salted cod. The color, water content, water holding capacity (WHC), cooking yield, total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) of the samples were determined. Results showed that the whiteness of the salted cod decreased slightly, whereas the yellow/orange color increased during the storage period. The WHC and cooking yield increased and were inversely related to water content. The TVB-N value increased slightly, whilst a lightly decrease in TMA value was observed. Storage at -4°C and lower temperatures had a detrimental influence on the color of the product which is the main quality criterion for salted cod. Therefore, it is not suitable to store the product at -4°C or lower temperatures.

The Effects of Light Salting on Physicochemical Characteristics of Frozen Cod (Gadus morhua) Fillets

Abstract The effects of light salting by brine injection and brine immersion on physicochemical and textural properties of cod fillets were evaluated. Light salting significantly increased yield and water holding capacity. Adding brine injection to the process can be used to shorten the process time needed to obtain the desired salt content and increase yield. The effects on chemical composition were most significant in salt content, but water and protein content were also affected. Water content decreased from the tail to head direction of the fillets, both in unsalted and light salted fillets. Changes in protein content were in opposite proportion to changes in water content. This could be seen in the fresh fish and also after freezing, both in unsalted and light salted fillets. Texture of the fish was not significantly affected by salting and freezing.

Development of Hermes, a new person-centered assessment tool in nursing rehabilitation, through action research

In this article, an action-research project has been outlined, aimed at exploring ways for developing an assessment tool, underpinned by phenomenology, which would enhance a person-centered approach to the participation of patients in nursing assessment and care planning in rehabilitation. Participants were nurses in physical rehabilitation and a consultant. Data were collected by interviews and observation of the documentation on the tool. The tool, Hermes, was adopted in practice. Through its use, important person-centered assessment practices were enhanced and several aspects of its phenomenological grounding were supported. Hermes has potential for facilitating the transfusion of phenomenology into nursing practice.

Lipid Degradation of Cod Liver During Frozen Storage as Influenced by Temperature, Packaging Method, and Seasonal Variation

ABSTRACT Lipid degradation of cod liver during frozen storage was studied, where the effects of storage temperatures (−18/−24°C), packaging methods (vacuum packing/regular plastic bag and waxed cardboard box), and seasonal variations (March/June/September) were evaluated. For this, the formations of free fatty acids (FFA) and peroxide value (PV) were analyzed. Lipid degradation within different parts of the liver (middle/surface) was also investigated. Increase in FFA and PV was observed for most of the samples throughout the frozen storage period. Vacuum packaging and lower storage temperature had a significantly stronger preservative effect on lipid degradation in all seasons. Higher FFA content was observed in cod liver captured in June than in its counterparts from September and March. More intense increase in PV was observed for liver collected in June compared to September. Furthermore, significant difference in PV was observed in different layers of the liver while FFA showed minimum variation between the surface and the middle part of the cod liver. Based on the present results, packaging method and storage temperature have a significant effect on lipid hydrolysis and oxidation in frozen cod liver.

Facilitation of a Person-Centered Approach in Health Assessment of patients with chronic pain: An Ethnographic Study:

A phenomenologically derived assessment tool, Hermes, was developed in a rehabilitation setting for adopting the central ideals of person-centered care and patient participation into health-assessment practices in nursing. This focused ethnographic study aimed at exploring the feasibility of using Hermes for enabling the application of these ideals into assessment of patients with chronic pain upon admission to a rehabilitation center. Participants were patients with chronic pain, enrolled in rehabilitation, and their nurses. Data were collected by participant observation and interviews, and analyzed by thematic analysis. By the use of Hermes, the impact of illness was explored through supportive connection and dialogue with open, reflective, and interpretative features; understanding of the illness situation was enhanced; and possibilities provided in adjusting to health issues of concern. In sum, Hermes facilitated person-centered participation of patients with chronic pain in their health assessment and made a phenomenological philosophy usable in nursing-assessment practices.

The Effects of Short‐Time Temperature Abuse on the Microbial and Sensory Quality of Chilled Saithe (Pollachius virens) Fillets

Chilled fish products are highly perishable with a limited shelf life (10 to 14 d). For this reason, the control of the cold chain for fish is essential. This study´s objective was to investigate the effects of short-time temperature abuse during processing on spoilage of chilled saithe (Pollachius virens) fillets. Analysis of microbial growth, freshness grades, and sensory score by Quality Index method, as well as pH, were carried out during a 10-d storage period at 2 ± 2 °C. Before storage, the fillets were kept at 16 °C for 0, 1, and 2 h. The results showed that spoilage of the fillets was accelerated with longer holding time at 16 °C. The 1- and 2-h holding before packing and storage caused a 22% (2 d) and 44% (4 d) loss of shelf life, respectively, compared to fillets that were packed immediately after processing. These findings indicate how bottlenecks and delays during processing may result in loss of microbial and sensory quality of chilled fish products. PRACTICAL APPLICATION The observations show the importance of maintaining a low temperature in fish, even for a short period such as during processing. Any delays, such as due to buffering or mechanical failure, may accelerate spoilage of chilled products during subsequent storage. This effect is even more pronounced when products are packed in bulk volumes as the cooling rate is much slower than the piece-by-piece cooling rate.

Effects of Injection of Protein Solutions Prepared from Fish By-products on Yield and Chemical Properties of Chilled and Frozen Saithe (Pollachius virens) Fillets

Fish gelatine and protein solutions prepared from saithe by-products were injected into saithe fillets. Effects on weight changes, water holding capacity, and chemical composition of the fillets were investigated after chilled (2, 5, and 7 days) and frozen (14 and 49 days) storage. The results showed that higher weight yields were obtained by adding proteins and salt to the fillets in comparison with only salt, especially in chilled fillets. The drawback of the injection was that higher drip losses were found during storage and thawing than for untreated fillets. Effects of injection on water content were only significant after 2 days of chilled storage, but differences leveled out after longer storage time and with freezing and thawing of the fillets. The procedure applied in this study seems to be promising for utilization of by-products such as trimmings as an ingredient in higher value products like fillets, in comparison to mince products.