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State of the art in benefit–risk analysis: Food and nutrition

Benefit–risk assessment in food and nutrition is relatively new. It weighs the beneficial and adverse effects that a food (component) may have, in order to facilitate more informed management decisions regarding public health issues. It is rooted in the recognition that good food and nutrition can improve health and that some risk may be acceptable if benefit is expected to outweigh it. This paper presents an overview of current concepts and practices in benefit–risk analysis for food and nutrition. It aims to facilitate scientists and policy makers in performing, interpreting and evaluating benefit–risk assessments.

Historically, the assessments of risks and benefits have been separate processes. Risk assessment is mainly addressed by toxicology, as demanded by regulation. It traditionally assumes that a maximum safe dose can be determined from experimental studies (usually in animals) and that applying appropriate uncertainty factors then defines the ‘safe’ intake for human populations. There is a minor role for other research traditions in risk assessment, such as epidemiology, which quantifies associations between determinants and health effects in humans. These effects can be both adverse and beneficial. Benefit assessment is newly developing in regulatory terms, but has been the subject of research for a long time within nutrition and epidemiology. The exact scope is yet to be defined. Reductions in risk can be termed benefits, but also states rising above ‘the average health’ are explored as benefits. In nutrition, current interest is in ‘optimal’ intake; from a population perspective, but also from a more individualised perspective.

In current approaches to combine benefit and risk assessment, benefit assessment mirrors the traditional risk assessment paradigm of hazard identification, hazard characterization, exposure assessment and risk characterization. Benefit–risk comparison can be qualitative and quantitative. In a quantitative comparison, benefits and risks are expressed in a common currency, for which the input may be deterministic or (increasingly more) probabilistic. A tiered approach is advocated, as this allows for transparency, an early stop in the analysis and interim interaction with the decision-maker. A general problem in the disciplines underlying benefit–risk assessment is that good dose–response data, i.e. at relevant intake levels and suitable for the target population, are scarce.

It is concluded that, provided it is clearly explained, benefit–risk assessment is a valuable approach to systematically show current knowledge and its gaps and to transparently provide the best possible science-based answer to complicated questions with a large potential impact on public health.

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State of the Art in Benefit-risk Analysis: Introduction

Risk-taking is normal in everyday life if there are associated (perceived) benefits. Benefit-Risk Analysis (BRA) compares the risk of a situation to its related benefits and addresses the acceptability of the risk. Over the past years BRA in relation to food and food ingredients has gained attention. Food, and even the same food ingredient, may confer both beneficial and adverse effects. Measures directed at food safety may lead to suboptimal or insufficient levels of ingredients from a benefit perspective. In BRA, benefits and risks of food (ingredients) are assessed in one go and may conditionally be expressed into one currency. This allows the comparison of adverse and beneficial effects to be qualitative and quantitative. A BRA should help policy-makers to make more informed and balanced benefit-risk management decisions. Not allowing food benefits to occur in order to guarantee food safety is a risk management decision much the same as accepting some risk in order to achieve more benefits. BRA in food and nutrition is making progress, but difficulties remain. The field may benefit from looking across its borders to learn from other research areas. The BEPRARIBEAN project (Best Practices for Risk-Benefit Analysis: experience from out of food into food; http://en.opasnet.org/w/Bepraribean) aims to do so, by working together with Medicines, Food Microbiology, Environmental Health, Economics & Marketing-Finance and Consumer Perception. All perspectives are reviewed and subsequently integrated to identify opportunities for further development of BRA for food and food ingredients. Interesting issues that emerge are the varying degrees of risk that are deemed acceptable within the areas and the trend towards more open and participatory BRA processes. A set of 6 ‘state of the art’ papers covering the above areas and a paper integrating the separate (re)views are published in this volume.

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The composition of adult overwintering and juvenile aggregations of Atlantic cod (Gadus morhua L.) around Iceland using neutral and functional markers:  a statistical challenge

The collapse of marine fisheries worldwide has forced recognition of the fact that sustainable fisheries management cannot be achieved without a reasonable understanding of stock structure. Fisheries focusing on species that exhibit seasonal migrations between spawning and feeding grounds should consider the composition of feeding aggregations of presumed mixed origin. Using nine microsatellites and the Pan I locus, we assess the contribution of two previously described major spawning components of Icelandic cod Gadus morhua (southwest and northeast) to two large feeding and two large juvenile aggregations of presumed mixed origin and situated in the northwest and northeast of Iceland. The Bayesian approaches (STRUCTURE and BAYES) revealed that, with the exception of the juvenile samples collected in 2002 and 2003 in the northeast, most of the individuals originated from the southwest. These results confirmed that the Icelandic cod exhibit a complex biological pattern involving spawning site fidelity and migration to and from feeding aggregations. The sustainable management of the Icelandic cod is likely to be compromised if its complex dynamics is not properly integrated into fisheries management plans.

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Genetic structure of the Atlantic wolffish (Anarhichas lupus L.) at Icelandic fishing grounds : another evidence of panmixia in Iceland?

The stock structure of the Atlantic wolffish was investigated at Icelandic fishing grounds, using 16 microsatellite loci. Despite the potential of the Atlantic wolffish to exhibit genetic structure (lack of eggs/larval dispersal and adults are sedentary), none of the genetic tests applied in this study detected significant genetic differentiation among the contemporary samples as well as among the contemporary and archived samples. The results of this study therefore suggested a lack of genetic structure among the populations of Atlantic wolffish in Icelandic waters and temporal stability over a period of ∼10 years. These results are discussed in terms of biological characteristics of Atlantic wolffish, recent isolation of populations, and their application to sustainable fisheries management issues.

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Quality changes of fresh and frozen protein solutions extracted from Atlantic Cod (Gadus morhua) trim as affected by salt, cryoprotectants and storage time

Fish protein solutions were extracted from cod (Gadusmorhua) trim using the pH-shift process. Fresh and frozen stability of cod protein solutions (CPS) [at 3% protein, pH 7.9, and different levels of salt, with/without cryoprotectants (sucrose, sorbitol and polyphosphate)] stored for different times and temperatures were studied. The results indicated that the fresh CPS was spoiled microbiologically after 3 days of storage at +2°C. Viscosity (Brabander Unit) decreased in samples containing 3% and 5% salt and increased in samples containing 10 and 15% salt after 2 days of storage at +2°C. Viscosity of fresh samples containing 10% and 15% salt decreased with storage time. The expressible moisture and whiteness of fresh samples were not influenced by the storage time. Adding cryoprotectants to CPS containing 1.2, 3, 5 and 15% salt increased the water holding capacity (WHC) and decreased the expressible moisture. It also increased viscosity (BU) in samples containing 3 and 5% salt significantly after 14 weeks of storage at -24°C. The cryoprotectants had no significant effect on improving the whiteness of the samples. The storage time also increased the expressible moistureand decreased WHC in frozen samples. The most stable frozen samples were those with 5% salt and cryoprotectants followed by the samples with 3% salt and cryoprotectants.

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Quantitative and qualitative changes in added phosphates in cod (Gadus morhua) during salting, storage and rehydration

Phosphate blend can be used in salted cod processing to improve yields, water holding capacity and appearance of the final product. However, added phosphates are gradually degraded during processing and storage, leading to changes in functional properties of phosphates. The objective of the study was to monitor the quantitative and qualitative changes in added phosphates in cod during salting, storage and rehydration using ion chromatography (IC) and spectrophotometric analysis. The phosphates diffused into the fish muscle during brining but the phosphate content (mg P2O5/g sample) decreased again as liquid drained away from the muscle in the following dry salting step. Changes during six months storage of the dry salted products were minor. Further losses were observed during rehydration where the phosphates were washed out to levels lower than in the raw material.

The advantage of the IC method was the ability to separate and determine different soluble phosphate species in the fish muscle. The IC results showed that pyrophosphate (P2O7) and triphosphate (P3O10) were partly degraded into orthophosphate (PO4) during the storage period. Lower values were obtained for the total phosphate content by IC than with the spectrophotometric method, which explained by difference is sample preparation.

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Optimum feed formulation for turbot, Scophthalmus maximus (Rafinesque, 1810) in the grow-out phase

A dietary study was undertaken to test the effect of different protein and lipid levels in feed for turbot, Scophthalmus maximus (Rafinesque, 1810) in the grow-out phase (initial size 580 g). The experimental diets were formulated to contain 35 (LP), 42.5 (MP) and 50 (HP) % crude protein (CP), protein with a subsequent level of 15 (LL) and 25 (HL) % crude lipid (CL) for each protein level. Final weights and specific growth rates were significantly affected by the dietary treatments. Fish fed the low protein low lipid (LP/LL) diet displayed lower final mean weight compared to fish fed the high protein (HP/LL and HP/HL) diets. The overall SGR was higher in the HP/LL group compared to both low protein groups and the MP/LL group. The calculated feed conversion efficiency (FCE) demonstrated that turbot are able utilize high lipid feed efficiently and that lipids are essential when fish are fed diets with reduced amounts of protein. No clear relationship was found between CP content in feed and CP in fillet. CL in fillet were, however, affected by dietary CL, where fish fed the LP/HL and MP/HL diets had elevated levels of CL in fillet. The diets did not affect the texture properties of the fillet, whereas some differences were found regarding water holding capacity (WHC) and muscle pH in fillet. The present findings suggest that CP can be reduced by approximately 10% compared to current level in commercial feed without negative effects on growth. This will make production of a more cost efficient and less expensive feed for large turbot (> 500 g) possible.

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Temperature fluctuations and quality deterioration of chilled cod (Gadus morhua) fillets packaged in different boxes stored on pallets under dynamic temperature conditions

A study was carried out to evaluate temperature variation and quality deterioration of packaged cod fillets as influenced by the box type used and their position on pallets under dynamic temperature storage. Storage life of thermally abused fillets was compared to that of fillets stored at steady temperature. Thermal performance of fish boxes, made of corrugated plastic on one hand and expanded polystyrene on the other hand, was also compared. Fillet temperature at multiple positions on the pallets along with environmental temperature and humidity were monitored during storage. Differences in product temperature of up to 10.5 °C were recorded on the thermally abused pallets stored for 6.4 h at mean ambient temperature of 18.5 °C. A reduction in storage life of 1.5–3 days was observed depending on the box position on the abused pallets compared to steady temperature storage.

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Mathematical model for estimation of the three-dimensional unsteady temperature variation in chilled packaging

A mathematical model for heat transfer from surrounding environment to a single food package is developed. A simplified analytical solution for three-dimensional (3D) unsteady temperature distribution in the food package with rectangular geometry taking into account the ambient temperature is obtained. The model is developed to be used as an efficient tool for estimating the effects of temperature abuse on the food product inside a single packaging unit. The food product is considered to be a homogenous solid body. The packaging material and air inside the package are modeled using an effective heat transfer coefficient. The developed model is validated by a comparison with experimental results obtained for fresh haddock fillets in expanded polystyrene (EPS) boxes exposed to temperature abuse and by comparison with numerical results obtained by the commercial software FLUENT. A satisfactory agreement was obtained between the experimental and numerical results.

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Numerical modelling of temperature fluctuations of chilled and superchilled cod fillets packaged in expanded polystyrene boxes stored on pallets under dynamic temperature conditions

Temperature variations in cod fillets packaged in four levels of EPS boxes stored on pallets under thermal load were studied numerically and experimentally. In the experiment the fillet temperature along with environmental temperature were monitored at 39 positions on the pallets during 9-h dynamic temperature storage between 7 and 23 °C. A three-dimensional time-dependent heat transfer model was developed using the ANSYS FLUENT Computational Fluid Dynamics (CFD) software. The overall mean absolute error of the model was 0.3 °C and the maximum error obtained at a single position over the whole period was 2.4 °C. The model was further developed in order to simulate temperature evolution inside a fully loaded, 12-level pallet under the same dynamic temperature conditions as a four-level pallet studied before. The mean temperature after 9-h thermal load was 1.0 °C lower in the 12-level pallet but the maximum temperature evolution was similar in both pallets. Finally, the model was used to investigate the temperature-maintaining effect of superchilling fish before the thermal load.

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