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The aim was to develop a Quality Index Method (QIM) scheme for fresh tilapia fillets and evaluate the scheme in a shelf life study. Farmed tilapia fillets were stored at 1 and −1°C for up to 20 days, and changes during storage were observed with sensory evaluation using the QIM scheme and General Descriptive Analysis (GDA), total viable counts (TVC), and hydrogen sulphide (H2S) producing bacteria. The maximum shelf life of fillets stored at1 and −1°C was determined with GDA and microbial counts as 16 and 19 days, respectively. A high correlation of R2 = 0.943 between Quality Index (QI) and storage time at 1C° was found to be 0.843 at −1°C. At the end of shelf life, the QI was 5.3 and 6.5 out of a maximum score of 15 for fillets stored at 1 and −1°C, respectively. Total viable counts and H2S-producing bacteria showed an increasing trend during storage time for both groups. At the end of shelf life, TVC was log 7 cfu/g in the flesh of both groups, with H2S producing bacteria constituting a higher proportion...

Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system (RAS) was filleted and packaged in 100% air and 50% CO2: 50% N2 modified atmosphere (MA) prior to storage at 1˚C and -1˚C for up to 27 days. Fillets were sampled regularly and analysed for headspace gas composition, sensory and microbial changes. Shelf life varied with apparent relation to storage temperature, package atmosphere and microflora. Pseudomonads were reported as the main spoilage organisms in tilapia fillets during chilled storage conditions. Sensory analysis of cooked samples as well as microbial growth indicated fillets packaged in 100% air had a shelf life of 13-15 days during storage at 1˚C and 20 days at -1˚C. At the end of shelf life in 100% air packaged groups, TVC and pseudomonads counts reached log 7 colony-forming units g-1 in flesh. Whereas in 50% CO2: 50% N2 packaged fillets, the lag phase and generation time of bacteria was extended and recorded counts of < log 4 colony-forming units g-1 up to 27 days of storage at both 1˚C and -1˚C. However, 50% CO2 : 50% N2 conditions restricted fillets shelf life to 23 days based on sensorial changes mainly fillets colour characteristics.

Diet plays an important role in the etiology of hypertension. Blood pressure (BP)-lowering properties of long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) are promising. The aim was to investigate whether different formulations of fish oil differently affect blood pressure in community-dwelling adults. The hypothesis was that fish oil formulations would improve BP in comparison with a placebo.In this 4-week randomized, placebo-controlled, doubly-blinded dietary intervention study, participants (N = 99, 50 years) from the capital area of Iceland were randomized into three groups. Group 1 (n = 38) received 6 meals/week fortified with a liquid fish oil and placebo powder. Group 2 (n = 30) received conventional (unfortified) meals and microencapsulated powder. Group 3 (n = 31) was the control group which received conventional meals and placebo powder. Calculated on a weekly basis, the amount of EPA + DHA provided was 1.5 g/d. Systolic (SBP) and diastolic BP (DBP) were measured before and after the intervention period.Seventy-seven subjects finished the study (77.8%). Drop-out rates were not different between groups. According to multivariate statistics, endpoint SBP was lower in Group 1 (-7.0 mmHg, p = 0.037) and in Group 2 (-7.2 mmHg, p = 0.037) as compared with Group 3. There was no significant difference in DBP between the groups.Our study shows that LC n-3 PUFA from microencapsulated powder are equally effective to meaningfully reduce SBP as LC n-3 PUFA from meals enriched with liquid fish oil in comparison with a control group.

Optimal packaging and storage conditions for fresh tilapia fillets were established by evaluating sensory and microbiological changes, as well as monitoring physicochemical properties. Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system was filleted, deskinned, and packaged in air and 50% CO2/50% N2 prior to chilling and superchilling storage at 1°C and -1°C. Sensory analysis of cooked samples revealed a shelf life of 13-15 days for air-packaged fillets during storage at 1°C and 20 days at -1°C. At the end of shelf life in air-packaged fillets, total viable counts (TVC) and pseudomonads counts reached log 8 colony-forming units (CFU) g(-1). In 50% CO2/50% N2-packaged fillets, the lag phase and generation time of bacteria were extended and recorded counts were below the limit for consumption (log 8 CFU g(-1)) after 23 days of storage at both 1°C and -1°C. However, modified atmosphere (MA) packaging negatively affected color characteristics of the fillets soon after packaging (day 6). Color is an important indicator of tilapia fillets quality and a major factor in influencing retail purchase decisions. In view of that, air packaged at -1°C storage temperature was the optimal condition for fresh tilapia fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) were not good indicators of spoilage of tilapia fillets in this study.

PurposeThe purpose of this study is to examine attitudes towards fish consumption, social pressure, fish preparation and cooking skills, sensory beliefs, health involvement and fish consumption in childhood as predictors of fish consumption among consumers in their early adulthood. While the impact of these factors on fish consumption has been examined in some extent among adult consumers, this is believed to be the first study where the focus is on people in their late teens and their early 20s.Design/methodology/approachA cross sectional sample of Icelanders between 17 and 26 years old (n=1,735) responded to a questionnaire. Structural equation modelling was used to estimate the direction and strength of relationships between variables.FindingsThe paper finds that attitude towards fish consumption, social pressure and fish preparation and cooking skills were correlated to fish consumption. Sensory beliefs and health involvement were also correlated to fish consumption, but this relationship was mediated by attitudes. Finally, there was a relationship between fish consumption in childhood and fish consumption but that relationship was mediated by sensory beliefs and attitude.Research limitations/implicationsThe number of external variables included in the model is limited and correlational methods were used to estimate the relationship between factors.Originality/valueThe decrease in fish consumption among young consumers is of concern. Understanding the role different variables play in their fish consumption habits can provide health authorities and managers in the fish industry with useful insights for strategies for increasing the intake of fish among young consumers.

This study investigated the applicability of a new photochromic time-temperature indicator (TTI) to monitor the quality and shelf life of fresh cod loins in retail packs at different storage conditions; also compared this automatic monitoring method with other methods of quality control, such as sensory, chemical and microbiological analyses; and with a shelf life prediction model. TTI placed on the bottom of the packs effectively reflected the temperature condition of the product. TTI with the initial square value of 61 was suitable for continuous monitoring of the quality and shelf life of the product repacked on day 6 after processing. The estimated product shelf lives based on TTI and on the square-root model for relative rate of spoilage of fresh seafood were well correlated.

Low field Nuclear Magnetic Resonance was used to evaluate the effect of salt and modified atmosphere packaging (MAP) on cod loins during superchilled storage. Transversal and longitudinal proton relaxation times of the cod loins were measured with Carr–Purcell–Meiboom–Gill (CPMG) and Inversion Recovery (IR) pulse sequences respectively. The relaxation parameters reflected the observed differences in the muscle caused by variation in salt concentration, the choice of salting method (brining or brine injection) and packaging (air or MAP), as well as superchilled storage temperature and storage time. Significant correlations were found between the NMR parameters and parameters describing the water dynamics of the muscle (moisture and salt content, water holding capacity, drip and cooking yield), as well as muscle pH and counts of H2S-producing bacteria in chosen sample groups. The study showed the possibility of using low field NMR to indicate fish quality deterioration, when the spoilage mechanisms affect the water properties and muscle structure.

An intervention study was conducted at early juvenile stage of Atlantic cod ( Gadus morhua L.) rearing to confirm the properties of two prospective probionts, Arthrobacter sp. and Enterococcus sp. isolated from a cod hatchery. Juveniles (10 g) were fed expanded dry feed for 28 or 55 days, either untreated or treated with the probiotic bacteria in mixture or singly (10 7–9 CFU g −1 feed). Viability of probionts supplemented to the feed was evaluated during a two-month storage at −20, 4 and 15 °C and sensory evaluation of the probiotic feed performed at the end of storage. Juvenile growth, survival, feed conversion ratio, and microbial load of rearing water, juvenile gills and gut were examined. Microbiological stability of the probionts added to the feed was demonstrated at all temperatures, while sensory evaluation detected faint oxidative off-odours in feed stored frozen. Juveniles fed the Enterococcus -probiotic feed grew significantly faster and had significantly lower gut Vibrio counts than control juveniles ( p Enterococcus strain, modified the gut microbiota and contributed to enhanced juvenile growth and survival.

Effective cooling of newly caught fish is of great importance to inhibit bacterial growth and therefore increase quality, safety and shelf life of the product. In this study, two commercial cooling media (liquid ice A and B) were tested and their performance was compared to conventional plate ice during chilled 8-day storage of whole, gutted haddock. Temperature was monitored, and deteriorative changes were followed by conventional microbiological counts [(total viable psychrotrophic; specific spoilage organisms and physicochemical methods (pH, TVB-N, TMA, salt content)]. A cultivation-independent method (16S rRNA clone analysis) was used to study the effect of cooling treatments on the bacterial community of haddock initially and at the end of storage. The results show that the bacterial growth behaviour observed for differently cooled fish was not supported by their temperature profiles. Growth of the SSOs, Photobacterium phosphoreum and H2S-producing bacteria was delayed at early storage, independently of the cooling methods. With further storage, little or no count differences were seen among traditionally iced fish and those cooled in liquid ice with a top ice layer. At the end of storage, significant (p

Sensory characteristics of cod products available to consumers were analyzed, and different ways to analyze sensory results were viewed. Ten cod samples of different origin (wild and farmed cod), storage time (short and extended) and storage method (stored fresh, frozen or packed in modified atmosphere) were evaluated with quantitative descriptive analysis by a trained sensory panel. Signal-to-noise analysis, p*MSE (discrimination and repeatability) and line plots proved to be very useful in studying panelists' performance. Most sensory attributes described significant differences between the products, and principal component analysis provided an overview of the differences and similarities between the products with regard to sensory characteristics. Farmed cod had different sensory characteristics compared with wild cod, such as more meat flavor, and rubbery and meaty texture. Different storage methods had minor influence on sensory characteristics of cod fillets after short storage time, but after extended storage, the groups were different with regard to most attributes. PRACTICAL APPLICATIONS This paper presents different ways of analyzing sensory data. The process of analysis of sensory results with focus on the panelists using a free program (PanelCheck) and signal-to-noise analysis was studied. The results showed that PanelCheck is a very user-friendly tool to monitor the performance of panelists and the study results of short-term projects. Signal-to-noise analysis proved to be more applicable for studying results of extensive data sets by handling missing values and estimating the significance of sensory attributes. The practical use of the paper is also a quantitative descriptive analysis vocabulary, which may be used as a basis for other studies with cod. It may also be a basis for sensory schemes for the fish industry in quality control and product development.

Fish protein isolate (FPI) made from haddock (Melanogrammus aeglefinus) cut-offs by the pH-shift process was added to haddock mince to make two groups of fried fish balls. The proportions (%) of mince to isolate were 100:0 (control group), 75:25 and 50:50. All groups were air packed and kept frozen at −18C. The sample groups were evaluated by sensory evaluation 1 day after processing and after 2, 4 and 8 weeks of storage at −18C. The results indicated that added FPI to mince and frozen storage affected the odor, flavor, texture and appearance of fish balls significantly, possibly because of chemical and biochemical changes of all groups. This study also revealed that most negative features are attributed to the groups containing 50% mince and 50% isolate. The results can be considered for product development of FPI. PRACTICAL APPLICATIONS Fish protein isolate from by-products is a new source of fish protein to produce ready-to-eat or value-added products. Little information has been published on product development about fish protein isolate and quality and sensory attributes of such products. Therefore, the results of this study could be useful for applying fish protein isolate to food systems.

Sensory characteristics of farmed cod exposed to low or conventional stress levels prior to slaughter were evaluated by a trained sensory panel. Consumers in two different settings, central location test (CLT) and home-use test (HUT), also tasted the products and rated them according to overall liking on a 9-point hedonic scale and sensory attributes on a 9-point intensity scale. Differences were observed in texture attributes of the two cod groups by the trained sensory panel. Consumers in the CLT distinguished between the two cod groups whereas consumers in the HUT setting did not. Consumers in the CLT scored the products lower with regard to liking, and evaluated sensory attributes differently from consumers in the HUT setting. The results indicated that the cooking method chosen by consumers in the HUT setting influenced the consumer evaluation of cod. Similar cooking methods used in CLT and HUT produced similar results of liking. PRACTICAL APPLICATIONS This paper presents a comparison of sensory evaluation carried out by a trained sensory panel and consumer evaluation of farmed fish. Cod produced with conventional and reduced stress prior to slaughter differed in texture attributes according to sensory evaluation. Information about consumer liking of the end-product when changing production systems of farmed fish is very important. The sensory evaluation by a trained panel provides good product knowledge, but to be able to estimate the actual consumer liking of the fish products, consumer studies are needed. The results indicated that a central location test (CLT) could be used to predict consumer acceptance in a real-life setting, given that similar cooking methods are used in both settings. Fish is a very perishable product, and its sensory quality depends very much on factors such as storage time and preparation. Therefore, CLT may be well suited for consumer testing of fish products.

Quantitative descriptive analysis (QDA) was used to analyse the sensory quality of eight cod products, different with regard to origin (wild/farmed), storage time (short/extended) and storage method (fresh/ frozen/packed in modified atmosphere). At the same time, 378 consumers in four European countries tasted and scored the cod products on a 9-point hedonic scale. In addition information on the consumers attitudes, motives/barriers and fish purchase behaviour was collected. The aim was to investigate how sensory quality corresponded to consumers liking of different cod products and to study the liking in terms of different consumer attitudes and demographics. The QDA discriminated well between the products. The farmed cod products were considerably different from wild cod, with more light and even colour, meaty texture, odour and flavour. Country differences were considerable with regard to fish consumption, attitudes and preferences of the eight cod products. However, it was demonstrated that within each country, different segments of consumers existed with different preferences, motives/barriers and demographic background. The results indicated various potential to increase fish consumption.

The focus in this article is on the relation between consumer preference and objective description of the product profile of salmon. A consumer study of eight salmon products was carried out in Iceland, Denmark, the Netherlands, and Ireland. In addition, objective sensory profiling using a trained sensory panel was performed on the products, which varied according to storage method, storage time, origin, and species. For five out of eight samples, no significant differences in overall liking between the countries were found in the consumer study. However, the consumers gave the samples significantly different descriptions. There was a strong correspondence between the consumer descriptions and the sensory profile.

Farmed arctic char were divided into two groups after slaughtering. One group (T1) was stored in ice up to 18 d and the other (T2) was stored at 18°C for 24 h (temperature increased from 3°C up to 12°C), then iced and stored up to 18 d. Changes during storage were observed with sensory evaluation using the Quality Index Method (QIM) and Quantitative Descriptive Analysis (QDA), total viable counts (TVC), and hydrogen sulphide (H2S)-producing bacteria. A high correlation between Quality Index (QI) and storage time in ice was found. Storage time could be predicted within ± 1.3 d. The maximum shelf life, determined with QDA and microbial counts, was 17 and 15 d, respectively, for iced (T1) and temperature-abused (T2) arctic char. At the end of shelf life, TVC was 105–106 CFU/g in the flesh of both groups, with H2S producing bacteria constituting a higher proportion of TVC in T2.

The aim was to develop and evaluate a Quality Index Method (QIM) scheme for fresh cod Wllets. Cod Wllets were stored at 0–1 °C on ice up to 14 days. Total viable counts (TVC) and counts of H2S-producing bacteria were done. A QIM scheme for fresh cod Wllets to evaluate freshness was proposed. A high correlation between the Quality Index (QI) and storage time on ice was found. The remaining storage time could be estimated with accuracy of §1.3 days when the cod Wllets were evaluated with QIM. The maximum storage time was estimated 8 days based on Quantitative Descriptive Analysis and H2S-producing bacteria counts. © 2005 Elsevier Ltd. All rights reserved.

To meet modern consumer demands, it is important to be able to offer “ready-to-use” desalted cod in consumer packs with sufficient keeping quality at chill temperatures. The aim of this work was to investigate the effect of potassium sorbate, citric acid, and modified atmosphere packaging (MAP) in varying combinations on the keeping quality of desalted cod fillets in consumer packs. After desalting, cod fillets were packed in trays and stored at 1.0 ± 0.2 °C for up to 33 d. The fillets were packed in open bags, in modified atmosphere (MA) (CO2/N2/O2:75/ 20/5) only, or in MS following a potassium sorbate and/or a citric acid treatment. The rate of microbial growth was by far fastest in fillets in open bags. MAP alone decreased the growth rate considerably and still further decrease was obtained in MAP fillets treated with citric acid and/or sorbate solutions. The concurrent effect of these treatments was distinct. Quantitative descriptive analysis (QDA) was used to assess cooked samples. During the 1st d of storage, the samples were described by sweet and butter odor, salt taste, clammy and rubberlike texture, which became less evident with increasing storage time, but differed by groups and the least in samples treated with sorbate and citric acid/sorbate solutions. Sensory spoilage attributes and total volatile bases (TVB-N)/trimethylamine (TMA) measurements correlated well with microbial counts. Use of MAP increased the shelf life from 6 to 10 d to 18 to 24 d, MAP and citric acid to 24 to 28 d, while the addition of sorbate to MAP fillets extended the shelf life to at least 33 d.

Characterization of the flavors of ripened roe products is of importance to establish a basis for a standardized product. Flavor profiles of commercially processed ripened roe from Iceland and Norway were studied by sensory analysis, gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC-MS), and an electronic nose to characterize the headspace of ripened roe. Sensory analysis showed that ripened roe odor and flavor in combination with caviar flavor and whey/caramel-like odor give the overall positive effect of the complex characteristic roe flavor. Analysis of volatiles by GC-MS and electronic nose confirmed the presence of aroma compounds contributing to the typical ripening and spoilage flavors detected by the sensory analysis. Methional, 1-octen-3-ol, and 2,6-nonadienal were the most important compounds contributing to ripened roe odor. Spoilage flavors were partly contributed by 3-methyl-1-butanol and 3-methylbutanal, which can be measured by the electronic nose and are suggested as quality indicators for objectively assessing the ripening of roe. Principal component analysis of the overall data showed that GC-O correlated well with sensory evaluation and the electronic nose measurements.

The aim of the study was to develop a Quality Index Method (QIM) scheme for raw, farmed Atlantic salmon ( Salmo salar ) and to evaluate the scheme in a shelf life study. QIM is based on the evaluation of key parameters in the deterioration of seafood's. Demerit points are assigned to selected parameters according to their importance and a Quality Index (QI) is established by cumulating the resulting scores. The maximum storage time in ice was determined with Quantitative Descriptive Analysis (QDA) of the salmon after cooking and found to be 20–21 days. This was used as a reference to enable prediction of the remaining storage time of raw salmon in ice with QIM. The calculated QI evolved linearly with storage time in ice (QI=0.82x (days in ice)+0.18, R 2 =0.97). Individual salmon varied in QI within each storage day. However, the multivariate analysis (PLS1) demonstrated that storage time could be predicted with an accuracy of±1. 5 days, assuming that five salmon from each batch were included in the QIM assessment.

The feasibility of enriching fish cakes with long chain omega-3 polyunsaturated fatty acids (n-3 LC-PUFAs) as a source of high quality lipids and seaweed extracts as a natural antioxidant was investigated. The LC-PUFAs were in the form of bulk cod liver oil and microencapsulated fish oil. The sensory quality and lipid oxidation were studied by means of chemical analysis, namely peroxide value (PV) and thiobarbituric acid reactive substances (TBARS), and sensory evaluation (descriptive analysis), throughout 28-days of refrigerate storage. In addition near-infrared (NIR) spectroscopy was assessed as a rapid tool to evaluate TBARS content. Omega-3 enriched samples showed slightly higher levels of lipid oxidation than the control samples but microencapsulation of fish oil seemed to protect PUFAs, leading to a lower content of peroxides and a lower rate of formation of secondary compounds during storage. Addition of seaweed extracts did not affect lipid oxidation nor the quality of the products as evaluated with descriptive analysis. No off-flavor was detected in any of the samples and low scores in rancid odor and flavor were registered.

Despite the potential benefits of long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs), intake is often low because of low consumption of oily seafood. Microencapsulated fish oil powder can improve tolerance and acceptance of LC n-3 PUFAs. Bioavailability is important to achieve efficacy. We investigated the bioavailability of LC n-3 PUFAs from microencapsulated powder in comparison with meals enriched with liquid fish oil.Participants (N=99, age⩾50 years) of this 4-week double-blinded dietary intervention were randomized into three groups. Group 1 (n=38) received 1.5 g/d eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as ready-to-eat meals enriched with liquid fish oil; group 2 (n=30) received the same amount of these LC n-3 PUFAs as microencapsulated fish oil powder and regular meals; and group 3 (n=31) was the control group, which received placebo powder and regular meals. Blood samples were taken from fingertips at baseline and at the end point.Seventy-seven subjects (77.8%) completed the study. The amount of EPA in blood doubled in both groups that received LC n-3 PUFAs (P0.05), but it did not change in the control group. The changes in DHA were less but still significant in both intervention groups. According to multivariate analysis, both intervention groups had higher end-point LC n-3 PUFA concentrations compared with placebo, but differences between intervention groups were not significant.Bioavailability of LC n-3 PUFAs in encapsulated powder is very similar to the bioavailability of LC n-3 PUFAs in ready-to-eat meals enriched with liquid fish oil. Thus, encapsulated powder can be considered useful to increase LC n-3 PUFA concentrations in blood.

Current work in a European concerted action project ‘Evaluation of Fish Freshness’ (AIR3 CT94-2283) focuses on harmonizing research activities in the area of fish freshness evaluation in leading fish laboratories in Europe (see Box 1). The overall aim of the concerted action project is to validate methods for the assessment of fish freshness and to discuss the freshness criteria for fish commercialized within the European Union. The project's participants are working in subgroups studying sensory analysis, microbiology, volatile compounds, proteins, lipids, adenosine triphosphate and physical measurements with respect to fish freshness evaluation. In this article, the different subgroups have summarized changes that occur in fish and methods to evaluate fish freshness as a first step towards the definition of criteria for fish freshness.

Meat and meat products are of high nutritional value; however, they frequently provide salt and fat in high amounts, which can have negative health effects when consumed in excess. We investigated salt- and fat-reduced meat products, i.e. sensory evaluation and consumer surveys were carried out as well as a dietary intervention study was carried out in overweight individuals who used salt- and fat-reduced products as a part of an energy-restricted diet. Although differences were detected in the sensory evaluation between reduced and regular meat products, the participants in the consumer surveys and in the dietary intervention study gave good ratings for the fat and fat-reduced meat products. The intervention study led to weight loss and improved cardiovascular risk, but did not reveal side effects associated with the consumption of these products. Our study indicates that such products are well accepted by potential consumers and can be included successfully in a weight loss programme.

The aim of these experiments was to evaluate the effect of brining, modified atmosphere packaging (MAP), and superchilling on the quality changes of cod loins as measured by microbial, sensory, and chemical analysis. Unbrined and brined (2.5 +/- 1.0% NaCl) cod loins were kept in styrofoam boxes (air) and under modified atmosphere (MA, CO(2)/O(2)/N(2): 50/5/45) at 0, -2, and -3.6 degrees C. Samples were examined over a 4-wk period. Total viable psychrotrophic counts and counts of H(2)S-producing bacteria reached higher numbers in the air-packed brined fish at -2 and -3.6 degrees C than in comparable unbrined groups, being significantly different (P < 0.05) at the lower temperature. However, lower counts of these bacteria were obtained in the brined MAP fish than in comparable unbrined fish. Counts of Photobacterium phosphoreum increased most rapidly in air- and MA-packed loins kept at 0 degrees C. Lower counts were found at superchilled temperatures. According to sensory analysis the shelf life of unbrined air-packed loins was about 11 d at 0 degrees C and 14 to 15 d at -2 degrees C. The shelf life of MA-packed unbrined loins was about 14 to 15 d at 0 degrees C but 21 d at -2 degrees C. Thus, synergism of combined superchilling (-2 degrees C) and MA led to a considerable shelf life increase for unbrined loins despite the fact that processing and packaging took place 4 to 5 d post-catch. The shelf life of air-packed brined loins at -2 degrees C was 12 to 15 d but only 13 d under MA. The same synergistic effect did therefore not apply to brined loins as with unbrined ones.

The proliferation of specific spoilage organisms (SSO) and quality changes were evaluated in haddock fillets stored in styrofoam boxes at 0, 7 and 15 degrees C and under temperature fluctuations. A rapid electronic nose technique was used to monitor different classes of compounds, representing microbial metabolites that were characteristic for the onset of spoilage odors. Photobacterium phosphoreum predominated among the spoilage bacteria and high levels of TVB-N were observed at sensory rejection. Pseudomonas spp. appeared to be responsible for the development of sweet, fruity spoilage odors in haddock fillets coinciding with increasing response of the electronic nose CO sensor. H(2)S-producing bacteria, most likely Shewanella putrefaciens, were associated with the H(2)S sensor's response at abusive temperature conditions. Partial Least Squares Regression (PLSR) was used as an explorative tool to provide a better understanding of the spoilage potential of SSOs, by evaluating models based on electronic nose responses and counts of specific spoilage organisms to predict sensory quality (Torry scores). The best prediction of the sensory quality was obtained by PLSR models based on five variables: the electronic nose sensors (CO, NH(3) and H(2)S), pseudomonads counts and a time-temperature variable. Good agreement between the predicted and experimental data indicates that these variables characterize the sensory quality of haddock fillets stored under different temperatures.

In this project tin oxide sensors are used to measure volatile aroma compounds of fish to evaluate fish freshness. Spoilage of fish kept in ice occurs because of microbial action on the flesh. Aroma changes during spoilage of fish are well recognized and organoleptic tests have traditionally been used to evaluate fish freshness. There is, however, a demand for methods to objectively measure fish aroma quality. Gas chromatography (GC) has been used to measure volatile compounds of fish, as these provide a means to define the chemical basis of seafood aromas, but GC is not suitable for high speed on-line applications. In the work reported here, a few aroma compounds that are produced during spoilage of fish were selected and the response of tin oxide sensors to them was measured. The response of the sensors to fish odours was also measured, initially by letting the fish deteriorate at room temperature, but later also under normal storage conditions in ice. Comparison was made with sensory evaluation and methods based on chemical and physical tests. So far the results have been encouraging but further tests have to be made under normal storage conditions.

The Handbook of Meat, Poultry and Seafood Quality commences with a discussion of basic scientific factors responsible for the quality of fresh, frozen and processed muscle foods, especially sensory attributes and flavors. Following sections discuss factors affecting the quality of beef, pork, poultry, and seafood. Under each muscle food, some or all of the following factors affecting the quality are discussed: additives; aroma; color; contaminants; flavors; microbiology; moisture; mouthfeel; nutrition; packaging; safety; sensory attributes; shelf-life; stability; tainting; texture; water activity. Editor Nollet heads a stellar editorial team and leads an international collection of over 60 expert contributors from government, industry, and academia in covering the key factors affecting the quality of beef, pork, poultry and fish and presenting them in a single source. [Book Synopsis]

Quality changes of aerobically packed cod fillets stored under superchilling and abusive temperature conditions were characterized by the growth of specific spoilage organisms (SSO) and the production of microbial metabolites measured by an electronic nose along with traditional sensory and chemical analysis (total volatile basic nitrogen [TVB-N], pH). A new process based on quick contact freezing and cold air blasting was used to achieve superchilling of fillets before chilled (0.5 °C) or superchilled (-1.5 °C) storage. Photobacterium phosphoreum dominated under temperature abusive conditions coinciding with high levels of TVB-N and increased electronic nose responses indicating increased levels of alcohols and aldehydes at sensory rejection. Dominating growth of Pseudomonas spp. in 1 batch was associated with the origin, the catching method, and the cooling conditions during processing. The superchilling process followed by superchilled storage (-1.5 °C) extended the sensory shelf life of the fillets for at least 3 d compared with traditional process, resulting in a total shelf life of 15 d. High content of TVB-N was observed in superchilled fillets at sensory rejection. P. phosphoreum counts were lower under superchilling conditions (6.0 to 6.8 log colony-forming units [CFU]/g), compared with the traditionally processed chilled fillets (7.2 log CFU/g). However, H2S-producing bacteria appeared to grow steadily under superchilling conditions reaching counts as high as 7.6 log CFU/g at sensory rejection.