Emilía Martinsdóttir

Quality Index Method (QIM) scheme developed for farmed Atlantic salmon (Salmo salar)

Abstract 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 seafoods. 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.

Application of Quality Index Method (QIM) Scheme and Effects of Short-Time Temperature Abuse in Shelf Life Study of Fresh Water Arctic Char (Salvelinus alpinus)

ABSTRACT 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.

Effect of brining, modified atmosphere packaging, and superchilling on the shelf life of cod (Gadus morhua) loins.

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.

Shelf life of air and modified atmosphere-packaged fresh tilapia (Oreochromis niloticus) fillets stored under chilled and superchilled conditions

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.

A model of fish consumption among young consumers

Purpose – The 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/approach – A 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.Findings – The 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...

Development of Quality Index Method (QIM) Scheme for Farmed Tilapia Fillets and Its Application in Shelf Life Study

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 (log 6 cfu/g) of the total. The scheme was modified at the end of the study to better characterize deskinned farmed tilapia fillets.

Consumer Preference and Description of Salmon in Four Northern Atlantic Countries and Association with Sensory Characteristics

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.

Blood pressure-lowering effects of long chain n-3 fatty acids from meals enriched with liquid fish oil and from microencapsulated powder

Abstract Background: 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. Methods: 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. Results: 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. Conclusion: 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.

Sensory analysis and consumer surveys of fat- and salt-reduced meat products and their use in an energy-reduced diet in overweight individuals

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.