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Currently, side-streams (e.g., head, backbone, tail, and intestines) generated in the fish processing industry often end up as low-value products for feed applications or even as waste. In order to upcycle such side-streams, they need to be preserved to avoid oxidative degradation of the lipids between the generation point and the valorization plant. In the cod filleting industry, three main solid side-streams: viscera, heads, and backbones, are obtained. Hence, this study aimed to identify the most efficient antioxidant for preserving the cod side-streams using a dipping-based strategy prior to pre-valorization storage at low temperatures (ice and frozen storage). The dipping solutions evaluated contained: (i) a lipophilic rosemary extract (0.05% and 0.2% in 0.9% NaCl), (ii) Duralox MANC (a mixture of rosemary extract, ascorbic acid, tocopherols, and citric acid; 2% in 0.9% NaCl), and (iii) NaCl (0.9%) w/w solution. One group was not dipped. No dipping and dipping in NaCl were included as controls. The results showed a positive effect of dipping with solutions containing antioxidants as measured by peroxide value (PV), TBA-reactive substances (TBARS), and sensory profiling, e.g., rancid odor. Moreover, the oxidative stability increased with decreased storage temperature. The cod side-streams were in general most efficiently preserved by Duralox MANC, followed by the lipophilic rosemary extract (0.2%), compared to no dipping and dipping in NaCl solution and the lower concentration of the lipophilic rosemary extract (0.05%). The efficiency of the antioxidant treatments was independent of the side-stream fraction and storage temperature. Thus, using antioxidant dipping combined with low temperature storage is an efficient preservation method for maintaining the quality of the lipids in cod solid side-streams during their pre-valorization storage.
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Antioxidantes , Solución Salina , Antioxidantes/farmacología , Temperatura , Cloruro de Sodio , Ríos , Lípidos , Estrés OxidativoRESUMEN
OBJECTIVE: The purpose of this study was to identify an effective lipid oxidation initiator which could predict, within 1 month, the long-term oxidative stability of a prototype skincare formulation. The main purpose was to find a potential initiator not to assess oxidation stability of the formulations. METHODS: Four initiators (below) were examined in three steps: Reaction kinetics using a Clark electrode (Oxygraph); Effect of adding an initiator on the product's physical and oxidative stability in prototype skincare formulations by visual observation, peroxide value and headspace GC-MS determination of volatile oxidation products; and Ability to differentiate unstable vs. stable prototype creams by initiator addition. The four initiators explored were: FeCl2 /H2 O2 , FeCl3 /ascorbic acid, 2,2'-Azobis(2,4-dimethylvaleronitrile) (AMVN) and 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH) RESULTS: In Oxygraph, the initiator systems FeCl2 /H2 O2 and FeCl3 /ascorbic acid were good accelerators of oxygen consumption. The addition of FeCl2 /H2 O2 to prototype formulations did not affect the physical stability. However, the addition of FeCl3 /ascorbic acid to prototype formulations resulted in phase separation and FeCl3 /ascorbic acid was therefore deemed unusable. Moreover, the addition of AAPH or AMVN resulted in an increased and decreased viscosity respectively. In the oxidation stability study, peroxide value increased significantly when AMVN was added. However, the peroxide value remained low for the other initiators and the control (no initiator). The secondary volatile oxidation product, butanal, increased most with the FeCl2 /H2 O2 addition. Three out of the four initiators did not have the ability to rank the stable and unstable formulations in accordance with the result obtained for volatile oxidation products after 42 days of storage at 20°C of formulations without initiator. Only, FeCl2 /H2 O2 was able to rank the formulations in accordance with the oxidative stability observed for volatile oxidation products after 42 days of storage. CONCLUSION: FeCl2 /H2 O2 showed potential as an initiator to predict the oxidative stability of skincare formulations, but more studies are needed to confirm the result in a broader range of products over a longer time.
OBJECTIF: Le but de cette étude était d'identifier un initiateur efficace de l'oxydation des lipides qui pourrait prédire, dans un délai d'1 mois, la stabilité oxydative à long terme d'une formulation prototype de soins pour la peau. Le principal objectif était de trouver un initiateur potentiel et non pas d'évaluer la stabilité à l'oxydation des formulations. MÉTHODES: Quatre initiateurs (ci-dessous) ont été évalués au cours de trois étapes: Cinétique de réaction à l'aide d'une électrode de Clark (Oxygraphe); Effet de l'addition d'un initiateur sur la stabilité physique et oxydative du produit dans des prototypes de formulations par observation visuelle de l'indice de peroxyde et détermination des produits d'oxydation volatiles par GC-MS - espace de tête; et Capacité à différencier les prototypes de crèmes instables des prototypes de crèmes stables par addition d'un initiateur. Les quatre initiateurs étudiés étaient : FeCl2 /H2 O2 , FeCl3 /acide ascorbique, 2,2'-azobis (2,4-diméthylvaléronitrile) (AMVN) et 2,2'-azobis (2-méthylpropionamidine), dichlorhydrate (AAPH) RÉSULTATS: Dans l'oxygraphe, les systèmes initiateurs FeCl2 /H2 O2 et FeCl3 /acide ascorbique étaient de bons accélérateurs de la consommation en oxygène. L'addition de FeCl2 /H2 O2 aux prototypes de formulations n'a pas eu d'impact sur la stabilité physique. Cependant, l'addition de FeCl3 /acide ascorbique aux prototypes de formulations a entraîné une séparation des phases et le système FeCl3 /acide ascorbique a donc été jugé inutilisable. De plus, l'addition d'AAPH ou d'AMVN a entraîné une augmentation et une diminution de la viscosité, respectivement. Dans l'étude de stabilité oxydative, l'indice de peroxyde a significativement augmenté lorsque l'AMVN a été ajouté. Cependant, l'indice de peroxyde est resté faible pour les autres initiateurs et le témoin (sans initiateur). L'augmentation la plus importante du produit d'oxydation volatile secondaire, le butanal, a été observée avec l'addition de FeCl2 /H2 O2 . Trois des quatre initiateurs n'ont pas permis de classer les formulations stables et instables d'après le résultat obtenu pour les produits d'oxydation volatiles après 42 jours de conservation à 20 °C des formulations sans initiateur. Seul FeCl2 /H2 O2 a été en mesure de classer les formulations conformément à la stabilité oxydative observée pour les produits d'oxydation volatiles après 42 jours de conservation. CONCLUSION: FeCl2 /H2 O2 a montré un potentiel comme initiateur pour prédire la stabilité oxydative de formulations de soins pour la peau, mais des études supplémentaires sont nécessaires pour confirmer le résultat sur une plus large gamme de produits et sur une plus longue période.
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Lípidos/química , Crema para la Piel/química , Cromatografía de Gases y Espectrometría de Masas , Cinética , Oxidantes/química , Oxidación-ReducciónRESUMEN
The objective of this study was to gain a better understanding of the multiple determinants to food satisfaction from a consumer perspective. The study includes two focus groups with a total of 20 consumers varying in gender, age, employment and food interest. The results were divided into sections based on the main themes that arose from analysing the focus groups; i) sensory properties, ii) physical wellbeing, iii) expectations and desires, iv) the food context and v) comparison of the importance of the various determinants to satisfaction. Factors important for food satisfaction appear before as well as during and after intake. Before intake, the important factors are; expectations and desires based on memories about previous food experiences and the context in which the food is perceived. Physical wellbeing was mentioned important for the feeling of satisfaction, included in physical wellbeing is the experience of an appropriate energy level after intake. In general the sensory experience seems to be the primary determinant to satisfaction. The hedonic experience of eating could be enhanced by the social company and knowledge about the food inclusive health value and origin. Findings from the study will prospectively be used to develop a questionnaire. The questionnaire will be applied in case studies to measure factors influential in food satisfaction.
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Comportamiento del Consumidor , Alimentos , Satisfacción Personal , Adolescente , Adulto , Anciano , Autoevaluación Diagnóstica , Femenino , Grupos Focales , Preferencias Alimentarias/psicología , Humanos , Relaciones Interpersonales , Masculino , Recuerdo Mental , Persona de Mediana Edad , Percepción , Investigación Cualitativa , Adulto JovenRESUMEN
Is being, say, a macaroon or a smoothie a matter of what these products look and taste like and how they feel in the mouth? Or is it a matter of which ingredients have been used and how they have been processed? Will ordinary consumers always rely on their own judgment in such matters, or delegate the final judgment to experts of some sort? The present experimental study addressed these issues in combination by testing the limits for consumers' acceptance of three different name-product combinations when exposed to taste samples alone (sensory product attributes), taste samples in combination with ingredients lists and nutrition facts (adding factual information), and both, in combination with authoritative definitions (adding experts' final judgments). The examples were modelled around authentic cases from the Danish food market which have been subject to vast legal as well as public concern. The results provide new insights into the socio-cognitive dynamics behind consumers' acceptance or rejection of specific name-product combinations and new leads for supporting the fairness of food naming practices with a view also to the product type, the stage it has reached in its life-cycle, and its degree of familiarity on the market.
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Comportamiento del Consumidor , Etiquetado de Alimentos , Terminología como Asunto , Adulto , Anciano , Femenino , Alimentos , Preferencias Alimentarias/psicología , Humanos , Masculino , Persona de Mediana Edad , Percepción Olfatoria , Encuestas y Cuestionarios , Gusto , Adulto JovenRESUMEN
For ages, indigenous small fish species have been important in food and nutritional security of poor communities in low income countries. Freshwater fish, in particular fatty fish species are attracting a great attention because they are good sources of health promoting long chain omega-3 fatty acids. Docosahexaenoic acid (DHA, C22:6n-3), Docosapentaenoic acid (DPA, C22:5n-3) and eicosapentaenoic acid (EPA, C20:5n-3) are the main omega-3 PUFAs known to confer health benefits in humans if consumed in required amounts. While nutritionally valued, omega-3 PUFAs in fish are susceptible to oxidative damage during processing, transportation and subsequent storage. Lake Victoria sardines (Rastrineobola argentea), are rich source of chemically unstable omega-3 fatty acids DHA, DPA and EPA. Traditionally, sardines are preserved by sun drying, deep frying and smoking. Sardine products are transported, stored and marketed at ambient temperatures. Generally, uncontrolled and higher temperatures are known to increase vulnerability of polyunsaturated fatty acids to oxidation which in turn results into loss of nutritional and sensory qualities. This study investigated changes of fat acids in sun dried, deep fried and smoked sardines during storage. Lipolysis and the progressive hydroperoxides formation were monitored by free fatty acids (FFAs) and peroxide value (PV) respectively. None volatile secondary products of lipid oxidation were measured by thiobabituric acid reactive substances (TBARS). Fatty acids were analyzed by gas chromatography with a flameionization detector (GC-FID). Deep fried sardines maintained the lowest and apparently stable PV, TBARS and FFAs. Proportions of saturated fatty acids and polyunsaturated fatty acids decreased with time while that of monounsaturated fatty acids increased. Omega-3 fatty acids EPA, DPA and DHA decreased with increase in storage time. In 21 days of storage, DHA was oxidized beyond detectable levels in all sardine products. Gradual increase in FFAs in sun dried sardines was suggestive of lipid hydrolysis induced by enzymes.
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An increasing demand for fish products has led to an intensive aquaculture production in Brazil, and cultivation of fish constituted 860 × 103 tons in 2022, contributing to the 87% of total fish consumption. Nile tilapia constitutes almost half of the aquaculture production, and most tilapia farms use floating net cages. One of the major constraints of intensive fish production is production of off-flavors. Release of nutrients by the fish leads to deterioration of the water quality and stimulates growth of microorganisms, also including off-flavor producing species. The objective of this study was to determine levels of taste and odor compounds (geosmin, 2-MIB and a selection of volatile compounds) and their impact on the flavor quality of Nile tilapia produced in net cages in reservoirs in São Paulo State, Brazil. GC-MS analysis of fish and water from six different farms showed concentrations of geosmin in the water from 1 to 8 ng/L, while geosmin in fish flesh ranged from 40 to 750 ng/kg. The level of 2-MIB in water was 2 to 25 ng/L, and 0 to 800 ng/kg fish. The GC-MS analysis also revealed presence of more than 100 volatile organic compounds in the fish flesh, consisting of aldehydes, alcohols, benzene derivatives, hydrocarbons, ketones and few other compounds. Geosmin and 2-MIB related flavor notes were detected in all fish by a sensory panel, and a high correlation between the chemical and sensory analyses was found. The potential impact of the volatile organic compounds on the fish flavor is discussed. Analysis of the water quality in the reservoirs indicated that levels of geosmin and 2-MIB levels were highly influenced by the nutrient levels in the water.
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Cíclidos , Compuestos Orgánicos Volátiles , Animales , Brasil , Naftoles/análisis , Naftoles/químicaRESUMEN
This work studies the emulsifying and antioxidant properties of potato protein hydrolysates (PPHs) fractions obtained through enzymatic hydrolysis of potato protein using trypsin followed by ultrafiltration. Unfractionated (PPH1) and fractionated (PPH2 as >10 kDa, PPH3 as 10-5 kDa, PPH4 as 5-0.8 kDa, and PPH5 as <0.8 kDa) protein hydrolysates were evaluated. Pendant drop tensiometry and dilatational rheology were applied for determining the ability of PPHs to reduce interfacial tension and affect the viscoelasticity of the interfacial films at the oil-water interface. Peptides >10 kDa showed the highest ability to decrease oil-water interfacial tension. All PPH fractions predominantly provided elastic, weak, and easily stretchable interfaces. PPH2 provided a more rigid interfacial layer than the other hydrolysates. Radical scavenging and metal chelating activities of PPHs were also tested and the highest activities were provided by the unfractionated hydrolysate and the fractions with peptides >5 kDa. Furthermore, the ability of PPHs to form physically and oxidatively stable 5% fish oil-in-water emulsions (pH 7) was investigated during 8-day storage at 20 °C. Our results generally show that the fractions with peptides >5 kDa provided the highest physicochemical stability, followed by the fraction with peptides between 5 and 0.8 kDa. Lastly, promising sensory results with mostly mild attributes were obtained even at protein concentration levels that are higher than needed to obtain functional properties. The more prominent attributes (e.g., bitterness and astringency) were within an acceptable range for PPH3 and PPH4.
RESUMEN
Sensory quality has a key influence of consumer perception of a product. It is therefore of great importance for the processing industry that the sensory quality fulfils the expectations of the consumer. Sensory evaluations are the ultimate tool to measure and communicate sensory quality, but it is generally not fully implemented in the chain from catch to consumer. The importance of communicating sensory demands and results from evaluations in the seafood processing chain is described and a Seafood Sensory Quality Model (SSQM) is suggested as a communication tool.
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Comportamiento del Consumidor , Etiquetado de Alimentos , Industria de Procesamiento de Alimentos , Modelos Económicos , Alimentos Marinos/análisis , Animales , Comportamiento del Consumidor/economía , Productos Pesqueros/análisis , Productos Pesqueros/economía , Peces , Industria de Procesamiento de Alimentos/economía , Humanos , Control de Calidad , Alimentos Marinos/economía , SensaciónRESUMEN
Since few foods are naturally rich in vitamin D, novel food products with a high content of vitamin D are needed to decrease the prevalence of vitamin D deficiency. Pork cracklings are Danish snacks with high contents of protein and fat. They are consumed mostly during wintertime when sun exposure cannot fulfil human needs for vitamin D3. Pork cracklings were produced in an industrially friendly manner from UVB LED illuminated pork rind, using a combination of sous vide (85 °C, 60 min) and roasting in the oven (200 °C, 20 min). Thermal processing resulted in a significant loss of vitamin D3 (>90%). Thus, the process was optimized by the UVB exposure of pork cracklings, i.e., after thermal processing. The produced pork cracklings had a vitamin D3 level of ~10 µg/100 g, with a possibility of tailoring its final content. Furthermore, the fat content at 15−20% was a reduction of 50% compared to marketed products in 2021. No significant difference was found in the content of vitamin D3 during 31 days of storage in the air. A consumer preference test (n = 53) indicated that >80% of participants liked the product and saw its potential as a new food source of vitamin D3.
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Enrichment of mayonnaise using delivery emulsions (DEs) containing 70% fish oil versus neat fish oil was investigated. DEs were produced with combined use of sodium caseinate, diacetyl tartaric acid esters of mono- and diglycerides (DATEM), and/or modified DATEMs with different length (C12 or C14) and covalently attached caffeic acid. Physical and oxidative stability of the mayonnaises were analyzed based on parameters including droplet size, viscosity, peroxide value, volatile compounds, and sensory properties. DEs addition to mayonnaise resulted in larger droplets and lower viscosity compared to neat fish oil. However, zeta potential was higher in mayonnaises with DEs containing DATEMs. Mayonnaise containing DATEM C14 had higher protein surface load leading to a thicker interfacial layer, lower formation of hexanal, (E)-2-hexenal, and (E)-2-heptenal as well as lower rancid odour intensity compared to mayonnaise containing DATEM and free caffeic acid, and thus benefitted from the location of the antioxidant at the interface.
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Condimentos , Diglicéridos/química , Emulsiones/química , Aldehídos/química , Antioxidantes/química , Ácidos Cafeicos/química , Caseínas/química , Condimentos/análisis , Aceites de Pescado/química , Almacenamiento de Alimentos , Humanos , Odorantes , Oxidación-Reducción , Tartratos/química , Gusto , Viscosidad , Compuestos Orgánicos Volátiles/análisis , Agua/químicaRESUMEN
Small indigenous fish species play a significant role in food and nutritional security of poor communities in developing countries. Sardines (Rastrineobola argentea) are fish species of Lake Victoria known to be a good source of health-promoting omega-3 fatty acids. Open sun drying is a common and traditional sardine processing and preservation method. Sun-dried products suffer from characteristic off-flavor due to lipid oxidation which discourage product consumption and limit diversification. This study investigated the use of clove (Syzygium aromaticum) and seaweed (Kappaphycus alvarezii) water extracts as natural antioxidants to impede lipid oxidation in sun-dried sardines. Lipid oxidation was assessed by peroxide value, volatile secondary oxidation products, and fatty acid profiles. The antioxidant capacity of extracts was evaluated by total phenolic content, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, and iron (Fe2+) chelating ability. Results showed that 5, 10, and 20 g/L clove extracts significantly reduced peroxidation in sun-dried sardines by 38.7%, 54.6%, and 56%, respectively. Clove extracts resulted in higher retention of omega-3 fatty acids and lower concentrations of secondary lipid oxidation products as opposed to seaweed counterpart. This research has demonstrated feasibility of pretreating whole, omega-3-rich small sardines with natural antioxidants to avert lipid oxidation during sun drying.
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Growth of Listeria monocytogenes in ready-to-eat fish products such as cold-smoked salmon is an important food safety issue. The objective of this study was to evaluate the antilisterial activity of potassium lactate (PL) in combination with sodium acetate (SA) or sodium diacetate (SDA) in cold-smoked salmon and to determine whether these compounds could be incorporated easily into the formulations and technology currently used by processors. A commercial brine injector was used to inject salmon filets with either saturated saline brine or saturated saline brine supplemented with combinations of PL and SA (PURASAL Opti. Form PA 4) or PL and SDA (PURASAL Opti. Form PD 4). In the brine-injected cold-smoked salmon, 2.1% (water phase) PL and 0.12% (water phase) SDA delayed the growth of L. monocytogenes for up to 42 days of vacuum-packaged storage at 10 degrees C. Storage at 25 degrees C for 6 h resulted in only a 1-log CFU/g increase in L. monocytogenes. Treatments with lower concentrations of PL and SDA or similar concentrations of PL and SA resulted in an extended lag phase and slower growth of L. monocytogenes. It was not possible to incorporate more than 2% (water phase) PL while ensuring a minimum of 3% (water phase) NaCl in the finished product because PL decreased the solubility of NaCl. Sensory analyses revealed that the preservatives did not negatively affect flavor or odor. The combination of PL and SDA is therefore a viable technology for preventing L. monocytogenes growth on cold-smoked salmon.
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Embalaje de Alimentos/métodos , Conservantes de Alimentos/farmacología , Listeria monocytogenes/efectos de los fármacos , Salmón/microbiología , Alimentos Marinos/microbiología , Gusto , Animales , Frío , Recuento de Colonia Microbiana , Seguridad de Productos para el Consumidor , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Microbiología de Alimentos , Conservación de Alimentos/métodos , Humanos , Lactatos/farmacología , Listeria monocytogenes/crecimiento & desarrollo , Acetato de Sodio/farmacología , Temperatura , Factores de Tiempo , VacioRESUMEN
UNLABELLED: Freezing of herring (Clupea harengus) for human consumption is increasing in the Nordic herring industry, either onboard the fishing vessels or right after landing. The quality of frozen herring as a raw material does not only depend on the frozen storage conditions applied, but also on compositional features, something which in turn can vary with season and catching ground. To unravel the link between biological variations, basic muscle composition, and sensory properties of frozen herring, a unique herring raw material was caught by commercial fishing vessels at three locations: around Iceland, outside the Norwegian coast, and in Kattegat/Skagerrak. The samplings were done according to a specific scheme and conducted over several seasons and 2 years. The herring was converted into butterfly fillets, packed in cardboard boxes, frozen, and then stored at -20 °C or -80 °C for up to 18 mo. The sensory quality was characterized by objective sensory profiling. It was shown that two generalized sensory variables could be defined from a principal component analysis of the sensory data. Except for the expected pronounced effect from storage time, the most distinct variation followed the lipid content, which in turn varied with season. An unexpected conclusion was that catching location only had a minor affect on the changes in sensory quality of herring during frozen storage. Knowledge about how season and catching location affect herring during frozen storage will be useful for optimizing the utilization of herring for frozen storage for human consumption. PRACTICAL APPLICATION: The results of this study constitute important information for the herring processing industry when handling raw materials with different geographical and seasonal history. The reported information on a highly equal sensory quality of geographically diverse raw materials will give consumers and retailers valuable knowledge on the changes in eating quality to expect after long-term frozen storage under conditions similar to household freezers or refrigerated counters in supermarkets.
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Almacenamiento de Alimentos/métodos , Congelación , Odorantes/análisis , Alimentos Marinos/análisis , Gusto , Animales , Peces/fisiología , Conservación de Alimentos/métodos , Humanos , Islandia , Noruega , Estaciones del AñoRESUMEN
Globally, aquaculture systems with water recirculation experience increasing problems with microbial taste and odor compounds (TOCs) such as geosmin and 2-methylisoborneol (MIB). This study investigated the content of geosmin and MIB in water and the flesh of 200 rainbow trouts from eight recirculated aquaculture systems in Denmark. TOC content in the fish flesh was measured by a dynamic headspace extraction method and was evaluated by a sensory panel. The results showed significant correlations between TOC content in water and fish and between chemical analysis and sensory perception. When geosmin exceeded 20 ng/L in the water, 96% of the fish had an intense muddy flavor, but below 10 ng geosmin/L, 18% of the fish (only 3% in special depuration ponds) had an intense muddy flavor. The results indicate that TOC levels <10 ng/L will ensure that a negligible portion of the fish obtains an unpalatable taste and flavor due to TOCs.
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Acuicultura/métodos , Canfanos/análisis , Carne/análisis , Naftoles/análisis , Oncorhynchus mykiss , Sensación , Animales , Dinamarca , Contaminación de Alimentos/análisis , Humanos , Odorantes/análisis , Gusto , Agua/químicaRESUMEN
The variation in sensory profile of rainbow trout (Oncorhynchus mykiss), belonging to the same aquaculture production batch and handled the same way, was explored by using objective sensory profiling on heat-treated minced fillets. In addition, quality index, mechanical texture, pH, fat, and water content were measured. Different groups of fish were sampled 3 different times during a production day. The results showed significant differences in the sensory profiles of individual fish within all 3 groups as well as significant differences between the groups. Differences in mechanical texture were found between individuals in 2 of the 3 groups and between the groups. No differences were found in quality index neither between individuals nor groups. A significant negative correlation between lipid content and firm texture was observed, but in general, the chemical and physical measurements could not explain the differences in the sensory profiling or in the mechanical texture measurements. The results showed that significant differences in the sensory profiles of individual fish from the same aquaculture production batch may occur. Furthermore, the results also showed sensory differences between groups of samples taken at different times during a production day.
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Odorantes/análisis , Oncorhynchus mykiss , Gusto , Animales , Acuicultura , Concentración de Iones de Hidrógeno , Lípidos/análisis , Agua/análisisRESUMEN
Rainbow trout ( Oncorhynchus mykiss ) were fed a diet containing either fish oil or rapeseed oil and with or without 200 mg/kg carotenoid (either astaxanthin or canthaxanthin). A total of six diets were obtained: (1) fish oil/astaxanthin; (2) vegetable oil/astaxanthin; (3) fish oil/canthaxanthin; (4) vegetable oil/canthaxanthin; (5) fish oil/no pigment; and (6) vegetable oil/no pigment. The fish were slaughtered and stored in polyethylene bags individually as butterfly fillets for up to 22 months at -20 °C. The composition of the fish muscle at slaughter and during frozen storage was evaluated by sampling after 4, 8, 13, 18, and 22 months. The carotenoid content in the muscle was found to be approximately 9-10 mg/kg of fish for both carotenoids. Primary oxidation lipid products (peroxides) as well as secondary oxidation products (volatiles) were measured. In addition, the level of protein carbonyl groups and the content of tocopherols and carotenoids in the muscle were also measured. To estimate the overall changes in sensory properties of the different samples during storage, a trained sensory panel also evaluated the samples. Both the sensory panel and the chemical analysis revealed that in this investigation fish fed fish oil were slightly more oxidized than fish fed vegetable oil. Results showed that canthaxanthin effectively protected both protein and lipid against oxidation during frozen storage. In contrast, astaxanthin did not seem to have a clear and systematic effect. Results indicated that the feed composition influenced the fish muscle composition and subsequently the oxidative stability of the fish during frozen storage. Besides, other constituents in the feed might influence deposition of antioxidants in the tissue and consequently affect the oxidative stability of the muscle.
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Dieta , Conservación de Alimentos , Congelación , Carne/análisis , Oncorhynchus mykiss , Animales , Carotenoides/administración & dosificación , Ácidos Grasos Monoinsaturados , Aceites de Pescado/administración & dosificación , Músculos/química , Oxidación-Reducción , Aceites de Plantas/administración & dosificación , Aceite de Brassica napusRESUMEN
BACKGROUND: During recent years, increases in liquid loss and soft texture in cold smoked salmon have been reported, possibly due to increased lipid content and a change in muscle structure. These problems can lead to downgrading of the product. This study aimed to investigate the influence of raw material composition and chill storage on quality parameters of cold smoked salmon. RESULTS: Initial smoked fish had a higher liquid-holding capacity (LHC) than samples stored for 20 days. Large fish lost more liquid than small fish. The difference in LHC was consistent with a change in water distribution, which could indicate denaturation of muscle protein. Studies of the microstructure showed the influence of both processing and chill storage. An indication of lipid released from the cells was seen after 20 days of chill storage, which could be related to the reduced LHC at that time. CONCLUSION: Both raw material composition and chill storage affected the quality parameters of smoked salmon. This study has improved knowledge about the relationships between muscle structure, liquid-holding properties and water distribution in smoked salmon. Copyright © 2007 Society of Chemical Industry.