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Santiago P Aubourg - One of the best experts on this subject based on the ideXlab platform.
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Desired section: Sensory and nutritive qualities of food
2020Co-Authors: Oscar Rodríguez, Santiago P Aubourg, Jorge Barros-velázquez, Professor Jorge Barros-velázquezAbstract:Short title: Extended shelf life of horse mackerel in Slurry Ice Horse mackerel shelf-life in Slurry Ice Slurry Ice, a biphasic system consisting of small spherical Ice crystals surrounded by seawater, was evaluated in parallel to flake Ice for the storage of horse mackerel (Trachurus trachurus). Storage in Slurry Ice implied a significant enhancement of the shelf life (5d for flake Ice to 15d for Slurry Ice), better control of pH value, and lower counts of total aerobes, proteolytic and lipolytic bacteria, these reaching average differences between batches of 2, 1.43 and 1.98 log units, respectively, after 8 d of Slurry Ice can be defined as a biphasic system consisting of small spherical Ice crystals suspended in Iced water at a temperature slightly above the initial freezing point of fish (0ºC to -2ºC). Among the main advantages of Slurry Ice, two should be highlighted: its faster chilling rate -due to its higher heat-exchange capacity-, and the limited physical damage that causes to fish food products -due to the spherical geometry of its microscopic Ice crystals-. Other advantages of Slurry Ice derive from its complete coverage of the fish surface, which affords a better protection of the fish surface with respect to oxidation and dehydration events. Slurry Ice can also be pumped, this guaranteeing a more hygienic handling of the fish products, and may be combined with other agents, such as ozone, to achieve an antiseptic surface effect, or melanosis inhibitors, to prevent browning reactions in shellfish (Huidobro and others 2002). Chapman (1990) reported a better maintenance of quality of finfish stored on-board in Slurry Ice as compared with other chilling methods, a result similar to that found for the on-board storage of albacore tuna by other authors (PrIce and others 1991). Harada (1991) also underlined the advantages of Slurry Ice as a pre-cooling method for fish. The scientific literature recently accounts for the use of Slurry Ice systems for the storage of Australian prawns (Chinivasagam and others 1998), and shrimp (Huidobro and others 2002). Other authors have also reported that Slurry Ice represents a good slaughter method to sacrifIce and store farmed seabream (Huidobro and others 2001). Horse mackerel is a medium-fat species abundant in Northeast Atlantic In this work we have applied an advanced Slurry Ice system to the storage of horse mackerel (Trachurus trachurus) during 22 d, and compared with a control batch stored in parallel in conventional flake Ice. With a view to investigating the shelf life of horse mackerel, here the effects of storage of horse mackerel in Slurry Ice on sensory and microbiological quality were investigated during 22 d. In addition, the isolation and identification of major bacteria involved in the proteolytic and lipolytic breakdown of horse mackerel muscle was also undertaken. Slurry Ice and flake Ice systems A Slurry Ice prototype (FLO-Ice, Kinarca S.A.U., Vigo, Spain) was used in the present work. The composition of the Slurry Ice binary mixture was 40% Ice and 60% water, prepared from filtered seawater (salinity: 3.3%). The temperature of the Slurry Ice mixture was -1.5ºC. Flake Ice was prepared with an Icematic F100 Compact devIce (CASTELMAC SPA, Castelfranco, Italy). Fish material, processing and sampling Specimens of horse mackerel (Trachurus trachurus) were caught during the day at a local fishing bank close to Northwestern Spain and kept on Ice until they arrived at our laboratory. The fish specimens were neither headed nor gutted. The length of the specimens was in the range of 16-21 cm; the weight was in the range of 230-270 g. The fish specimens were placed in either Slurry or flake Ice at a fish:Ice proportion of 1:1, and stored for up to 22 d in a refrigerated room at 2ºC. When required, the flake Ice and the Slurry Ice mixture were renewed. For each chilling treatment, three different batches were used and studied separately along the whole experimental period. Samples were taken from each batch on days 0, 2, 5, 8, 12, 15, 19 and 22. Once the intact specimens had been subjected to sensory analyses, the white muscle was separated and used for microbiological and chemical analyses; all analyses were performed in triplicate. Sensory analyses 6 Sensory analyses were conducted by a taste panel consisting of five experienced judges, according to the guidelines presented in Microbiological analyses Samples of 25 g of fish muscle were dissected aseptically from chilled horse mackerel specimens, mixed with 225 ml of 0.1% peptone water, and homogenised in a stomacher (Seward Medical, London, UK) as previously described others 1998, 1999). For assays at abusive temperatures, whole fish fillets were placed inside sterile bags and kept at 30ºC for 3 d before the fish extracts were prepared. In all cases, serial dilutions from the microbial extracts were prepared in 0.1% peptone water. Total aerobes were investigated in plate count agar (PCA, Oxoid Ltd., London, UK) after incubation at 31ºC for 72 h. Anaerobes were investigated in the same way, except that an anaerobic atmosphere kit (Oxoid) was placed together with the plates inside the anaerobiosis jar. Lactose-fermenting Enterobacteriaceae (coliforms) were investigated in Violet Red Bile Agar (VRBA medium, Merck, Darmstadt, Germany) after incubation at 30ºC±1ºC for 24±2 h, as recommended by the manufacturer (Merck Microbiology Manual, 2002). Microorganisms exhibiting a proteolytic phenotype were investigated in casein-agar medium (30ºC/48 h) (Phaff and others 1994), as previously described (Ben-Gigirey and others 2000). Bacterial colonies exhibiting a lipolytic phenotype were detected in tributyrine-agar medium, as described elsewhere (Ben-Gigirey and others 2000). Chemical analyses The evolution of pH values along the storage time was carried out using a 6-mm diameter insertion electrode (Crison, Barcelona, Spain). Total volatile base-nitrogen (TVB-N) values were measured according to Aubourg and others (1997). On it, fish muscle (10 g) is extracted with perchloric acid (6%) and made up to 50 ml, the TVB-N content being determined -after steam-distillation of the acid extracts rendered alkaline to pH 13 with NaOH (20%)-by titration of the distillate with 10 mM hydrochloric acid. The results are expressed as mg TVB-N/100 g muscle. Trimethylamine-nitrogen (TMA-N) values were obtained by the Tozawa and others (1971) method, which involves the preparation of a 5% trichloracetic acid extract of fish muscle (10 g/25 ml) and reaction with picric acid. Data are expressed as mg TMA-N/100 g muscle. RESULTS AND DISCUSSION Sensory analyses According to the results of the sensory analyses Quantitative microbiological analyses a Freshness categories are as expressed in Thus, the average numbers of coliforms throughout storage were very low (< 1 log CFU/g), no statistically significant (p<0.05) difference being observed between both batches, and neither with respect to the initial counts at day 0. Similar low numbers of anaerobes and coliforms had been obtained by Figueroa and others (1990) in jack mackerel. It should also be remarked that the counts of total aerobes, proteolytic and lipolytic bacteria, correlated well with the differences observed in the sensory evaluation, a result that also agreed with previous reports for shrimp (Huidobro and others 2002) Chemical analyses Statistically significant (p<0.05) differences were observed for the pH value in horse mackerel stored in Slurry Ice and flake Ice With respect to the P. penneri strains, two of them -P8 and P9-produced cisteine aryl amidase, showed a weak production of extracellular lipases and proteases and almost equivalent phenotypic profiles. Isolates L5, L7 and L8 of P. penneri did not produce cisteine aryl amidase and exhibited moderate proteolytic/moderate lipolytic activity. Finally, isolate L1 did not produce cisteine aryl amidase and exhibited very 24 strong proteolytic/weak lipolytic activity. Thus, at least three different P. penneri strains -P8, L5 and L1-were isolated from horse mackerel under abusive temperature conditions. Interestingly, all P. penneri strains isolated from horse mackerel also biosynthethized and secreted alkaline phosphatase, acid phosphatase, leucine aryl amidase, naphtol-phosphohydrolase and α-glycosidase
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improved microbial and sensory quality of clams venerupis rhomboideus oysters ostrea edulis and mussels mytilus galloprovincialis by refrigeration in a Slurry Ice packaging system
International Journal of Food Science and Technology, 2012Co-Authors: Minia Sanjuas Rey, Jose M Miranda, Santiago P Aubourg, Jorge BarrosvelazquezAbstract:Summary The aim of this work was to evaluate a Slurry Ice (SI) packaging system on three bivalve species: clams (Venerupis rhomboideus), oysters (Ostrea edulis) and mussels (Mytilus galloprovincialis). Comparative analyses were performed on specimens caught in autumn and spring and compared to batches stored in conventional flake Ice. Microbiological analysis of autumn specimens stored in SI showed significantly (P < 0.05) reduced numbers of mesophiles and psychrotrophs in all three species, as well as fewer Enterobacteriaceae in clams and oysters. Spring specimens also exhibited significantly (P < 0.05) lower microbial loads, with SI storage significantly (P < 0.05) improving the control of mesophiles, psychrotrophs and proteolytic bacteria in clams and oysters. Sensory analysis correlated well with microbial analyses, with a significantly (P < 0.05) better quality in terms of odour, taste, juiciness, appearance and shelf life. The SI packaging system evaluated in this work proved to be a valuable method for maintaining quality of these bivalve species.
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quality preservation in chilled and frozen fish products by employment of Slurry Ice and natural antioxidants
International Journal of Food Science and Technology, 2009Co-Authors: Isabel Medina, Jose Manuel Gallardo, Santiago P AubourgAbstract:Summary Fish products are known to provide high levels of constituents important for the human diet. At the same time, wild and farmed fish species are highly perishable products, the quality and freshness of which rapidly declines post-mortem. Accordingly, efficient storage and processing technologies need to be employed to reduce postmortem quality losses until the product reaches the consumer. The present review covers recent efforts carried out on some new and advanced strategies related to chilled and frozen storage. In the first part, research concerning the use of binary systems (Slurry Ice) is reviewed, this focussed on the commercialisation of fresh fish products as such or to its employment as raw material for processing. Then, the application of exogenous antioxidants to ensure retention of high quality is addressed; in this part, special attention is accorded to the endogenous antioxidant content retention and to the antioxidant/pro-oxidant balance in fish foods.
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changes in the flesh of cooked farmed salmon oncorhynchus kisutch with previous storage in Slurry Ice 1 5 c
Lwt - Food Science and Technology, 2008Co-Authors: Alicia Rodriguez, Nicolas Carriles, J M Cruz, Santiago P AubourgAbstract:Abstract Whole, farmed Coho salmon ( Oncorhynchus kisutch ) were sacrifIced in Slurry Ice (−1.5 °C) then stored in this medium for further processing after 0, 5 and 9 days. They were cooked whole and the flesh was evaluated by sensory, physical and chemical techniques to establish if significant changes had occurred as a result of the storage period. Initial samples from harvest were also evaluated for comparison. There was evidence of increases in trimethylamine, lipid hydrolysis, lipid oxidation (anisidine and thiobarbituric acid values) and interaction compound formation (fluorescence and browning measurements). The fish structure became more breakable with longer storage but there were no changes in sensory assessments for rancid and putrid odours, so that scores were less than 0.5 on a 11-point scale. From the present results, primary and secondary lipid oxidation development and further interaction compound formation appear to be the main measurable indicators of quality changes in cooked Coho salmon. However, and according to sensory appreciation, Slurry Ice has shown to be a suitable medium for previous storage of Coho salmon for periods of up to 9 days.
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rancidity development in frozen pelagic fish influence of Slurry Ice as preliminary chilling treatment
Lwt - Food Science and Technology, 2007Co-Authors: Vanesa Losada, Jorge Barrosvelazquez, Santiago P AubourgAbstract:Abstract The Slurry Ice technology has shown profitable advantages when employed instead of traditional flake Ice for the manufacture of chilled aquatic species. The present work is aimed at evaluating the effect of Slurry Ice as a preliminary treatment prior to frozen storage. For it, specimens of a small pelagic fatty fish species (sardine; Sardina pilchardus) were stored in Slurry Ice for 2, 5 and 9 days, then subjected to freezing (–80 °C; 24 h) and finally kept frozen (−20 °C) during 1, 2 and 4 months. At such times, rancidity development in frozen sardine was measured by sensory (odour, skin, colour and flesh appearance) and biochemical (lipid hydrolysis and oxidation) analyses and compared to a control batch previously chilled in flake Ice. Sensory analysis indicated an extended shelf-life time for frozen sardine that was preliminary stored under Slurry Ice for 2, 5 or 9 days, as compared to their counterparts subjected to flake icing. Sensory results were corroborated ( P 0.05 ) by biochemical lipid oxidation indIces (thiobarbituric acid reactive substances and the fluorescence formation). The present work opens the way to the use of Slurry Ice instead of flake Ice as preliminary treatment of fish material prior to the frozen storage.
Jorge Barrosvelazquez - One of the best experts on this subject based on the ideXlab platform.
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improved microbial and sensory quality of clams venerupis rhomboideus oysters ostrea edulis and mussels mytilus galloprovincialis by refrigeration in a Slurry Ice packaging system
International Journal of Food Science and Technology, 2012Co-Authors: Minia Sanjuas Rey, Jose M Miranda, Santiago P Aubourg, Jorge BarrosvelazquezAbstract:Summary The aim of this work was to evaluate a Slurry Ice (SI) packaging system on three bivalve species: clams (Venerupis rhomboideus), oysters (Ostrea edulis) and mussels (Mytilus galloprovincialis). Comparative analyses were performed on specimens caught in autumn and spring and compared to batches stored in conventional flake Ice. Microbiological analysis of autumn specimens stored in SI showed significantly (P < 0.05) reduced numbers of mesophiles and psychrotrophs in all three species, as well as fewer Enterobacteriaceae in clams and oysters. Spring specimens also exhibited significantly (P < 0.05) lower microbial loads, with SI storage significantly (P < 0.05) improving the control of mesophiles, psychrotrophs and proteolytic bacteria in clams and oysters. Sensory analysis correlated well with microbial analyses, with a significantly (P < 0.05) better quality in terms of odour, taste, juiciness, appearance and shelf life. The SI packaging system evaluated in this work proved to be a valuable method for maintaining quality of these bivalve species.
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evaluation of a Slurry Ice system for the commercialization of ray raja clavata effects on spoilage mechanisms directly affecting quality loss and shelf life
Lwt - Food Science and Technology, 2008Co-Authors: Begoña Múgica, Jorge Barrosvelazquez, Jose M MirandaAbstract:The application of Slurry Ice, a biphasic system formed by small spherical Ice crystals surrounded by seawater at sub-zero temperature, was evaluated as a new storage method for ray (Raja clavata), the elasmobranch fish species that exhibits highest commercial value in the European food markets. This advanced technique was used to compare with a control batch stored 10 days in flake Ice. The results obtained in the sensory analysis indicated a significant extension of the overall quality (A class fish) from 3 days (flake Ice) to 6 days (Slurry Ice). The development of ammonia external odour was the limiting parameter in both batches and was correlated with the activity of the endogenous mechanisms involved in the degradation of proteins and non-protein-nitrogen (NPN) rather than with the activity of proteolytic microorganisms. Storage of ray in Slurry Ice significantly (P<0.05) slowed down both biochemical (as estimated by the follow-up of the pH, TVB-N and K-value evolution) and microbial degradation mechanisms (estimated by the development of psychrotrophes and mesophiles counts) in chilled ray muscle. According to the parameters evaluated, storage of ray in Slurry Ice extends the shelf-life of this elasmobranch fish species due to a better maintenance of sensory, biochemical and microbiological quality, thus facilitating its commercialization.
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rancidity development in frozen pelagic fish influence of Slurry Ice as preliminary chilling treatment
Lwt - Food Science and Technology, 2007Co-Authors: Vanesa Losada, Jorge Barrosvelazquez, Santiago P AubourgAbstract:Abstract The Slurry Ice technology has shown profitable advantages when employed instead of traditional flake Ice for the manufacture of chilled aquatic species. The present work is aimed at evaluating the effect of Slurry Ice as a preliminary treatment prior to frozen storage. For it, specimens of a small pelagic fatty fish species (sardine; Sardina pilchardus) were stored in Slurry Ice for 2, 5 and 9 days, then subjected to freezing (–80 °C; 24 h) and finally kept frozen (−20 °C) during 1, 2 and 4 months. At such times, rancidity development in frozen sardine was measured by sensory (odour, skin, colour and flesh appearance) and biochemical (lipid hydrolysis and oxidation) analyses and compared to a control batch previously chilled in flake Ice. Sensory analysis indicated an extended shelf-life time for frozen sardine that was preliminary stored under Slurry Ice for 2, 5 or 9 days, as compared to their counterparts subjected to flake icing. Sensory results were corroborated ( P 0.05 ) by biochemical lipid oxidation indIces (thiobarbituric acid reactive substances and the fluorescence formation). The present work opens the way to the use of Slurry Ice instead of flake Ice as preliminary treatment of fish material prior to the frozen storage.
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improvement of the commercial quality of chilled norway lobster nephrops norvegicus stored in Slurry Ice effects of a preliminary treatment with an antimelanosic agent on enzymatic browning
Food Chemistry, 2007Co-Authors: Santiago P Aubourg, Jose M Miranda, Vanesa Losada, Marta Prado, Jorge BarrosvelazquezAbstract:Abstract The use of Slurry Ice is gaining increasing importance as an advanced method for the hygienic and efficient chilling and sub-zero storage of aquatic food products. In this work, this technology was applied as a novel technique for the chilling and storage of Norway lobster ( Nephrops norvegicus ) – a crustacean species of high-commercial value – under refrigeration conditions at −1.5 °C. In addition, the effects of a preliminary treatment with 0.5% Na HSO 3 on surface browning were evaluated and compared with the results obtained in control batches not subjected to such treatment. The processing of lobster in Slurry Ice significantly ( p Enterobacteriaceae , and by the formation of volatile amines. Likewise, the autolytic breakdown mechanisms – as determined by the K value – were also significantly ( p
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evaluation of an ozone Slurry Ice combined refrigeration system for the storage of farmed turbot psetta maxima
Food Chemistry, 2006Co-Authors: Vanesa Losada, Oscar Rodríguez, Santiago P Aubourg, Carmen Adriana Campos, Jorge BarrosvelazquezAbstract:Fil: Campos, Carmen Adriana. Universidad de Santiago de Compostela; Espana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
Vanesa Losada - One of the best experts on this subject based on the ideXlab platform.
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rancidity development in frozen pelagic fish influence of Slurry Ice as preliminary chilling treatment
Lwt - Food Science and Technology, 2007Co-Authors: Vanesa Losada, Jorge Barrosvelazquez, Santiago P AubourgAbstract:Abstract The Slurry Ice technology has shown profitable advantages when employed instead of traditional flake Ice for the manufacture of chilled aquatic species. The present work is aimed at evaluating the effect of Slurry Ice as a preliminary treatment prior to frozen storage. For it, specimens of a small pelagic fatty fish species (sardine; Sardina pilchardus) were stored in Slurry Ice for 2, 5 and 9 days, then subjected to freezing (–80 °C; 24 h) and finally kept frozen (−20 °C) during 1, 2 and 4 months. At such times, rancidity development in frozen sardine was measured by sensory (odour, skin, colour and flesh appearance) and biochemical (lipid hydrolysis and oxidation) analyses and compared to a control batch previously chilled in flake Ice. Sensory analysis indicated an extended shelf-life time for frozen sardine that was preliminary stored under Slurry Ice for 2, 5 or 9 days, as compared to their counterparts subjected to flake icing. Sensory results were corroborated ( P 0.05 ) by biochemical lipid oxidation indIces (thiobarbituric acid reactive substances and the fluorescence formation). The present work opens the way to the use of Slurry Ice instead of flake Ice as preliminary treatment of fish material prior to the frozen storage.
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improvement of the commercial quality of chilled norway lobster nephrops norvegicus stored in Slurry Ice effects of a preliminary treatment with an antimelanosic agent on enzymatic browning
Food Chemistry, 2007Co-Authors: Santiago P Aubourg, Jose M Miranda, Vanesa Losada, Marta Prado, Jorge BarrosvelazquezAbstract:Abstract The use of Slurry Ice is gaining increasing importance as an advanced method for the hygienic and efficient chilling and sub-zero storage of aquatic food products. In this work, this technology was applied as a novel technique for the chilling and storage of Norway lobster ( Nephrops norvegicus ) – a crustacean species of high-commercial value – under refrigeration conditions at −1.5 °C. In addition, the effects of a preliminary treatment with 0.5% Na HSO 3 on surface browning were evaluated and compared with the results obtained in control batches not subjected to such treatment. The processing of lobster in Slurry Ice significantly ( p Enterobacteriaceae , and by the formation of volatile amines. Likewise, the autolytic breakdown mechanisms – as determined by the K value – were also significantly ( p
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Development of different damage pathways in Norway lobster (Nephrops norvegicus) stored under different chilling systems
Journal of the Science of Food and Agriculture, 2006Co-Authors: Vanesa Losada, Jose M Miranda, Oscar Rodríguez, Jorge Barros-velázquez, Santiago P AubourgAbstract:Slurry Ice is a biphasic system that has recently shown a number of advantages when employed as a chilling medium for fish species. Its use for a crustacean species of high commercial value, Norway lobster (Nephrops norvegicus), was evaluated in parallel with traditional flake icing. Quality parameters related to microbial spoilage and biochemical breakdown (aerobe and psychrotroph counts, pH, K value, total volatile amines, trimethylamine, free fatty acids and non-enzymatic browning reactions) were assessed and compared with sensory (carapace, eyes, gills, odour and flesh) acceptability. Storage in Slurry Ice produced a significant (P < 0.05) inhibitory effect on both microbial growth (as determined by aerobes, psychrotrophs and volatile amines) and autolysis breakdown (as determined by K values and the release of free fatty acids) in comparison with the flake Ice batch. In contrast, an enhancement effect of Slurry Ice on carapace browning was observed as a result of enzymatic browning development. Slurry Ice batch also showed a more intense non-enzymatic browning reaction in the lipid extract of the edible flesh. With a view to limiting both browning effects, the incorporation of an anti-melanosis agent in the liquid phase of the Slurry Ice system is envisaged. Copyright © 2006 Society of Chemical Industry
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evaluation of an ozone Slurry Ice combined refrigeration system for the storage of farmed turbot psetta maxima
Food Chemistry, 2006Co-Authors: Vanesa Losada, Oscar Rodríguez, Santiago P Aubourg, Carmen Adriana Campos, Jorge BarrosvelazquezAbstract:Fil: Campos, Carmen Adriana. Universidad de Santiago de Compostela; Espana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
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effect of previous Slurry Ice treatment on the quality of cooked sardine sardina pilchardus
European Food Research and Technology, 2006Co-Authors: Vanesa Losada, Jorge Barrosvelazquez, José M. Gallardo, Santiago P AubourgAbstract:The use of Slurry Ice was evaluated as a technological treatment prior to cooking processing of fish. Thus, sardine (Sardina pilchardus) was stored in Slurry Ice for 2, 5 and 8 days. At such times, sardine specimens were taken and subjected to steam cooking, and the results were compared with those from a parallel control batch previously stored in flake Ice. Quality assessment of lipid damage in cooked fish was performed by measuring the formation of free fatty acids, peroxides, thiobarbituric acid-reactive substances and interaction compounds. The volatile amines–total and trimethylamine–assessment was also carried out. A significant (p<0.05) inhibition of lipid damage–peroxides and fluorescent compounds assessment–and trimethylamine formation was observed in cooked sardine as a consequence of the preliminary treatment in Slurry Ice. This work opens the way to the use of Slurry Ice as a preliminary treatment of fish material prior to its thermal processing.
Oscar Rodríguez - One of the best experts on this subject based on the ideXlab platform.
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Desired section: Sensory and nutritive qualities of food
2020Co-Authors: Oscar Rodríguez, Santiago P Aubourg, Jorge Barros-velázquez, Professor Jorge Barros-velázquezAbstract:Short title: Extended shelf life of horse mackerel in Slurry Ice Horse mackerel shelf-life in Slurry Ice Slurry Ice, a biphasic system consisting of small spherical Ice crystals surrounded by seawater, was evaluated in parallel to flake Ice for the storage of horse mackerel (Trachurus trachurus). Storage in Slurry Ice implied a significant enhancement of the shelf life (5d for flake Ice to 15d for Slurry Ice), better control of pH value, and lower counts of total aerobes, proteolytic and lipolytic bacteria, these reaching average differences between batches of 2, 1.43 and 1.98 log units, respectively, after 8 d of Slurry Ice can be defined as a biphasic system consisting of small spherical Ice crystals suspended in Iced water at a temperature slightly above the initial freezing point of fish (0ºC to -2ºC). Among the main advantages of Slurry Ice, two should be highlighted: its faster chilling rate -due to its higher heat-exchange capacity-, and the limited physical damage that causes to fish food products -due to the spherical geometry of its microscopic Ice crystals-. Other advantages of Slurry Ice derive from its complete coverage of the fish surface, which affords a better protection of the fish surface with respect to oxidation and dehydration events. Slurry Ice can also be pumped, this guaranteeing a more hygienic handling of the fish products, and may be combined with other agents, such as ozone, to achieve an antiseptic surface effect, or melanosis inhibitors, to prevent browning reactions in shellfish (Huidobro and others 2002). Chapman (1990) reported a better maintenance of quality of finfish stored on-board in Slurry Ice as compared with other chilling methods, a result similar to that found for the on-board storage of albacore tuna by other authors (PrIce and others 1991). Harada (1991) also underlined the advantages of Slurry Ice as a pre-cooling method for fish. The scientific literature recently accounts for the use of Slurry Ice systems for the storage of Australian prawns (Chinivasagam and others 1998), and shrimp (Huidobro and others 2002). Other authors have also reported that Slurry Ice represents a good slaughter method to sacrifIce and store farmed seabream (Huidobro and others 2001). Horse mackerel is a medium-fat species abundant in Northeast Atlantic In this work we have applied an advanced Slurry Ice system to the storage of horse mackerel (Trachurus trachurus) during 22 d, and compared with a control batch stored in parallel in conventional flake Ice. With a view to investigating the shelf life of horse mackerel, here the effects of storage of horse mackerel in Slurry Ice on sensory and microbiological quality were investigated during 22 d. In addition, the isolation and identification of major bacteria involved in the proteolytic and lipolytic breakdown of horse mackerel muscle was also undertaken. Slurry Ice and flake Ice systems A Slurry Ice prototype (FLO-Ice, Kinarca S.A.U., Vigo, Spain) was used in the present work. The composition of the Slurry Ice binary mixture was 40% Ice and 60% water, prepared from filtered seawater (salinity: 3.3%). The temperature of the Slurry Ice mixture was -1.5ºC. Flake Ice was prepared with an Icematic F100 Compact devIce (CASTELMAC SPA, Castelfranco, Italy). Fish material, processing and sampling Specimens of horse mackerel (Trachurus trachurus) were caught during the day at a local fishing bank close to Northwestern Spain and kept on Ice until they arrived at our laboratory. The fish specimens were neither headed nor gutted. The length of the specimens was in the range of 16-21 cm; the weight was in the range of 230-270 g. The fish specimens were placed in either Slurry or flake Ice at a fish:Ice proportion of 1:1, and stored for up to 22 d in a refrigerated room at 2ºC. When required, the flake Ice and the Slurry Ice mixture were renewed. For each chilling treatment, three different batches were used and studied separately along the whole experimental period. Samples were taken from each batch on days 0, 2, 5, 8, 12, 15, 19 and 22. Once the intact specimens had been subjected to sensory analyses, the white muscle was separated and used for microbiological and chemical analyses; all analyses were performed in triplicate. Sensory analyses 6 Sensory analyses were conducted by a taste panel consisting of five experienced judges, according to the guidelines presented in Microbiological analyses Samples of 25 g of fish muscle were dissected aseptically from chilled horse mackerel specimens, mixed with 225 ml of 0.1% peptone water, and homogenised in a stomacher (Seward Medical, London, UK) as previously described others 1998, 1999). For assays at abusive temperatures, whole fish fillets were placed inside sterile bags and kept at 30ºC for 3 d before the fish extracts were prepared. In all cases, serial dilutions from the microbial extracts were prepared in 0.1% peptone water. Total aerobes were investigated in plate count agar (PCA, Oxoid Ltd., London, UK) after incubation at 31ºC for 72 h. Anaerobes were investigated in the same way, except that an anaerobic atmosphere kit (Oxoid) was placed together with the plates inside the anaerobiosis jar. Lactose-fermenting Enterobacteriaceae (coliforms) were investigated in Violet Red Bile Agar (VRBA medium, Merck, Darmstadt, Germany) after incubation at 30ºC±1ºC for 24±2 h, as recommended by the manufacturer (Merck Microbiology Manual, 2002). Microorganisms exhibiting a proteolytic phenotype were investigated in casein-agar medium (30ºC/48 h) (Phaff and others 1994), as previously described (Ben-Gigirey and others 2000). Bacterial colonies exhibiting a lipolytic phenotype were detected in tributyrine-agar medium, as described elsewhere (Ben-Gigirey and others 2000). Chemical analyses The evolution of pH values along the storage time was carried out using a 6-mm diameter insertion electrode (Crison, Barcelona, Spain). Total volatile base-nitrogen (TVB-N) values were measured according to Aubourg and others (1997). On it, fish muscle (10 g) is extracted with perchloric acid (6%) and made up to 50 ml, the TVB-N content being determined -after steam-distillation of the acid extracts rendered alkaline to pH 13 with NaOH (20%)-by titration of the distillate with 10 mM hydrochloric acid. The results are expressed as mg TVB-N/100 g muscle. Trimethylamine-nitrogen (TMA-N) values were obtained by the Tozawa and others (1971) method, which involves the preparation of a 5% trichloracetic acid extract of fish muscle (10 g/25 ml) and reaction with picric acid. Data are expressed as mg TMA-N/100 g muscle. RESULTS AND DISCUSSION Sensory analyses According to the results of the sensory analyses Quantitative microbiological analyses a Freshness categories are as expressed in Thus, the average numbers of coliforms throughout storage were very low (< 1 log CFU/g), no statistically significant (p<0.05) difference being observed between both batches, and neither with respect to the initial counts at day 0. Similar low numbers of anaerobes and coliforms had been obtained by Figueroa and others (1990) in jack mackerel. It should also be remarked that the counts of total aerobes, proteolytic and lipolytic bacteria, correlated well with the differences observed in the sensory evaluation, a result that also agreed with previous reports for shrimp (Huidobro and others 2002) Chemical analyses Statistically significant (p<0.05) differences were observed for the pH value in horse mackerel stored in Slurry Ice and flake Ice With respect to the P. penneri strains, two of them -P8 and P9-produced cisteine aryl amidase, showed a weak production of extracellular lipases and proteases and almost equivalent phenotypic profiles. Isolates L5, L7 and L8 of P. penneri did not produce cisteine aryl amidase and exhibited moderate proteolytic/moderate lipolytic activity. Finally, isolate L1 did not produce cisteine aryl amidase and exhibited very 24 strong proteolytic/weak lipolytic activity. Thus, at least three different P. penneri strains -P8, L5 and L1-were isolated from horse mackerel under abusive temperature conditions. Interestingly, all P. penneri strains isolated from horse mackerel also biosynthethized and secreted alkaline phosphatase, acid phosphatase, leucine aryl amidase, naphtol-phosphohydrolase and α-glycosidase
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Development of different damage pathways in Norway lobster (Nephrops norvegicus) stored under different chilling systems
Journal of the Science of Food and Agriculture, 2006Co-Authors: Vanesa Losada, Jose M Miranda, Oscar Rodríguez, Jorge Barros-velázquez, Santiago P AubourgAbstract:Slurry Ice is a biphasic system that has recently shown a number of advantages when employed as a chilling medium for fish species. Its use for a crustacean species of high commercial value, Norway lobster (Nephrops norvegicus), was evaluated in parallel with traditional flake icing. Quality parameters related to microbial spoilage and biochemical breakdown (aerobe and psychrotroph counts, pH, K value, total volatile amines, trimethylamine, free fatty acids and non-enzymatic browning reactions) were assessed and compared with sensory (carapace, eyes, gills, odour and flesh) acceptability. Storage in Slurry Ice produced a significant (P < 0.05) inhibitory effect on both microbial growth (as determined by aerobes, psychrotrophs and volatile amines) and autolysis breakdown (as determined by K values and the release of free fatty acids) in comparison with the flake Ice batch. In contrast, an enhancement effect of Slurry Ice on carapace browning was observed as a result of enzymatic browning development. Slurry Ice batch also showed a more intense non-enzymatic browning reaction in the lipid extract of the edible flesh. With a view to limiting both browning effects, the incorporation of an anti-melanosis agent in the liquid phase of the Slurry Ice system is envisaged. Copyright © 2006 Society of Chemical Industry
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evaluation of an ozone Slurry Ice combined refrigeration system for the storage of farmed turbot psetta maxima
Food Chemistry, 2006Co-Authors: Vanesa Losada, Oscar Rodríguez, Santiago P Aubourg, Carmen Adriana Campos, Jorge BarrosvelazquezAbstract:Fil: Campos, Carmen Adriana. Universidad de Santiago de Compostela; Espana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
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effects of storage in Slurry Ice on the microbial chemical and sensory quality and on the shelf life of farmed turbot psetta maxima
Food Chemistry, 2006Co-Authors: Oscar Rodríguez, Carmen Pineiro, Jose Manuel GallardoAbstract:The application of Slurry Ice, a binary mixture of small spherical Ice crystals surrounded by seawater at subzero temperature, is a potentially new preservation method for farmed turbot (Psetta maxima), a flat fish species of increasing commercial interest. Comparative biochemical, microbiological and sensory analyses were carried on turbot specimens stored in either Slurry Ice or flake Ice for up to 40 days. The results obtained in the sensory analysis correlated well with the observed chemical and microbial changes. Storage of turbot in Slurry Ice resulted in a slowing-down of the nucleotide degradation pathway and lipid oxidation mechanisms. A good stabilisation of the high molecular weight protein fraction of turbot muscle was also achieved as a consequence of storage in Slurry Ice. A slower production of both trimethylamine and total volatile bases was also observed. Likewise, low levels of total aerobes, anaerobes, coliforms, and proteolytic bacteria were attained. The application of Slurry Ice to farmed turbot is advisable to achieve better quality maintenance during storage and distribution.
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effects of storage in ozonised Slurry Ice on the sensory and microbial quality of sardine sardina pilchardus
International Journal of Food Microbiology, 2005Co-Authors: Carmen A Campos, Oscar Rodríguez, Vanesa Losada, Santiago P Aubourg, Jorge BarrosvelazquezAbstract:The use of Slurry Ice, both alone and in combination with ozone, as compared with traditional flake Ice was investigated as a new refrigeration system for the storage of sardine (Sardina pilchardus). Microbiological, chemical and sensory analyses were carried out throughout a storage period of 22 days. According to sensory analyses, sardine specimens stored in ozonised Slurry Ice had a shelf life of 19 days, while counterpart batches stored in Slurry Ice or flake Ice had shelf lives of 15 and 8 days, respectively. Storage in ozonised Slurry Ice led to significantly lower counts of aerobic mesophiles, psychrotrophic bacteria, anaerobes, coliforms, and both lipolytic and proteolytic microorganisms in sardine muscle, and of surface counts of mesophiles and psychrotrophic bacteria in sardine skin as compared with the Slurry Ice and the flake Ice batches. In all cases, the Slurry Ice batch also exhibited significantly lower microbial counts, both in muscle and skin, than the flake Ice batch. Chemical parameters revealed that the use of Slurry Ice slowed down the formation of TVB-N and TMA-N to a significant extent in comparison with storage in flake Ice. A combination of Slurry Ice with ozone also allowed a better control of pH and TMA-N formation as compared with Slurry Ice alone. This work demonstrates that the combined use of Slurry Ice and ozone for the storage of sardine can be recommended to improve the quality and extend the shelf life of this fish species.
Carmen Adriana Campos - One of the best experts on this subject based on the ideXlab platform.
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evaluation of an ozone Slurry Ice combined refrigeration system for the storage of farmed turbot psetta maxima
Food Chemistry, 2006Co-Authors: Vanesa Losada, Oscar Rodríguez, Santiago P Aubourg, Carmen Adriana Campos, Jorge BarrosvelazquezAbstract:Fil: Campos, Carmen Adriana. Universidad de Santiago de Compostela; Espana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina