Days Of Ice Storage Research Articles

Biochemical, sensory and microbiological attributes of wild turbot ( Scophthalmus maximus), from the Black Sea, during chilled storage

Freshness of wild turbot ( Scophtalmus maximus) stored in ice was assessed by chemical, sensory and microbiological methods. The limit for sensory acceptability of wild turbot stored in ice was ∼12–15 days. The quality of turbot decreased on day 15 (B) and they were no longer acceptable on day 19 (C). The TVB-N level showed fluctuations during storage, indicating that TVB-N could not be a good indicator of turbot quality. The release of FFA increased from an initial value of 6.33 (expressed as % of oleic acid) to a final value of 20.6 during the storage period. The initial PV value was 5.60 meq/kg for turbot stored in ice and it started to increase to 21.6 meq/kg on day 12 and then started to decrease to 13.6 meq/kg at the end of storage period. The level of TMA in wild turbot increased sharply from an initial value of 9.36 mg/kg to a final value of 38.9 mg/kg. Linear regressions ( r 2) obtained from K, K i , G, P, H and F r were 0.92, 0.89, 0.99, 0.89, 0.96 and 0.89, respectively, for the wild turbot stored in ice. Turbot maintained high (E) and good quality (A) during the first 12 days of chilled storage when the average K, K i and P values were ∼78–85%, and H, F r and G values were ∼45%, 15% and 149%, respectively. Eight biogenic amines were investigated, namely, histamine, putrescine, cadaverine, spermidine, spermine, tryptamine, tyramine, and 2-phenylethylamine, three amines (histamine, tyramine, and tryptamine) were not detected in any of the fish samples during the storage period. As storage time progressed, putrescine and cadaverine became the dominant amines, reaching 22.7, and 16.9 mg/kg, respectively, at 19 days of storage in ice. Total viable counts of whole gutted turbot increased from the initial value of 3.3 log cfu g −1 (day 0) to 7.87 log cfu g −1 (day 19) over the period of storage. If 10 6 microorganisms/g are considered to be the TVC limit of acceptability, the shelf life of turbot was approximately ∼13–14 days.

Changes of lipids in sardine ( Sardinella gibbosa) muscle during iced storage

Changes in lipids of sardine ( Sardinella gibbosa) muscle during 15 days of iced storage were investigated. Lipid deterioration, lipolysis and lipid oxidation, occurred throughout the storage. The progressive peroxide formation was monitored by the increase in the absorbance band at 3600–3200 cm −1 in Fourier transform infrared (FTIR) spectra and increased peroxide values were observed in sardine muscle up to 6 days of iced storage, followed by a continuous decrease from then for 9 days ( P < 0.05). The increase in thiobarbituric acid reactive substances (TBARS) was noticeable throughout the iced storage ( P < 0.05). However, no difference in conjugated diene (CD) of sardine muscle was found within the first 12 days of iced storage ( P > 0.05). Marked decreases in unsaturated fatty acids, especially eicosapentaenoic acid (EPA; C20:5( n − 3)) and docosahexaenoic acid (DHA; C22:6( n − 3)) were observed as the storage time increased. Those changes indicated that lipid oxidation occurred in sardine muscle. A gradual increase in free fatty acid formation, with decreases in triglyceride and phospholipid contents, was found during iced storage ( P < 0.05), suggesting hydrolysis induced by lipases and phospholipases.

Microbiological changes in farm reared freshwater prawn ( Macrobrachium rosenbergii de Man) in ice

The microbiological changes in farm reared freshwater prawn ( Macrobrachium rosenbergii de Man) during ice storage were studied. A total of 156 bacterial cultures from fresh and ice-stored farmed freshwater prawn were isolated and characterized. Total aerobic, mesophilic and psychrotrophic counts and hydrogen sulphide producing bacterial counts were determined. The total aerobic counts at 20 and 37 °C on fresh prawn was in the range of 4–5 log 10 cfu g −1. Aerobic counts on M. rosenbergii at 20 °C and 7 °C exceeded 10 7 cfu g −1 by the end of storage, of which 40–52% were H 2S producers. Gram-negative bacteria constituted 73% of the total flora of fresh prawn and Enterobacteriaceae and Aeromonadaceae dominated. After 19 days of iced storage, more than 80% of the bacterial flora of prawn were Gram-negative. Pseudomonas, Aeromonas hydrophila, A. veronii boivar sobria and Shewanella putrefaciens were identified as the dominant spoilage organisms of farm reared M. rosenbergii stored in ice. This study confirms that freshwater prawn carry significant numbers of motile aeromonads capable of growth at low temperature. The results of the study indicated that the shelf-life of freshwater prawn as determined by microbiological data is 12–16 days. Immediate icing of harvested M. rosenbergii is essential to improve the microbiological stability.

Sensory, microbiological, and chemical spoilage of cultured common sea bass ( Dicentrarchus labrax) stored in ice: a seasonal differentiation

Common sea bass ( Dicentrarchus labrax) of a Greek cage-culture origin, sampled in December and July, were stored in ice, and their sensory, microbiological and chemical spoilage patterns were studied as well as their seasonal differentiation. The sensory storage life was determined at 15 days of ice storage. The microbial population in the muscle reached levels of 105 at the acceptability limit. The ATP breakdown pattern showed a quick depletion of inosine-monophosphate (IMP) in the first 8–9 days of ice storage and slower depletion thereafter. Inosine (INO) and hypoxanthine (Hx) were formed at significant quantities. TVBN and TBA, as indicators of protein breakdown and lipid oxidation, respectively, showed low and delayed increase. A seasonal effect was observed with summer fish showing higher rates of K-value increase during early spoilage, while winter fish showed higher K-values, microbial populations and TVBN at late spoilage stages.

Changes in firmness and thermal behavior of ice-stored muscle of jumbo squid (Dosidicus gigas)

Changes in firmness, muscle total protease activity, and the thermal behavior of jumbo squid (Dosidicus gigas) were measured throughout 15 days of ice-storage. A significant decrease (p<0.05) in the shear force of raw mantle muscle was observed after 7-days ice-storage. The highest total protease activity detected was 1.24 U/g mantle. The thermograms obtained at day zero showed four transition states. The first three transition states were endothermic and correspond to myosin (50 °C), sarcoplasmic proteins (69 °C), and actin (79 °C). The fourth transition state was exothermic at 107 °C, and was probably associated with protein aggregation. The thermal behavior of the muscle showed a decreasing trend in temperature and enthalpy of transition for myosin, sarcoplasmic proteins, and actin with storage time. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis showed a change in the myofibrillar protein pattern, which with the shear force, and differential scanning calorimetry data, suggests a partial denaturation of that protein fraction during ice-storage.

Gilthead seabream (Sparus aurata): suitability for freezing and commercial alternatives

AbstractThe quality of portion‐size farmed gilthead seabream (Sparus aurata) during frozen storage and the influence of post‐mortem treatments were studied in order to find new ways of marketing this species. Portion‐sized gilthead seabream, fasted for 48 h prior to slaughter, were frozen and stored at −20 °C for up to one year. Whole fish were frozen immediately after rigor mortis; gutted fish were frozen immediately after rigor and after 5 days of storage in ice. All lots were stored at −20 °C for up to one year. The myofibrillar protein of this species was very stable and a slight decrease of solubility in salt solutions was found only after one year of frozen storage. A slight decrease in water‐holding capacity and a slight increase in shear strength were observed, but these were lower than in other species. These changes were reflected as increased toughness and reduced juiciness in sensory analysis of the cooked fillets after one year. The main changes in the cooked fillets were observed in odour and flavour. No significant detrimental effect due to the guts was detected during frozen storage. Storage in ice prior to freezing was reflected in sensory assessment of the raw fish, mainly in terms of initial higher demerit points for fishy odour, gills and eyes; however, no effect was observed in the cooked fillets. Copyright © 2004 Society of Chemical Industry

Biochemical changes and quality loss during chilled storage of farmed turbot ( Psetta maxima)

Changes in three of the major biochemical components – nucleotides, lipids and proteins – related to quality loss in farmed turbot, were determined during 29 days of iced storage; results were complemented with sensory analysis. Nucleotide degradation, as estimated by the K value, underwent a gradual increase until day 19, in agreement with the loss of freshness observed for the sensory scores (high quality: days 0–2; good quality: days 3–14; fair quality: days 15–19). After day 19, the fish was judged unacceptable and the K value did not show differences until the end of storage. Lipid hydrolysis and oxidation occurred at slow rates, free fatty acid contents and the peroxide value being below 20.0 g kg −1 lipids and 4.00 meq active oxygen kg −1 lipids, respectively, during the whole storage. The content of fluorescent compounds did not increase significantly until day 19, when a sharp increase was detected. The electrophoretic protein profiles of turbot muscle did not point to any major protein degradation event or any significant change in protein during storage. However, a new band, corresponding to 22 kDa, could be observed at day 2 in the low-ionic strength buffer extract, whose concentration seemed to increase at days 9 and 14 and was present until the end of the chilled storage. The results obtained in this work indicate slow and gradual biochemical changes and long shelf life and good quality times (19 and 14 days, respectively) for iced turbot; these long times would be very profitable when turbot commercialisation is carried out in places distant from production farms.

Microflora of fresh and ice-stored sardines (Sardina pilchardus) from the Moroccan Atlantic coast

Sardines (Sardina pilchardus) caught on the Moroccan Atlantic coast (off El Jadida) were examined fresh (February, May and July trials) and after 10 days of storage in ice (July trial). From fresh fish, a total of 193 strains were isolated from the muscle with skin, gills and viscera, whereas from ice-stored fish, 122 strains were isolated from the muscle. Gram-negative bacteria always predominated among the initial flora in all trials. The predominant Gram-negative microflora of the fresh fish consisted of Moraxellaceae (Moraxella sp., Acinetobacter sp., Psychrobacter sp.), Enterobacteriaceae, Pseudomonadaceae (Pseudomonas sp.), and the genera Shewanella and Flavobacterium. The Gram-positive flora was identified as Staphylococcus sp., Micrococcus sp. and coryneform bacteria. Significant seasonal variation in initial flora was not noted. Ice storage allowed the growth of Gramnegative bacteria, with Pseudomonas as the dominant microflora, followed by Shewanella putrefaciens. The present study indicates that Pseudomonas sp. probably contribute to the spoilage of sardines caught in the Atlantic Ocean.

Microbiological, chemical and sensory assessment of iced whole and filleted aquacultured rainbow trout

The effect of filleting on microbiological, chemical, and sensory properties of aquacultured freshwater trout ( Onchorynchus mykiss) stored in ice was studied. Pseudomonads, H 2S-producing bacteria (including Shewanella putrefaciens) and Brochothrix thermosphacta were the dominant bacteria while, Enterobacteriaceae in lower counts were also found in the spoilage microflora of whole ungutted and filleted trout over an 18-day storage period in ice. Bacterial counts of whole ungutted trout were always lower than those obtained for filleted trout samples. Mesophilic counts for filleted and ungutted fish exceeded 7 log cfu/cm 2 after 10 and 18 days of ice storage, respectively. Of the chemical indicators of spoilage, trimethylamine (TMA) values of ungutted trout increased very slowly whereas for filleted samples higher values were obtained reaching a final value of 4.29 and 6.38 mg N/100 g, respectively (day 18). Total volatile basic nitrogen (TVB-N) values showed no significant increase for whole ungutted trout during storage reaching a value of 20.16 mg N/100 g (day 18) whereas for filleted fish a respective value of 26.06 mg N/100 g was recorded. Thiobarbituric acid (TBA) values of ungutted trout increased very slowly whereas for filleted samples higher values were obtained reaching a final value of 16.21 and 19.41 μg MA/g, respectively (day 18). Of the chemical indices used, none proved useful means of monitoring early freshness for ungutted and filleted trout freshness in ice. Sensory assessment using the EC freshness scale gave a grade E for up to 6 days for the ungutted trout, a grade A for a further 3 days and a grade B for an additional 6 days, after which trout was graded as C (unfit). Acceptability scores for odor, taste and texture of cooked ungutted and filleted trout decreased with time of storage. Results of this study indicated that the shelf-life of whole ungutted and filleted trout stored in ice as determined by sensorial and microbiological data is 15–16 and 10–12 days, respectively.

Iced storage of Atlantic salmon ( Salmo salar) – effects on endogenous enzymes and their impact on muscle proteins and texture

Endogenous salmon enzymes and their impact on muscle proteins and texture were studied. To reduce interfering effects of microbial enzymes, the fish were irradiated. Irradiation of salmon fillets resulted in severe inhibition of cathepsin B-like and collagenase-like enzymes. The effect was most pronounced for the cathepsins. The textural properties and amounts of free amino acids and extractable proteins in the irradiated fillets and control group were different after 14 days of iced storage. Even with the increased load of microorganisms seen in the control group, no severe deterioration of fish texture or increase in proteolytic activity was observed during the storage period. It therefore seems that microorganisms are not important for changes in salmon texture.

Effect of washing with tap and treated seawater on the quality of whole scad ( Trachurus trachurus )

The effects of washing whole scad (Trachurus trachurus) with fresh water and seawater were evaluated. Fish evaluations for 12 days of storage in ice included sensory (EU and the QIM scheme), physical (Torrymeter and Freshmeter) and microbiological changes (counts of total bacterial numbers, specific spoilage organisms (SSO) and Pseudomonas). The main conclusions are that both kinds of wash influenced physical and microbiolog- ical evaluations (mainly on Freshmeter values and counts of SSO). Washes seemed to interfere with properties of the fish skin cells that influenced the instrumental readings. By sensory means, the effects were not detected, resulting in similar shelf-lives, although some slight differences could be observed in mucus brightness in the first 2 days storage in ice. No significant differences were found between washing with tap water and treated seawater, but slightly lower values were obtained initially with seawater, in the first 24-48 h, with the Torrymeter and the Freshmeter.

Effect of gutting on microbiological, chemical, and sensory properties of aquacultured sea bass ( Dicentrarchus labrax) stored in ice

The effect of gutting on microbiological, chemical, and sensory properties of aqua-cultured sea bass ( Dicentrarchus labrax) stored in ice was studied. Pseudomonads and H 2S-producing bacteria (including Shewanella putrefaciens) were the dominant bacteria at the end of the 16-day storage period in ice for both whole ungutted and gutted sea bass. Brochothrix thermosphacta and Enterobacteriaceae were also found in the spoilage microflora of ungutted and gutted sea bass but their counts were always less than those of Pseudomonads and H 2S-producing bacteria. Bacterial counts of whole ungutted sea bass were always higher than those obtained for gutted sea bass samples. Mesophilic counts for gutted and ungutted fish exceeded 7 log cfu g −1 after 9 and 15 days of ice storage, respectively. Of the chemical indicators of spoilage, TMA values of ungutted sea bass increased very slowly whereas for gutted samples higher values were obtained reaching a final value of 0.73 and 4.39 mg N 100 g −1, respectively (day 16). TVB-N values showed no significant increase for whole ungutted sea bass during storage reaching a value of 27.7 mg N 100 g −1 (day 16) whereas for gutted fish 36.9 mg N 100 g −1 was recorded. TBA values remained low for ungutted sea bass samples until day 16 of storage, whereas for gutted fish were variable. Of the chemical indices used, none proved useful means of monitoring early ungutted and gutted sea bass freshness in ice. Sensory assessment using the EC freshness scale gave a grade E for up to 5 days for the ungutted sea bass, a grade A for a further 2 days and a grade B for an additional 4 days, after which sea bass was graded as C (unfit). Gutted sea bass was given a grade E for up to 3 days, a grade A for the 4–7th days, and a grade B for the 8–10th days of storage, whereas on day 11 it was graded as unfit. Acceptability scores for odor, taste and texture of cooked ungutted and gutted sea bass decreased with time of storage. Results of this study indicate that the shelf-life of whole ungutted and gutted sea bass stored in ice as determined by the overall acceptability sensory scores and microbiological data is 13 and 8 days, respectively.

Seasonal patterns of spoilage of ice-stored cultured gilthead sea bream ( Sparus aurata)

Cage-cultured gilt-head sea bream ( Sparus aurata) from Greek sea waters was sampled in January and in August for some chemical and microbial spoilage indicators during 15 days of ice storage. Winter fish reached higher levels of microbial populations (10 9 vs 10 7 in summer fish) at the end of the storage period. The pH showed an increase after 8 days of storage. TVBN showed a slow and uniform increase. The catabolism of adenine nucleotides showed a slow rate of inosine monophosphate decomposition and a small linear rate of hypoxanthine accumulation. The K value of summer fish was found to be initially higher than that of fish sampled in winter in the early stages of storage, but lower in the later stages when microbial spoilage occurred. These results indicate that summer fish have higher rates of autolytic activity but lower rates of microbial spoilage.

CHARACTERISTICS OF MUSCLE FROM TWO SPECIES OF BIGEYE SNAPPER, PRIACANTHUS TAYENUS AND PRIACANTHUS MACRACANTHUS

Composition and some properties of muscle from two species of bigeye snapper, P. tayenus and P. mcracanthus, were investigated. Both species had a similar composition with the same myofibrillar protein content. However, muscle proteins from P. tayenus had higher them1 stability than those from P. macracanthus, as indicated by the higher enthalm for transitions as well as the lower inactivation rate constant (KD). Upon 15 days of iced storage, natural actomyosin Cd'-ATPase and M$'-~'-ATPase aciivities decreased, whereas M&+-EGTA-ATPase activity increased, suggesting the denaturation of myosin, actomyosin andtroponin/tropomyosin complexes, respectively. Increased surface hydrophobicity and decreased suljhydryl groups indicated the denatumtion possibly occurred via hydrophobic interaction and disulfi& formation. Heading and eviscerating offish retarded the denaturation and physicochemical changes of proteins during iced storage. The results indicated that a rapid and proper post harvest handling was of importance to maintain the muscle quality of bigeye snapper.

Effect of ice storage on the functional properties of proteins from shark (Scoliodon laticaudus) meat.

Ice storage characteristics of Scoliodon laticaudus with reference to physicochemical and functional properties have been assessed. Total nitrogen content reduced to a value of 3.90 g/100 g from an initial value of 4.27 g/100 g of meat. Moisture content did not show much variation. The initial nonprotein nitrogen content which was 1.09% w/w of meat reduced to 0.98% during ice storage. Urea content of shark meat reduced by 25% during 12 days of ice storage. The increase in total volatile base nitrogen of shark meat was more than twofold at the end of 12 days of ice storage. Solubility of proteins showed an initial increase reaching a value of 87.9%, further reduced with ice storage. Gel filtration profile and SDS-PAGE pattern indicated aggregation of protein fractions and also showed dissociation or cleavage to small molecular weight fractions. Slope of reduced viscosity curve as a function of protein concentration decreased with ice storage period. Emulsion capacity of proteins from shark meat reduced from a value of 0.18 mL oil/mg protein to 0.14 mL oil/mg protein after 12 days of ice storage. Gel forming ability of shark meat monitored by dynamic viscoelastic measurement, gel strength, expressible water content and folding test showed that shark meat has got excellent ability to form gel and this property was marginally reduced during ice storage.

Decomposition of trimethylamine oxide during iced storage of blue whiting ( Micromesistius poutassou )

Products of the decomposition of trimethylamine N-oxide (TMAO) during iced storage of blue whiting were monitored over 15 days. Increasing amounts of trimethylamine (TMA) and dimethylamine (DMA) were found in the white muscle with increasing storage time. The production of TMA was interpreted as a consequence of bacterial growth, while DMA production was due to enzymatic activity of trimethylamine N-oxide demethylase (TMAOase). TMAOase activity was monitored with time in different organs. The highest activities always corresponded to kidney and spleen. Also, TMAOase was found to remain active during the 15 days of iced storage. A relationship was found between TMAOase in kidney and DMA concentrations in white muscle.

Collagen content in farmed Atlantic salmon (Salmo salar L.).

To clarify fish flesh quality problems and softening of fish muscle tissue during chilled storage, the collagen content, types I and V, and its changes in solubility during storage on ice in muscle of farmed Atlantic salmon (Salmo salar L.) were analyzed. The contents of acid-soluble, pepsin-soluble, and insoluble collagen in white muscle were determined in fresh fish muscle and after 3 days of storage in ice. The total collagen content was 2.9 g kg(-)(1) fresh weight. During storage on ice, a progressive change in solubility of muscle collagen was found. For acid- and pepsin-soluble collagen fractions, significantly higher and lower values, respectively, were detected. The presence and quantification of types I and V collagen in the different collagen fractions was determined also, but no significant difference in solubility during storage was found. The result suggested that collagen fibers of Atlantic salmon have a high solubility in acid solutions and contain few cross-links.

Starvation prior to slaughter in Atlantic salmon ( Salmo salar) : II. White muscle composition and evaluation of freshness, texture and colour characteristics in raw and cooked fillets

Muscle composition and quality characteristics of fillets were investigated in triplicate groups of 5-kg Atlantic salmon starved at low water temperatures for 0, 3, 7, 14, 30, 58 or 86 days prior to slaughter. White muscle and raw fillets were analysed at slaughter and after 4 and 12 days of ice-storage of gutted fish, whereas sensory analyses of cooked fillets were performed after storage for 13–16 days. At slaughter, the level of glycogen in white muscle decreased with the length of starvation. After 4 and 12 days of ice-storage, lactate and glycogen levels decreased and pH increased in white muscle with increasing starvation time. The K-value, determined after 4 and 12 days of ice-storage, decreased as the duration of starvation increased. Trimethylamine was not detected in white muscle. Sensory analyses showed that cooked fillets from groups starved for 86 days had less fresh flavour than that of groups starved for 30 days or less. The fillets of groups starved for 30 days had significantly higher acidulous flavour compared with that of groups starved for 0–14 days, whereas groups starved for 58 or 86 days had significantly less acidulous flavour than all other groups. The sensory assessed hardness of cooked fillets was significantly lower in groups starved for 86 days vs. those starved for 0, 14 or 30 days. In contrast, instrumental texture analyses of raw fillets, after 4 days of ice-storage, showed that the force against compression (at 5 mm) was higher in groups starved for 58 or 86 days than in those starved for a shorter time. Although astaxanthin concentration was not significantly affected by starvation time, instrumental colour analyses (CIE 1976) of raw fillets revealed changes in lightness ( L*) and yellowness ( b*). Although starvation produced some changes in white muscle composition, the rather marginal differences in freshness, texture and colour characteristics of raw or cooked fillets when starvation time varied from 0 to 86 days, suggest that starvation is a rather weak tool for changing fillet quality in Atlantic salmon.

The formation of non-volatile amines in relation to concentrations of free basic amino acids during postmortem storage of the muscle of scallop ( Pecten maximus), herring ( Clupea harengus) and mackerel ( Scomber scombrus)

The concentrations of the non-volatile biogenic amines that form during storage of the adductor muscle of scallop ( Pecten maximus ) and the skeletal muscles of mackerel (Scomber scombrus) and herring ( Clupea harengus ) were determined by high-performance liquid chromatography, using postcolumn derivatisation with o-phthalaldehyde. Initially, concentrations of amines were low in all muscles but, as time of storage progressed, the concentration of agmatine increased steadily in scallop muscle reaching a level of 100 mg per 100 g wet weight after 10 days of storage in ice or 3 days at 10°C. In mackerel and herring only slight increases were observed, with levels of less than 1.0 mg after 10 days in ice or 2 days at 10°C. In scallop, arginine, the precursor of agmatine, decreased steadily in concentration. In herring muscle, histidine, the precursor of histamine, decreased considerably in concentration, whereas in mackerel it changed only slightly. © 1997 Published by Elsevier Science Ltd

Post-Mortem Changes in Adenosine Triphosphate and Related Compounds in Mantle of Squid (Illex argentinus) at Different Stages of Sexual Maturation

Post-mortem catabolism of ATP and catabolitc compounds of ATP breakdown in the mantle of squid at different sexual maturation stages were investigated during ice storage of either isolated mantle or whole squid. Similar profiles of ATP and catabolites, except AMP, related to ATP breakdown were found in the mantle of ice-stored whole squid at both sexual maturation stages. Independent of the sexual maturation stage of specimens, as compared with whole squid mantles, isolated mantles had a lower (p<0.01) content of AMP and IMP and a higher (p<0.01) content of Hx up to 6 days of storage. IMP was detected in all the samples analyzed. Conversely, adenosine (Ado) was not detected. The K values show that the initial quality of the isolated mantle was lower than that of whole squid mantle. K values increased (p<0.01) in both isolated and whole squid mantles after 6 days of ice storage. The increase was higher (p<0.01) in the mantle from iced whole squid, especially when the specimens were at stage 5 of sexual maturation.