Effect of marinating process on the microbiological quality of Pacific saury (Cololabis saira) during vacuum-packaged storage at 4 °C

This study was carried out to evaluate the microbiological quality of Pacific saury ( Cololabis saira ) treated with marinating solutions containing either 12% NaCl + 2% acetic acid or 12% NaCl + 3% acetic acid, followed by vacuum packaging and storage at 4 °C for 90 days. The fish-to-marinating-solution ratio was 1:1.5. The growth rate of aerobic, halophilic, lactic acid bacteria and Pseudomonas spp. were significantly ( P  < 0.05) reduced in marinated vs. brined (12% NaCl + 0% acetic acid) fillets. Complete inhibition in the growth of both Enterobacteriaceae and Staphylococcus aureus was detected in fillets marinated in 3% and 2% acetic acid by the days 30 and 50 of storage, respectively. Both marinating conditions resulted in shelf life extension of the product to more than 90 vs. 60 days only for the brined fillets. Listeria monocytogenes , Vibrio parahaemolyticus and Salmonella spp. could not be detected in any of the analysed raw or treated samples.     

Effect of marinating time and low pH on marinade performance and sensory acceptability of poultry meat

The effects of marinating time (30, 60, 120 and 180 min) and acidic marinade pH (3.0, 3.2, 3.4, 3.6, 3.8, 4.0 and 4.2) on the instrumental and sensory properties of cooked Chinese-style marinated chicken were investigated. With increasing marinating time up to 180 min, a significant (P < 0.05) increase in surface redness (a∗ value) and the dark pink sensory attribute was observed, along with a corresponding decrease in lightness (L∗ value) and colour penetration. Increased marinating times of 120–180 min were found to produce more acceptable end products with increased scores for colour, aroma and flavour attributes. Marinade uptake was greater at higher marinade pH levels of 3.8, 4.0 and 4.2, with the highest marinade uptake (3.34%) recorded at pH 4.0. As changes to core meat pH were not observed, the effect of marinating time (up to 180 min) and marinade pH on the instrumental and sensory properties of Chinese-style marinated chicken were located principally at the surface of samples. Consumers considered surface colour as contributing to acceptability of marinated chicken to a greater degree compared to colour penetration.     

Chemical,microbiological and sensory changes in thawed frozen fillets of sardine (Sardina pilchardus) during marination

Frozen fillets of sardine (Sardina pilchardus) were used to make marinades. The marinating process was performed in 7% acetic acid and 14% sodium chloride in barrels. The fish : solution ratio was (1.5:1). The marination was carried out at 4 °C until the end point of marinating was assessed by sensory texture analysis. The complete marinating of sardine fillets required 22 days at 4 °C. According to statistical analysis at the beginning and at the end of the storage in barrels there were no significant differences (p>0.05) in chemical analytical results. After the sardine fillets were put into the barrels, total viable count, lactic acid bacteria count, psychrotrophic bacteria count, yeast and mould counts were reduced.     

Effects of low concentration of salt and sucrose on the quality of bighead carp (Aristichthys nobilis) fillets stored at 4 °C

The effect of low concentration of salt and sucrose on the quality of bighead carp (Aristichthys nobilis) fillets was evaluated over a 16-day storage at refrigerated temperature (4 °C). Fish samples were brined with 1.1% salt (T1) and 1.1% salt + 0.9% sucrose (T2). The control and the treated fish samples were analysed periodically for physicochemical (pH, total volatile base nitrogen (TVB-N), water loss, electrical conductivity (EC), color), microbial (total viable counts) and sensory characteristics. No significant differences were observed between T1 and T2 for sensory score and EC (p > 0.05). Brining treatments predominantly decreased chemical changes, reflected in TVB-N and pH, retarded water loss and discoloration, inhibited bacterial growth and increased the overall sensory quality of fish, compared to untreated fillets. The results indicated that brining treatments improved the quality and safety of bighead carp fillet, which can be exploited by fish processors.     

Shelf life of meat from lambs given essential oil-free rosemary extract containing carnosic acid plus carnosol at 200 or 400 mg kg

The use of dietary rosemary extract (DRE) at low doses is proposed as a nutritional strategy to improve meat preservation. Lamb diet was supplemented with 0, 200 or 400 mg DRE (containing carnosic acid and carnosol at 1:1 w:w) per kg feed during the fattening stage. Meat quality was evaluated in lamb fillets packed under protective atmosphere and kept in retail conditions for up to 14 days. The effects of diet and storage time were determined on different physical–chemical (L*a*b* color, pH, TBARS, protein oxidation and volatiles from lipid oxidation), microbial (total viable and psychrophilic bacteria, Enterobacteriaceae, molds and yeasts) and sensory (appearance and odor) characteristics of the meat. The antioxidant and antimicrobial effects of DRE on meat were demonstrated. DRE delayed lean and fat discoloration, lipid oxidation, odor deterioration and microbial spoilage, extending the shelf life time of fillets from around 9 to 13 days. Both DRE doses provided similar shelf life extension.     

Survival of Anisakis larvae in marinated herring fillets

The survival of Anisakis sp. larvae in herring fillets marinated in brines with different concentrations of salt (NaCl) and acetic acid was examined. Traditional German and Danish procedures for marinating herring fillets require a storage time of at least 5 and 6 weeks, respectively, for all larvae to be killed. Other concentrations of salt and acetic acid were also studied. A reduction of the salt content in the water phase of the fish tissue from 9% (w/w) to 4.3% (w/w), while keeping the concentration of acetic acid constant at 2.6%, increased the survival time of the nematodes from at least 35 days to more than 119 days. Increases in the acetic acid concentration or the addition of potassium sorbate had little or no effect on the viability of the larvae.     

Postmortem changes in yellow grouper (Epinephelus awoara) fillets stored under vacuum packaging at 0 °C

The freshness of yellow grouper (Epinephelus awoara) stored under vacuum-packing at 0 °C was assessed by physicochemical, sensory and microbiological methods. No significant differences were found in pH and thiobarbituric acid (TBA) values during the storage, while TVB-N, TMA-N, HxR, Hx and K values increased significantly with time. The content of IMP was decreased significantly with the storage time. The texture profile, hardness and chewiness were significantly decreased with the time. L∗ values, the values of chroma and hue were all decreased. However, the increased b∗ values were observed. Furthermore, the significant variations and correlations of sensory attributes were shown with the storage time. A regression analysis for total viable counts yielded a shelf life of 26 days. This suggested that the TMA-N, IMP, HxR, Hx, K value, hardness, chewiness, colour, sensory attributes and microbiological counts may be considered suitable indicators for evaluating yellow grouper fillets spoilage during refrigerated storage.     

Combined effect of MAP and thyme essential oil on the microbiological,chemical and sensory attributes of organically aquacultured sea bass (Dicentrarchus labrax) fillets

The present study evaluated the combined effect of Modified Atmosphere Packaging (MAP) using two different gas mixtures (40% CO₂/50% N₂/10% O₂; treatment M1, 60% CO₂/30% N₂/10% O₂, treatment M2), and thyme oil (0.2% v/w, T) used as a natural preservative, on the quality and shelf life extension of fresh filleted sea bass, product of organic aquaculture, during refrigerated storage (4± 0.5 °C), for a period of 21 days. Aerobically packaged sea bass fillets (A) were used as control samples. The dominant bacteria in the microflora of sea bass fillets, irrespective of treatment, were the pseudomonads and the H₂S-producing bacteria while lactic acid bacteria were also part of the dominant microflora. Total viable counts for fresh sea bass fillets stored aerobically exceeded 7 log CFU/g after 7 days, while treatments A+T, M1, M2 and M2+T reached the same value on days 9, 10, 12 and 19, respectively. Among the chemical indices determined, TBA values were within the good quality limits (2–4 mg MDA/kg), during the sensory shelf lives of sea bass samples, irrespective of treatment. TVB-N proved to be a suitable index for the spoilage of sea bass fillets stored at 4 °C. Samples A and A+T, M1, M2, M2+T exceeded the proposed upper TVB-N acceptability limit (10 mg N/100 g) on days 6, 8, 9, 13 and 17 of storage respectively. TMA-N values of the samples A, A+T and M1, M2, M2+T exceeded the proposed limit (4 mg N/100 g) on days 6, 9, 9–10, 13 and 19 of storage, respectively, and correlated well with the microbiological data, indicating that along with TVB-N, TMA-N may serve as a useful index for sea bass fillets spoilage. As regards sensory evaluation, the presence of thyme oil proved to improve the sensory quality of sea bass fillets when used in combination with MAP2, providing a shelf life of 17 days as compared to 6 days of the control samples.     

The effects of thyme (Thymus vulgaris L.) oil concentration on liquid-smoked vacuum-packed rainbow trout (Oncorhynchus mykiss Walbaum, 1792) fillets during chilled storage

This study examined the effects of thyme oil on chemical properties, microbiological changes, and sensory quality in vacuum-packed liquid-smoked rainbow trout fillets under chilled storage. After 150 days of storage, the total volatile basic nitrogen (TVB-N) values were 30.52, 27.5 and 39.43 mg/100 g, and total viable counts (TVC) were 5.34, 4.96 and 5.53, for thyme oil additions of 10 (T10), 50 (T50) and 0 (control; T0) mL/L brine, respectively. The highest acceptable TVB-N value was adopted as 30 mg /100 g, corresponding to shelf lives of 135, 150, and 105 days for T10, T50, and T0, respectively. T50 addition of thyme oil to liquid-smoked rainbow fillets extended shelf life T10 and T50, gave acceptable sensory quality and limited microbiological growth during chilled storage.     

Comparison of physicochemical and sensory changes in fresh and frozen herring (Clupea harrengus L.) during marinating

BACKGROUND: The influence of freezing on the changes during ripening is better described for salted fish than marinades. Therefore in the present study the effect of preliminary freezing of raw material on the ripening of carcasses and fillets marinated during 18 days at a temperature of 10 °C, in brine with 6% salt and 5% acetic acid was examined. RESULTS: In both cases the marinating of thawed frozen material resulted in larger mass losses and decrease of the value of meat colour parameters. The semi‐marinades from raw herring were characterised by higher values of total estimation based on sensory analysis. The statistical analysis showed weak correlation between the discriminants of sensory assessment and the studied physicochemical parameters of semi‐marinades. CONCLUSIONS: These results suggest that the semi‐marinades from raw fish are characterised by higher sensory quality, better colour parameters and higher yield than those from frozen thawed fish. Copyright © 2010 Society of Chemical Industry     

Sensory,physical, chemical and microbiological changes in aquacultured meagre (Argyrosomus regius) fillets during ice storage

Commercial-sized meagre fillets were stored on ice at 4 °C for 18 days, in order to evaluate the loss of quality and freshness that occurs over this period of time. Physicochemical (pH, thiobarbituric acid (TBA), total volatile basic nitrogen (TVBN), trimethylamine (TMA), water activity, water-holding capacity, colour, texture and fatty acid profile), sensory and microbiological analyses were carried out at 0, 4, 7, 11, 14 and 18 days of storage. As part of the sensory analysis, attributes associated with fillet appearance, odour and texture were examined. Variations in pH, TBA, TVBN and TMA were observed throughout the storage period, although only TBA displayed a significant correlation with time (r = 0.96). L^∗ and b^∗ values increased, and the chroma and hue values decreased, reflecting the colour changes experienced by the fillets over time. With regards to the texture profile, hardness was significantly correlated with time (−0.68). All the sensory analysis attributes exhibited significant variations and correlations close to 1.00 with storage time, which is a reflection of the fillets’ loss of freshness. The correlation coefficients between aerobic mesophilic and psychrophilic bacteria, enterobacteria and coliform counts on the one hand and storage time on the other were also very high (0.99–1.00). A regression analysis using the acceptability limit set by the ICMSF standard (1986) for total aerobic mesophilic counts (7 log cfu/g) yielded a shelf-life for meagre fillets of 9 days. The TBA, sensory and microbiological analyses displayed very strong correlations with storage time, and they may be considered suitable indicators for evaluating meagre fillet spoilage during refrigerated storage.     

Effect of green tea marinades on the formation of heterocyclic aromatic amines and sensory quality of pan-fried beef

The effect of a green tea marinade on the formation of heterocyclic aromatic amines (HAs) was examined in pan-fried beef cooked at 180–200 °C for 4 min each side. Different marinating times were assayed and unmarinated samples cooked in similar conditions provided reference HAs levels. A green tea marinade catechin rich was prepared taking 1 g of green tea and infusing with 125 ml of boiling tap water during 10 min. Four HAs were quantified in unmarinated and marinated meat samples during 1, 2, 4 and 6 h at 5 °C. Compared with the unmarinated samples, marinating in green tea resulted in a significant decrease (p < 0.05) of levels of PhIP and AαC. Person correlation indicated that the reduction of the levels of these HAs in meat marinated with the increase of marinating time was significant (respectively, r = −0.799, p < 0.0001; r = −0.631, p < 0.05). No reduction was observed for 4,8-DiMeIQx and MeIQx.     

Losses of nitrogen fractions from herring to brine during marinating

Fish meat is characterized by a high content of valuable nutrients. During the marinating process, however, the process of proteins diffusion and other nitrogen fractions from fish to the surrounding brine is commonly observed. It was determined that the total nitrogen loss from herring meat of industrial maturity (4-5 day) amounted to 6-19% of raw material nitrogen. Extension of the marinating time to 16-18 days increases nitrogen losses even to 18-27%. Less loss was observed during marinating of fresh than of frozen herring and during marinating of carcasses, as opposite to fillets. Higher nitrogen content in fish was not proved to influence higher nitrogen losses in a brine. The majority of loss consisted of nitrogen fractions soluble in TCA, of which one third was formed by α-amine nitrogen. Nitrogen contained in brine suspension accounted for only 1.5-4% of total nitrogen losses. With increasing salt or acid concentration the amount of total nitrogen loss was lower from fresh herring and higher from frozen one. Higher salt concentration significantly reduced the amount of non-protein nitrogen and all its fractions during marinating of fresh and frozen herring. In case of acetic acid, the influence of its concentration was diverse and depended on type of herring and its dressing.     

Chemical,enzymatical and textural changes during marination and storage period of sardine (<Emphasis Type="Italic">Sardina pilchardus</Emphasis>) marinades

In this study frozen fillets of sardine (Sardina pilchardus) were used to make marinades. The marinating process was performed in 7% acetic acid and 14% sodium chloride in barrels. The fish:solution ratio was (1.5:1). After the marination process, sardine fillets were packed in glass jars in two different formulations fish:solution ratio of (1.5:1); the first formulation contained 2% acetic acid and 4% sodium chloride with tomato sauce and spices and the other was 2% citric acid and 4% sodium chloride with lemon and also the same spices. Pasteurization process had been applied on half of the jars at 70 °C for 20 min. Chemical, enzymatical and textural changes during marination and 6 months storage period of sardine marinades were determined. The results obtained in proteolytic activities correlated well with the observed texture measurements according to time of storage. A decrease in the histidine content and an increase in glutamic acid and aspartic acid contents of marinated sardines were determined. Histamine levels were lower than the toxic limit (100 mg/kg) during the marination and storage period of sardine marinades.     

Cryoprotective effects of polyphosphates on Rutilus frisii kutum fillets during ice storage

Polyphosphates have profound effects on the functional properties of the food products. In this study, the effects of (2% w/v) solutions of tetrasodium pyrophosphate (TSPP) and sodium tripolyphosphate (STPP) and a mixture of them on the shelf life of filleted Rutilus frisii kutum during ice storage were examined. Common zipper pouches were used for packing fish fillets. The packs were placed beside ice with a fish/ice ratio of 1:1 (w/w) in an insulated box and were maintained at 4 °C. The control and the treated packs were analysed periodically for chemical, microbiological (psychrophilic bacterial counts), textural and sensory characteristics. Control samples were found to have a shelf life of about 6 days, whereas samples treated with polyphosphate were found to be acceptable up to 9 days. Thus being treated with polyphosphates was found to delay the spoilage and extend the shelf life of R.f. kutum in ice.     

Effect of freezing on the physicochemical, textural and sensorial characteristics of salmon (Salmo salar) smoked with a liquid smoke flavouring

This study reports the effect of different refrigeration/freezing treatments on the physicochemical, textural and sensorial properties of farmed Atlantic salmon (Salmo salar) treated with a commercial liquid smoke flavouring. Observations were made on three groups of fillets - group RFS: salted, smoked and stored at 4 °C; group BFS: frozen at −25 °C for 24 h, thawed, salted, smoked and stored at 4 °C; and group AFS: salted, smoked and frozen at −25 °C for 24 h and stored at −18 °C - over a period of 45 days. Scores (on a scale of 1-9) were provided for different sensorial attributes by a panel of 10 trained tasters. Sixty percent of the panellists consistently preferred the AFS fillets. The maximum shelf life associated with each treatment was defined as the last sampling day on which a mean score of ≤5 was awarded for the fillet sensorial attributes by ≥50% of the panellists. Freezing the salmon for 24 h before smoking (BFS) did not increase its shelf life (30 days) over that of refrigerated smoked salmon (RFS). In addition, the former treatment had a negative effect on the adhesiveness, cohesiveness, smoke odour intensity and colour intensity of the flesh. However, maintaining the fish frozen at −18 °C (AFS) increased its shelf life (>45 days) and invested the flesh with greater firmness, cohesiveness and colour intensity.     

Efficacy of Chitosan-Gallic Acid Coating on Shelf Life Extension of Refrigerated Pacific Mackerel Fillets

The synergistic effect of gallic acid (GA) and chitosan (CS) as edible coatings on the quality and shelf life of Pacific mackerel (Pneumatophorus japonicus) fillets during chilled storage was investigated in this study. Pacific mackerel fillets were periodically evaluated to assess their microbiological (total viable count), physicochemical (pH, total volatile basic nitrogen, biogenic amine, thiobarbituric acid, and K value), and sensory characteristics. The results indicated that CS?+?GA was more effective than either treatment alone in inhibiting microbial growth, protein decomposition, biogenic amine formation, lipid oxidation and nucleotide breakdown, and maintaining better sensory characteristics during storage, thereby extending the shelf life of mackerel by 6 days compared with the control group. Therefore, a coating with the combination of chitosan with GA represents a promising method for maintaining the storage quality of Pacific mackerel fillets and has broad potential applications in the seafood industry as a food-grade biopreservative.     

A new technology for fish preservation by combined treatment with electrolyzed NaCl solutions and essential oil compounds

This study was undertaken to establish a new technology, using pre-treatment with electrolyzed NaCl solutions and essential oil compounds, to extend the shelf-life of carp fillets. Samples of skinless carp fillets were treated with 100-fold (by weight) of electrolyzed NaCl solutions [cathodic solution, EW(−) and/or anodic solution, EW(+)] and 1% oil (0.5% carvacrol + 0.5% thymol) [1%(C + T)]. Then chemical [pH, volatile basic nitrogen, peroxide value, and thiobarbituric acid], microbiological (total viable count) and sensory analyses were used to evaluate the preservative effect of this new technology during storage at 5 and 25 °C. Our results from the chemical assays indicated that EW(−), followed by EW(+) and subsequently 1%(C + T) [EW(−)/EW(+)/1%(C + T)], significantly suppressed the lipid oxidation compared with other treatments. Data from sensory evaluation and microbiological assay showed that treatment with EW(−)/EW(+)/1%(C + T) extended the shelf-life of carp fillets to 16 and 1.3 days compared with 4 and 0.3 days for the control samples during storage at 5 and 25 °C, respectively.     

Effect of marinating and vacuum storage at 6 °C on the fate of chemical, microbial and sensory quality indices of echinoid gonads Paracentrotus lividus Lamark, 1816

Chemical, microbial and sensory quality indices of raw and marinated sea urchin Paracentrotus lividus Lamark, 1816, were determined. Marinades were prepared using three different formulations and stored over a 75-day period at 6 °C, under vacuum and air (control) packaging conditions. Significant differences were found between chemical (pH, moisture, ash, NaCI, ammonia and lactic acid), microbial [pseudomonads (Ps), lactic acid bacteria (LAB) and yeast–moulds] and sensory analysis of three different marinated groups ( P  <   0.05) during the storage period. The marinating process did not lead to significant differences in fatty acid, protein, fat and carbohydrate contents relative to raw sample. A notable decrease of the ω-3 per ω-6 ratio after marinating and during storage in both packages was observed. Ammonia concentration changes were found to be useful as index of freshness and decomposition of roe in storage. Shelf life of roe marinades at 6 °C was found to be 75 and 60 days under vacuum and air storage conditions respectively.     

BIOGENIC AMINES FORMATION IN SARDINE MARINADE DURING REFRIGERATED STORAGE

Biogenic amines (tyramine, putrescine, cadaverine, histamine, spermidine, spermine) in sardine marinade were investigated. Sardine were beheaded, gutted, filleted, washed and marinated by immersing the fish into solutions containing 2 and 4% acetic acid and 10% NaCl for 24 h. Biogenic amine content, sensory scores and pH values of marinated sardine were recorded during the storage at 4C for up to 5 months. Biogenic amine content in marinated sardine was higher than in raw material. There were significant (P<0.05) differences in biogenic amine content between acetic acid concentrations of 2% and 4% just after marinating. Initial values of biogenic amines in marinade with 4% acetic acid were significantly (P<0.05) lower than those in marinade with 2% acetic acid. The contents of tyramine***, putrescine and histamine in sardine marinade decreased in the first 2–3 months of storage, followed by continuous increase up to 5 months of the storage. After decrease in the first month, cadaverine level did not significantly change. According to results, the marination process influences biogenic amine accumulation.