DETERMINATION OF THE QUALITY AND SHELF LIFE OF SOUS VIDE PACKAGED BONITO (SARDA SARDA,BLOCH, 1793) STORED AT 4 AND 12C

ABSTRACT

The aim of this study was to determine the quality and shelf life of sous vide bonito stored at 4 and 12C. The total volatile basic nitrogen (TVB‐N) values of cold stored samples exceeded the recommended limit on 35th day of storage, while they were unacceptable according to sensory scores. The TVB‐N and trimethylamine‐N values of sous vide samples stored at 12C exceeded the limits at the 18th day, while sensory scores were very close to the acceptability limit. For all samples, mesophilic and psychrophilic bacterial counts exceeded the limits after they were regarded as spoiled. Therefore, the shelf life of the sous vide bonito, cooked at 70C for 10 min, was 28 days at 4C while 15 days at 12C. It was seen that sous vide packaging provided a long shelf life for bonito.

PRACTICAL APPLICATIONS

Sous vide is a long established but relatively little known cooking process. The data regarding the effect of storage temperature on shelf life and quality of sous vide fish are very limited. Therefore, this study aimed to determine the sensory, microbiological and chemical quality of sous vides packaged bonito during refrigerated storage (4 ± 1C) and abuse temperature conditions (12 ± 1C). The results of this study can be utilized by researchers in future studies as well as by manufacturers to determine the processing and storage conditions of sous vide fish.     

Microbiological,chemical and sensory changes of whole and filleted Mediterranean aquacultured sea bass (Dicentrarchus labrax) stored in ice

The effect of filleting on the microbiological, chemical and sensory properties of aquacultured sea bass (Dicentrarchus labrax) stored in ice was studied. Pseudomonads, H₂S‐producing bacteria (including Shewanella putrefaciens) and Brochothrix thermosphacta were the dominant bacteria at the end of the 16 day storage period in ice for both whole ungutted and filleted sea bass. Enterobacteriaceae were also found in the spoilage microflora of whole ungutted and filleted sea bass, but their counts were always lower than those of pseudomonads, H₂S‐producing bacteria (including S putrefaciens) and B thermosphacta. Total viable counts for whole ungutted sea bass were always lower than those for filleted sea bass samples. Of the chemical indicators of spoilage, TMA (trimethylamine) values of whole ungutted sea bass increased very slowly, whereas significantly higher values were obtained for filleted samples, with respective values of 0.253 and 1.515 mg N per 100 g muscle being reached at the end of their shelf‐life (days 13 and 9 respectively). TVB‐N (total volatile basic nitrogen) values showed a slight increase for whole ungutted sea bass during storage, reaching a value of 26.77 mg N per 100 g muscle (day 13), whereas for filleted fish a corresponding value of 26.88 mg N per 100 g muscle was recorded (day 9). TBA (thiobarbituric acid) values increased slowly for whole ungutted and filleted sea bass samples throughout the entire storage period, reaching final values of 4.48 (day 13) and 13.84 (day 9) mg malonaldehyde kg^?1 respectively. Sensory assessment of raw fish using the EC freshness scale gave a grade E for up to 5 days for whole ungutted sea bass, a grade A for a further 4 days and a grade B for an additional 4 days, after which sea bass was graded as C (unfit). Overall acceptability scores for odour, taste and texture of cooked whole ungutted and filleted sea bass decreased with increasing time of storage. The results of this study indicate that the shelf‐life of sea bass stored in ice, as determined by overall acceptability sensory scores and microbiological data, is 8–9 days for filleted and 12–13 days for whole ungutted fish. Copyright © 2003 Society of Chemical Industry     

Quality retention during the chilled distribution of farmed turbot (Psetta maxima): effect of a primary slurry ice treatment

The quality and shelf‐life of chilled farmed turbot (Psetta maxima) was evaluated by sensory, microbiological and biochemical procedures after being subjected to a two‐step refrigeration storage in slurry ice and flake ice, respectively. Turbot specimens were stored for 10 or 17 days in slurry ice, and then were transferred to flake ice for 1–3 days to simulate the sale conditions in the market. The results were compared with control batches stored only in flake ice and processed in parallel. Storage of turbot in the two‐step strategy resulted in a better maintenance of sensory quality, especially with regard to its mucus production and gill odour development, better control of microbial activity, especially of aerobes, and the slowing down of some biochemical degradation mechanisms such as the nucleotide degradation pathway and trimethylamine production. As a consequence, the shelf‐life was extended significantly. From these results it can be concluded that the refrigerated transport of farmed turbot in slurry ice enhances its shelf‐life, before its transfer into flake ice in the retail market.     

Effect of the Icing with Rosemary Extract on the Oxidative Stability and Biogenic Amine Formation in Sardine (Sardinella aurita) During Chilled Storage

The effect of icing with the rosemary extract on the quality and safety of sardines (Sardinella aurita) was assessed through the chemical, sensory and microbiological methods. The sensory acceptability limit was 12?days for sardine stored in traditional ice and 15?days for sardine stored in ice prepared from rosemary extract solution. There were no significant differences between sardine stored in ice with both 0.05% and 0.1% rosemary extract in terms of sensory acceptability. Storage of sardine in ice containing rosemary extract improved the sensory and some of the chemical quality parameters as compared with the traditional icing, which resulted in a significant extension in the shelf life of sardine. Eleven biogenic amines were determined for food quality and safety. Icing containing rosemary extract had a positive effect, causing low biogenic amine content, especially histamine and putrescine. Histamine content of sardine also increased rapidly with time when the number of bacteria reached above 10⁶ cell/g, which is a good correlation between histamine content and number of bacteria. Consequently, the application of ice containing rosemary extract improved the quality and safety of sardine, which can be explored by the food industry.     

Sensory,microbial and chemical effects of a slurry ice system on horse mackerel (Trachurus trachurus)

Slurry ice, a biphasic system consisting of small spherical ice crystals surrounded by seawater, was evaluated in parallel with flake ice for the storage of horse mackerel (Trachurus trachurus). Storage in slurry ice led to a significant enhancement of shelf life (5 days for flake ice to 15 days for slurry ice), better control of pH and lower counts of total aerobes and proteolytic and lipolytic bacteria, these reaching an average difference between batches of 2, 1.43 and 1.98 log units respectively after 8 days of storage. Storage in slurry ice also involved a significantly slower formation of total volatile basic nitrogen and trimethylamine after 8 days of storage. Staphylococcus xylosus and Proteus penneri were identified as the leading proteolytic and lipolytic organisms in horse mackerel muscle. Storage of horse mackerel in slurry ice enhances the shelf life of this medium‐fat fish species through better maintenance of sensory and microbiological quality. Copyright © 2004 Society of Chemical Industry     

Freshness and quality attributes of cold stored Atlantic bonito (Sarda sarda) gravad

Quality and safety parameters of Atlantic bonito gravad during 42 days of storage at 7 ± 1 °C were analysed using monitoring sensory quality, microbial contamination, nucleotide degradation products, biogenic amines (BA), trimethylamine (TMA) and thiobarbituric acid reactive substances (TBARS). The shelf‐life of vacuum packed Atlantic bonito gravad was found to be 28 days. Total viable count (TVC) did not exceed 6 log CFU g^?1. Malonodialdehyde (MDA) content did not surpass 10 mg kg^?1. Nine biogenic amines were detected. Histamine level at the end of the storage was 355.3 mg kg^?1. TMA increased from 53.9 to 619.1 mg kg^?1. Among indicators based on the products of nucleotide degradation, the H value is best correlated with the sensory assessment. It can be concluded that the storage temperature of bonito gravad must be below 7 °C to prevent the threat to safety and quality posed by biogenic amines, especially histamine.     

The effect of lemon juice on bonito (Sarda sarda,Bloch, 1793) preserved by sous vide packaging

This study examined the effect of lemon juice on sensory, biochemical and microbiological quality of sous vide (SV)‐packaged bonito. Bonitos were salted (0.2%) and divided into two groups. The first group (SV) was vacuum‐packaged in a gas barrier plastic pouch, pasteurised (70 °C, 10 min) and stored at 4 ± 1 °C. The second group [(lemon juice‐treated sous vide (LSV)] was treated with lemon juice, vacuum‐packaged, pasteurised and stored similarly. LSV samples had lower pH, mesophilic and psychrophilic aerobic counts than SV samples (P < 0.05), and they had better sensory quality. SV samples spoiled on the 35th day, while the LSV samples were acceptable until 49th day of storage. This result shows that treatment with lemon juice increased the acceptability and shelf life of SV packaged bonito for 2 weeks (40%). When compared to several other mild preservation procedures, addition of lemon juice to SV fish is inexpensive and uncomplicated method.     

Preservation of iced refrigerated sea bream (Sparus aurata) by irradiation: microbiological, chemical and sensory attributes

Quality and shelf life of non-irradiated and irradiated (2.5 and 5 kGy) sea bream in ice conditions and stored at +4 °C were investigated by measurement of microbiological, chemical and sensory analysis. Microbial counts for non-irradiated sea bream samples were higher than respective irradiated fish. Total volatile base nitrogen (TVB-N) values increased value of 38.64 mg/100 g for non-irradiated, sea bream during iced storage whereas for irradiated fish lower values of 13.48 and 12.06 mg/100 g were recorded at 2.5 and 5 kGy, respectively (day 19). Trimethylamine (TMA-N) values and thiobarbituric acid (TBA) values for irradiated samples were lower than non-irradiated samples. Acceptability scores for odour, taste and texture of cooked decreased with storage time. The sensory scores of sea bream stored in control and 2.5–5 kGy at +4 °C were 13 and 15 days, respectively. The results obtained from this study showed that the shelf life of sea bream stored in ice, as determined by overall acceptability all data, is 13 days for non-irradiated sea bream and 15 days for 2.5 kGy irradiated and 17 days for 5 kGy irradiated sea bream.     

Quality assessment of whole and gutted sardines (Sardina pilchardus) stored in ice

The quality and shelf life of whole ungutted and gutted sardines ( Sardina pilchardus ) stored in ice were studied. The changes in the fish were investigated by sensory assessments, chemical analyses and microbiological analyses. The sensory scores of uneviscerated and gutted sardines stored in ice at +4 °C were 7 days. The chemical indicators of spoilage, total volatile basic nitrogen and trimethylamine values of gutted sardine increased very slowly, whereas for whole ungutted samples higher values were obtained reaching a final value of 15.03–29.23 mg per 100 g and 2.36–4.16 mg per 100 g, respectively (day 9). Peroxide and thiobarbituric acid values remained lower for whole ungutted sardine samples until day 9 of storage, whereas for gutted fish were higher. The level of histamine exceeded the legal limit in whole ungutted sardine after 7 days of storage in ice, during which sardines were rejected by the sensory panel. Mesophilic aerobic bacteria count, H₂S-producing bacteria, sulphide reducing anaerobe Clostridias, Enterobacteriaceae count of whole ungutted sardine samples are higher than gutted sardine samples during the storage. Psychrotrophic bacteria counts of the two groups were not different. The limits of microbiological data were not exceeded throughout the storage in both the groups' samples.     

Quality of monosex tilapia under ice storage: Gutting effects on the formation of biogenic amines,biochemical, and microbiological characteristics

Effects of gutting on biogenic amine (putrescine, cadaverine, histamine, agmatine, tyramine, spermidine, and spermine) formation, biochemical (pH, TVBN, K value), microbial (APC, H₂S producing, Coliform bacteria), and sensory quality of farmed monosex tilapia (Oreochromis niloticus) was studied during ice stored at 4 ± 2ºC. Spermine and spermidine levels were high with cadaverine reached 4.66 ppm in gutted sample. The other amines were detected at relatively low level. K value of both samples crossed 60% on 15th and 18th day, respectively. The total phenolic content exceeded 7 log cfu/g after sensory rejection. The shelf life of whole and gutted samples was estimated to be 24 and 21 days, respectively.     

Effect of ungutting on microbiological, chemical and sensory properties of aquacultured sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) stored in ice

The effect of ungutting on microbiological, chemical and sensory properties of aquacultured sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) stored in ice were studied. The total viable mesophilic and psychrophilic bacterial counts increased throughout the storage period of ungutted sea bream and sea bass. Mesophilic counts of ungutted sea bream and sea bass reached 7.39 log cfu/g and 7.26 log cfu/g after 9 days. At the end of the storage period of 14 days; TVB-N, TBA, TMA-N values of ungutted sea bream were determined as 37.5±0.51 mg/100 g, 3.82±0.03 mg MA/kg, 7.73±0.25 mg/100 g, respectively. TVB-N, TBA, TMA-N values of ungutted sea bass were reached 35.4±0.9 mg/100 g, 3.75±0.81 mg MA/kg, 6.94±0.08 mg/100 g on day 14th, respectively. Result of this study indicates that the shelf life of whole ungutted sea bream stored in ice as determined by the overall acceptability sensory scores, chemical quality and microbiological data is 12, 9 and 9 days, respectively. Each chemical, sensory and microbiological results for sea bream showed us that there was a correlation and similarity, and day 9 was the beginning of spoilage. Whole ungutted sea bass stored in ice as chemical results for sea bass showed us that day 7 was the beginning of spoilage and for sea bream day 9 was the beginning of spoilage.     

Biogenic amine survey and organoleptic changes in fresh, stored, and temperature-abused bluefish (Pomatomus saltatrix).

Changes in histamine, putrescine, and cadaverine concentrations in bluefish filets (Pomatomus saltatrix) stored at 5, 10, and 15 degrees C were determined using high-performance liquid chromatography. An organoleptic assessment was conducted simultaneously with the biogenic amine analyses. The histamine levels found in fresh bluefish obtained from wholesale seafood distributors ranged between <1 ppm and 99 with an average of 39 ppm. Putrescine and cadaverine were not found in fresh bluefish. Fish fillets stored at each of the three temperatures developed histamine. The greatest accumulation of histamine was observed in fish stored at 15 degrees C, which developed histamine levels as high as 2,200 ppm. Putrescine levels increased at each temperature during storage. Cadaverine was present only in uninoculated bluefish stored at 15 degrees C. Histamine achieved higher levels in bluefish pieces inoculated with Morganella morganii, which demonstrates that bluefish support bacterial histamine formation. Histamine levels at each temperature exceeded the 50-ppm advisory level established by the Food and Drug Administration before 100% sensory rejection. Standard plate counts increased during storage of fish at all temperatures, but the correlation between histamine levels and standard plate count was not significant.     

Chilled storage of golden gray mullet (Liza aurata)

This study determined quality changes of whole ungutted golden gray mullet (Liza aurata) while stored in ice or in a refrigerator (without ice). Changes in microbiological quality (total viable and psychrophilic counts, lactic acid bacteria and Enterobacteriaceae), chemical quality (pH, total volatile basic nitrogen, trimethylamine, peroxide value, thiobarbituric acid, and free fatty acids), and raw fish sensory attributes were evaluated during 16 days of storage. The sensory attributes of golden gray mullet correlated well with the microbiological analyses (r = 0.92). Based on the overall raw acceptability sensory scores and the microbiological tests, the shelf life of the raw golden gray mullet was 10 days in ice and about 14 days in a refrigerator.     

The effects of partial replacement of fish meal by vegetable protein sources in the diet of rainbow trout (Onchorynchus mykiss) on post mortem spoilage of fillets

Five test diets were formulated with decreasing levels of fish meal (up to 50%) replaced by alternative protein sources. Rainbow trout were fed the experimental diets for 12 weeks.The effects of feed ingredients on spoilage of Oncorhynchus mykiss in ice and under MAP/ice (40% CO₂, 30% N₂ and 30% O₂) were investigated in terms of sensory, chemical and microbiological analyses. The results showed that the trout in MAP/ice was rejected at 14 days, after sensory analysis, due to excessive drip, whereas trout in ice were found to be acceptable even after 14 days of storage. However, cooked trout fillets, under both storage conditions, were rejected at 17 days. Fish in ice produced higher K values and higher concentrations of biogenic amines during the storage period of 17 days than the fish in MAP/ice. Bacteria grew more quickly in rainbow trout kept in ice than in MAP/ice. MAP/ice storage extended the shelf life of rainbow trout by approximately 2 days compared to ice storage alone in terms of microbiological analyses.     

大菱鲆冷藏过程中新鲜度评价

为研究大菱鲆冷藏过程中的新鲜度变化规律,以菌落总数、挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、硫代巴比妥酸（thiobarbituric acid,TBA）值、腺苷三磷酸关联物和K相关值（K、Ki、H、Fr、G和P值,鱼肉新鲜度的参考指标）为指标,结合感官评定,探究大菱鲆在20 d贮藏期内的品质变化情况。结果表明：肌苷酸和Fr与贮藏时间呈显著负相关（r=－0.870,r=－0.887）;K值随贮藏时间延长显著升高直至趋于稳定（r=0.895）。因此,菌落总数、TVB-N含量、K值、感官评定适宜作为冷藏大菱鲆的新鲜度评价指标,且K值的灵敏度要高于菌落总数和TVB-N含量;TBA值不适宜作为冷藏大菱鲆的新鲜度指标;4 ℃冷藏环境下的大菱鲆货架期为12 d。     

Histamine, Putrescine and Cadaverine Formation in Spanish Semipreserved Anchovies as Affected by Time/Temperature

We studied the changes in counts of mesophilic, psychrotrophic, entera-bacteria, sulphite-reducing and Vibrio microorganisms in commercial samples of Spanish semipreserved anchovies. The influence of NaCl, oxygen concentration and pH on bacterial growth and histamine, putrescine and cadaverine formation were also studied. Notable histamine formation was detected in samples incubated at 20°C and preserved in olive oil (443.68 ppm-3012.13 ppm). This accumulation was probably caused by the conditions of the product, pH 5–6, relatively low NaCl (< 15%), and permissive temperature (product not refrigerated). Correlation between the microorganisms and histamine formation was not clear. Histamine was produced by too high storage temperatures but not by the ripening process.     

Development of a long‐life vacuum‐packaged ready‐to‐eat meat product based on a traditional Portuguese seasoned meat

Carne do alguidar is a Portuguese traditional pork fried meat, usually manufactured for self‐consumption purposes. This study developed a ready‐to‐eat (RTE) meat product, to meet today's consumers’ convenience, manufactured at the industrial scale evaluating its quality and shelf life, assessing the effect of vacuum packaging and the use of an antioxidant (50 ppm BHT) to enhance oxidative stability. Physicochemical and microbiological parameters were assessed, and a sensory analysis was performed. Interestingly, no significant differences were recorded between control (non‐BHT) and antioxidant (BHT) samples. Microbiological counts remained at low levels throughout the storage period, ensuring the product's required microbiological quality. At later storage stages, higher values of thiobarbituric acid‐reactive substances arose and off flavours and aromas were perceived. Still, overall appreciation was not affected until 12 months of storage and a significant depreciation was perceived only after 15 months. Fibrousness and rising of off flavours were negatively correlated with overall appreciation.     

The use of nisin as a preservative in fish sausage stored at ambient (28 ± 2 °C) and refrigerated (6 ± 2 °C) temperatures

Summary The efficacy of nisin at three different concentrations, 12.5, 25 and 50 ppm, on the keeping quality of fish sausage in synthetic casing at ambient (28 ± 2 °C) and refrigerated (6 ± 2 °C) temperatures was assessed. Gel strength, expressible water content, total volatile base nitrogen, total plate count and aerobic spore counts were affected by the storage temperatures and nisin concentrations used. Fish sausage treated with 50 ppm of nisin was acceptable after storage at ambient temperature for 20–22 days compared with the control, which were acceptable only for 2 days. The keeping quality of the sausages, at refrigerated temperature, varied from 30 days in the control to 150 days in 50‐ppm nisin‐treated samples. The residual nisin decreased slowly in samples stored at refrigerated temperature, whereas, in fish sausages stored at ambient temperature, the decrease was rapid. Nisin at 50‐ppm level showed a significant effect (P ≤ 0.05) on the gel strength and overall acceptability scores both at ambient and refrigerated temperature.     

Sensory, physical, chemical and microbiological changes in European sea bass (Dicentrarchus labrax) fillets packed under modified atmosphere/air or prepared from whole fish stored in ice

Quality changes and shelf‐life in European sea bass fillets packed under 40% CO₂: 60% N₂ (MAP) and air (AIR) or prepared from the whole ungutted fish stored in ice (ROUND) were compared. Raw and cooked sensory scores, pH, colour, expressible water, malonaldehyde, total viable count, Pseudomonas spp., H₂S‐producing bacteria, Lactobacillus spp., Streptococcus spp., Staphylococcus spp., coliforms and proteolytic counts, were determined until AIR and MAP raw fillet spoilage. Raw ROUND fillets had the best quality and shelf‐life (10 vs. 8 vs. 7 days after slaughtering in ROUND, MAP and AIR, respectively), while the MAP fillets had better sensorial scores, lower pH values and better microbiological counts, but greater lightness values than the corresponding AIR fillets. MAP fillets also had the highest malonaldehyde levels. The higher correlation between Streptococcus spp. and odour scores (r = ?0.971, P < 0.01) compared to the other species could suggest that it is a specific spoilage organism in the MAP condition used.