花鲈冰藏过程中肌原纤维蛋白生化特性与新鲜度变化的相关性

为研究冰藏期间花鲈鱼片的品质及蛋白质生化特性的变化,通过感官评分、pH、质构、色差、硫代巴比妥酸值(TBA值)、挥发性盐基氮(TVB-N)值、菌落总数(TVC)和肌原纤维蛋白含量、巯基、羰基含量的测定及十二烷基硫酸钠—聚丙烯酰胺凝胶电泳(SDS-PAGE)确定了冰藏花鲈鱼片理化指标变化,并对肌原纤维蛋白生化特性与主要的...     

Effect of Soluble CO2 Stabilization on the Quality of Fillets from Farmed Gilthead Sea Bream (Sparus aurata) and European Sea Bass (Dicentrarchus labrax)

ABSTRACT

Soluble gas stabilization (SGS) is a relatively recent methodology of active packaging that has been proposed to extend the shelf life of packaged fish. The aim of the present work was to study the effect of SGS applied at different extents (2 bars: 30 and 60 min) on the shelf life of sea bream and sea bass fillets packed in air during chilled storage. Quality changes were evaluated by sensory assessment, microbiological analysis (TVC), TBARs, pH value, TVB-N, and TMA-N. No significant extension of sensory shelf life was visible as a function of SGS treatment. The treatment of fillets in CO₂ at 2 bars during 60 min had a positive effect on the microbiological shelf life of both species. On the other hand, TMA-N and TVB-N showed similar changes during storage period and were not affected by the CO₂ treatment. Sea bream treated with SGS always presented higher TBARs than control samples. Nevertheless, oxidation of sea bream and in particular, of sea bass fillets, did not appear to be a significant problem during chilled storage.     

竹叶抗氧化物浸泡结合乳清分离蛋白涂膜对冷藏富硒虹鳟食用品质的影响

为延长冷藏富硒虹鳟的货架期,实验以3种浓度的竹叶抗氧化物溶液(AOBS,质量浓度分别为0.5％、1.0％和1.5％)分别浸泡富硒虹鳟鱼块,再进行乳清分离蛋白溶液(WPIS)涂膜,(25±1)℃下鼓风吹干表面水后置于4℃冰箱贮藏1、4、7、10和13 d,测定鱼块的pH值、TVB-N值、K值、菌落总数和嗜冷菌数、结合水分...     

Comparison of the effects of six stunning/killing procedures on flesh quality of sea bass (Dicentrarchus labrax,Linnaeus 1758) and evaluation of clove oil anaesthesia followed by chilling on ice/water slurry for potential implementation in aquaculture

The effects of different stunning/killing procedures on flesh quality of European sea bass were investigated: (1) anaesthesia with clove oil, (2) anaesthesia with 2‐phenoxyethanol, (3) percussive stunning, (4) immersion in ice/water slurry, (5) chilling on ice and (6) anaesthesia with clove oil followed by immersion in ice/water slurry. Muscle pH values were significantly lower in sea bass anaesthetized or stunned by a blow to the head compared with fish immersed in ice/water slurry, chilled on ice or immersed in ice/water slurry after clove oil anaesthesia. Lightness was highest in sea bass anaesthetized by 2‐phenoxyethanol or percussively stunned and lowest in ice‐chilled fish. Redness and yellowness were highest in fish chilled on ice and lowest in fish anaesthetized with clove oil. Liquid loss, fat loss and shear values were not significantly different among the procedures. In general, lipid oxidation values during refrigerated or frozen storage did not significantly differ among treatment groups. Combination of clove oil anaesthesia followed by chilling on ice/water slurry appears to improve both flesh quality and welfare of sea bass, although the implementation of further studies is warranted to consolidate this finding.     

北极虾在不同冷藏条件下的质量变化与质量指标

采用感官评估、物理、化学、微生物分析方法,对贮藏在不同冷藏条件下的北极虾的质量变化与质量指标进行了研究。保藏方法分别为传统冰块冷却法、液态冰冷却法、盐水-冰混合冷却剂法,贮藏环境温度为-1．5℃或1．5℃。研究结果表明,液态冰冷藏法对延缓虾腐败变质的效果比传统冰块冷藏法、盐水-冰混合冷却剂冷藏法好。经过1d的贮藏后发现,无论在-1．5℃还是1．5℃的环境温度下,保藏在液态冰中虾的挥发性总氮(TVB-N)都有所下降,并且在-1．5℃的环境温度下,其TVB-N值在3d后才回升到刚开始贮藏时的水平,而在其它保藏方法中,虾的TVB-N值始终随贮藏时间的延长而增加;除保藏在液态冰-1．5℃环境中虾的三甲胺(TMA)在贮藏的第1天有所降低以外,其它各试验组虾的TMA值均随贮藏时间的延长而增加。检测结果还表明,保藏在传统冰块及盐水-冰混合冷却剂中虾的细菌总数(TVC)增加最快,其次是保藏在液态冰中1．5℃的环境下。而保藏在液态冰中-1．5℃的环境下,虾的细菌繁殖最慢,并且在贮藏初期,产生了明显的细菌总数降低及细菌繁殖被抑制的现象。采用主要因子分析(PCA)和方差分析(ANOVA)发现,质量指标如TVB-N、TMA、TVC、pH、NH3(电子鼻测量值)和感官评估结果等相互之间存在着良好的相关性。     

Effects of Modified Atmospheric Packaging Conditions on the Quality Changes of Pasteurized Oyster (Crassostrea belcheri) Meat during Chilled Storage

ABSTRACT

The effects of different atmospheric conditions on the quality and the shelf life of pasteurized oyster meat in chilled storage were investigated. The alternatives tested for pasteurized oyster meat were normal air (Control), 75% CO₂/25% N₂ (MAP-1), 75% CO₂/25% O₂ (MAP-2), 75% CO₂/5% O₂/20% N₂ (MAP-3), and vacuum packing (VP). The various observations of microbiological (total viable count (TVC), Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria (LAB), and hydrogen sulfide–producing bacteria), physical (color coordinates L*, a*, and b*, and cutting strength), chemical (moisture, pH, total volatile basic nitrogen (TVB-N), peroxide value (PV), and thiobarbituric acid reactive substances (TBARS)) and sensory properties were performed every 3 days over a total of 27 days. During storage across all the treatments, L*, a*, cutting strength, pH, moisture content, and sensory scores decreased; whereas, b*, TVB-N, PV, TBARS, and microorganisms increased. However, among the various alternatives, MAP-1 had the best retention of oyster quality during storage. Based on sensory and microbiological qualities, the shelf lives in chilled storage were 9 days for control, 15 days for VP, 21 days for MAP-2 and MAP-3, and 24 days for MAP-1-treated cases.     

Linseed oil inclusion in sea bream diets: effect on muscle quality and shelf life

Dietary lipid source in aquaculture has become a central topic in research whilst natural resources availability diminishes. Hence, to weigh up and forecast consumers impressions, the impact of partial (70%) and complete (100%) dietary replacement of fish oil (FO) by linseed oil (LO) on sensory and quality attributes was studied during the edible shelf life of gilthead sea bream (Sparus aurata). Physico‐chemical parameters (pH, torrymeter, total volatile basic nitrogen, thiobarbituric acid reactive substances and texture), and sensory analysis, both in cooked and raw fish were carried out during 17 days of ice storage. Throughout ice storage, feeding with LO diets, TBARS values remained lower on muscle than those found when feeding FO control diet. On freshly caught fish (day 0 of ice storage), statistically significant dietary texture variations were recorded on cooked fillet fed FO diet. No sensory differences on Quality Index Method, sensory profile or Torry scheme were found with partial or total LO replacement diets.     

Stress assessment,quality indicators and shelf life of three aquaculture important marine fish,in relation to harvest practices,water temperature and slaughter method

The objective of this study was to evaluate the effect of harvest practices and slaughter method on stress, quality and shelf life of whole fish (gilthead sea bream, European sea bass and red sea bream) towards the development of a humane slaughter practice. The use of hook and line resulted in significantly lower plasma cortisol and glucose in European sea bass and gilthead sea bream. Water temperature at harvest affected significantly the concentrations of stress indicators (plasma cortisol and glucose), mainly in European sea bass and gilthead sea bream. No significant differences were observed between the harvesting methods, regarding fish appearance, microbial spoilage and sensory scoring and subsequently shelf life. However, significantly lower hardness was recorded in fish harvested using the electric stunner, compared to the fish killed with slurry ice of the same harvesting period. Shelf life ranged between 13–18 days for gilthead seabream, 10–16 days for European sea bass and 10–14 days for red sea bream, depending on harvesting period.     

南极磷虾冻藏温度下的品质变化及其货架期分析

以出肉率及化学变化(pH、TVB-N、TBARS、Ca² -ATPase活性)为指标,结合感官评价,探讨了南极磷虾冻藏温度下(-8、-18和-28 ℃)的品质变化及货架期。实验结果显示,南极磷虾感官评分与冻藏时间和冻藏温度均有显著的相关性(r=0.982和0.981),-8 ℃条件下20 d后南极磷虾感官不可接受,-18和-28 ℃条件下南极磷虾分别在75和120 d时感官不可接受;出肉率与冻藏时间有显著的相关性(r=0.953),在-8、-18和-28 ℃条件下南极磷虾出肉率在货架期终点分别达到31.62%、31.21%、34.52%;pH与冻藏时间和冻藏温度相关性不明显,不适宜用作反映南极磷虾冻藏条件下的品质指标,但随时间的延长pH仍呈增长趋势,在货架期终点3种冻藏温度下南极磷虾pH分别达到7.94、7.99、7.84;TVB-N和TBARS分别与冻藏时间有显著相关性(r=0.944和0.935),但TVB-N只与-8 ℃条件下的温度有显著相关性,TBARS只与-18和-28 ℃冻藏温度有显著相关性,在货架期终点时(感官不能接受)3种冻藏温度下南极磷虾TVB-N和TBARS分别为21.43、20.49、19.74 mg/100 g和0.88、0.78、0.66 mg MA/kg,均低于腐败水平阈值;Ca² -ATPase活性下降显著,与冻藏时间呈显著相关性(r=-0.929)。南极磷虾感官指标、出肉率、TVB-N、TBARS、Ca² -ATPase活性均在冻藏期间有明显变化,且与冻藏时间有明显的相关性,可以考虑用作反映冻藏条件下南极磷虾品质变化指标。因此,综合各项指标并结合感官评价,可以判断实验过程中3种冻藏温度下南极磷虾货架期终点分别为20、75、120 d。     

Effect of Chitosan and Garlic Essential Oil on Microbiological and Biochemical Changes that Affect Quality in Grass Carp (Ctenopharyngodon idellus) Fillets During Storage at 4°C

Solutions of chitosan (2%, w/v), garlic essential oil (5%, v/v), and their combination (2%, w/v chitosan +5%, v/v garlic essential oil) were applied to the surface of grass carp fillets. Subsequently, sensory, microbiological analyses (total viable count (TVC), Pseudomonas spp., Aeromonas spp., and H₂S-producing bacteria), and physicochemical changes (total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and centrifugation loss) of grass carp fillets were evaluated over a 16-day storage at 4 ± 1°C. The treated samples resulted in significantly (p < 0.05) higher overall acceptance scores than the control from day 8. The TVC of grass carp fillets was reduced from the initial level (4.0 log CFU/g) to 2–3 log CFU/g when the fillets were treated with either garlic essential oil or chitosan solution. After 4 days of storage, the Pseudomonas spp. counts in the chitosan-treated samples were significantly lower (p < 0.05) than the counts in control and samples treated with garlic essential oil. A lag phase of 6 days for the counts of H₂S-producing bacteria of fish fillets that were treated with chitosan or the combination solution was observed. The combination of chitosan with garlic essential oil did not show synergistic effects, although it displayed a higher degree of antimicrobial efficacy with respect to the spoiled bacteria. However, the combination of chitosan with garlic essential oil was the most effective at inhibiting the formation of TVB-N. Samples that were treated with garlic essential oil displayed the highest TBARS levels on days 4 and 6 (p < 0.05).     

Quality Indices of Squid (Photololigo duvaucelii) and Cuttlefish (Sepia aculeata) Stored in Ice

The objective quality indices of squid (Photololigo duvaucelii) and cuttlefish (Sepia aculeata) stored in ice were compared with the subjective counterparts. Sensory (overall quality rating, quality index method [QIM], and multisample difference test), microbiological (total viable count [TVC], psychrophilic count), chemical (trichloroacetic acid-soluble peptide [TCA-soluble peptide], trimethylamine nitrogen [TMA-N], total volatile bases nitrogen [TVB-N], ammonia content, and protein pattern), and physical analyses (expressible drip, color, and texture) were determined in both species during 16 days of iced storage. As storage time increased, TCA-soluble peptide, TVB, ammonia content, and expressible drip were increased (p < 0.05). TMA content was markedly increased after 10 and 8 days of storage in squid and cuttlefish, respectively. Both TVC and psychrophilic count increased as the storage time increased (p < 0.01). Myosin heavy chain was degraded with coincidental decrease in shear force and sensory texture during storage (p < 0.05). According to the overall rating score, shelf life of both species in ice was estimated to be 6 days. The increases in ammonia content and expressible drip were highly correlated with the decrease in overall quality rating and increase in quality index score of squid and cuttlefish (p < 0.01).     

A Comparative Study on the Quality Changes of Croaker (Johnius dussumieri) Fish Stored in Slurry Ice and Flake Ice

In the present study, the effect of storage in slurry ice compared to conventional flake ice (control) on the quality of croaker (Johnius dussumieri) fish was evaluated. Biochemical, microbiological, and sensory analyses were performed. Total volatile base nitrogen, trimethylamine nitrogen, and pH values were lower for fish stored in slurry ice than in control. Similarly, aerobic plate count and Pseudomonas sp. count were also found at lower population levels in fish stored in slurry ice. Texture profile analysis revealed that fish stored in slurry ice showed improved texture. Based on the microbiological and sensory analysis, the shelf life of croaker fish stored in slurry ice was 15 days.     

日本枪乌贼(Loligo japonica)不同温度冻藏过程中的品质变化

选取-20℃、-30℃和-50℃3个冻藏温度,以TVB-N值、肌原纤维蛋白含量、Ca2+-ATPase活性、巯基含量、TBARS值及肌肉组织微观结构为指标,结合感官评分,对比分析90 d内日本枪乌贼(Loligo japonica)的品质变化规律。结果显示,在不同冻藏温度下,随着时间的延长,Ca2+-ATPase活性和感官评分不断下降;肌原纤维蛋白和巯基含量,则先略微上升而后快速下降;TVB-N值和TBARS值呈不断上升的趋势,且温度越高上升速率越快;肌肉组织微观结构分析表明,枪乌贼肌纤维结构在冻藏过程中逐渐变得松散。相比-20℃,-30℃和-50℃冻藏温度条件下更能长久地保持枪乌贼品质,且品质无显著差异。综合分析认为,冻藏温度低于-30℃时,可较好地保持枪乌贼品质。     

Effect of Delayed Icing on the Microbiological,Chemical, and Sensory Properties of Caspian Sea Golden Grey Mullet (Liza aurata)

Research has shown that fresh fish is an extremely perishable food as compared to other food commodities. In this study, quality deterioration during storage of golden grey mullet (GGM) iced for 0, 6, and 12 h after landing was monitored. Microbiological indices (total viable count, TVC; psychrophilic counts, PTC; lactic acid bacteria, LAB; and Enterobacteriaceae counts, EBC), chemical parameters (pH; total volatile basic nitrogen, TVB-N; peroxide value, PV; thiobarbituric acid, TBA; and free fatty acids, FFA) values increased over the preicing duration. Delayed icing did not lead to significant increases (p > 0.05) in TVC, PTC, LAB, and EBC throughout the period of storage. All chemical indices increased during storage (p < 0.05). This study showed that sensorial analysis of GGM correlated well with microbiological analysis. Results of this study based on the microbiological and raw fish sensorial data indicated that the shelf life of GGM stored in ice immediately after catch was approximately 10–11 days, while the 6- and 12-h delays in icing shortened the shelf life to approximately 6–7 and 2–3 days, respectively.     

Effects of Lactic Acid Bacteria and Citrus Essential Oil on the Quality of Vacuum-Packed Sea Bass (Dicentrarchus labrax) Fillets During Refrigerated Storage

The preservative effect of refrigerated and vacuum-packed sea bass (Dicentrarchus labrax) fillets inoculated with four mixtures of lactic acid bacteria (LAB) (Lactococcus lactis, Lactobacillus plantarum, and Carnobacterium piscicola) and incorporated with citrus essential oil (CEO) was evaluated on the basis of microbiological and biochemical analysis.

Initially, sea bass fillets showed high nutritional quality. During refrigerated storage, lipid contents did not show a significant decrease in any fish fillets; meanwhile, important proteolysis was observed in untreated control. In addition, results indicated that both CEO and LAB strains exhibited antimicrobial activity against spoilage, pathogenic, and fungi flora. Moreover, the total volatile bases (TVB-N) values were higher in control fillets, and the lowest TVB-N values were observed in Control CEO and C3 + CEO (30.47 ± 0.00 and 32.29 ± 1.12 mg TVB-N/100 g, respectively). Also, the levels of biogenic amines increased in all fillets without exceeding the upper limit of acceptability except for untreated control (sum of about 1396.63 ppm). Furthermore, this combined treatment ameliorated the muscle liquid-holding capacity, which improves technological properties.

Overall, this treatment may open new promising opportunities for the biopreservation of fish products by enhancing the period of storage of refrigerated and vacuum-packed sea bass fillets.     

南极大磷虾0、5和20℃贮藏中的品质变化

以感官、细菌总数、嗜冷菌数、TVB-N和TMA-N为指标,探讨了南极大磷虾在0、5和20℃贮藏中的品质变化,结合三氯乙酸可溶性氮含量和细菌菌相的变化对南极大磷虾腐败作用进行了分析。结果表明,南极大磷虾品质下降很快,0℃和5℃温度下15 h后品质不可接受,20℃温度下8 h后品质不可接受。0、5和20℃贮藏中南极大磷虾细菌总数、嗜冷菌数、TVB-N、TMA-N都有增加,三氯乙酸可溶性氮含量变化明显,细菌菌相变化不大,表明0、5和20℃贮藏中南极大磷虾自溶迅速,酶对其腐败起主要作用。     

Determination of the quality parameters of pike perch <Emphasis Type="Italic">Sander lucioperca</Emphasis> caught by gillnet,longline and harpoon in Turkey

ABSTRACT:   The effects of the different catching methods (gillnet, longline, harpoon) on sensory, chemical (pH, total volatile base nitrogen, K -value) and microbiological (total viable count [TVC]) changes in pike perch Sander lucioperca stored in ice were investigated. The same soaking time was used for both gillnet and longline fishing. The catching method had considerable influence on the freshness quality of pike perch. The acceptable shelf life was 15 days for pike perch caught by gillnet, and 22 days for longline and harpoon. The initial concentrations of inosine monophosphate (2.4 μmol/g) in pike perch caught by gillnet were significantly lower ( P  < 0.05) than longline (4.1 μmol/g), and especially by harpoon (16.7 μmol/g). However, the initial K -values for fish caught by harpoon were significantly ( P  < 0.05) lower (24.36%) than fish caught by longline and gillnet (57.69%, 64.41%, respectively). The average K , Ki, G and H -values at rejection day in terms of sensory assessment were approximately 90, 98, 156 and 40%, respectively, for all catching methods during ice storage. However, TVC reached 7.0 log cfu/g after approximately 11 days of storage for fish caught by gillnet, 19 days for fish caught by longline and 8 days for fish caught by harpoon. The result of this study suggests that the best catching method for preserving the freshness of pike perch is longline, based on the data obtained from the sensory and microbiological analysis.     

The Relationship Between Electric Impedance and Quality Parameters of Ungutted and Gutted Common Carp (Cyprinus carpio) Stored at 4°C

In order to understand the relationship between electric conductivity and quality parameters of common carp during storage, the electric impedances in the frequencies ranging from 1 to 20 kHz, total viable count (TVC), total volatile basic nitrogen (TVB-N), and K values of gutted and ungutted common carp were determined during 4°C storage. The result showed that the change ratio of electric impedance (Q value) of both gutted and ungutted common carp decreased with increasing storage time, while TVC, TVB-N, and K values increased gradually. There was a good correlation between Q values and TVC, TVB-N, and K values of gutted and ungutted common carp, and their correlation coefficients were 0.952, 0.965, 0.928, and 0.956, 0.975, and 0.938, respectively. This result demonstrated that Q value is valid to predict some quality parameters of common carp during 4°C storage.     

Chemical Parameters for Traceability of Raw Material Freshness of Tropical Surimi

ABSTRACT

Changes in chemical parameters of tropical fish used for surimi production—namely, threadfin bream (TB; Nemipterus spp.), lizardfish (LZ; Saurida spp.), and goatfish (GF; Upeneus spp.)—during ice storage and their respective washed mince were investigated. Total volatile basic nitrogen (TVB-N), trimethylamine (TMA), hypoxanthine (Hx), and total biogenic amine (BA) content of mince increased with storage time. Crude protein of fish and their respective washed mince reduced as storage time of fish was prolonged. Principal component analysis (PCA) revealed that washed mince produced from fish stored in ice for 7–12 days showed chemical characteristics that were distinct from those of washed mince prepared from spoiled fish. The TMA, TVB-N, and Hx content of washed mince appeared to be sufficient raw material freshness indicators in these three species.     

Effect of Fish Gelatin Coating Enriched with Oregano Essential Oil on the Quality of Refrigerated Rainbow Trout Fillet

ABSTRACT

In the present study, the effect of fish gelatin coating (FG; 4%, w/v) containing oregano (Origanum vulgare L.) essential oil (OEO; 1.2% w/v) on shelf-life extension of rainbow trout (Oncorhynchus mykiss) fillet stored under refrigerated storage (4 ± 1ºC) was investigated. The control and the treated fish samples were analyzed periodically for chemical (pH; total volatile basic nitrogen, TVB-N; peroxide value, PV; thiobarbituric acid, TBA) and microbiological (total viable count, TVC; psychrotrophic count) characteristics. The FG + OEO treatment produced significantly lower (p < 0.05) TVB-N values as compared to control and FG-coated samples after Day 6 and until the end of the storage period. The TBA values remained low and were found to fluctuate during storage. Results showed that TVC exceeded 6 log CFU g^?1 on Day 8 of storage for control and FG-coated samples and Day 12 for samples coated with FG + OEO. The reduction of 1.05 and 0.83 log CFU g^?1 of psychrotrophic counts was achieved by FG + OEO coating in trout fillet (p < 0.05) as compared with control and FG-coated samples, respectively. Therefore, the incorporation of OEO into FG coating may be a promising method of maintaining the storage quality of the rainbow trout fillet stored at refrigerated temperature.