冰温发酵鳜鱼对鱼肉滋味及其生物胺含量的影响

以新鲜鳜鱼为原料,分别在冰温带(-2.5～0℃)和10℃条件下进行低盐自然发酵,研究冰温发酵鳜鱼相对于10℃发酵鱼肉滋味及鱼肉中生物胺含量的变化.分别测定2组发酵鱼肉呈味核苷酸、游离氨基酸、生物胺、pH、微生物、总挥发性盐基氮(total volatile basic nitrogen,TVB-N)等指标,结果表明,冰...     

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 assessment of gutted wild sea bass (Dicentrarchus Labrax) stored in ice, cling film and aluminium foil

The effects of aluminium foil and cling film on microbiological, chemical and sensory changes in wild sea bass (Dicentrarchus labrax) stored at chill temperature (4 °C) were studied. A quality assessment of wild sea bass stored in ice, in boxes without ice, wrapped in aluminium foil (WAF) and wrapped in cling film (WCF) at 4 °C was performed by monitoring sensory quality, nucleotide breakdown products, total volatile base nitrogen (TVB-N), and total viable counts (TVCs). The observed organoleptic shelf-life of sea bass was found to be 16 days in ice, 4 days in boxes without ice, 8 days in aluminium foil and 8 days in cling film. Demerit points did not differ significantly (P>0.05) between WCF fish and WAF fish. The nucleotide degradation pattern was found to be similar for all storage conditions except for inosine and hypoxanthine contents, which decreased after 12 days of storage for WAF and WCF. The content of TVB-N for all storage conditions showed similar tendencies until 12 days storage but reached the highest level (41.6 mg TVB-N 100 g^–1 flesh) for fish stored in WAF and WCF. No significant differences (P>0.05) were found in TVB-N concentrations within the treatments during the early stages of the storage period. Bacteria grew most quickly in the sea bass kept in boxes without ice, followed by those kept WAF, WCF and in ice. Significant differences (P<0.05) in TVC were observed amongst the treatments, especially between fish stored in boxes without ice and fish stored in ice     

Effects of using slurry ice during transportation on the microbiological, chemical, and sensory assessments of aquacultured sea bass (Dicentrarchus labrax) stored at 4 degrees C

Slurry ice, a biphasic system consisting of small spherical ice crystals surrounded by seawater at subzero temperature, was evaluated as a new chilled storage method for whole sea bass (Dicentrarchus labrax) a sparidae fish species of remarkable commercial interests. In this study two different group of chilling methods were used during transportation; in slurry ice packaged (Group A), and flake ice packaged (Group B). The effect of this advanced system during transportation on quality losses and the shelf life of aquacultured sea bass was evaluated. Mesophilic counts for sea bass exceeded 7 log cfu/g, which is considered the maximum level for acceptability for freshwater and marine fish after 13 days for groups A and B. On day 13 TVB-N values of groups A and B, reached the legal limits (35 mg/100 g set for TVB-N) for consumption. According to the results of sensory analyses, up to day 9 all the groups were determined as "acceptable" but on day 13 the groups A and B were no longer acceptable. The main negative aspect related to quality loss in slurry ice group corresponded to the appearance of eyes and gills. Using slurry ice during transportation did not extend the shelf life of sea bass stored at 4 degrees C.     

Evaluation of a slurry ice system for the commercialization of ray (Raja clavata): Effects on spoilage mechanisms directly affecting quality loss and shelf-life

The application of slurry ice, a biphasic system formed by small spherical ice crystals surrounded by seawater at sub-zero temperature, was evaluated as a new storage method for ray (Raja clavata), the elasmobranch fish species that exhibits highest commercial value in the European food markets. This advanced technique was used to compare with a control batch stored 10 days in flake ice. The results obtained in the sensory analysis indicated a significant extension of the overall quality (A class fish) from 3 days (flake ice) to 6 days (slurry ice). The development of ammonia external odour was the limiting parameter in both batches and was correlated with the activity of the endogenous mechanisms involved in the degradation of proteins and non-protein-nitrogen (NPN) rather than with the activity of proteolytic microorganisms. Storage of ray in slurry ice significantly (P<0.05) slowed down both biochemical (as estimated by the follow-up of the pH, TVB-N and K-value evolution) and microbial degradation mechanisms (estimated by the development of psychrotrophes and mesophiles counts) in chilled ray muscle. According to the parameters evaluated, storage of ray in slurry ice extends the shelf-life of this elasmobranch fish species due to a better maintenance of sensory, biochemical and microbiological quality, thus facilitating its commercialization.     

沙棘冰酒发酵条件的优化

以自然冷冻的沙棘果为原料,研究沙棘冰酒的发酵工艺。通过单因素试验和正交试验探讨了发酵温度、初始糖度、酵母接种量、发酵时间对沙棘冰酒酒精度和感官评分的影响。结果表明,沙棘冰酒的最优发酵工艺为：发酵温度15 ℃、初始糖度22 °Bx、酵母接种量3%、发酵时间20 d。在此工艺条件下制得的沙棘冰酒酒精度为10.65%vol,感官评分为87.20分,产品具有典型的冰酒品质。     

Effects of using slurry ice on the microbiological, chemical and sensory assessments of aquacultured sea bass (Dicentrarchus labrax) stored at 4 °C

Slurry ice, a biphasic system consisting of small spherical ice crystals surrounded by seawater at subzero temperature, was evaluated as a new chilled storage method for whole sea bass (Dicentrarchus labrax) a sparidae fish species of remarkable commercial interests. Four different group of chilling methods were used in this study; in slurry ice packaged on board (group A), in slurry ice packaged on company after 2 h (group B), slurry + flake ice packaged on board (group C) and only flake ice packaged on board (group D). The effect of this advanced system at the beginning of storage on quality losses and the shelf-life of aquacultured sea bass was evaluated. Mesophilic counts for sea bass exceeded 7 log cfu/g, which is considered the maximum level for acceptability for freshwater and marine fish after 13 days for groups C and D, and 15 days for groups A and B. At day 15; total volatile basic nitrogen (TVB-N) values of groups A–D reached the legal limits (35 mg/100 g set for TVB-N) for consumption. According to the results of sensory analyses, up to day 11, all the groups were determined as ‘acceptable’ but on day 13, the groups A–D were no longer acceptable. The main negative aspect related to quality loss in slurry ice group corresponded to the appearance of eyes and gills. Using slurry ice at the beginning of packaging did not affect the shelf-life of sea bass stored at 4 °C.     

Thermal insulation requirements and new cardboard packaging for chilled seafood exports

Three expanded polystyrene (EPS) boxes with different thermal resistance (R-value), a box-in-box type cardboard prototype and commercial EPS boxes were packed with fish using standard industry procedures and subjected to a simulated airfreight temperature regime replicating commercial practice. The Quality Index Method was used to assess the fish quality. The boxes with lower R-values did not have a measurable negative effect on the quality compared to the commercial EPS box. There was also no measurable difference in quality between fish stored in the corners or centre of all the boxes. For another experiment a double fluted cardboard prototype and commercial EPS boxes were filled with ice and subjected to a constant temperature regime to determine their R-value. The second prototype had slightly lower R-values than commercial EPS boxes. However, the double fluted wall structure might limit the foldability and manufacturability and will need to be further investigated.     

海洋低值小杂鱼的加工方向和现状

海洋低值小杂鱼是我国非常重要的一类鱼资源 ,本文从 4个方面论述了其加工现状 ,从 5个方面论述了加工的方向 ,指出有效的海洋低值小杂鱼加工将使其综合利用价值进一步提高。     

Bulk preservation of small pelagic fish by gamma irradiation: studies on a model storage system using Anchovies

Non-packaged, whole anchovy (Stolephorus commersonii) in lots of 20 kg were subjected to gamma irradiation at 2 kGy. The treated fish were stored under ice in insulated boxes which were held at 13°C. The slow melting of the ice under the storage conditions continuously washed the fish during storage. At periodic intervals, quality of the fish was determined by sensory, chemical and microbiological parameters. The non-packaged irradiated fish had better quality attributes which was acceptable up to 17 days in comparison to a storage life of 13 days for the unirradiated counterpart. Although packaged irradiated fish had a longer shelf life of 20 days, packaging caused drip accumulation and poor appearance of the fish. The advantages of the non-packaged storage system in commercial handling of irradiated small pelagic fish species are discussed.     

Efficacy of Sanitized Ice in Reducing Bacterial Load on Fish Fillet and in the Water Collected from the Melted Ice

ABSTRACT: This study investigated the efficacy of sanitized ice for the reduction of bacteria in the water collected from the ice that melted during storage of whole and filleted Tilapia fish. Also, bacterial reductions on the fish fillets were investigated. The sanitized ice was prepared by freezing solutions of PRO-SAN^® (an organic acid formulation) and neutral electrolyzed water (NEW). For the whole fish study, the survival of the natural microflora was determined from the water of the melted ice prepared with PRO-SAN^® and tap water. These water samples were collected during an 8 h storage period. For the fish fillet study, samples were inoculated with Escherichia coli K12, Listeria innocua, and Pseudomonas putida then stored on crushed sanitized ice. The efficacies of these were tested by enumerating each bacterial species on the fish fillet and in the water samples at 12 and 24 h intervals for 72 h, respectively. Results showed that each bacterial population was reduced during the test. However, a bacterial reduction of < 1 log CFU was obtained for the fillet samples. A maximum of approximately 2 log CFU and > 3 log CFU reductions were obtained in the waters sampled after the storage of whole fish and the fillets, respectively. These reductions were significantly (P < 0.05) higher in the water from sanitized ice when compared with the water from the unsanitized melted ice. These results showed that the organic acid formulation and NEW considerably reduced the bacterial numbers in the melted ice and thus reduced the potential for cross-contamination.     

Anchovy shelf life as affected by different chilling methods during distribution

Anchovies are a very labile fish and deteriorate fast under chilling conditions. In the South of Spain, fishing boats land their catches in wooden boxes with ice (12 to 14 kg). For some years now, fish processors have prepared this species for market distribution by placing about 7 kg fish in expanded polystyrene (EPS) boxes containing water and ice. Then, in the distribution market, boxes are dewatered and re-iced. Transportation of the fish in EPS boxes containing water and ice was recently forbidden on the grounds that boxes for transportation of fish in ice must have holes to let melted ice drain away. In this paper, the effect of preserving the anchovy in water and ice from landing to the distribution market was studied and compared with the more traditional methods of storing the fish in ice in either wooden or EPS boxes. Physical, chemical, microbiological, and sensory analyses were carried out over three different storage trials to account for the effect of seasonality. Little differences were found among lots, but some of the parameters showed that fish transported in water and ice did present less spoilage than fish stored in ice, especially when compared to the wooden boxes. According to these results, chilling of this fish in water and ice can be used as an alternative preserving method during transport.     

Icy affairs: Understanding recent advancements in the freezing and frozen storage of fish

Freezing methods have evolved over the last 30 years. This review states the effect of various freezing methods on the quality of fish and seafood. Freezing temperatures, freezing, and frozen storage temperatures were also analyzed and reviewed. The changes in the ice crystal, protein, and lipid affect the fish quality and nutritional value during freezing and frozen storage. Freezing methods when combined with various additives or preprocessing approaches help improve the efficacy of freezing and frozen storage. Several experimental or emerging methods also have positive effects on the products' quality. According to the metadata reanalysis of quality markers, freshly frozen fish using different freezing methods may vary much in terms of ice diameter, but not others. High pressure freezing or immersion freezing-derived fish retains the best quality through frozen storage. More data are required on freezing methods (electrical-assisted freezing, microwave-assisted freezing, magnetic-assisted freezing, radiofrequency-assisted freezing, and the commercial's application and investment should be considered in the future. This review sheds light on finding a balanced initial shear force during freezing and the use of certain additives to control freezing-related damages. Focusing on ice diameter alone may be futile (e.g., liquid N₂ freezing). Future optimization of technologies should be in a way that several processes along the farm to fork such as freezing, frozen storage, thawing, thermal processing of fish, and even refabrication of food should mutually complement each other's needs to deliver safe and high-quality fish to the consumer's plate, even after a prolonged shelf-life.     

The use of water and ice with bactericide to prevent onboard and onshore spoilage of refrigerated megrim (Lepidorhombus whiffiagonis)

This study investigates the effectiveness of ozonated water and flake ice (combined Petfrost system) to increase the quality and stability of fresh megrim on fishing boats. The captured fish were washed, placed in plastic boxes, covered with flake ice and refrigerated at 2 °C for up to 2-weeks onboard and, thereafter, for 11 days onshore. The experiments employed sterile, filtered and ozonated water at a concentration of 2 ppm for washing the fish and making the flake ice. The results are compared with samples from a traditional treatment consisting of water and flake ice of marine origin. Fish were caught in four different hauls, which took 14, 12, 8 and 3 days in being landed. Subsequently, fish were stored for 1, 5, 7 and 11 days at 3 °C. The different treatments were evaluated using sensory, microbiological and chemical techniques. Fish treated with ozone always showed the best quality. Megrim treated with ozone was still suitable for consumption after 14 days on board, and megrim stored for 12, 8 and 3 days on board could be stored for a further five days in the ice state once landed with an acceptable quality. In contrast, control fish were not suitable for consumption if stored for longer than three days on board.The results indicate that treatment with water and ice flakes made from sterile and ozonated water maintains the quality of fresh megrim onboard fishing boats and upon arrival onshore.     

高效液相色谱法测定海水鱼中嘌呤含量

本文建立同时检测海水鱼中腺嘌呤、鸟嘌呤、次黄嘌呤、黄嘌呤的高效液相色谱检测方法。对部分海水鱼可食用部分及内脏中的4种嘌呤含量进行检测。结果表明,当使用Agilent ZORBAX Eclipse XDB-C18(4.6 mm×250 mm,5μm)色谱柱,以水-甲醇-冰乙酸-20%四丁基氢氧化铵(V/V/V/V=879/100/15/6)为流动相,设置流速为0.8 mL/min,柱温30℃,检测波长254 nm,进样量10μL时,4种嘌呤可完全分离且峰型较好。经方法学验证,得出此方法在0.1~400 mg/L范围线性关系良好,相关系数(R)在0.9998~1.0000之间,方法检出限范围0.0465~0.1056 mg/L。高效液相色谱检测方法精密度RSD在0.0200%~0.7000%之间,样品处理重复性腺嘌呤、鸟嘌呤、次黄嘌呤、黄嘌呤依次为1.2421%,0.9711%,0.8836%,1.9727%。加标回收率在94.2888%~102.9188%之间,适用于海水鱼中4种嘌呤的测定。经检测,不同种类海水鱼可食用部分(鱼眼睛、腹部鱼肉、背部鱼肉、鱼皮)嘌呤总含量由高到低依次为海鲈鱼、大菱鲆、金仓鱼、黄花鱼、美国红鱼、踏板鱼、鳕鱼。     

TRANSPORTATION of FROZEN FOOD IN INSULATED CONTAINERS — THEORETICAL and EXPERIMENTAL RESULTS

A study was conducted on the ability of two insulated containers to maintain the low temperature of ice cream in an ambient environment. A mathematical model was solved using Continuous System Modeling Program (CSMP) and finite difference technique to predict the temperature distribution in the product with time. the model predicted the temperature profiles within ± 5% of the experimental data.     

Chemical properties and sensory quality of ice cream fortified with fish protein

BACKGROUND: Fish protein powder is a functional ingredient that can be used for enhancing the nutritional value of food products. In this study the effect of fortification with different levels of fish protein powder (FP) on chemical properties and sensory quality of Persian ice cream with 0, 30 and 50 g kg^?1 FP during storage at ? 18 °C for 4 months was investigated. RESULTS: Ice creams fortified with 50 and 30 g kg^?1 FP had significantly higher protein and solid‐non‐fat content than ice cream with 0% FP or 83, 69 and 51 g kg^?1 protein and 215, 204 and 181 g kg^?1 solid non‐fat, respectively. All products had the same levels of fat, lactose, acidity and pH. They had similar sensory quality after production except for colour, but sensory properties of fortified samples changed significantly after 2 months of storage. Colour faded, cohesiveness decreased, sandiness/coarseness increased, sweetness decreased and fish flavour and off‐odour increased. The control ice cream scored highest for additives odour and flavour. CONCLUSION: Development of ice cream fortified with fish protein powder could be an effective way to enhance nutritional and functional value of ice cream. But studies on storage stability, consumers' acceptance and attitudes are recommended if companies are planning to do so. Copyright © 2011 Society of Chemical Industry     

抑菌流化冰提高白鲳鱼的贮藏品质

为了提高冰鲜海鱼的品质,对比研究了3种抑菌物质二氧化氯(Cl O2)、乳酸链球菌素(Nisin)和二甲基二碳酸盐(DMDC)制备的流化冰在24天贮藏期内对白鲳鱼品质特性的影响。结果显示:在平均温度为1℃的贮藏环境中,随着冰鲜时间的延长,白鲳鱼的TVB-N值和TBARS值升高,升高幅度显著小于普通流化冰(p<0.05),TVB-N值显示Cl O2样品24 d为33.47 mg/mL,DMDC样品20 d为34.45 mg/mL,Nisin样品16 d为37.41 mg/mL,普通流化冰样品12 d为39.53 mg/mL,抑菌流化冰延长了白鲳鱼的货架期。抑菌流化冰可以促进白鲳鱼鱼肉p H值、硬度、弹性和色度等的稳定性,证明Cl O2抑菌流化冰样品的新鲜度保持更好。通过研究白鲳鱼在不同贮藏环境中的品质变化,建立微生物学Logistic模型能够较准确地预测白鲳鱼在冰鲜保藏温度-1至5℃的货架期,其相对误差范围不超过3.22%。研究结果有助于提高白鲳鱼等海洋鱼在贮藏期间的品质,延长其货架期。     

Comparison of effects of slurry ice and flake ice pretreatments on the quality of aquacultured sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) stored at 4 °C

Slurry ice, a biphasic system consisting of small particles of spherical ice immersed in seawater at subzero temperature, was evaluated as a new chilled method for whole sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). Two types of different chilling methods were used for two species in this study; slurry ice-treated sea bream (Group A), slurry ice-treated sea bass (Group B), flake-ice treated sea bream (Group C) and flake ice-treated sea bass (Group D). The effects of this system on the quality and shelf life of these two species were evaluated. Mesophilic counts for sea bass exceeded 7 log cfu/g, which is considered the maximum level for acceptability for freshwater and marine fish after 13 days for Groups C, D and 15 days for Groups A, B. At day 13, TVB-N values of Groups C, D reached the legal limits (35 mg/100 g set for TVB-N) for consumption. According to the results of sensory analyses, up to day 13, all the Groups were determined as ‘acceptable’ but, on day 15, the Groups A, B, C, D were no longer acceptable. Using slurry ice pretreatment for 2 h before the storage period presumably caused the deleterious effect on appearance as well as salt and water uptake. According to the results of chemical and microbiological analyses, use of slurry ice pretreatment for 2 h extended the shelf life of sea bream and sea bass stored at 4 °C for only two days longer than did use of flake ice.     

流化冰预冷处理对鲈鱼贮藏期间品质变化的影响

目的：模拟鲈鱼生产流通过程（即预冷、运输、贮藏环节）,以碎冰为对照,研究了流化冰预冷对新鲜 鲈鱼运输期间的控温效果与贮藏期间品质变化的影响。方法：将新鲜鲈鱼随机分组,分别进行流化冰预冷-运输-贮 藏（slurry ice,SI）、流化冰预冷-无冰运输-碎冰贮藏（slurry ice-no ice-crush ice,SNI）与碎冰预冷-运输-贮藏 （CK）3 种流通方式,在贮藏期间定期取样进行感官、理化（pH值、盐度、质构与硫代巴比妥酸值）及微生物 （菌落总数）指标测定,并结合扫描电子显微镜与聚丙烯酰胺凝胶电泳分析,综合评价其鲜度变化。结果：流化冰 在1.0～1.5 h内将鲈鱼中心温度降至0 ℃,鱼体终温为－1.1 ℃,降温速率显著高于碎冰预冷处理。在贮藏中后期, 与CK组相比,SI组能较好保持鲈鱼的感官品质和质构特性,抑制硫代巴比妥酸值、pH值与菌落总数的升高,有效 延缓蛋白质分解与肌肉组织降解速率,货架期为18 d左右,相对CK组延长了6 d。SNI组无冰运输过程中鲈鱼体温 维持在0.8 ℃以下,贮藏期间其样品质构特性、微生物生长及蛋白质降解水平与CK组差异不大,两组货架期均为 12 d;说明流化冰预冷具有较好的控温作用,能在一定程度上维持鲈鱼的鲜度。结论：流化冰是一种快速、高效的 保鲜处理方式,SNI组无冰运输操作可提高鱼样装载量,节约运输成本,因此该研究对水产品的短途运输具一定的 参考价值。