The effect of different salting procedures and qualities of raw material on some nutrients during processing and storage of salted-dried mackerel

Salted-dried mackerel ( Scomber scombrus ) was prepared using fresh fish or fish which had been stored in ice for 75h and four methods of salting, namely 15% brine, saturated brine, pickle and dry salting. Samples were analysed for available lysine, thiamine and riboflavin before salting, after salting, after drying and after 1 month's storage at 20°C. Final losses of each of these nutrients were lowest when the fish were pickle cured. Losses were also lower when fresher raw material was used. the use of good quality fish and a pickle salting method is therefore recommended for this type of product.     

Seasonal changes in the proximate chemical compositions and fatty acids of chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus) from the north eastern Mediterranean Sea

The effects of seasonal variations on the proximate chemical compositions and fatty acid profiles of chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus) captured in the north‐eastern Mediterranean Sea were investigated. Protein fluctuations were observed in two species for all seasons. The lipid content of both species was lower in winter than in autumn and spring. In all seasons, the major fatty acids in both species were observed to be palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1 ω9), eicosapentaenoic acid (20:5 ω3) and docosahexaenoic acid (20:6 ω3). Chub mackerel and horse mackerel exhibited seasonal fluctuations in their fatty acid contents. The fatty acid profile of the two species had a higher degree of unsaturation during winter. The levels of EPA in chub mackerel in winter, spring and autumn were 5.96%, 4.86% and 4.33%, respectively, while those of DHA were 24.94%, 18.75% and 17.12%, respectively. The levels of EPA in horse mackerel in winter, spring and autumn were 5.42%, 5.03% and 4.86%, respectively, while those of DHA were 14.96%, 13.31% and 11.10%, respectively. The PUFA (polyunsaturated fatty acids) values and ω3/ω6 ratios in the two species were highest in winter. The results indicate that chub mackerel and horse mackerel captured in the north‐eastern Mediterranean Sea, which are among the most important fish in Turkey and of international commercial value, are a good source of nutrition for human consumption in terms of their proximate chemical composition and fatty acids.     

鲐鱼多肽的提取工艺优化及抗疲劳研究现状

鲐鱼具有丰富的蛋白质和矿物质成分,同时拥有大量的生物活性功能成分,这些功能成分具有抗氧化、抗疲劳、抗肿瘤、抗高血压和降血脂的作用.我国鲐鱼资源丰富、价格低,为了保护我国的鲐鱼产业,发展鲐鱼的深加工是目前主要的方法和措施.我国鲐鱼多肽的提取技术目前还在起步阶段,该研究在鲐鱼多肽提取过程中,从最佳水解蛋白酶种类、水解蛋白酶...     

Effect of modified atmosphere packaging and vacuum packaging on the shelf-life of refrigerated chub mackerel (<Emphasis Type="Italic">Scomber japonicus</Emphasis>): biochemical and sensory attributes

The effect of modified atmosphere packaging (MAP 1: 70% CO₂/30% N₂ and MAP 2: 50% CO₂/30% N₂/20% O₂) and vacuum packaging (VP), on the shelf-life of chub mackerel (Scomber japonicus) fillets stored under refrigeration was studied. Quality assessment was based on sensory analysis and biochemical indices determination. Increase in total volatile basic nitrogen (TVBN) and trimethylamine nitrogen (TMAN) followed the order: MAP 1 < MAP 2 < VP < air (control samples). The presence of oxygen into the fish package (air or MAP) resulted in an increase in the 2-thiobarbituric acid (TBA) values in comparison with samples packaged in the absence of oxygen. The most effective MAP used was MAP 1 which contributed to a considerably slower rate of fish spoilage. Based primarily on odour scores it was observed that raw chub mackerel fillets stored in the presence of air remained acceptable up to ca. 11 days, VP and MAP 2 samples up to ca. 15–16 days, while MAP 1 samples up to ca. 20–21 days of storage. On the other hand, flesh texture and flesh colour of all packaged samples received scores above or equal than the acceptability limit up to ca. 13–14 days of storage.     

不同贮藏温度条件下鲐鱼货架期预测模型的构建

为了探索海上移动运输船上东海鲐鱼新鲜度随温度变化规律及其动力学特性,将鲐鱼贮藏在0、5、10、15 ℃条件下,测定K值、挥发性盐基氮（total volatile base nitrogen,TVB-N）值与菌落总数（total viable count,TVC）,并进行感官评分,研究其货架期预测模型。结果显示,随贮藏时间的延长,鲐鱼的感官品质指标逐渐下降,K值、TVB-N值和TVC均逐渐上升。实验用Arrhenius方程构建了贮藏温度、贮藏时间与K值、TVB-N值和TVC之间的动力学模型,其中,K值变化的活化能（Ea）及速率常数（k0）分别为30.54 kJ/mol和1.54×104;TVB-N变化的Ea及k0分别为41.21 kJ/mol和4.40×105;TVC变化的Ea及k0分别为46.78 kJ/mol 和2.93×106。建立的动力学模型可以在0～15 ℃范围内对鲐鱼的货架期进行准确预测。     

Microbial Activity Inhibition in Chilled Mackerel (Scomber Scombrus) by Employment of an Organic Acid‐Icing System

Abstract: The present study concerns Atlantic mackerel (Scomber scombrus) traded as a chilled product. The study was aimed to investigate the effect of including a mixture of organic acids (citric, ascorbic, and lactic) in the icing medium employed during the fish chilled storage. To this end and according to preliminary trials results, an aqueous solution including 0.050% (w/v) of each acid was employed as icing medium; its effect on the microbial activity development in mackerel muscle was monitored for up to 13 d of chilled storage and compared to a counterpart‐fish batch kept under traditional water ice considered as control. Results indicated a lower bacterial growth in mackerel muscle subjected to storage in the organic acid‐icing system by comparison with control fish. Thus, statistically‐significant (P < 0.05) differences between both batches for all 6 microbial groups investigated (aerobes, anaerobes, psychrotrophes, Enterobacteriaceae, lipolytics, and proteolytics) and for 2 chemical indices related to microbial activity development (total volatile bases and trimethylamine) were obtained. The surface wash caused by the melting of the ice during storage and the subsequent antimicrobial effect of such acids on skin microflora of the fish can be invoked as the main reasons for the limited bacterial growth found in the corresponding mackerel muscle. Practical Application: Among natural antioxidants, citric, ascorbic, and lactic acids are low molecular weight organic compounds that represent a relevant choice because of their easy availability, low commercial cost, and wide range of permitted concentrations for their use in foods. Present results obtained by their inclusion in a novel icing system have led to a lower microbial development in chilled mackerel when compared to its counterpart fish kept under traditional icing conditions. Such a finding indicated that inclusion of this acid mixture in the icing medium can lead to a marked quality and safety enhancement as well as to profitable commercial value increases.     

Elucidation of a major IgE epitope of Pacific mackerel parvalbumin

Ten overlapping peptides (20 amino acids in length with an offset of 10 amino acids) spanning the amino acid sequence of Pacific mackerel, Scomber japonicus parvalbumin (Sco j 1), were synthesized and evaluated for IgE-binding ability by fluorescence ELISA using fish-allergic patient sera. As a result, the region 21–40 was judged to contain a major IgE epitope of Sco j 1. However, this region was not necessarily assumed to be a major IgE epitope for the parvalbumins from seven other species of fish (sardine, Japanese eel, cod, horse mackerel, crimson sea bream, skipjack and flounder). Ala-scanning experiments revealed that eight amino acid residues (Ser-23, His-26, Lys-27, Lys-28, Lys-31, Cys-33, Leu-35 and Lys-38) are important for the IgE-binding of Sco j 1. Some of these residues are replaced by different residues in the parvalbumins of the other seven species of fish.     

Improved utilization of flesh from mackerel as salted dried fish cakes

The composition and yield of mince prepared by passing mackerel ( S. scombrus ) frames through a flesh-bone separator were determined. Salt (10 to 40%) was added to the unwashed mince to prepare dried cakes with enhanced keeping quality. The dried cakes were assessed for peroxide and TBA values, total viable count and for sensory attributes after preparation and after a 3-month storage period at 29±1°C. The cakes were reconstituted by desalting in boiling water. Salted dried cakes prepared with 15,20,30 and 40% salt were found to be stable and have little sensory deterioration over the 3-month storage period which is adequate to simulate distribution of products at tropical ambient temperature.     

不同解冻方式对鲐鱼鲜度及品质的影响

采用4 种解冻方式（空气解冻、静水解冻、微波解冻、鼓气流水解冻）对－18 ℃贮藏的船冻鲐鱼进行解冻,分析其持水力、挥发性盐基氮（total volatile basic nitrogen,TVB-N）值、组胺含量、盐溶性蛋白含量、质构值的变化,并进行电子鼻分析和微观结构的观察。结果表明：解冻时间、TVB-N值和组胺之间、持水力与解冻损失率和盐溶性蛋白含量之间分别有极显著的相关性（P＜0.01）。电子鼻的Fisher判别分析能明显区分各种解冻方式,其检测结果与TVB-N值和组胺含量的测定结果一致。4 种解冻方式中,鼓气流水解冻后鲐鱼的持水力、盐溶性蛋白含量最高,质构特性最好,肌束排列紧密,肌内膜较完整,鲜度比微波解冻稍差,与静水和空气解冻相比缩短了解冻时间,与微波解冻相比大大节约了成本。因此,鼓气流水解冻是一种理想的鲐鱼解冻方式。