延迟加冰对冰藏大黄鱼品质变化的影响

通过微生物、化学和感官指标,以立即加冰为对照研究在25℃环境中延迟4h 和8h 后加冰对养殖大黄鱼(Pseudosciaena crocea)冰藏期间品质变化和货架期的影响。结果表明在延迟加冰阶段菌落总数(TVC)、嗜冷菌数、假单胞菌数、产硫化氢细菌数和总挥发性盐基氮(TVB-N)显著增加;感官品质显著降低;三甲胺氮(TMA-N)变化不明显。延迟加冰可显著增加大黄鱼冰藏期间各种微生物的数量,加快TMA-N 和TVB-N 的产生速率,显著缩短冰藏大黄鱼的货架期和产生异味的时间。感官评价显示立即加冰和延迟4h 与8h 加冰大黄鱼的货架期分别为648、550h 和408h,立即加冰比延迟加冰货架期分别延长98h 和240h,鲜鱼捕获后立即进行加冰处理是相当必要的。     

超高压处理对冷藏带鱼鱼丸保鲜效果的影响

为延长带鱼鱼丸保质期,以带鱼鱼丸为原料,分别在250、300、350 MPa压力下处理5 min,以冷藏期间鱼丸菌落总数、总挥发性盐基氮(total volatile base nitrogen,TVB-N)含量、pH值为指标,并结合感官评价、色值、凝胶强度及质地剖面分析,探究超高压处理对冷藏带鱼鱼丸保鲜效果的影响.结...     

臭氧联合二氧化氯处理对草鱼鱼糕保质期及品质的影响

制备草鱼鱼糕,采用0.65 mg/L臭氧水溶液和10 mg/L二氧化氯（ClO2）联合对鱼糕进行预处理,研究该处 理方式对鱼糕冷藏（4 ℃）保质期及品质的影响。结果表明：臭氧-ClO2处理能够有效延长草鱼鱼糕的保质期（与 对照组相比延长10 d）,4 ℃冷藏25 d后草鱼鱼糕的挥发性盐基氮含量、菌落总数等指标均未超过国家相应限量标 准;十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析表明,臭氧-ClO2处理可通过抑制内源酶活性来抑制蛋白质降解,从 而提高鱼糕的持水力,使草鱼鱼糕在贮藏过程中维持原有的白度和质构特性。     

Microbiological and Sensorial Quality Assessment of Ready-to-Cook Seafood Products Packaged under Modified Atmosphere

ABSTRACT:  The effects of modified atmosphere packaging (MAP) (30:40:30 O₂:CO₂:N₂ and 5:95 O₂:CO₂) on the quality of 4 ready-to-cook seafood products were studied. In particular, the investigation was carried out on hake fillets, yellow gurnard fillets, chub mackerel fillets, and entire eviscerated cuttlefish. Quality assessment was based on microbiological and sensorial indices determination. Both packaging gas mixtures contributed to a considerable slowing down of the microbial and sensorial quality loss of the investigated seafood products. Results showed that sensorial quality was the subindex that limited their shelf life. In fact, based primarily on microbiological results, samples under MAP remained acceptable up to the end of storage (that is, 14 d), regardless of fish specie. On the other hand, results from sensory analyses showed that chub mackerel fillets in MAP were acceptable up to the 6th storage d, whilst hake fillets, yellow gurnard fillets, and entire cuttlefish became unacceptable after 10 to 11 d. However, compared to control samples, an increase in the sensorial shelf life of MAP samples (ranging from about 95% to 250%) was always recorded.
Practical Application: Modified atmosphere packaging (MAP) is an inexpensive and uncomplicated method of extending shelf life of packed seafood. It could gain great attention from the fish industrial sector due to the fact that MAP is a practical and economic technique, realizable by small technical expedients. Moreover, there is great attention from the food industry and retailers to react to the growing demand for convenience food, thus promoting an increase in the assortments of ready-to-cook seafood products.     

Deterioration due to delayed icing and its impacts on the nutritional quality of Malabar travally (Carangoides malabaricus)

Effect of delayed icing of the fish Carangoides malabaricus was assessed using chemical and microbial methods to determine the impacts on the nutritional quality and sensory changes. The shelf life of the fishes iced immediately after harvest had a shelf life of 18 days, whereas the delay of icing for 4, 6, 8 and 10 h shortened the shelf life to 14, 10, 6 and 3 days respectively. The spoilage indicators, such as trimethylamine nitrogen, Total volatile basic nitrogen, free fatty acids, peroxide value, thiobarbituric acid and pH values, significantly increased (P < 0.05) during the storage period of fishes with delayed icing. The total bacterial count also increased during the storage period and due to quality deterioration, the protein and lipid contents were found significantly low (P < 0.05). This study showed that chemical and microbial changes of the sample are well correlated with nutritional and sensory qualities so that immediate icing is important for maintaining the quality and shelf life of C. malabaricus.     

冷藏温度对河豚鱼微生物及品质特性的影响

研究冷藏温度对河豚鱼微生物及品质特性的影响。将河豚鱼宰杀、清理、分块后,放置于(0±1)、(4±1)、(8±1)℃冰箱中冷藏。对鱼肉中几种优势菌种(肠杆菌、假单胞菌及乳酸菌),鱼肉质构、挥发性盐基氮、pH值、三甲胺、持水力等指标进行测定,评价河豚鱼冷藏过程中的品质变化。结果表明：(0±1)℃可贮藏6d左右,能够一定程度地抑制鱼肉中几种特定腐败菌的生长,减慢TVB-N值、pH值和TMA值的上升,延缓持水力的下降,并降低河豚鱼肉的硬度、弹性和回复性等质构特性的变化,有效延长河豚鱼的货架期,维持良好的鲜度。     

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     

超声波技术在鱼类加工中的应用研究进展

超声波技术是一种高新加工技术,具有重复性好、时间短、效率高等特点,能够改善鱼类品质,延长货架期。在介绍超声波工作原理的基础上,叙述了其应用于鱼类加工过程(提取、干燥、冷冻、解冻、杀菌)对鱼品质的影响。同时阐述了超声波在实际应用中的不足,对未来超声波技术在鱼类加工中的应用进行了展望,旨在为鱼类加工研究提供基础性参考,提高鱼类利用率和经济价值。     

谷氨酰胺转氨酶对鳜鱼鱼糜凝胶的品质影响

以鳜鱼鱼糜热诱导凝胶为研究对象,检测盐度、持水性、色泽、质构、感官评分、蛋白质二级结构、微观结构以及十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)指标.研究谷氨酰胺转氨酶(transglutami...     

复配生物防腐剂延长海鲶鱼肉的贮藏时间

海产品由于其高营养价值所以极易腐败,而微生物是引起海产品腐败的重要原因。本研究通过对腐败海鲶鱼中的腐败菌进行分离鉴定,得到乙酰微小杆菌、约氏不动杆菌、考克氏菌属、节杆菌属、施氏假单胞菌、枯草芽孢杆菌、速生嗜冷杆菌和洛菲不动杆菌等菌株。采用三种不同的生物防腐剂(ε-聚赖氨酸、乳酸链球菌素和溶菌酶)对分离出的菌株进行最小抑菌浓度实验,分析其抑菌效果。运用响应面法,复配出最优组合的生物防腐剂,其配比量为ε-聚赖氨酸367.5 mg/kg、乳酸链球菌素375.0 mg/kg、溶菌酶235.0 mg/kg。通过扫描电镜观察,复配剂可以破坏枯草芽孢杆菌细胞膜的完整性,增加细胞膜的通透性。将优化的复配剂应用于海鲶鱼肉保鲜,通过测定菌落总数、pH值和TVB-N等指标,对其防腐抑菌效果进行验证。实验结果表明,在4℃储存条件下,添加复配剂的鱼肉的货架期相比未添加的延长了一倍。     

辐照结合复配保鲜剂对鲈鱼贮藏品质的影响

为延长大口黑鲈鱼片货架期,将新鲜鲈鱼片分别用无菌蒸馏水（对照）、大蒜素、4 kGy 60Co-γ射线辐照、大蒜素＋辐照、复配保鲜剂A（含0.3 g/100 mL大蒜素、0.3 g/100 mL葡萄籽提取物、1 g/100 mL壳聚糖）＋辐照和复配保鲜剂B（含0.3 g/100 mL大蒜素、0.3 g/100 mL茶多酚、1 g/100 mL壳聚糖）＋辐照处理后,于4 ℃贮藏15 d,考察各处理对鲈鱼片菌落总数、汁液流失率、pH值、硫代巴比妥酸反应物（thiobarbituric acid reactive substance,TBARs）值、总挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、感官品质及Ca2＋-ATPase活性的影响。结果表明：在贮藏初期,经辐照的鲈鱼TBARs值、TVB-N含量较对照组略高,辐照加速了脂质氧化;而复配保鲜剂结合辐照处理的鲈鱼能有效减缓脂质氧化,减少菌落总数,延缓汁液流失率和pH值的升高,抑制肌原纤维蛋白Ca2＋-ATPase活性的下降;贮藏15 d时,2 种复配保鲜剂结合辐照处理的鲈鱼片菌落总数均未达到6（lg（CFU/g））,仍符合可食用标准,而复配保鲜剂B结合辐照处理组具有最好的保鲜效果;鲈鱼经辐照处理后货架期可延长6 d,而经过复配保鲜剂结合辐照处理均可延长9 d以上,表明辐照与复配保鲜剂在鲈鱼贮藏中具有协同保鲜作用,能有效延长鲈鱼货架期。     

The Shelf Life of Farmed Turbot (Scophthalmus maximus)

A total of 18 farmed turbot (Scophthalmus maximus) were slaughtered over 4 successive weeks in November 2012 and stored in polystyrene boxes with ice until analyzed. The fish were stored between 1 and 22 d and presented to a taste panel and further analyzed for quality index method (QIM), microbiological analysis by real‐time quantitative PCR (qPCR), taste, pH, color by computer imaging, protein denaturation with differential scanner calorimeter (DSC), texture hardness, and shear force. Results show small, but significant changes in physical and visual attributes such as texture and color. No gaping was observed. Only small changes in texture were observed explained by lack of myosin denaturation. The fillets became more white and yellow during storage, whereas the major changes occurred during the 1st week. A panel evaluating QIM and taste could not distinguish major differences in appearance and taste and over 15 d storage period, but were able to quantify the age by smell. Analysis of microorganisms on the epidermis displayed growth of Carnobacterium maltaromaticum, potentially inhibiting growth of other spoilage bacteria. Fish stored for 22 d were rejected by the taste panel caused by a stale smell and taste, but not bitter or rancid. It is concluded that turbot has a shelf life of at least 16 d.     

Effect of previous chilled storage on rancidity development in frozen horse mackerel (Trachurus trachurus)

Rancidity development during frozen storage (?20 °C) of an underutilised medium‐fat‐content fish species, horse mackerel (Trachurus trachurus), was studied. Special attention was given to the effect of previous chilled storage (0, 1, 3 and 5 days) on the quality of the frozen fish. For this, chemical (free fatty acid and conjugated diene contents; peroxide value, PV; thiobarbituric acid index, TBA‐i; fluorescent compound formation) and sensory (rancid odour and taste) analyses were carried out. Hydrolytic rancidity showed an increase with frozen storage time; however, no effect of previous chilling time was observed on the frozen product. Oxidative rancidity measured by chemical (PV, TBA‐i and fluorescence) and sensory (odour and taste) indices increased with frozen storage time and also with previous chilling time. Satisfactory quality was maintained up to 7 months of frozen storage of horse mackerel provided that a short chilling time (not longer than 3 days) was employed. © 2002 Society of Chemical Industry     

The effect of a flaxseed oil-enhanced diet on the product quality of farmed brook trout (Salvelinus fontinalis) fillets

Abstract: The effects of dietary modification with flaxseed oil‐enhanced (Flax) feed on the product quality of brook trout fillets were examined. Trout were fed a commercial feed supplemented with fish oil (CD) or flaxseed oil (Flax) for 165 d before harvesting. Proximate composition and fatty acid profile were determined on fillets. Quality parameters of the raw fillets were examined over the storage period by measuring color (L*, a*, b*), muscle pH, and thiobarbituric acid reactive substances test. Evaluations on the cooked fillets included sensory evaluation with triangle tests and a paired preference test. There were no differences in proximate composition between the groups; however, the total omega‐3 fatty acids were greater in Flax fillets (P < 0.05). Diet and day were shown to interact in their effect on whiteness, pH, and lipid oxidation (P < 0.05); however, linear regression did not determine that malondialdehyde concentration was associated with time in either diet type implying that lipid oxidation in the vacuum‐packed fish was controlled at storage temperatures (4°C). Sensory panelists were able to choose the odd sample in a replicated triangle test analyzed using the β‐binomial model, and there was preference for Flax fillets (P < 0.05). Results indicate that a Flax‐enhanced diet would have favorable effects on product quality of farmed brook trout.     

外源脂肪酶对腌腊鱼品质的影响

用白鲢制作腌腊鱼,研究外源脂肪酶对腌腊鱼品质的影响,探索脂肪酶在腌腊鱼风味形成中的作用。结果表明:外源脂肪酶可促进腌腊鱼中脂肪的水解,从而加快二十碳五烯酸(DHA)、二十二碳六烯酸(EPA)等n-3多烯酸的分解,使粗脂肪含量和2-硫代巴比妥酸(TBA)值降低,酸价升高,这些变化与脂肪酶的添加方式和添加量有关。鱼肉中添加0.01%的外源脂肪酶(Novozym 435),然后用3%的花椒盐涂抹后于15℃干腌72h,可改善腌腊鱼的感官品质,即外源脂肪酶可促进腌腊鱼风味的形成。     

Modeling Microbial Spoilage and Quality of Gilthead Seabream Fillets: Combined Effect of Osmotic Pretreatment,Modified Atmosphere Packaging,and Nisin on Shelf Life

ABSTRACT: The objective of the study was the kinetic modeling of the effect of storage temperature on the quality and shelf life of chilled fish, modified atmosphere-packed (MAP), and osmotically pretreated with the addition of nisin as antimicrobial agent. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (DE 47) plus 5% NaCl. Water loss, solid gain, salt content, and water activity were monitored throughout treatment and treatment conditions were selected for the shelf life study. Untreated and osmotically pretreated slices with and without nisin (2 × 10⁴ IU/100 g osmotic solution), packed in air or modified atmosphere (50% CO₂–50% air), and stored at controlled isothermal conditions (0, 5, 10, and 15 °C) were studied. Quality assessment and modeling were based on growth of several microbial indices, total volatile nitrogen, trimethylamine nitrogen, lipid oxidation (TBARS), and sensory scoring. Temperature dependence of quality loss rates was modeled by the Arrhenius equation, validated under dynamic conditions. Pretreated samples showed improved quality stability during subsequent refrigerated storage, in terms of microbial growth, chemical changes, and organoleptic degradation. Osmotic pretreatment with the addition of nisin in combination with MAP was the most effective treatment resulting in significant shelf life extension of gilthead seabream fillets (48 days compared to 10 days for the control at 0 °C).     

壳聚糖微胶囊对鱼油品质的影响

为探究微胶囊化对鱼油品质的影响,以壳聚糖为壁材,金枪鱼油为芯材,采用喷雾干燥法制备鱼油微胶囊,分别检测鱼油及鱼油微胶囊的理化指标、脂肪酸组成及挥发性成分,并通过加速贮藏试验考察以上指标的变化。结果显示:鱼油微胶囊过氧化值高,不饱和脂肪含量低,与腥味相关的关键挥发性成分多,品质较低。贮藏期间鱼油微胶囊能明显抑制过氧化值的增长和关键挥发性成分含量的升高,对DHA和EPA的保留率影响不大,说明鱼油微胶囊制备过程会在一定程度上降低鱼油品质,然而对延缓鱼油氧化、掩蔽不良风味确实有一定作用。