Influence of salt concentration on properties of marinated meat from fresh and frozen herring (Clupea harengus L.)

Salt concentrations of brine above 10% are still commonly used in fish marinating process. The study has showed an increasing salt concentrations affect to adversely all the properties of marinated herring meat. Increase in salt concentration from 5% to 15% resulted in significantly (P < 0.05) decrease content of water, non‐protein nitrogen and products of protein hydrolysis. Consequently, weight yield of marinated fresh herring decreased from 83% to 74%. The most palatable marinades contained 2–3% NaCl in meat only. The higher salt concentrations applied significantly (P < 0.05) worsened the taste, texture and colour of marinated herring. Texture profile analyses (TPA), free hydroxyproline content and colour analyses (L*a*b) confirmed the negative influence of high salt concentration on the marinades quality. Frozen and thawed herring tissue showed greater sensitivity to salt. Namely, marinades from frozen fish contained by 0.3 more salt (P < 0.05), and the weight yield was by 2.3–10.3 percent point lower than from the fresh herring. Meat from frozen herring when matured has significantly (P < 0.05) lower sensory value, lower content of protein hydrolysis products, free hydroxyproline and higher parameter b* value of than the fresh one.     

Fatty acids of a salami-type sausage made of Baltic herring fillets, pork and lard

 The fatty acid composition of "fish wurst", a fermented salami-type sausage made of pork, lard and Baltic herring fillets (Clupea harengus var. membras) was investigated. Changes in the proportions of the 35 most abundant fatty acids were examined throughout the 1-month ripening period followed by a 4-month storage period. The fat composition of the product was stable (32–35%) and retained the characteristics of the main ingredients: oleic acid (37.4%, mean of three production batches) palmitic acid (23.7%) and linoleic acid (10.7%) from lard and fish, stearic acid (11.7%) mainly from lard, and palmitoleic acid (3.0%) and long-chain (C20–C24), polyunsaturated fatty acids (c.a. 6%) mainly from fish. During the 4-week ripening period a statistically significant increase (P≤0.05) was detected in the proportions of minor fatty acids only, i.e. eicosenoic acid (20 : 1n-9), eicosadienoic acid (20 : 2n-6), docosadienoic acid (22 : 2n-6) and docosatrienoic acid (22 : 3n-3). During the 4-month storage of the ripe sausage, the fatty acid composition stabilized. Only the proportion of stearic acid increased significantly during storage, from 11.7% to 12.5%. Received: 23 January 1998 / Revised version: 1 April 1998     

Fatty acids of a salami-type sausage made of Baltic herring fillets, pork and lard

 The fatty acid composition of "fish wurst", a fermented salami-type sausage made of pork, lard and Baltic herring fillets (Clupea harengus var. membras) was investigated. Changes in the proportions of the 35 most abundant fatty acids were examined throughout the 1-month ripening period followed by a 4-month storage period. The fat composition of the product was stable (32–35%) and retained the characteristics of the main ingredients: oleic acid (37.4%, mean of three production batches) palmitic acid (23.7%) and linoleic acid (10.7%) from lard and fish, stearic acid (11.7%) mainly from lard, and palmitoleic acid (3.0%) and long-chain (C20–C24), polyunsaturated fatty acids (c.a. 6%) mainly from fish. During the 4-week ripening period a statistically significant increase (P≤0.05) was detected in the proportions of minor fatty acids only, i.e. eicosenoic acid (20 : 1n-9), eicosadienoic acid (20 : 2n-6), docosadienoic acid (22 : 2n-6) and docosatrienoic acid (22 : 3n-3). During the 4-month storage of the ripe sausage, the fatty acid composition stabilized. Only the proportion of stearic acid increased significantly during storage, from 11.7% to 12.5%. Received: 23 January 1998 / Revised version: 1 April 1998     

Influence of acetic acid preservation of chilean mackerel (Trachurus murphy) on fish meal production

The influence of acetic acid preservation of Chilean mackerel (Trachurus murphy) on its suitability of processing a fish meal quality was studied on a pilot-plant scale and on the industrial level. In particular, the influence of acetic acid preservation of raw material on water-oil separation during cooking-pressing and resulting quality changes in fish meal produced was investigated. The results have shown that preservation of raw fish by acetic acid may improve water-oil separation after cooking, whereas the quality of oil and fish meal measured as acid value and available lysine, respectively, remain constant. A concentration of 1000–3000 μg kg^?1 of acetic acid in the raw material is recommended.     

Effects of storage time and chemical preservatives on the total volatile basic nitrogen content in chilean mackerel (Trachurus murphy) prior to fish meal production

Total volatile basic nitrogen (TVB-N) as a measure of protein degradation and total microbial counts or stored raw mackerel (Trachurus murphy), which had been treated with chemical preservatives, were compared with the TVB-N and microbial counts of untreated fish. In unpreserved fish, decomposition of fish protein was rapid. Treatment of mackerel with acetic (1000-5000 μg kg^?1), which was the most effective of the parameters studied, approximately halved the rate of increase in TVB-N compared with the untreated samples. Changes in the total microbial counts presented a similar trend.     

Microbiological quality of retail fresh fish fillets in The Netherlands

A total of 242 samples of ready-for-sale fish fillets of validated good sensory quality was examined for colony counts at 20, 30 and 37°C, Enterobacteriaceae at 37°C, Escherichia coli, Salmonella and Vibrio parahaemolyticus in 10 g aliquots. Staphylococcus aureus and yeast and mould propagules. Gram negative pathogens were not detected in any sample. The following reference values were found attainable: colony counts at 30°C, 10⁶ g^?1; E. coli 10 g^?1; S. aereus 10² g^?1; yeast and mould propagules 10⁴ g^?1. These reference values include, as customary, a tolerance of about 20% of samples exceeding the stated levels without, however, reaching the next log₁₀ level.     

The effect of glucose supplementation on the spoilage microflora and chemical composition of minced beef stored aerobically or under a modified atmosphere at 4 °C

Glucose was added to minced meat (pH 6.0) and stored under aerobic or a modified atmosphere (MA) composed of 80% O₂ and 20% CO₂ to assess the effects of carbohydrate on the microbial association and the chemical properties of the meat. The type of packaging affected the size and the final composition of the microflora. The microbial composition of the mince without added glucose in air or MA, given in log₁₀cfu/g respectively, were pseudomonads (9.8 and 7.3), Brochothrix thermosphacta (8.5 and 8.1), lactic acid bacteria (8.8 and 8.7), Enterobacteriaceae (7.2 and 6.1) and yeasts (4.3 and 4.2). In mince supplemented with 0.2% (w/w) glucose, similar composition and numbers were observed. Glucose, glucose 6-phosphate and lactic acid were consumed at slower rates by the flora on meat stored under MA than by the flora on meat stored in air. The addition of glucose enhanced gluconate production by the flora on meat stored in air. D-lactic and acetic acid were produced in all samples stored under the MA.     

Partial replacement of sodium chloride with potassium chloride in marinated rabbit meat

This study was aimed at evaluating the consequences of sodium chloride reduction by potassium chloride up to 50% on technological, sensorial and microbiological traits of marinated rabbit meat. In total, 226 rabbit loin meat samples were obtained and subjected to vacuum tumbling using solutions with different NaCl/KCl ratios. Replacing of sodium chloride up to 30% by potassium chloride did not change microbiological traits (total aerobic mesophilic and lactic acid bacteria maximum cell loads), sensorial acceptability (perceived saltiness and overall liking) and technological traits (pH, colour, texture, cooking loss and yield). Otherwise, reduction in sodium chloride to 50% significantly decreased perceived saltiness (4.15 vs. 4.73; P < 0.05) and reduced microbial shelf life by 1 day when compared to control, even if there was still no effect on technological traits. In conclusion, it is feasible imparting an added value for processed rabbit meat products by reduction in sodium content that could increase market interest.     

Absorption of benzoic and sorbic acids by herring and prawns in marinades

The preservatives benzoic acid and sorbic acid are rapidly removed from marinades in which they are incorporated to the flesh of herring and prawn. Allowing for the water content of each species and the fish/marinade ratio, concentrations of both acids in the fish are markedly in excess of that predicted from a simple equilibrium.     

热反应鸡粉、鸡肉膏及其在卤制品(盐焗鸡制品)中的应用

通过介绍热反应鸡粉、鸡肉膏的特点,以及他们的调味增香机理,通过比较拌合型香精特点,从盐焗鸡翅制品的产品风味等方面阐述了应用肉味调味料的必要性,利用富农产品天然、营养,耐高温等优势,通过盐焗鸡翅的生产工艺配方应用举例,确定热反应鸡粉、鸡肉膏在盐焗鸡翅制品中广泛的应用。     

3 种添加物对咸鱼加工贮藏过程中生物胺的抑制效果

为解决咸鱼加工、贮藏过程中生物胺的安全问题,本研究在咸鱼加工过程分别添加3 种食用级添加物（山梨酸钾、姜辣素、混合乳酸菌液）,采用生物胺初筛培养基检测产生物胺微生物的变化,高效液相色谱法检测咸鱼中腐胺、尸胺、组胺、酪胺等含量变化,比较3 种添加物对咸鱼中生物胺的抑制效果。结果表明：腌制后的咸鱼,在干燥过程和贮藏过程产生物胺菌数量和生物胺含量较高,3 种添加物均对咸鱼中生物胺的产生有一定抑制效果。其中,山梨酸钾对咸鱼中腐胺和尸胺的抑制效果最显著,抑制率分别为65.30%和69.77%,姜辣素对咸鱼中组胺的抑制效果最显著,抑制率为76.75%,乳酸菌对腐胺、尸胺和组胺有一定的抑制效果,但不及山梨酸钾和姜辣素;3种添加物对酪胺有一定的抑制效果,但均不明显。     

Structural changes in marinated fillets of gilthead sea bream (Sparus aurata L.) during vacuum storage at refrigerated temperature

Fillets of Sparus aurata were marinated in a mixture of salt (5.5%) and citric acid (48.9 g/kg) for 1 h, then vacuum packed and refrigerated for 1, 5, 16, and 21 d. Structural and ultrastructural parameters were evaluated in 6 specimens per time period. At day 1, the preservative solution appeared among the muscle fibers, thus increasing the interfibrillar spaces; cytoplasmic organelles were swollen and the sarcolemma-endomysium appeared very altered and electron-dense. At 5 to 10 d, the marinade solution had penetrated into the muscle fibers. The subsarcolemmal and intermyofibrillar spaces were dilated and granular lines of electron-dense material appeared among the fibers. From 16 d, broad interfibrillar spaces were occupied by granular material derived from denatured sarcolemma-endomysium and denatured myofibrils. Sarcomeres were already altered from initial stages, mainly at the I-band level. The Z-line also appeared disrupted. Such alterations were more severe from 10 d on, such that most of the sarcomeres showed disintegration of myofilaments.     

Effect of soaking medium on the physicochemical properties of parboiled glutinous rice of selected Laotian cultivars

The effect of various soaking mediums, viz. water (control), 3% NaCl and 0.2% acetic acid, and without soaking on the physicochemical properties of parboiled selected glutinous (TDK8 and TDK11) and non-glutinous (Doongara) was investigated in the present study. Results showed that the chemistry of soaking had a significant effect on the head rice yield (HRY), grain hardness, crystallinity, color, pasting and thermal properties, textural attributes, and glycemic index of these rice varieties. Soaking with NaCl and acetic acid significantly increased the grain hardness and HRY than control and without soaking treatments. Acetic acid and NaCl soaking significantly affected crystalline regions of starch resulting in reduced crystallinity in X-ray diffraction analysis and thermal endotherms in DSC analysis. NaCl soaking induced swelling of starch granules resulting in high peak and final viscosities. However, acetic acid restricted swelling resulting in reduced peak and final viscosities. NaCl and acetic acid soakings also resulted in increased hardness and adhesiveness of cooked grains than normal water soaked and un-soaked parboiled rice samples. Interestingly, change in textural attributes was prominent in parboiled glutinous rice. The color difference value for fresh parboiled samples was significantly lower for acetic acid soaked samples compared to NaCl soaked and un-soaked samples probably due to bleaching effect of acetic acid. Moreover, parboiling also resulted in significant reduction in glycemic index of glutinous rice. These findings revealed the potential application of parboiling with modified soaking techniques to improve the grain quality.     

Comparative rates of spoilage of fillets and whole fish during storage of haddock (Melanogrammus aeglefinus) and herring (Clupea harengus) as determined by the formation of non-volatile and volatile amines

The concentrations of the non-volatile and volatile amines that formed in herring ( Clupea harengus ) and haddock ( Melanogrammus aeglefinus ) during storage as fillets and as whole fish in ice and at 5°C were determined. Comparison of the rates of formation of the major non-volatile amines (histamine, cadaverine and putrescine) and trimethylamine showed that haddock fillets deteriorated more rapidly than the whole gutted fish and that ungutted herring spoiled more rapidly than fillets. The value of amines as indices of spoilage in fish is discussed.     

Freezing of tilapia fillets in an air blast freezer

This paper explores the numerical simulation of freezing tilapia fillets of five different geometries, which are the slab, elliptical, disc, spherical and cylindrical shapes, in an air blast freezer. The air velocities and temperatures inside the freezer are varied in the simulation to determine the freezing times and energy consumptions for freezing the tilapia fillets of different shapes. The results show that the cylindrical-shaped fillet has the longest freezing time and also required the most energy for freezing. The slab-shaped fillet has the shortest freezing time, but the spherical-shaped fillet requires the least energy to freeze. The simulation is also applied to a case study to compare the processing rate, energy consumption and the cost of freezing the fillets of different shapes. The freezing cost for a tray of spherical-shaped fillet is the lowest among all.     

辽宁省海鱼异尖线虫感染调查及分子鉴定

目的了解辽宁省市售海洋鱼类异尖线虫感染情况,并对异尖线虫Ⅲ期幼虫进行分子鉴定,确定感染异尖线虫虫种。方法采用直接剖检法从市售海鱼中检出异尖线虫Ⅲ期幼虫后,在显微镜下观察形态进行初步鉴定;提取异尖线虫虫体总DNA,采用通用引物扩增异尖线虫核糖体DNA内转录间隔区(ITS)序列,并对其ITS1和ITS2序列进行序列比对和进化分析。结果采集222份市售海鱼样品进行剖检,共有70份检出异尖线虫幼虫,检出率为31.53%,其中小黄花鱼和带鱼的检出率较高,感染度最高为233条/份。测序结果经序列比对和进化分析,结果显示检出的异尖线虫幼虫分别为异尖线虫属和宫脂线虫属的5种异尖线虫,包括简单异尖线虫(Anisakis simplex)、派氏异尖线虫(Anisakis pegreffii)、典型异尖线虫(Anisakis typical)、内弯宫脂线虫(Hysterothylcaium aduncum)和厦门宫脂线虫(Hysterothylacium amoyense)。结论辽宁省市售海洋鱼类异尖线虫感染情况较严重,且感染的异尖线虫种类多样,其感染优势种为派氏异尖线虫。     

Cinnamon and nisin in alginate-calcium coating maintain quality of fresh northern snakehead fish fillets

Cinnamon (Cinnamomum zeylanicum) and nisin in alginate-calcium coating were used to maintain quality of northern snakehead fish fillets at refrigeration temperature (4 ± 1 °C). Northern snakehead fish fillets were left untreated (CK), or were treated with alginate-calcium coating (Y0), alginate-calcium coating incorporating 10 μL mL⁻¹ cinnamon (Y1), alginate-calcium coating incorporating 2000 IU mL⁻¹ nisin and 150 μg mL⁻¹ ethylene diamine tetraacetic acid (EDTA) (Y2), or alginate-calcium coating incorporating 10 μL mL⁻¹ cinnamon and 2000 IU mL⁻¹ nisin and 150 μg mL⁻¹ EDTA (Y3). Y1 and Y3 had better effects on inhibiting bacterial growth and maintaining values of pH, total volatile base nitrogen (TVB-N) and thiobarbituric acid (TBA) of northern snakehead fish than CK, Y0 and Y2. Lightness (L*) values of fish fillets of all treatments were higher than CK. Cinnamon in alginate-calcium coating treatments could efficiently maintain quality of northern snakehead fish fillets during storage, but colors of fish fillets of Y1 and Y3 were evidently changed due to the color of cinnamon.     

Detection of nematodes in cod (Gadus morhua) fillets by imaging spectroscopy

ABSTRACT:  A promising method for detection of parasites in whitefish fillets has been developed. By use of imaging spectroscopy it is possible to record both spectral and spatial information from an object. In this work it is shown that by applying a white light transmission setup and imaging spectroscopy to cod ( Gadus morhua ) fillets, it is possible to make spectral images containing information to differentiate between fish muscle and parasites. The spectral images are analyzed by discriminant partial least square regression as well as image-filtering techniques. The method identifies parasites on the surface of the fillets as well as embedded parasites. One parasite was detected at 0.8 cm below the fillet surface, which is 2 to 3 mm deeper than what can be found by manual inspection of fish fillets. The method is nonintrusive and should thus be feasible for industrial purposes.