Biogenic amine index for freshness evaluation in iced Mediterranean hake (Merluccius merluccius)

Biogenic amine accumulation was studied during the ice storage of Mediterranean hake. Sensory analysis and counts of Shewanella, Pseudomonas, enterobacteria, psychrotrophic, and mesophilic bacteria provided complementary information on hake spoilage. Putrescine and cadaverine were the main amines accumulated, whereas histamine and tyramine were minor amines but had qualitative interest from the hygienic point of view. Although all biogenic amines were less abundant than in pelagic fish, they may also be used as indicators of freshness and/or spoilage in hake. Cadaverine was the amine best correlated with Shewanella, which was the specific spoilage organism. Therefore, cadaverine may be regarded as the specific spoilage biogenic amine for hake stored at chilling temperatures. However, the biogenic amine index, which considers cadaverine, putrescine, histamine, and tyramine, has several advantages as an indicator of hake quality. Taking into account sensory data, an acceptability limit of the biogenic amine index could be established in 15 to 20 microg/g.     

Production of Biogenic Amines and Their Potential Use as Quality Control Indices for Hake (Merluccius merluccius, L.) Stored in Ice

ABSTRACT: The production of tyramine, histamine, putrescine, cadaverine, agmatine, and spermidine was studied for use as quality indices in muscle of gutted hake stored in ice for 25 d. The changes in biogenic amine concentrations were correlated with trimethylamine nitrogen levels. All concentrations except for spermidine, increased progressively throughout storage. During storage, cadaverine reached 72.14 mg/kg while there were no significant increases in histamine and tyramine. The levels of free amino acids, which may be metabolized into biogenic amines, were not correlated to respective biogenic amines levels. The production of cadaverine and agmatine occurred prior to spoilage and these biogenic amines may indicate freshness of hake stored in ice.     

Suitability of Volatile Amines as Freshness Indexes for Iced Mediterranean Hake

Batches of gutted Mediterranean hake (Merluccius merluccius var. Mediterraneus) were stored, in different seasons of the year, for up to 20 d in ice. Changes in trimethylamine (TMA‐N), total volatile bases (TVB‐N), P‐ratio and trimethylamine oxide (TMAO) were measured; sensory evaluation of raw and cooked hake samples was also carried out. Similar profiles were observed between the different trials for all the parameters studied. TVB‐N was not correlated with the time of ice storage, and proved to be better as a spoilage index than a freshness one. In contrast, TMA‐N appears to be a good index of hake quality, and the value of 5 mg/100g offish seems an appropriate limit of acceptability. P‐ratio was a poorer index of freshness than was TMA‐N.     

Development of a Quality Index Method to Evaluate Freshness in Mediterranean Hake (Merluccius merluccius)

A Quality Index Method for the sensory assessment of freshness of Mediterranean hake was developed and validated by sensory, chemical, and microbiological parameters. The Quality Index was the ratio between the overall sensory score obtained and the total achievable sensory score of the scheme and ranging 0 (fresh) to 1 (spoiled). This index increased significantly along the time of ice storage, allowing prediction of the remaining shelf life of hake. A value of 0.60 to 0.65 was estimated by statistical treatment as the rejection value, being concordant with sensory score of cooked hake, trimethylamine content, pH, as well as with legal regulations for mesophylic and enterobacteria counts.     

Use of volatile and non‐volatile amines to evaluate the freshness of anchovies stored in ice

Amounts of volatile and biogenic amines, pH and microbial counts were monitored in Mediterranean anchovy (Engraulis encrasicholus) over 23 days of ice storage with the aim of examining their suitability as indicators of freshness. Counts of Enterobacteriaceae reached the maximum limits stipulated by Spanish regulations after 5 days of storage in ice, while those of mesophilic bacteria took 7 days. Levels of volatile amines hardly increased during ice storage. Amounts of biogenic amines did increase, though there were differences from one amine to the other. Cadaverine, the most abundant biogenic amine, showing the earliest increase, coinciding with the shelf‐life time as determined through Enterobacteriaceae counts. Amounts of histamine remained below the maximum levels established by both European Union and Food and Drug Administration regulations. Other biogenic amines were found at much higher levels than histamine. Results demonstrated the suitability of the biogenic amine index (as the sum of histamine + tyramine + putrescine + cadaverine) as a freshness indicator for anchovies stored in ice, with a limit of acceptability set at 15 mg kg^?1. Copyright © 2005 Society of Chemical Industry     

Sensory and flavor profiles as a means of assessing freshness of hake (Merluccius merluccius) during ice storage

Freshness of hake stored in ice was evaluated by sensory and instrumental means. The European Union scheme and the quality index method (QIM) were used to sensorially index freshness. Aroma extract dilution analysis (AEDA) and SPME-headspace determinations were applied to monitor important odorants of hake at different freshness stages. Based on AEDA, potent odorants of hake in the very fresh state were (Z)-1,5-octadien-3-one and 3 unknown volatiles. Attempts were made to relate overall odor changes to individual volatiles: after 2 days storage, the higher FD-factors found for trans-4,5-epoxy-(E)-2-decenal, (Z)-4-heptenal, methional, and 2-acetyl-1-pyrroline were associated with the “masking” of the seaweed character, whereas the higher concentrations of (Z)-1,5-octadien-3-one and (Z)-4-heptenal in hake that reached the B grade were likely responsible for the pungent odor. No highly volatile odorants were detected in hake using SPME-headspace analysis, but in contrast to AEDA, the odor intensity of some volatiles, e.g., (E,Z)-2,6-nonadienal and 3-methylnonane-2,4-dione indicated a higher contribution. The detection of two low boiling odorants associated with fresh fish flavor is reported for the first time.     

Volatile and Nonvolatile Amines in Mediterranean Hake as Function of their Storage Temperature

ABSTRACT: The main amines in frozen and fresh hake (Merluccius merluccius) are the natural polyamines, spermidine. The levels of volatile and nonvolatile amines during storage of hake were strogly dependent on temperature. In samples stored at -20° only changes in dimethylamine and agmatine were found, whereas major changes were observed in samples stored at higher temperatures. Cadaverine was the major amine formed followed by histamine, putrescine and tyramine. The maximum levels of biogenic amines were lower than those reported for other fish species. Trimethylamine and biogenic amines related to hake spollage showed levels higher in fresh than in frozen samples, whereas levels of natural polyamines were not statistically different.     

Quality Properties,Fatty Acids,and Biogenic Amines Profile of Fresh Tilapia Stored in Ice

This work determines quality properties and fatty acids content of Nile tilapia (Oreochromis niloticus) stored in ice for 21 d. The quality properties consist of thiobarbituic acid (TBA), total volatile basic nitrogen (TVB‐N), trimethylamine (TMA), and microbiological analysis (total viable count (TVC), total coliform, Salmonella and Staphylococcus aureus) and determination of biogenic amines content (histamine, cadaverine, putrescine, spermine, spermidine, 2‐phenylethylamine, agmatine, tyramine, and ammonia). Moreover, the fat, moisture, and ash composition as well as fatty acids profile have also been analyzed. The TBA, TVB‐N, and biogenic amines analysis showed rather low levels of spoilage even after 21 d of storage. The microbiological analysis, however, showed that tilapia was unsuitable for consumption after just 10 d. The fat, ash, moisture, and fatty acids profile analysis showed that tilapia is not a good source of n?3 fatty acids. The research indicated that the microbiological analysis was the best method to establish spoilage of tilapia stored in ice, of all analytical methods performed in this study.     

The effects of ice storage on inosine monophosphate, inosine, hypoxanthine, and biogenic amine formation in European catfish (Silurus glanis) fillets

European catfish fillets in ice were evaluated by measuring nucleotide components and biogenic amine contents and these then compared with sensory and microbiological assessment during the 21 days of iced storage. Analyses were carried out using two different rapid HPLC methods for nucleotid degradation products and biogenic amine contents in European catfish fillets. Sensory evaluation showed that storage life of European catfish found to be 14–18 days. Initial inosine monophosphate (IMP) level was 12.6 μmol g^­1 and then decreased during the rest of storage period. Inosine (INO) level increased rapidly until 7 days of storage. Hypoxanthine (Hx) level increased almost linearly with storage time. The most accumulated biogenic amines were putrescine, cadaverine, spermidine, spermine, and serotonin in all the European catfish fillets during the storage, although the formation of biogenic amines levels was fluctuated. Histamine was only detectable at 4 and 7 days of storage as low as 1 mg 100 g^­1 fish. Total viable count in European catfish increased rapidly with storage time and reached ≤10⁹ cfu g^­1 when the fillets were not acceptable for consumption.     

The effects of partial replacement of fish meal by vegetable protein sources in the diet of rainbow trout (Onchorynchus mykiss) on post mortem spoilage of fillets

Five test diets were formulated with decreasing levels of fish meal (up to 50%) replaced by alternative protein sources. Rainbow trout were fed the experimental diets for 12 weeks.The effects of feed ingredients on spoilage of Oncorhynchus mykiss in ice and under MAP/ice (40% CO₂, 30% N₂ and 30% O₂) were investigated in terms of sensory, chemical and microbiological analyses. The results showed that the trout in MAP/ice was rejected at 14 days, after sensory analysis, due to excessive drip, whereas trout in ice were found to be acceptable even after 14 days of storage. However, cooked trout fillets, under both storage conditions, were rejected at 17 days. Fish in ice produced higher K values and higher concentrations of biogenic amines during the storage period of 17 days than the fish in MAP/ice. Bacteria grew more quickly in rainbow trout kept in ice than in MAP/ice. MAP/ice storage extended the shelf life of rainbow trout by approximately 2 days compared to ice storage alone in terms of microbiological analyses.     

Effect of delayed icing on the storage life of rainbow trout

Rainbow trout ( Salmo irideus ), were divided into groups: (1) iced immediately, or (2) kept at 10 °C for 6 hr, (3) 20 °C for 6 hr, (4) 20 °C for 18 hr, (5) 30 °C for 4 hr, (6) 30 °C for 6 hr. Fish in groups 2–6 were iced at the end of the stipulated temperature/time period of holding. Quality was subsequently assessed every 2 days for 14 days during iced storage: sensory assessment using criteria of appearance, texture and odour; chemical assessments by measurement of total volatile bases, hypoxanthine and thiobarbituric acid: microbiological assessments by total bacterial counts at 20 °C/72 hr and 37 °C/48 hr incubation. The results indicate that deamination due to bacterial action and hydrolysis of fats increases progressively with rising temperature prolonged periods of storage prior to icing, and results in final spoilage. Fish iced immediately after delivery and those iced after being kept at 10 °C for 6 hr were acceptable to quality even after 14 days of iced storage. Recommendations are made for maintenance of quality and extension of shelf life.     

Changes in biogenic amines during iced and ambient temperature storage of tilapia

BACKGROUND: Changes in the biogenic amine content of tilapia (Oreochromis mossambicus) with time during iced and ambient temperature (28 °C) storage were quantified by high‐performance liquid chromatography in a gradient elution system using acetonitrile and water as solvents. RESULTS: The levels of amines in tilapia were significantly low even after a long storage period (18 h under ambient temperature storage and 15 days under iced storage). All amines except spermidine and spermine increased with time during both iced and ambient temperature storage. Spermidine and spermine showed a decrease with increasing storage time. CONCLUSION: Being euryhaline (tolerant of a wide range of salinity) in nature, tilapia shows significantly low quantities of biogenic amines even after a long period of ambient temperature or iced storage, unlike most other marine fish. Copyright © 2008 Society of Chemical Industry     

萝卜籽蛋白提取物对托盘包装鲟鱼片冷藏品质的影响

本实验旨在探究萝卜籽蛋白提取物对冷藏鲟鱼片的防腐保鲜效果。研究了萝卜籽蛋白提取物对9 株鲟鱼 腐败菌的抑菌活性;将鲟鱼片分别用64（T1组）、32（T2组）、2 AU/mL（T3组）的萝卜籽蛋白提取液和无菌生 理盐水（CK组）处理,测定各组贮藏期间的微生物指标（菌落总数、肠科菌数、气单胞菌数、假单胞菌数和耐冷 菌数）、理化指标（pH值、色泽、挥发性盐基氮含量、硫代巴比妥酸值和生物胺含量）和感官得分变化。结果显 示：萝卜籽蛋白提取物对9 株鲟鱼腐败菌均具有很好的抑制作用,其抑菌圈直径均大于17.5 mm;微生物指标结果 显示CK组、T1组、T2组和T3组鲟鱼片的货架期分别为7、11、9 d和7 d;理化指标结果显示,与对照组相比,萝卜 籽蛋白提取物可延缓鲟鱼片中总挥发性盐基氮、硫代巴比妥酸和生物胺的积累,且蛋白提取物效价越高,效果越显 著;感官评价结果与微生物指标、理化指标结果基本一致。研究结果表明萝卜籽蛋白提取物可以有效地抑制鲟鱼腐 败菌的生长,并能降低冷藏鲟鱼片腐败速率,因此具有开发成新型水产品防腐保鲜剂的潜力。     

Influence of ice storage on ray (raja clavata) wing muscle

Determinations of pH, urea, extractable protein (EP), apparent viscosity (AV), water-binding capacity (WBC), hardness (H), Hunter L, a and b values and sensory evaluation (SE) (raw and cooked), as well as microbiological analysis, were used to study the effects of ice storage on the stability of ray (Raja clavata) muscle. Significant changes were found in pH, bacterial growth and sensory assessment (ammoniacal odour and colour) during the storage period. Urea content, EP, AP, WBC (measured as water loss) and Hunter L value (in cooked muscle) decreased significantly. Statistical analyses did not show significant differences in H and Hunter L value (in raw muscle). The decrease in urea concentration can be described as a linear function of the number of microorganisms suggesting the microbiological character of the process. No dependence was observed between pH or number of microorganisms and EP, whereas AP was much more affected and showed a marked dependence on these two parameters treated independently. The results of this research showed that wings could be stored in ice for 9–10 days without causing important loss of quality. The fish was considered excellent up to day 7 and acceptable after 9 days but unacceptable after 11–12 days onwards. Nonetheless, the shelf-life of the ray in the iced state can vary depending upon the initial state of freshness, handling and the biological conditions of the fish. Microbiological analysis, pH, EP, AV, WBC, SE and Hunter L value have been demonstrated to be factors which could be used to monitor the deterioration of ray during ice storage.     

冰藏三文鱼品质变化及菌相分析

以感官、物理(质构、色差)、化学(TVB-N、TMA-N、K值)及微生物(菌落总数、嗜冷菌落数、致病菌数)为指标,研究三文鱼冰藏期间的品质变化,并对三文鱼冰藏期间的菌相变化及优势腐败菌进行分析。结果表明:三文鱼在冰藏期间品质变化明显,第4天到达高品质期终点,第10天感官即已不可接受。冰藏过程中,色差变化很小,质构变化中剪切力与咀嚼性逐渐减小,硬度与弹性先增加后减小,黏附性在贮藏后期上升,前期波动较大。TVB-N、TMA-N、TVC和K值变化明显,冰藏到第10天已分别达到17.36 mg/100 g、7.62 mg/100 g、7.64 lg(CFU/g)和68.7%。菌相分析表明假单胞杆菌属(Pseudomonas spp.)为冰藏三文鱼的特定腐败菌。     

Comparison of gilthead sea bream (Sparus aurata) and hake (Merluccius merluccius) muscle proteins during iced and frozen storage

Gilthead sea bream (Sparus aurata) and hake (Merluccius merluccius) muscle behave differently during storage, whether in ice or deep frozen. Rapid changes have been observed in the texture of hake muscle during frozen storage, while gilthead sea bream has proved to be more stable. In order to ascertain the role of muscle proteins in the changes observed during storage, parameters related to protein functionality and the properties of extracted natural actomyosin (NAM) were studied initially and during storage in ice or at ?20 °C. Initially, the parameters related to functionality had higher values in hake muscle and extracted NAM than in gilthead sea bream. At the end of iced storage (22 days), less myosin heavy chain (MHC) and actin were extracted from hake, but there was practically no change in gilthead sea bream. This decrease was not accompanied by lower Ca²⁺‐ATPase activity. Freezing produced no drastic changes, with lower values for gilthead sea bream. However, this species was more stable after 1 year, except for the Ca²⁺‐ATPase activity of NAM. This suggests that the changes that hake proteins underwent during storage particularly affected properties related to aggregation, whereas in gilthead sea bream the changes hardly affected the formation of soluble or insoluble aggregates but did affect the active sites of myosin. © 2002 Society of Chemical Industry     

Survival of amine-forming bacteria during the ice storage of fish and shrimp

Survival of amine-forming bacteria during the ice storage of fish and shrimp was investigated up to 14 days of storage. On iced storage the total bacterial load was reduced to one log from an initial load of 10⁵ cfu g⁻¹ in fresh fish/shrimp due to cold shock. The total incidence of biogenic amine-forming bacteria was found to be 74·63% in fish and the same was recorded as 56·05% in shrimp. The amine-forming bacteria recorded were cadaverine- and putrescine-forming bacteria in fish/shrimp, and no histamine former was detected. Gram-negative, non-fermentative rods, viz. Alcaligenes. Flavobacterium, Acinetobacter. Shewanella andPseudomonas , were the predominant amine-forming bacteria during the ice storage of fish and shrimp, in addition to the only Gram-positive genus Micrococcus. The genera Aeromonas and Photobacterium also survived ice storage to a certain extent and may also be responsible for the formation of amines in fish and shrimp.     

Histamine and Tyramine during Storage and Spoilage of Anchovie, Engraulis encrasicholus: Relationships with Other Fish Spoilage Indicators

The formation of biogenic amines (histamine and tyramine) during Engraulis encrasicholus storage and spoilage was studied and compared with changes of other fish spoilage indicators: trimethylamine nitrogen, volatile basic nitrogen, hypoxanthine and pH. Good correlations were observed between biogenic amines and the other indicators, at both refrigeration (4–6°C) and room temperature (18–22°C).Two trials were carried out at each temperature. Differences were observed in levels of biogenic amines as well as other indicators in experiments carried out under similar conditions.     

Comparison of Whole with Headed and Gutted Orange Roughy Stored in Ice: Sensory, Microbiology and Chemical Assessment

Sensory, microbiological and chemical analyses were used to compare whole orange roughy stored in ice with headed and gutted orange roughy stored in ice. Sensory results indicated that the whole fish had a shelf-life of 11 to 13 days. Heading and gutting gave only a slight increase in storage life. Microbiological results suggested that this increase was not due to any reduction in bacterial activity. However, chemical analyses indicated that there was reduced autolysis in the headed and gutted fish. Sulfide producing bacteria were not a significant proportion of the spoilage flora. The K value and results of analyses of inosine 5′-monophosphate and inosine were consistent with the sensory results and therefore these chemical tests are considered useful for monitoring changes in the freshness of orange roughy during ice storage.     

Quality changes and microbiological spoilage analysis of air‐packed and vacuum‐packed silver carp (Hypophthalmichthys molitrix) fillets during chilled storage

The effects of air‐packed (AP) and vacuum‐packed (VP) on quality and microbial characteristics of silver carp (Hypophthalmichthys molitrix) fillets during chilled storage (4 ± 1 °C) were investigated. The fillets were analyzed for sensory scores, total volatile basic nitrogen (TVB‐N), ATP‐related compounds (ATP, IMP, HxR, and Hx), K value, and biogenic amines (BAs). The results proved that VP inhibited the increase of microorganisms, TVB‐N, Hx, and putrescine in silver carp, and slowed the reduction in sensory score. Therefore, VP can be applied for preservation of the silver carp fillets to improve its quality. For identification, 16S rRNA genes of the isolated pure strains were sequenced and analyzed. On the initial day of storage, Chryseobacterium was the dominant bacterial genus. At the end of shelf life, Pseudomonas was the most common group in AP fillets and Aeromonas followed by Yersinia were found mainly in VP samples.

Practical applications

Silver carp (Hypophthalmichthys molitrix) are distributed widely in fresh water systems. The world aquaculture production of silver carp was 4,354,638 tons, and it ranked second highest among freshwater fish species in 2015, but they are perishable during storage because of microbial spoilage and biochemical reactions. Vacuum packaging (VP) has proved to be effective for extending the shelf‐life of aquatic products by excluding oxygen that prevents the growth of spoilage bacterial. However, little information is available on the microbial succession of VP silver carp. Therefore, this work was to determine the differences of microbiological succession on chilled silver carp fillets under air‐packed (AP) and VP conditions using a combination of culture‐based and 16S rRNA gene analysis methods. Furthermore, this study will give valuable information about development and spoilage of VP silver carp fillets.