Endotoxin and biogenic amine levels in Atlantic mackerel (Scomber scombrus), sardine (Sardina pilchardus) and Mediterranean hake (Merluccius merluccius) stored at 22 °C

Occurrence of biogenic amines and their correlation with bacterial communities in the Ivorian traditional fermented fish adjuevan during the storage

Adjuevan is an Ivorian traditional fermented fish used as a condiment. However, the fermentation process and storage conditions may lead to the production of biogenic amines (BA) which can induce severe human toxicological effects. Thus, this study aimed to reveal the bacterial community diversity and the BA contents during the storage. Samples of adjuevan from the fish species Chloroscombrus chrysurus, Galeoides decadactylus, and Thunnus thynnus were collected from local producers, stored at ambient temperature (28-30 °C) and in a refrigerator (4 °C) over a period of 8 weeks. At 2-week intervals, BA were determined by HPLC and the bacterial communities analyzed using high-throughput sequencing (NGS) of the V3-V4 region of the 16S rRNA gene. Results showed that histamine, cadaverine, putrescine, and tyramine were the major compounds. In adjuevan from T. thynnus, the level of histamine was over the maximum level of 200 mg/kg determined by Codex Alimentarius. For the other amines, no safety concerns are related. In total, 21 bacterial genera with a relative abundance ≥ 1% and belonging to 14 families and 5 phyla were detected. The Bacillaceae family was the most found at ambient temperature while Staphylococcaceae and Enterococcaceae were the most abundant in a refrigerator. The analysis of correlation showed that the increase of Lentibacillus leads to a decrease of the major BA at ambient temperature. On the contrary, the increase of Staphylococcus, Lactobacillus, Psychrobacter, Peptostreptococcus, and Fusobacterium leads to an increase of these biogenic compounds. Thus, Lentibacillus acted as BA-oxidizing bacteria while the others were found as BA-producing bacteria during adjuevan storage.

Mechanism of biogenic amine synthesis of Enterococcus faecium isolated from Sanchun ham

Sanchuan ham, produced in Yunnan, China, is food with ethnic characteristics favored by consumers. However, it can contain biogenic amines such as tyramine that are harmful to health, and the synthesis mechanism of biogenic amines in Sanchuan ham is not clear. This study focuses on the regulation of biogenic amine synthesis by quorum sensing. We used high‐performance liquid chromatography to detect the content of biogenic amine in different kinds of ham and found that the content of biogenic amine in Sanchuan ham was higher than that in others. Tyramine‐producing strain isolated from Sanchuan ham was identified as Enterococcus faecium. By monitoring the growth and tyramine synthesis of Enterococcus faecium under cultured conditions, the results found that high temperature and low salt increased tyramine production by E. faecium. After seven exogenous amino acids were applied to E. faecium, only tyrosine could promote the production of tyramine in E. faecium, and tyramine could not be synthesized in E. faecium until a certain amount was reached, indicating the presence of microbial quorum sensing signal molecules in the synthesis of tyramine in E. faecium. Untargeted metabolomics analysis of the differential metabolites produced by E. faecium showed that the contents of some peptides, especially alanyl‐leucine, were significantly increased. Further experiments with synthetic alanyl‐leucine illustrated that alanyl‐leucine activated the expression of tyrosine decarboxylase (tyrDC), thereby regulating the synthesis of tyramine by E. faecium. Alanyl‐leucine acted as quorum sensing signal molecules for biogenic amine synthesis by E. faecium, which provided a theoretical basis for reducing biogenic amine accumulation in ham. It is beneficial to control the content of biogenic amines in ham in the future.

Sensory evaluation of fresh/frozen mackerel products: A review

Mackerel has received considerable attention in the global food market as one of the most important pelagic commercial fish species. The quality of mackerel is influenced by species, season, fishing area, nutritional status, catching method, handling, and storage. Due to the mackerel's perishability, its quality is mainly measured by sensory procedures. Although considerable effort has been made to explore quick and reliable quality analysis, developing a practical and scientific sensory evaluation of mackerel has been an active ongoing study area to meet the quality evaluation demand of the industry. Different sensory evaluation methods have been used to assess the mackerel fish quality, including Palatability and Spoilage test, Torry scheme, EU scheme, Quality Index Method, Catch damage index and Processed fish damage index, Affective test, Discriminative test, and Descriptive test. Each method has its strength and weakness. Despite mackerel sensory evaluation protocols having undergone partial harmonization, specific sample process needs to be carefully followed to minimize the change during sample preparation. This review summarizes the sensory evaluation methods in mackerel research, the factors affecting sensory evaluation, and then updates the latest advances in mackerel sensory evaluation and offers guidance for presenting its application in the mackerel chain. Also, each technique's advantages and limitations are discussed. In our opinion, the future trends for sensory evaluation of mackerel should be consumer-centric.

The effects of active double-layered furcellaran/gelatin hydrolysate film system with Ala-Tyr peptide on fresh Atlantic mackerel stored at -18 °C

This is the first time that active double-layered furcellaran/gelatin hydrolysate films containing Ala-Tyr peptide were developed and characterised for their properties. Afterwards, films were used on Atlantic mackerel stored at -18 °C for 4 months and samples were analysed for changes in their microbiological quality, TVB-N, biogenic amine content, fatty acid composition and TBARS. Active films had higher TS (13.4 MPa) and lower WS (62.8%). The films showed no DPPH radical scavenging properties but high FRAP (6.6 mMol Trolox/mg). No significant effects on the oxidation of fish samples were observed with TBARS increasing from 12.04 to 22.50 mg/kg. Freezing successfully inhibited the growth of microorganisms and no differences in microbiological growth or biogenic amine formation were observed. However, the application of films inhibited the formation of TVB-N. Antimicrobiological properties of the film should be further investigated during storage of perishable food products at temperatures above 0 °C.

Biogenic Amine, Fatty Acid, and Volatile Compound Contents in Ivorian Traditionally Fermented Fish "Adjuevan"

This study identified biogenic amines, fatty acids, and volatile compounds in adjuevan, an Ivorian traditionally salted and fermented fish. Samples were obtained from two processing methods (method 1: entire fish adjuevan; method 2: both sides filleted adjuevan) with the fish species Galeoides decadactylus. Biogenic amines found in freshly produced adjuevan were histamine, putrescine, cadaverine, tyramine, β-phenyl ethylamine, and spermidine. Among these, the most prevalent were β-phenyl ethylamine and cadaverine. Biogenic amine contents varied according to the processing method but remained lower than levels considered hazardous for human health. The major fatty acids present in adjuevan from method 1 were docosahexaenoic acid, palmitic acid, and oleic acid. In adjuevan from method 2, the major fatty acids were oleic acid, stearic acid, and palmitic acid. The omega (w)-3/w-6 ratio was 8.87 and 4.12 for adjuevan from methods 1 and 2, respectively. Most of the fatty acids are considered healthy fats, making adjuevan a useful food for treating and preventing lifestyle diseases. The volatile compounds found composed of 19 aldehydes, 12 alcohols, 7 esters, 7 ketones, 3 furans, 10 aromatic compounds, and 7 acids with aldehyde, alcohol, and ester compounds as the predominant groups. Among the aldehydes, 2,4-heptadienal (E,Z), octanal, and 2-octenal (E) were most prevalent in adjuevan from method 1, whereas 2-nonenal (E), 2,4-heptadienal (E,Z), and octanal were most prevalent in adjuevan from method 2.

Detection of cold chain breaks using partial least squares-class modelling based on biogenic amine profiles in tuna

The maintenance of the cold chain is essential to ensure foodstuff conformity and safety. However, gaps in the cold chain may be expected so designing analytical methods capable to detect cold chain breaks is a worthwhile issue. In this paper, the possibility of using the amount of nine biogenic amines (BAs) determined in Thunnus albacares by HPLC-FLD for detecting cold chain breaks is approached. Tuna is stored at 3 different temperature conditions for 8 storage periods. The evolution of the content of BAs is analyzed through parallel factor analysis (PARAFAC), in such a way that storage temperature, BAs and storage time profiles are estimated. PARAFAC has made it possible to observe two spoilage routes with different relative evolution of BAs. In addition, it has enabled to estimate the storage time, by considering the three storage temperatures, with errors of 0.5 and 1.0 days in fitting and in prediction, respectively. Furthermore, a class-modelling technique based on partial least squares is sequentially applied to decide, from the amount of BAs, if there has been a cold chain break. Firstly, samples stored at 25 °C are statistically discriminated from those kept at 4 °C and -18 °C; next, frozen samples are distinguished from those refrigerated. In the first case, the probabilities of false non-compliance and false compliance are almost zero, whereas in the second one, both probabilities are 10%. Globally, the results of this work have pointed out the feasibility of using the amount of BAs together with PLS-CM to decide if the cold chain has been maintained or not.

Biogenic amines, amino acids and microflora changes in Indian mackerel (Rastrellinger kanagurta) stored at ambient (25-29 °C) and ice temperature (0 °C)

Biogenic amines formation in Indian mackerel of tropical region was investigated during storage at ambient (25-29 °C) and ice temperature (0 °C) in relation with changes of amino acids content and amines forming bacteria. All amines increased significantly during storage at two temperatures except for spermidine and spermine. Histamine concentration of 363.5 ppm was detected after 16 h stored at ambient temperature. Aerobic plate count of fish stored at ambient temperature reached 6.98 log CFU g(-1) after 16 h, close to the upper limit (7 log CFU g(-1)) suggested by International Commission on the Microbiological Specifications for Foods (ICMSF). However, proper icing procedure retarded the formation of histamine effectively, resulting only 8.31 ppm after 16 days of ice storage. Aerobic plate count of 5.99 and 7.72 log CFU g(-1) were recorded for fish stored in ice after 16 days and ambient temperature after 20 h, respectively. Histamine exhibited high correlation with histidine (r(2) = -0.963, P < 0.01) as well as cadaverine with lysine (r(2) = -0.750, P < 0.05). However, tyramine-tyrosine demonstrated a weaker relationship (r(2) = -0.138, P > 0.05). As storage time progressed, the amines forming bacteria grew significantly except for that stored in ice.

Effect of storage conditions on the biogenic amine content in wild boar meat

Hygienic quality of game meat depends on many factors during and after hunting. Freshness of meat is connected with the concentration of biogenic amines which is related to meat spoilage. The aim of this study was to assess changes in concentration of biogenic amines in raw meat of wild boar (n = 20, mean age 1–2 years) during storage at different temperatures. Carcases of wild boars hunted in winter 2012 in hunting districts of south Moravia were stored unskinned during 21 days at various temperatures (0, 7 and 15 °C). Concentrations of biogenic amines (putrescine, cadaverine, tyramine, tryptamine, phenylethylamine, histamine, spermine and spermidine) were determined in the shoulder and leg muscles by high-performance liquid chromatography in combination with triple quadrupole tandem mass spectrometry. Good hygienic quality was maintained when wild boar carcasses were stored for a maximum of 14 days at 0 °C (content of biogenic amines in 3 meat samples exceed the limit of 5 mg/kg on day 21 of storage) or a maximum of 7 days at 7 °C (content of biogenic amines in 4 meat samples exceed the limit of 5 mg/kg on day 14 of storage). The temperature of 15 °C should be considered as unsuitable storage temperature if good hygienic quality of game meat during storage is to be guaranteed (content of biogenic amines in 2 meat samples exceed the limit of 5 mg/kg already on day 7 of storage). The study brings new information about the biogenic amine content and its changes in wild boar meat during the storage period of 21 days.

The impact of drawing on the biogenic amines content in meat of pithed pheasant

With the increasing popularity of game meat, greater emphasis is being placed on ensuring high hygienic quality of this food. Biogenic amines are among possible indicators of the hygienic quality of meat. The aim of this study was to monitor biogenic amine concentrations in the muscle tissues of pheasants (n = 20) killed by pithing and treated by drawing (guts are removed from the body cavity through the cloaca using a specially fashioned hook). The pheasants’ bodies were stored hanged by the neck for 21 days at ±7 °C. Breast and thigh muscle samples were collected at weekly intervals (day 1, 7, 14 and 21 of storage). Biogenic amines (putrescine, cadaverine, tyramine, histamine, tryptamine and phenylethylamine) were analysed by reverse phase liquid chromatography and detected by tandem mass spectrometry. In breast muscle, the most evident change was noted in the concentration of cadaverine (0.026 and 1.070 mg/kg for storage day 1 and 21, respectively) and tyramine (0.001 and 0.958 mg/kg for storage day 1 and 21, respectively). Throughout the storage period, the concentration of 5 mg/kg (indicating a loss of high hygienic quality of meat) was not exceeded by any of the assessed biogenic amines. In thigh muscle, the concentration indicating high hygienic quality of meat was exceed after 14 days of storage in the case of cadaverine, tyramine and putrescine (at the end of storage their concentrations were 9.058, 10.708 and 3.345 mg/kg, respectively). Hygienic quality of thigh muscle decreased faster compared to breast muscle. This study brings new information about the content of biogenic amines in the meat of pithed pheasants treated by drawing.

Determination of Biogenic Amines and Endotoxin in Squid, Musky Octopus, Norway Lobster, and Mussel Stored at Room Temperature

Little research has been published on the indicators of spoilage in Mediterranean molluscan shellfish and crustaceans. Thus is why we studied changes in the concentrations of endotoxin and four biogenic amines (histamine, putrescine, tyramine and cadaverine) in European common squid (Loligo subulata, Lamarck, 1798), musky octopus (Eledone moschata, Lamarck, 1798), Norway lobster (Nephrops norvegicus, Linnaeus, 1758), and mussel (Mytilus galloprovincialis, Lamarck, 1819) from the Adriatic Sea stored at room temperature for 24 h. Endotoxin load in fresh squid, Norway lobster, and mussel (<1 EU mg-1) indicated good microbiological quality of raw samples. Biogenic amine index (as the sum of histamine, putrescine, tyramine, and cadaverine) correlated well with endotoxin load in squid (r=0.978, p<0.001) and musky octopus (r=0.874, p<0.01). A good correlation was also found between endotoxin and putrescine in Norway lobster (r=0.777, p<0.05). The highest endotoxin load was found in decomposed mussels and was associated with histamine alone. In conclusion, increase in biogenic amine levels is species-specific. Endotoxin analysis could be used for rapid assessment of microbiological quality of cephalopods and shellfish.

Control of biogenic amines in food--existing and emerging approaches

Biogenic amines have been reported in a variety of foods, such as fish, meat, cheese, vegetables, and wines. They are described as low molecular weight organic bases with aliphatic, aromatic, and heterocyclic structures. The most common biogenic amines found in foods are histamine, tyramine, cadaverine, 2-phenylethylamine, spermine, spermidine, putrescine, tryptamine, and agmatine. In addition octopamine and dopamine have been found in meat and meat products and fish. The formation of biogenic amines in food by the microbial decarboxylation of amino acids can result in consumers suffering allergic reactions, characterized by difficulty in breathing, itching, rash, vomiting, fever, and hypertension. Traditionally, biogenic amine formation in food has been prevented, primarily by limiting microbial growth through chilling and freezing. However, for many fishing based subsistence populations, such measures are not practical. Therefore, secondary control measures to prevent biogenic amine formation in foods or to reduce their levels once formed need to be considered as alternatives. Such approaches to limit microbial growth may include hydrostatic pressures, irradiation, controlled atmosphere packaging, or the use of food additives. Histamine may potentially be degraded by the use of bacterial amine oxidase or amine-negative bacteria. Only some will be cost-effective and practical for use in subsistence populations.