Inhibition of Food-Borne Pathogen Growth and Biogenic Amine Synthesis by Spice Extracts.

Food-borne pathogens and their toxins cause significant health problems in humans. Formation of biogenic amines (BAs) produced by microbial decarboxylation of amino acids in food is undesirable because it can induce toxic effects in consumers. Therefore, it is crucial to investigate the effects of natural additives with high bioactivity like spice extracts to inhibit the growth of these bacteria and the formation of BAs in food. In the present study, the antibacterial effects of diethyl ether spice (sumac, cumin, black pepper, and red pepper) extracts at doses of 1% (w/v) on Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative (Klebsiella pneumoniae, Pseudomonas aeruginosa, Campylobacter jejuni, Aeromonas hydrophila, Salmonella Paratyphi A, and Yersinia enterocolitica) food-borne pathogen bacterial strains (FBP) were established. In addition, the accumulation of ammonia (AMN), trimethylamine (TMA), and biogenic amines (BAs) in tyrosine decarboxylase broth (TDB) was investigated by using high performance liquid chromatography (HPLC). Sumac extract exhibited the highest antibacterial potential against all FBPs, followed by cumin and peppers. AMN (570.71 mg/L) and TMA (53.66 mg/L) production were strongly inhibited by sumac extract in the levels of 55.10 mg/L for Y. enterocolitica and 2.76 mg/L for A. hydrophila, respectively. With the exception of S. aureus, black pepper dramatically reduced the synthesis of putrescine, serotonin, dopamine, and agmatine by FBP especially for Gram-negative ones. Furthermore, sumac extracts inhibited histamine and tyramine production by the majority of FBP. This research suggests the application of sumac extracts as natural preservatives for inhibiting the growth of FBPs and limiting the production of AMN, TMA, and BAs.

Bioactivity of Microencapsulated Cell-Free Supernatant of Streptococcus thermophilus in Combination with Thyme Extract on Food-Related Bacteria.

The bioactive properties of the combination of microencapsulated cell-free supernatant (CFS) from Streptococcus thermophilus and thyme extract on food-related bacteria (Photobacterium damselae, Proteus mirabilis, Vibrio vulnificus, Staphylococcus aureus ATCC29213, Enterococcus faecalis ATCC29212, and Salmonella Paratyphi A NCTC13) were investigated. The microencapsulated CFS of S. thermophilus, in combination with ethanolic thyme extract, had a particle size in the range of 1.11 to 11.39 µm. The microencapsulated CFS of S. thermophilus had a wrinkled, spherical form. In the supernatant, especially at 2% (v/w), the thyme extract additive caused a decrease in the wrinkled form and a completely spherical structure. A total of 11 compounds were determined in the cell-free supernatant of S. thermophilus, and acetic acid (39.64%) and methyl-d3 1-dideuterio-2-propenyl ether (10.87%) were the main components. Thyme extract contained seven components, the main component being carvacrol at 67.96% and 1,2,3-propanetriol at 25.77%. Significant differences (p < 0.05) were observed in the inhibition zones of the extracts on bacteria. The inhibitory effect of thyme extract on bacteria varied between 25.00 (P. damselae) and 41.67 mm (V. vulnificus). Less antibacterial activity was shown by the microencapsulated CFS from S. thermophilus compared to their pure form. (p < 0.05). As a result, it was found that microencapsulated forms of CFS from S. thermophilus, especially those prepared in combination with 2% (v/w) thyme extract, generally showed higher bioactive effects on bacteria.

The Role of Selected Lactic Acid Bacteria on Organic Acid Accumulation during Wet and Spray-Dried Fish-based Silages. Contributions to the Winning Combination of Microbial Food Safety and Environmental Sustainability.

Organic acid contents of acidified and fermented fish silages made from gibel carp (Caracius gibelio) and klunzinger's ponyfish (Equulites klunzingeri) fishes, and from fish processing residues or by-products, were determined and studied. The silages were undertaken in wet and spray-dried fish-based raw-materials for 3 weeks at room temperature (ca. 25 °C). Selected lactic acid bacteria (LAB) of Enterococcus gallinarum, Lactobacillus brevis, Lactobacillus plantarum, Pediococcus acidilactici, and Streptococcus spp. were employed to produce fermented fish-based silages, while acidified silage was prepared resorting to the addition of formic acid (3%, v/v). Lactic and propionic acids were the dominant produced organic acids, while succinic acid was formed at the smallest amounts in fermented silages. In the acidified silage, lactic and formic acids were produced in amounts higher than 800 and 1000 mg organic acid/100g sample, respectively. Among the fermented fish-based silages, LAB strains unfolded considerable ability to presumptively produce propionic acid in gibel carp silage (>2370 mg organic acid/100g sample). Spray-dried fermented silages displayed significantly higher organic acid content than wet silages. Propionic acid accumulation was found at the highest levels in gibel carp silage fermented with L. plantarum (6335.40 mg propionic acid/100g sample). This research effort pointed out the good capability of various selected lactic acid bacteria strains to produce significant amounts of organic acids-especially lactic, acetic, and propionic acids-during the fermentation of fish-based silages. In terms of food safety and quality, such a production of relatively high amounts of organic acids in wet and spray-dried fish-based silages clearly indicated their suitableness to be used for animal feed.

Antimicrobial influence of nanoemulsified lemon essential oil and pure lemon essential oil on food-borne pathogens and fish spoilage bacteria.

The antimicrobial activities of lemon oil based nanoemulsion and two different concentrations of lemon essential oil (100% and 10%) on food-brne pathogens (Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis and Salmonella Paratyphi A) and fish spoilage bacteria (Photobacterium damselae, Enterococcus faecalis, Vibrio vulnificus, Proteus mirabilis, Serratia liquefaciens, and Pseudomonas luteola) were compared in terms of disc diffusion, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC). The constitutes of extracted lemon essential oil were identified by using GC-MS. Viscosity, the mean droplet size, thermodynamic stability and refractive index of nanoemulsions were determined. The main components detected in the lemon essential oil were d-limonene, p-cymene, ß-pinene with percentages of 52.85%, 14.36%, and 13.69%, respectively. It was found that lemon nanoemulsion was more effective on food-borne pathogens except K. pneumoniae than 100% lemon essential oil. 10% lemon essential oil showed the highest inhibition effect on S. Paratyphi A. The conversion of the essential oil into nanoemulsion improved antimicrobial activity. According to value of MIC, both nanoemulsion and 100% essential oil inhibited bacterial growth of all of the pathogen bacteria tested whereas they were less effective on inhibition of fish spoilage bacteria. However, 10% essential oil was more effective on spoilage bacteria than pathogens. MBC showed that nanoemulsion and 100% lemon essential oil presented a noticeable bactericidal activity against S. paratyphi A whereas 10% lemon essential oil was found as ≥25 mg/mL against pathogens and spoilage bacteria. Therefore, the use of nanoemulsion based on lemon essential oil can have potential as a natural antimicrobial agent against food-borne pathogen and spoilage bacteria for fish processing industry.

The Impact of Carvacrol on Ammonia and Biogenic Amine Production by Common Foodborne Pathogens.

The impact of carvacrol at different levels (0.1%, 0.5%, and 1%) on ammonia (AMN) and biogenic amines (BAs) production by 8 common foodborne pathogens (FBPs) (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Listeria monocytogenes, Aeromonas hydrophila, and Salmonella Paratyphi A) was studied using a rapid high-performance liquid chromatography method. Significant differences among bacteria (P < 0.05) in AMN and BA production were observed using a tyrosine decarboxylase broth. Tyramine, dopamine, agmatine, spermine, and putrescine were the main amines produced by the bacteria. Tyramine production by P. aeruginosa was the highest (967 mg/L), whereas K. pneumoniae was the poorest tyramine producer (6.42 mg/L). AMN and BA production varied significantly depending on carvacrol levels and the specific bacterial strains. Tyramine production for all bacterial strains was significantly suppressed by addition of carvacrol at levels of 0.5% and 1%, but not 0.1%. Consequently, the effect of carvacrol on BA and AMN formation by FBP was dependent on bacterial strain as well as carvacrol level.

Antimicrobial Impacts of Essential Oils on Food Borne-Pathogens.

The antimicrobial activity of twelve essential oil (pine oil, eucalyptus, thyme, sage tea, lavender, orange, laurel, lemon, myrtle, lemon, rosemary and juniper) was tested by a disc diffusion method against food borne pathogens (Escherichia coli, Salmonella paratyphi A, Klebsiella pneumoniae, Yersinia enterocolitica, Pseudomonas aeruginosa, Aeromonas hydrophila, Campylobacter jejuni, Enterococcus faecalis, Staphylococcus aureus). The major components in essential oils were monoterpenes hydrocarbons, α-pinene, limonene; monoterpene phenol, carvacrol and oxygenated monoterpenes, camphor, 1,8-cineole, eucalyptol, linalool and linalyl acetate. Although the antimicrobial effect of essential oils varied depending on the chemical composition of the essential oils and specific microorganism tested, majority of the oils exhibited antibacterial activity against one or more strains. The essential oil with the lowest inhibition zones was juniper with the values varied from 1.5 to 6 mm. However, the components of essential oil of thyme and pine oil are highly active against food borne pathogen, generating the largest inhibition zones for both gram negative and positive bacteria (5.25-28.25 mm vs. 12.5-30 mm inhibition zones). These results indicate the possible use of the essential oils on food system as antimicrobial agents against food-borne pathogen. The article also offers some promising patents on applications of essential oils on food industry as antimicrobial agent.

The influences of fish infusion broth on the biogenic amines formation by lactic acid bacteria.

The influences of fish infusion decarboxylase broth (IDB) on biogenic amines (BA) formation by lactic acid bacteria (LAB) were investigated. BA productions by single LAB strains were tested in five different fish (anchovy, mackerel, white shark, sardine and gilthead seabream) IDB. The result of the study showed that significant differences in ammonia (AMN) and BA production were observed among the LAB strains in fish IDB (p < 0.05). The highest AMN and TMA production by LAB strains were observed for white shark IDB. The all tested bacteria had decarboxylation activity in fish IDB. The uppermost accumulated amines by LAB strains were tyramine (TYM), dopamine, serotonin and spermidine. The maximum histamine production was observed in sardine (101.69 mg/L) and mackerel (100.84 mg/L) IDB by Leuconostoc mesenteroides subsp. cremoris and Pediococcus acidophilus, respectively. Lactobacillus delbrueckii subsp. lactis and Pediococcus acidophilus had a high TYM producing capability (2943 mg/L and 1157 mg/L) in sardine IDB.

Effect of Mentha spicata L. and Artemisia campestris extracts on the shelf life and quality of vacuum-packed refrigerated sardine (Sardina pilchardus) fillets.

The present study investigated the effects of ethanolic extracts obtained from Mentha spicata and Artemisia campestris on the shelf life and the quality of vacuum-packed sardine fillets stored at 3 ± 1°C for a period of 21 days. The three groups were tested were VC, control group; VM, group treated with 1 % mint extract; and VA, group treated with 1 % artemisia extract. The observed shelf life of sardine fillets was 10 days for control samples, whereas the combination of vacuum packaging with mint and artemisia extracts extended the product's shelf life to 17 days. Among the chemical indices determined, the thiobarbituric acid-reactive substances values were significantly lower in VM samples. Total volatile base nitrogen was maintained at low levels in VA samples until 17 days of chilled storage. Results of aerobic plate counts and coliform counts showed the existence of a reduced growth in VA group, whereas lactic acid bacteria did not show a significant difference among groups. Natural extract treatments combined with vacuum packaging showed lower microbiological and chemical indices, indicating that the presence of phenolic compounds in mint and artemisia extracts and the removal of oxygen in the pack retarded lipid oxidation and reduced the growth of microorganisms, which resulted in preventing spoilage and extending the product's shelf life.

Comparative seasonal sterol profiles in edible parts of Mediterranean fish and shellfish species.

The effect of different seasons on sterol content of seafoods was investigated. There were four sterols (cholesterol, sitosterol, desmosterol and stigmasterol) identified, with cholesterol being the predominant sterol. Stigmasterol was a minor component in fish muscle, whilst sitosterol was one of the main phytosterols found in fish muscle. Cholesterol content of fish consisted of 38-100% of total sterols in fish and 54-80% of total sterols in shellfish. The highest cholesterol content of fish muscle was found in summer and the lowest in autumn, whereas season did not have any effect on cholesterol level of green tiger prawn and speckled shrimp. Total sterol content of fish muscle ranged from 49 to 110 mg/100 g, although the range of total sterols in shrimp muscle was between 62 and 91 mg/100 g. The result of the study showed that total sterols in fish were generally found at lower levels in winter compared with other seasons.

Biogenic amines formation in Streptococcus thermophilus isolated from home-made natural yogurt.

Twelve different biogenic amines formation in 58 isolates of Streptococcus thermophilus from home-made natural yogurt were investigated in histidine (HDB) and lysine decarboxylase broth (LDB). All S. thermophilus isolates had an ability to produce twelve different biogenic amines in HDB and LDB. Most of the S. thermophilus isolates formed low amounts of histamine (1-50 mg/L) from histidine. Apart from one isolate, S. thermophilus produced tyramine at low (47 isolates) and medium (10 isolates) levels. The amount of each specific biogenic amine produced by S. thermophilus was generally lower than 100 mg L(-1). Also, the presence of hdcA gene was investigated using PCR technique and relation between gene and histamine production was conducted in S. thermophilus isolates. This study showed that most of the S. thermophilus isolates have the ability to form biogenic amines, especially histamine, and tyramine, which is an important consideration when selecting strains as starter cultures.

The influences of fish infusion broth on the biogenic amines formation by lactic acid bacteria

The influences of fish infusion decarboxylase broth (IDB) on biogenic amines (BA) formation by lactic acid bacteria (LAB) were investigated. BA productions by single LAB strains were tested in five different fish (anchovy, mackerel, white shark, sardine and gilthead seabream) IDB. The result of the study showed that significant differences in ammonia (AMN) and BA production were observed among the LAB strains in fish IDB (p < 0.05). The highest AMN and TMA production by LAB strains were observed for white shark IDB. The all tested bacteria had decarboxylation activity in fish IDB. The uppermost accumulated amines by LAB strains were tyramine (TYM), dopamine, serotonin and spermidine. The maximum histamine production was observed in sardine (101.69 mg/L) and mackerel (100.84 mg/L) IDB by Leuconostoc mesenteroides subsp. cremoris and Pediococcus acidophilus, respectively. Lactobacillus delbrueckii subsp. lactis and Pediococcus acidophilus had a high TYM producing capability (2943 mg/L and 1157 mg/L) in sardine IDB.

Stimulation of cadaverine production by foodborne pathogens in the presence of Lactobacillus, Lactococcus, and Streptococcus spp.

The effect of Lactobacillus plantarum (FI8595), Lactococcus lactis subsp. cremoris MG 1363), Lactococcus lactis subsp. lactis (IL 1403), and Streptococcus thermophilus on cadaverine and other biogenic amine production by foodborne pathogens was investigated lysine decarboxylase broth. Both of lactic acid bacteria and foodborne pathogens used (especially Staphylococcus aureus, E. coli, Lc. lactis subsp. lactis and Lb. plantarum) had an ability to convert aminoacids into biogenic amine. The conversion of lysine into cadaverine was the highest (167.11 mg/L) by Lactobacillus spp. Gram-positive bacteria generally had a greater ability to produce cadaverine with corresponding value of 46.26, 53.76, and 154.54 mg/L for Enterococcus faecalis, S. aureus, and Listeria monocytogenes, respectively. Significant variations on biogenic amine production were observed in the presence of lactic acid bacteria strains (P < 0.05). The role of lactic acid bacteria on biogenic amine production by foodborne pathogens varied depending on strains and specific amine. Cadaverine accumulation by Enterobactericeae was increased in the presence of lactic acid bacteria strains except for St. thermophilus, which induced 2-fold lower cadaverine production by S. Paratyphi A. Lc. lactis subsp. lactis and Lc. lactis subsp. cremoris induced 10-fold higher increases in histamine for E. coli and K. pneumoniae, respectively. Lactic acid bacteria resulted in strong increases in cadaverine production by P. aeruginosa, although remarkable decreases were observed for histamine, spermidine, dopamine, agmatine, and TMA in the presence of lactic acid bacteria in lysine decarboxylase broth . The result of the study showed that amine positive lactic acid bacteria strains in fermented food led to significant amine accumulation by contaminant bacteria and their accumulation in food product may be controlled by the use of proper starters with amine-negative activity.

The influences of natural zeolite (cliptinolite) on ammonia and biogenic amine formation by foodborne pathogen.

UNLABELLED: The influence of natural zeolite on biogenic amines (BAs) and ammonia (AMN) production by eight common gram negative and positive foodborne pathogens (FBP) were investigated in histidine decarboxylase broth (HDB). Presence of 1% zeolite in the HDB resulted in significantly higher AMN production. Histamine (HIS) production by gram positive bacteria was as low as 0.5 mg/L, whereas Escherichia coli produced 18.96 mg/L of HIS. The use of zeolite also significantly suppressed HIS accumulation by E. coli, Pseudomonas aeruginosa, S. paratyphi A (P < 0.05), although zeolite addition stimulated HIS production by K. pneumonia and Aeromonas hydrophila. The range of tyramine (TYR) production by gram positive bacteria was 1.19 and 4.06 mg/L for Enteroccus faecalis and Listeria monocytogenes respectively. The results of study showed that the effect of zeolite on BAs and AMN production was dependent on bacterial strains, as well as zeolite concentrations used. PRACTICAL APPLICATION: Natural zeolites are the main absorptive, low-cost material used in agriculture and industry. Although the effect of zeolite on ammonia formation in some industrial systems is well known, there is limited information regarding the impact of zeolite on biogenic amine (BA) production by foodborne pathogens. The data presented in this article will help us to understand the impact of natural zeolite on BA and ammonia production by eight common foodborne pathogens.

The function of lactic acid bacteria and brine solutions on biogenic amine formation by foodborne pathogens in trout fillets.

The influences of lactic acid bacteria and brine solutions on the biogenic amine formation by Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterococus faecalis, Pseudomonas aeruginosa, Listeria monocytogenes, Aeromonas hydrophila and Salmonella paratyphi A in fermented trout fillets were investigated. Fish fillets were divided into four groups, group 1 without any lactic acid bacteria inoculation, group 2 and group 3 with different salt concentration inoculated with lactic acid bacteria and food-borne pathogens, and group 4 inoculated with lactic acid bacteria and food-borne pathogens without a salt solution. The histamine content in trout fillets in group 4 was found to be more than 10mg/100g, while the other groups contained less than 7.5mg/100g. The highest tyramine production was found for group 1 and group 3, ranging from 3 to 18mg/100g. Lactic acid bacteria did not seem to play an important role on biogenic amine production by food borne pathogens, while adding brine solution on fillets has inhibitory effects on some of the biogenic amines.

Synergistic and antagonistic effect of lactic acid bacteria on tyramine production by food-borne pathogenic bacteria in tyrosine decarboxylase broth.

The effect of lactic acid bacteria (LAB) strains on tyramine (TYR) and also other biogenic amines (BA) production by eight common food-borne pathogen (FBP) in tyrosine decarboxylase broth (TDB) was investigated by using a rapid HPLC method. Significant differences were observed among the FBP strains in ammonia (AMN) and BA production apart from tryptamine, histamine (HIS) and spermine formation (p<0.05). Salmonella paratyphi A was characterised as the main amine producer. LAB had an important synergetic role in some BA production by food-borne pathogenic bacteria, although the effect of some LAB strains on BA production was strain-dependent. Lactococcus spp. and Streptococcus spp. resulted in significantly higher TYR accumulation by Aeromonas hydrophila and Enterococcus faecalis in TDB. The presence of Lactococcus and/or Lactobacillus in TDB significantly increased HIS production by A. hydrophila, Escherichia coli, Ent. faecalis, Klebsiella pneumoniae and Pseudomonas aeruginosa, whereas HIS accumulation was significantly reduced by Staphylococcus aureus, S. paratyphi A and Listeria monocytogenes.

Fat content and fatty acid compositions of 34 marine water fish species from the Mediterranean Sea.

Fish is the best source of polyunsaturated fatty acids (PUFA), specifically n-3 fatty acids, especially eicosapentaenoic acid and docosahexaenoic acid. The objective of the present study was to determine the fat content and fatty acid compositions of 34 marine water fish species from the Mediterranean Sea. The fatty acid compositions of fish consisted of 30.10-46.88% saturated fatty acids, 11.83-38.17% monounsaturated fatty acids and 20.49-49.31% PUFA. In most species, the following fatty acids were identified: mystiric acid (C14:0, 0.72-8.09%), pentadecanoic acid (15:0, 0.05-2.35%), palmitic acid (C16:0, 15.97-31.04%), palmitoleic acid (C16:1, 1.48-19.61%), heptadecanoic acid (C17:0, 0.31-1.84%), cis-10-heptadecenoic acid (C17:1, 0.17-2.01%), stearic acid (C18:0, 2.79-11.20%), oleic acid (C18:1n9, 2.44-28.97%), linoleic acid (C18:2n-6, 0.06-3.48%), arachidonic acid (C20:4n-6, 0.12-10.72%), cis-5,8,11,14,17-eicosapentaenoic acid (C20:5n-3, 1.94-10%) and cis-4,7,10,13,16,19-docosahexaenoic acid (C22:6n-3, 3.31-31.03%). The proportions of n-3 PUFA ranged from 12.66% for annular seabream to 36.54% for European hake, whereas the proportions of PUFA n-6 were between 1.24% for oceanic puffer and 12.76% for flathead mullet. The results of this study show that these fish species were rich in n-3 PUFA, especially, eicosapentaenoic acid and docosahexaenoic acid.

Bacteriological and biochemical assessment of marinating cephalopods, crustaceans and gastropoda during 24 weeks of storage.

The quality and safety parameters of mixed marinated seafood salad containing common octopus (Octopus vulgaris), shrimp (Parapenaeus longirostris), European squid (Loligo vulgaris), sea snail (Rapana thomasiana) and common cuttlefish (Sepia officinalis) at 4 degrees C during storage of 24 weeks were investigated. In addition, the nutritional value in terms of proximate and fatty acid composition of seafood salad was also determined. Sensory scores of seafood salad in terms of appearance, odour, flavour and texture slightly decreased throughout the storage period. However, at the end of the storage period (5 months), the marinated seafood salad was still acceptable by the panellist. At the beginning of storage the total volatile basic nitrogen (TVB-N) value was 6.05 mg/100 g flesh, and the TVB-N values rose to 11.19 mg TVB-N/flesh by the end of the storage period. The pH value of the marinated seafood salad showed fluctuations, ranging from 3.57 to 3.65, and did not change significantly during the storage period. The concentrations of the biogenic amines in both the muscle of all species and in the solution of salad were also investigated. Among the biogenic amines, histamine was not detected in all samples throughout the storage period. The putrescine and cadaverine levels increased throughout the storage period, with a lower increase in the solution of seafood salad. Salmonella, coliform, Escherichia coli and Staphylococcus aureus were not detected while the total viable count remained low (3 log CFU/g) after 3 months of storage.

Comparison of fatty acid and proximate compositions of the body and claw of male and female blue crabs (Callinectes sapidus) from different regions of the Mediterranean coast.

Fatty acid and proximate compositions of the body and claw of male and female blue crabs from Akyatan Lagoon and Hurma strait were investigated. Male blue crab meat had a higher protein and fat content, and lower moisture and ash content, than that of the female from Akyatan Lagoon. Moreover, there were variations of protein and fat amounts in both female crab meats between Akyatan Lagoon and Hurma strait. The dominant saturated fatty acids were palmitic acid (16:0; range from approximately 12% to 15%) and stearic acid (18:0; range from approximately 7.5% to 16.1%) for all samples. The total monounsaturated fatty acid content in the body of female crabs from Akyatan Lagoon was higher than those of Hurma Strait (22.04% versus 7.55%). There were no statistically significant differences (P>0.05) between eicosapentaenoic acid concentrations in body meat of the male crab than those of female crab meat from Akyatan Lagoon (P<0.05). Docosahexaenoic acid contents were different between the body meat of male crabs from Akyatan Lagoon and those of female crabs from Hurma strait. The total n3 was detected as 27.33% in body meat whereas it was 24.39% in claw meat of the male crab from Akyatan Lagoon. Those values were almost similar in the body and claw meat of female crab from Akyatan Lagoon.

Nucleotide degradation and biogenic amine formation of wild white grouper (Epinephelus aeneus) stored in ice and at chill temperature (4°C).

Sensory (cooked and uncooked), chemical (proximate composition, TVB-N, nucleotide degradation products and biogenic amines) and microbiological quality (TVC and total coliform) changes were investigated during storage of ungutted white grouper kept in ice and at chill temperature (4°C). According to the sensory assessment, the shelf life of white grouper was 16 days in ice and 4 days for fish stored at chill temperature. TVB-N values increased with storage time. Amines found in white grouper stored in ice were TMA, putrescine, cadaverine, 2-phenylethylamine, dopamine, agmatine, tryptamine and serotonin. Histamine, spermine, spermidine were never detected with either storage condition. The acceptability limit in terms of microbial count was exceeded at 8 days in ice and at 4 days for fish stored at chill temperature. Total coliform count was 2.8log10cfu/ml at 1 day and reached 10(5)cfu/ml for both storage conditions.