Inhibition performance of almond shell hydrochar-based fish oil emulsion gel on Klebsiella pneumonia inoculated fish skin and its characteristics.

In this study, the inhibition potential against Klebsiella pneumoniae (K. pneumoniae) and the characterization of fish oil (FO) emulsion gel (EGE) containing almond shell hydrochar (AH) were investigated. Oily water of mullet liver was emulsified using tween 80, then gelled using gelatin and finally immobilized into hydrochar using an ultrasonic homogenizer. Characteristics and surface analysis of hydrochar-based emulsion gel (HEGE) were examined using FTIR and SEM. Stability, particle size distribution and zeta potential of HEGE were measured. In this study, a zeta potential of -18.46 indicated that HEGE was more stable than EGE (35.7 mV). The addition of hydrochar to the emulsion gel containing micro-droplets enabled the structure to become fully layered and stable. Time-dependent inactivation of K. pneumoniae exposed to HEGE and fixed in 6 mm-fish skin was evaluated for the first time in this study. While the highest log reduction and percent reduction in the bacterial count were achieved within 5 min with 0.87 CFU/cm2 and 86.60% with EGE, the lowest log reduction and percent reduction were achieved with 0.003 CFU/cm2 and 0.082% with HEGE in 30 min. In conclusion, the almond shell hydrochar-immobilized emulsion gel is a functional adsorbent that can inhibit K. pneumonia, and its stability and performance make it a unique candidate for further studies in this field.

Metal levels of canned fish sold in Türkiye: health risk assessment.

This study analyzed 34 canned fish products, including 28 tuna specimens, 3 salmon specimens, 1 mackerel specimen, and 1 anchovy specimen, from 13 different brands purchased in Türkiye. The study aimed to determine metal/metalloid levels in canned fish and potential health risks for both children and adult consumers. The metal/metalloid levels in the samples were determined using an Inductively Coupled Plasma-Mass Spectrometer (ICP-MS), with the range of levels found as follows (mg/kg, ww): Fe (12.12-101.4), Cu (2.19-11.68), Zn (4.06-33.56), Se (0.24-10.74), Al (1.41-14.45), Cr (0.06-4.08), Pb (0.10-0.43), Cd (0.001-0.110), and As (0.01-0.13). Estimated weekly intake (EWI) levels were found that the consumption of canned fish products did not pose any risk based on the EWI levels and provisional tolerable weekly intake (PTWI) limits. However, three tuna samples had target hazard quotient (THQ) levels above the threshold (>1). Arsenic levels were found to increase the carcinogenic risk for child consumers if they heavily consumed 18 canned fish products, including 15 tuna, 2 salmon, and 1 mackerel. The maximum allowable consumption rates (CRmm) for each canned fish product were calculated monthly. Consequently, the consumption of canned fish by children can pose health risks.

Monthly Variation of Tetrodotoxin Levels in Pufferfish (Lagocephalus sceleratus) Caught from Antalya Bay, Mediterranean Sea.

The silver-cheeked toadfish (Lagocephalus sceleratus), an invasive alien pufferfish species that has rapidly settled throughout the Mediterranean region, poses significant threats not only to native marine species and fisheries but also to public health due to the tetrodotoxin (TTX) they harbor. In this study, TTX concentrations in L. sceleratus from Antalya Bay in the Northeastern Mediterranean Sea were investigated using Q-TOF-LC-MS on a monthly basis over a one-year period. Pufferfish were caught by angling from May 2018 to April 2019. The TTX levels in three different tissues (gonads, liver, and muscle) of 110 pufferfish in total were determined in both male and female individuals caught for 11 months. The highest TTX mean levels generally occurred in the gonads and the lowest in the muscle samples. As regards the maximum TTX contents, the highest concentrations determined were 68.2, 34.2, and 7.8 µg/g in the gonad, liver, and muscle tissues, respectively. The highest levels were generally observed in late autumn to winter (especially in November and December) in all tissues from both genders. Female individuals were generally found to be more toxic than male individuals. The TTX levels found confirm that the consumption of L. sceleratus from Antalya Bay remains dangerous throughout the year, and thus L. sceleratus constantly constitutes an important risk source for public health.

Chemical composition, antifungal activity, antifungal mechanism and interaction manner of the fatty acid of Prunus mahaleb L. with fluconazole.

The interaction manner of Prunus mahaleb L. (P. mahaleb) seed oil (MSO) and fluconazole (FLC: antimycotic) combinations (MSO*FLC) against C. albicans and C. parapsilosis were evaluated using the microdilution technique. The most representative compounds of mahaleb oil were found to be conjugated linolenic acid (34.39%), oleic acid (31.76%), and linoleic acid (25.54%) by GC-MS. In antimicrobial activity study, P. mahaleb had an inhibition zone (IZ) of C. albicans and C. parapsilosis with 6.89 mm and 11.39 mm and a minimum inhibitory concentration (MIC) with 35.3 µgmL-1 and 23.9 µgmL-1, respectively. The strongest indifferent effect was observed as 57.14% for C. albicans and 100% for C. parapsilosis in fluconazole-mahaleb oil combinations. An increase in DNA and protein leakage was observed when yeast was exposed to the FA. The destruction on the cell surface was visualized using Scanning Electron Microscopy (SEM) analysis.

Elemental composition of pufferfish species from Northeastern Mediterranean Sea.

This study aimed at comparing the elemental levels of muscle and liver tissues of four pufferfish (Lagocephalus sceleratus, Lagocephalus spadiceus, Lagocephalus suezensis, and Torquigener flavimaculosus), which are common in the Northeastern Mediterranean Sea (Mersin Bay), in terms of sex and seasonal variables. Na, Mg, P, K, and Ca levels in the muscle tissues of pufferfish range from 1848.4 to 16495.7, 824.4 to 2684.5, 6936.2 to 20486.6, 13019.3 to 36165.5, and 276.4 to 5566.5 µg g-1, respectively. Na, Mg, P, K, and Ca levels in the liver tissues of pufferfish range from 531.8 to 6136.1, 63.8 to 899.1, 773.1 to 6677.5, 1151.4 to 10165.4, and 47.4 to 1607.7 µg g-1, respectively. The levels of macroelements in the muscle and liver tissues can be represented as K > P ≥ Na > Ca ≥ Mg and K ≥ P ≥ Na > Ca ≥ Mg, respectively. Pufferfish muscle tissue has more abundant macroelement levels than liver tissue. Fe, Cu, and Zn levels in pufferfish muscle tissues range from 21.53 to 219.42, 0.73 to 6.54, and 25.38 to 100.47 µg g-1, respectively. Fe, Cu, and Zn levels in pufferfish liver tissues range from 157.8 to 1368.6, 0.86 to 11.23, and 23.17 to 507.75 µg g-1, respectively. Levels of trace elements in the muscle and liver tissues can be represented as Zn ≥ Fe > Cu and Fe ≥ Zn > Cu, respectively. The pufferfish liver tissue is richer than muscle tissue in terms of trace element levels. Cd, Pb, As, and Cr levels in pufferfish muscle tissues range from 0.66 to 6.30, 2.17 to 20.76, 41.90 to 258.37, and 0.34 to 3.70 µg g-1, respectively. Cd, Pb, As, and Cr levels in the liver tissues of pufferfish range from 0.22 to 2.34, 0.17 to 2.27, 9.35 to 61.93, and 0.14 to 2.10 µg g-1, respectively. Levels of metal in the muscle and liver tissues can be represented as As > Pb > Cd ≥ Cr and As > Cd ≥ Pb ≥ Cr, respectively. Pufferfish muscle tissue has a higher association with liver tissue due to metal level accumulation. All pufferfish are contaminated by Cd, Pb, As, Cr, Fe, and Zn metals.

Tetrodotoxin levels of three pufferfish species (Lagocephalus sp.) caught in the North-Eastern Mediterranean sea.

Tetrodotoxin (TTX) levels in Lagocephalus sceleratus (Silverstripe blaasop), Lagocephalus spadiceus (Half-smooth golden pufferfish) and Lagocephalus suezensis (Suez puffer) caught in Mersin Bay in the Northeastern Mediterranean Sea were analysed using Q-TOF LC/MS. Pufferfish were caught using trawl fishing, longlining and fishing line from December 2015 to October 2016. The TTX changes in the gonads, livers, intestines, skins and muscle tissues were evaluated according to sex and season. TTX levels for L. sceleratus and L. suezensis for all tissues were in the range of 0.69-35.6 µg/g and 0.67-3.09 µg/g, respectively. The highest TTX levels were observed in the gonads of female L. sceleratus caught in the autumn, and in the skin of L. suezensis caught in the spring but no quantifiable levels of TTX were found for L. spadiceus. In conclusion, L. sceleratus and L. suezensis species caught in the North-Eastern Mediterranean are toxic, and their consumption is unsafe.

First report on TTX levels of the yellow spotted pufferfish (Torquigener flavimaculosus) in the Mediterranean Sea.

The differences of tetrodotoxin (TTX) levels in various parts of pufferfish (Torquigener flavimaculosus) were examined in conjunction with the seasonal and sexual variations. The TTX levels in gonads, liver, intestines, skin and muscle tissue were determined using the Q-TOF LC/MS. Instrumental analysis revealed that all examined tissues from T. flavimaculosus contained high TTX concentrations. TTX levels in the gonads, liver, intestines, skin and muscle tissue of pufferfish were within the range of 5.03-100.71, 7.04-106.80, 12.59-86.30, 33.95-139.88 and 15.88-86.07 (µg/g), respectively. It was determined that in all seasons, except for summer, female individuals had higher TTX levels than males. Among all seasons, the highest level of TTX was found in winter and the lowest in autumn. Consequently, T. flavimaculosus is a highly toxic pufferfish that is dangerous for human consumption and should not be consumed under any circumstances.

Tetrodotoxin levels in pufferfish (Lagocephalus sceleratus) caught in the Northeastern Mediterranean Sea.

The toxicity of tetrodotoxin (TTX) in pufferfish (Lagocephalus sceleratus) from Mersin Bay in the Northeastern Mediterranean Sea was measured using a mouse bioassay (MBA) and LC-MS-MS. Pufferfish were caught by trawl fishing, longlining and fishing line from December 2012 to October 2013. Changes in the levels of TTX in the gonads, livers, intestines, skins and muscles as a function of season and sex were determined. The gonads of female fish were toxic in all seasons (>2µg/g), whereas the gonads of male fish were only toxic in the spring and autumn. The highest TTX levels in gonads, livers, intestines and skins of female fish were 52.1, 46.2, 7.64 and 3.43µg/g, respectively, using LC-MS-MS. The TTX level in the muscle of female fish in winter was 2.83µg/g but was otherwise below the toxic limit. Consequently, it can be dangerous to consume pufferfish, including the edible muscle, from the Eastern Mediterranean Sea.

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.

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.

The effects of season and sex on fat, fatty acids and protein contents of Sepia officinalis in the northeastern Mediterranean Sea.

The effects of season and sex on the fatty acids (FAs) and proximate compositions of the mantle of the mature common cuttlefish were evaluated. The results of the proximate composition showed that the lowest lipid content was obtained from females in winter (0.74%), whereas the highest level of lipid was found in males in autumn (0.94%; p < 0.05). The protein levels of the mantle of the mature male of common cuttlefish were significantly higher (p < 0.05) than those found in female specimens. The FA compositions of each sex for all seasons ranged from 29.4% to 32.5% saturated FAs, 8.7-11.1% monounsaturated FAs and 48.2-54.6% polyunsaturated fatty acids (PUFAs). The proportions of n-3 PUFAs (44.0-50.6%) were higher than n-6 PUFAs (3.4-4.3%) regardless of sex and seasons. The levels of eicosapentaenoic acid in the mature common cuttlefish mantle in spring, autumn and winter were 15.9-17.8%, 16.3-17.2% and 15.7-16.8% while those of docosahexaenoic acid were 32.5-33.0%, 27.5-29.0% and 28.7-31.1%, respectively.

The effects of season and sex in the metal levels of mature common cuttlefish (Sepia officinalis) in Mersin Bay, Northeastern Mediterranean.

The effects of sex and season on metal levels of the mantle of the common cuttlefish that was caught from Mersin Bay were evaluated. The annual range of mantle length (ML), total length (TL), and weight of common cuttlefish specimens were 110 to 183 mm, 380 to 581 mm, and 150.24 to 477.13 g, respectively. The annual range of metal levels in the mantle tissue of common cuttlefish were: 2.34 to 3.89 µg Cd g(-1), 0.30 to 0.63 µg Cr g(-1), 0.15 to 0.54 µg Pb g(-1), 2.35 to 14.90 µg Cu g(-1), 23.22 to 51.88 µg Zn g(-1), and 5.12 to 10.65 µg Fe g(-1). Cu levels of females were significantly higher (P < 0.05) than those found in male throughout all the seasons while Pb levels were lower (P < 0.05) in males than females. Cr levels in the mantle tissue of cuttlefish did not change throughout the seasons. On the contrary, Cd, Pb, Cu, Zn, and Fe levels in the mantle tissue of cuttlefish changed throughout all the seasons. The highest Cd, Zn, and Fe levels were obtained in spring while the highest Cu levels were obtained in autumn. It was also found out that this species was rich in terms of metal levels, particularly, Cd, Cu, Zn, and Fe. It was found out that the mantle tissue of the common cuttlefish, Sepia officinalis, which was caught from Mersin Bay, was contaminated with Cd in all the seasons.