Sterol Content of Fish,Crustacea and Mollusc: Effects of Cooking Methods

Sterol contents (desmosterol, cholesterol, stigmasterol, and sitosterol) of 36 fresh and cooked seafood and four freshwater fish species were investigated by high performance liquid chromatography (HPLC) method. Cholesterol and sitosterol were main sterols in seafood and freshwater fish species. Raw shellfish and molluscs contained cholesterol above 18.92 mg/100 g fish muscle, while the cholesterol content of marine fish ranged from 6.5 to 78.40 mg/100 g fish muscle. The cooking process resulted in significant effects on the sterol contents of seafood and freshwater species (p < 0.05). A remarkable increase in sitosterol (more than 3–4 fold compared to raw fish) was recorded for some fish species cooked in the oven. The highest desmosterol content was observed for fried fish, whereas the frying process resulted in a significant loss in cholesterol and sitosterol contents of marine fish (p < 0.05). The impacts of cooking methods on sterol content of seafood and their form varied depending on fish species and the cooking method used.     

Effects of different cooking methods on the mineral contents of wild and farmed sea bream (Sparus aurata)

The effects of different cooking methods (steaming, boiling, oven cooking, grilling, frying in olive oil, frying in soybean oil, frying in corn oil and frying in sunflower oil) on mineral contents (Ca, Mg, K, Na, Fe, Zn, Cu and Mn) of wild and farmed sea bream (Sparus aurata) were determined. The moisture rate decreased significantly (P < 0.05) after boiling, grilling, oven cooking and frying but remains stable after steaming. The fat content increased with different frying treatments. The Ca, Mg, Na, K and Zn contents of wild and farmed sea bream cooked by almost all methods significantly decreased (P < 0.05). The Cu content in grilled wild and farmed sea bream increased significantly (P < 0.05). Losses of mineral content in fried sea bream were higher than those of fish cooked by other methods. On comparing the raw and cooked fish, the results indicated that cooking had considerable effect on the mineral contents.     

Prevalence and Mean Intensity of Anisakidae Parasite in Seafood Caught in the Mediterranean Sea Focusing on Fish Species at Risk of Being Raw-consumed. A Meta Analysis and Systematic Review

Objective: To assess the prevalence and mean intensity of anisakids in seafood caught in the Mediterranean Sea, focusing on fish species at risk of being raw-consumed. Design: Systematic review and meta-analysis of studies published from 1960–2012. Study selection: Main criteria for the inclusion of studies were as follows: Findings of anisakid larvae, in both muscles and viscera; fish species for human consumption caught in the Mediterranean Sea; prevalence and mean intensity data for each species; and sample size equal to or more than 40 fishes. Results: Twelve studies were identified. Among these, four studies considered the following three fish species that are often consumed raw or preserved lightly, or not cooked thoroughly: anchovy, pilchard, and Atlantic mackerel. Data synthesis: All pooled analyses were based on the random-effect model. Anisakids prevalence in fish muscle was 0.64% (P < 0.0001), in viscera it was 1.34% (P < 0.0001), and overall prevalence was 0.95% (P < 0.0001). Mean intensity in muscle was 2.31 (P = 0.0083), in viscera it was 1.55 (P = 0.0174), and overall it was 1.81 (P < 0.0005). Heterogeneity indices (I²) were significantly high with the exception of viscera mean intensity. Conclusions: Anchovy, pilchard, and Atlantic mackerel have a low prevalence and mean intensity of anisakidae larvae in both viscera and muscles. Mean Intensity was also low.     

Amino Acid and Vitamin Composition of Raw and Cooked Horse Mackerel

Amino acid, vitamin (A, E, B₁, B₂, B₃ and B₆), and proximate composition were determined in raw and cooked horse mackerel. The changes in amino acid, vitamin, and proximate content were found to be significant for all cooking methods (frying, grilling, and steaming). Cooking did in general significantly increase the contents of essential, semi-essential, and other amino acids compared to raw fish species. Amino acid contents of grilled mackerel were significantly higher (p < 0.05) than those found in fried and steamed mackerel. The A, E, B₂, and B₆ vitamin content of fried horse mackerel was found to be significantly (p < 0.05) higher than the grilled and steamed samples. The B₁ content of steamed and B₃ content of grilled were found higher than the other cooked samples. Moisture, protein, fat, ash, and carbohydrate contents of cooked fish ranged between 56.52% to 61.34%, 20.79% and 23.93%, 13.44% and 19.61%, 1.70% and 2.47%, and 1.02% and 4.36 %, respectively. Fried fish had intermediate fat values, while grilled and steamed fishes had a comparatively low value.     

Antioxidant activity of pomegranate rind powder extract in cooked chicken patties

The radical scavenging activity, reducing power and phenolic composition of pomegranate rind powder extract (RP) were determined and antioxidant properties of RP was evaluated in cooked chicken patties compared with vitamin C (VC) during refrigerated storage. Freshly minced chicken meat were assigned to one of the following six treatments: control (meat without any antioxidant); RP 5, RP 10, RP 15 and RP 20 (5, 10, 15 and 20 mg equivalent RP phenolics 100 g^?1 meat, respectively) and VC 50 (50 mg VC 100 g^?1 meat). The RP exhibited significantly (P < 0.05) higher reducing power and 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity. Incorporation of RP into chicken patties significantly (P < 0.05) reduced the HunterLab L* values compared with control and VC patties. Total phenolic content (as tannic acid equivalent) significantly (P < 0.05) increased from 308 in control to 441 μg g^?1 in RP 20 patties. Addition of RP to chicken patties did not affect any of the sensory attributes. The values of thiobarbituric acid reactive substances were significantly (P < 0.05) reduced from 1.530 in control patties to 0.135 mg malonaldehyde kg^?1 samples in RP patties. Pomegranate rind powder extract treatment (RP 10, RP 15 and RP 20) substantially inhibited (P < 0.05) lipid oxidation in cooked chicken patties to a much greater extent than VC treatment. Therefore, pomegranate rind powder can be utilized as an excellent natural antioxidant source.     

Enhancement of the nutritional status and quality of fresh pork sausages following the addition of linseed oil, fish oil and natural antioxidants

Fresh pork sausages (pork shoulder, pork back fat, water, rusk and seasoning) were manufactured where 15% of the pork back fat was substituted with linseed oil (LO) or fish oil (FO). Green tea catechins (GTC) and green coffee antioxidant (GCA) were added to both LO (LGTC 200 and LGCA 200) and FO (FGTC 200 and FGCA 200) substituted sausages at a level of 200 mg/kg. Raw and cooked pork sausages were either over-wrapped with oxygen permeable film (aerobic storage) or stored in modified atmosphere packages (MAP) containing 80% O₂:20% CO₂ or 70% N₂:30% CO₂, respectively for 7 days at 4 °C. Effects on fatty acid profiles, lipid oxidation, colour and sensorial properties were investigated. α-Linolenic acid increased from 1.34% (control) to 8.91% (LO) and up to 11.2% (LGTC 200 and LGCA 200). Addition of fish oil increased levels of EPA from 0.05% (control) to 2.83% (FO), 3.02% (FGTC 200) and 2.87% (FGCA 200) and DHA levels increased from 0.04% (control) to a maximum of 1.93% (FGTC 200). Lipid oxidation was low in raw and cooked linseed oil containing sausages. GTC (200 mg/kg) significantly (P < 0.05) reduced lipid oxidation in raw fish oil containing sausages after 7 days of storage. Colour parameters in raw pork sausages were unaffected by the packaging atmosphere. L^* lightness values were lower (P < 0.05) in LGTC 200 and a^* redness values lower (P < 0.05) in LGTC 200 and FGTC 200 after 7 days of storage. Sensory scores of cooked pork sausages were unaffected by linseed oil addition. Flavour and overall acceptability scores in cooked fish oil containing sausages were improved by GTC addition. Results obtained demonstrate potential for the production of nutritionally enhanced fresh pork sausages.     

Enhancement of the nutritional status and quality of fresh pork sausages following the addition of linseed oil,fish oil and natural antioxidants

Fresh pork sausages (pork shoulder, pork back fat, water, rusk and seasoning) were manufactured where 15% of the pork back fat was substituted with linseed oil (LO) or fish oil (FO). Green tea catechins (GTC) and green coffee antioxidant (GCA) were added to both LO (LGTC 200 and LGCA 200) and FO (FGTC 200 and FGCA 200) substituted sausages at a level of 200 mg/kg. Raw and cooked pork sausages were either over-wrapped with oxygen permeable film (aerobic storage) or stored in modified atmosphere packages (MAP) containing 80% O₂:20% CO₂ or 70% N₂:30% CO₂, respectively for 7 days at 4 °C. Effects on fatty acid profiles, lipid oxidation, colour and sensorial properties were investigated. α-Linolenic acid increased from 1.34% (control) to 8.91% (LO) and up to 11.2% (LGTC 200 and LGCA 200). Addition of fish oil increased levels of EPA from 0.05% (control) to 2.83% (FO), 3.02% (FGTC 200) and 2.87% (FGCA 200) and DHA levels increased from 0.04% (control) to a maximum of 1.93% (FGTC 200). Lipid oxidation was low in raw and cooked linseed oil containing sausages. GTC (200 mg/kg) significantly (P < 0.05) reduced lipid oxidation in raw fish oil containing sausages after 7 days of storage. Colour parameters in raw pork sausages were unaffected by the packaging atmosphere. L¹ lightness values were lower (P < 0.05) in LGTC 200 and a¹ redness values lower (P < 0.05) in LGTC 200 and FGTC 200 after 7 days of storage. Sensory scores of cooked pork sausages were unaffected by linseed oil addition. Flavour and overall acceptability scores in cooked fish oil containing sausages were improved by GTC addition. Results obtained demonstrate potential for the production of nutritionally enhanced fresh pork sausages.     

Effect of sex, maturation stage and cooking methods on the nutritional quality and safety of black scabbard fish (Aphanopus carbo Lowe, 1839)

BACKGROUND: Black scabbard fish ( Aphanopus carbo Lowe, 1839) is a deep‐water fish resource that is highly appreciated in southern European countries and can accumulate high levels of mercury in the muscle. Currently, European legislation establishes limits for the presence of toxic contaminants in raw seafood, despite these products are generally cooked before consumption. In addition, there is still a lack of information concerning the nutritional quality and contaminants available in cooked products. Therefore, the aim of this study was to assess the effect of sex, maturation stages and three common cooking practices (steaming, grilling and frying) on the toxic elements (Hg, As, Cd and Pb) and nutritional value (chemical, elemental and fatty acid composition) of black scabbard fish. RESULTS: Few variations occurred between sexes and maturation stages, particularly in fatty acid and elemental content. Concerning cooked black scabbard fish, the greatest differences occurred in fried and grilled samples, attaining higher Hg levels, whereas steamed fish composition was closer to raw black scabbard fish. CONCLUSION: Raw and cooked black scabbard fish can be considered as a very good source of essential nutrients such as n‐3 PUFA, proteins, macro and trace elements. Yet, when the fish is grilled, the Hg content may be above the limits set by EU. Considering the alterations occurred during the cooking processes, steaming seems the best procedure to cook this species. Copyright © 2011 Society of Chemical Industry     

Antioxidative effect of added tea catechins on susceptibility of cooked red meat,poultry and fish patties to lipid oxidation

The comparative antioxidant activity of added tea catechins on susceptibility of cooked and overwrapped red meat (beef and pork), poultry (chicken, duck and ostrich) and fish (whiting and mackerel) to lipid oxidation was investigated. Fresh meats, poultry and fish, purchased from a local market, were trimmed to remove bones, skin and visible fat and minced through a 4-mm plate. The minced muscle from each species was treated with either 1% NaCl (S), 300 mg tea catechins kg⁻¹ minced muscle (TC) or 1% NaCl plus 300 mg tea catechins kg⁻¹ minced muscle (TCS). Control minced muscle samples (C) contained neither NaCl nor tea catechins. Patties (50 g), prepared from treated and untreated minced muscle, were cooked until the core temperature reached 75°C, cooled down to room temperature and held in a refrigerated (4°C) and illuminated (616 lux) display cabinet for 10 days. Oxidative stability (TBARS) was measured at 3-day intervals. The susceptibility of cooked patties to lipid oxidation was closely related to lipid content, concentration of unsaturated fatty acids and presence of iron in different species. Addition of NaCl to raw minced muscle significantly (P<0.05) promoted lipid oxidation for cooked patties regardless of species sources. Tea catechins added at a level of 300 mg kg⁻¹ minced muscle significantly (P<0.01) inhibited the pro-oxidation caused by NaCl and controlled lipid oxidation for all cooked muscle patties examined. Tea catechins at concentrations greater than 300 mg kg⁻¹ were necessary to reduce oxidation for mackerel patties containing high levels of lipids and unsaturated fatty acids. The high affinity of tea catechins for the lipid bilayers of muscle and the radical scavenging abilities of tea catechins may be possible mechanisms to explain the oxidative stability in cooked muscle foods.     

Gel‐forming properties of surimi produced from bigeye snapper,Priacanthus tayenus and P macracanthus,stored in ice

The influence of iced storage of two species of bigeye snapper, Priacanthus tayenus and P macracanthus, on the gel‐forming ability of the resulting surimi was investigated. Upon iced storage, whole fish underwent deterioration faster than beheaded/eviscerated fish. Total volatile base and trimethylamine contents of whole fish were higher than those of beheaded/eviscerated fish, particularly after 9 days of storage (P < 0.05). P macracanthus muscle was more susceptible to proteolytic degradation than P tayenus muscle. Ca²⁺‐ATPase activity decreased as the storage time increased (P < 0.05), indicating the denaturation of myosin. A marked decrease in Ca²⁺‐ATPase activity was found in whole fish kept for more than 6 days in ice (P < 0.05). Breaking force and deformation of surimi gels from both species decreased, with a concomitant decrease in whiteness, as the storage time increased (P < 0.05). Beheading and evisceration of fish retarded the deterioration. However, the gel‐forming ability of surimi produced from both species decreased continuously throughout iced storage (P < 0.05), probably owing to the denaturation and degradation of myofibrillar proteins. © 2002 Society of Chemical Industry     

Innovative Soaking and Grinding Methods and Cooking Affect the Retention of Isoflavones,Antioxidant and Antiproliferative Properties in Soymilk Prepared from Black Soybean

This study's objective was to characterize the effect of traditional and 3 newly devised (soaking+grinding) methods combined with cooking on the content and composition of phenolic substances, antioxidant, and antiproliferative properties of soymilk prepared from black soybean. Phenolic substances and antioxidant profile were characterized and antiproliferation of prostate cancer DU145 cells was conducted using a cell culture assay. Results indicated Grinding Method 4 produced significantly (P < 0.05) higher total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), and total isoflavone content in both raw and cooked black soymilk as compared to Method 1. Cooking soymilk reduced 23% to 38% of total phenolic substances. Raw black soymilk produced by Method 4 displayed the highest antioxidant capability, which was determined using ORAC, FRAP, and DPPH assays, and a higher antiprostate cell proliferation ability. Cooking only slightly reduced the potency to inhibit DU145 prostate cancer cells as IC₅₀ value was increased from the average of about 4.0 mg/mL of raw soymilk extracts to 5.5 mg/mL of cooked soymilk extracts of all grinding methods. Overall, total isoflavone content was the only component that was negatively correlated with IC₅₀ value (r = –0.93, P < 0.05) which indicates the ability to inhibit prostate cancer cell is associated with the increase in total isoflavone content, not with any other phenolic substances or antioxidant properties.     

Histological comparison of the dorsal ordinary muscles of wild and full‐cycle cultured Pacific bluefin tuna (Thunnus orientalis)

The histological properties of the cephalad parts of the dorsal ordinary muscles (CD‐OMs) of wild (body weight 33.3 ± 0.9 kg, n = 3) and full‐cycle cultured (body weights 13.1 ± 2.6 (FC 1), 20.2 ± 1.0 (FC 2) and 28.5 ± 3.6 (FC 3) kg, n = 3 respectively) Pacific bluefin tuna were investigated. The CD‐OMs of FC 1–3 tuna showed low moisture content (P < 0.05) and high fat content (about six times more, P < 0.05) in comparison with wild fish. A large quantity of adipose tissue was observed in the wide spaces between muscle fibres in the CD‐OMs of FC 1‐3 tuna. The muscle fibre diameter of the CD‐OM of FC 3 tuna was significantly lower than that of wild fish (P < 0.05). Myofibrils in the CD‐OM of wild tuna were surrounded by a developed sarcoplasmic reticulum and mitochondria; however, there were many glycogen granules among the myofibrils and a large quantity of fat in the CD‐OM of full‐cycle cultured fish. In particular, the glycogen content of the CD‐OM of FC 3 tuna was significantly higher (about 50 times) than that of wild fish. These results indicate that feeding and exercise conditions affect the histological structure and metabolism of the bluefin tuna muscle. Copyright © 2006 Society of Chemical Industry     

Effects of Metmyoglobin Reducing Activity and Thermal Stability of NADH‐Dependent Reductase and Lactate Dehydrogenase on Premature Browning in Ground Beef

Premature browning is a condition wherein ground beef exhibits a well‐done appearance before reaching the USDA recommended internal cooked meat temperature of 71.1 °C; however, the mechanism is unclear. The objectives of this study were: (1) to determine the effects of packaging and temperature on metmyoglobin reducing activity (MRA) of cooked ground beef patties and (2) to assess the effects of temperature and pH on thermal stability of NADH‐dependent reductase, lactate dehydrogenase (LDH), and oxymyoglobin (OxyMb) in‐vitro. Beef patties (lean: fat = 85:15) were packaged in high‐oxygen modified atmosphere (HiOX‐MAP) or vacuum (VP) and cooked to either 65 or 71 °C. Internal meat color and MRA of both raw and cooked patties were determined. Purified NADH‐dependent reductase and LDH were used to determine the effects of pH and temperature on enzyme activity. MRA of cooked patties was temperature and packaging dependent (P < 0.05). Vacuum packaged patties cooked to 71 °C had greater (P < 0.05) MRA than HiOX‐MAP counterparts. Thermal stability of OxyMb, NADH‐dependent reductase, and LDH were different and pH‐dependent. LDH was able to generate NADH at 84 °C; whereas NADH‐dependent reductase was least stable to heat. The results suggest that patties have MRA at cooking temperatures, which can influence cooked meat color.     

THE BIOCHEMICAL AND SENSORY PROPERTIES OF GILTHEAD SEA BREAM (SPARUS AURATA) FROZEN AT DIFFERENT CHARACTERISTIC FREEZING TIMES

ABSTRACT

Skinned, vacuum‐packed, postrigor gilthead sea bream fillets were frozen individually with characteristic freezing times of 2, 18, 74 and 640 min (times to cool the thermal center of the fillets from ?1 to ?7C). Immediately after freezing, the fillets were thawed, and their quality was evaluated with tests related to muscle integrity, myofibrillar protein denaturation and aggregation, lipid degradation and changes in tenderness. The muscle integrity indices (activities of α‐glucosidase, β‐N‐acetyl‐glucosaminidase and (β‐hydroxy‐acyl‐coenzyme‐A dehydrogenase and the amount and protein content of centrifugal tissue fluids) showed that the freezing process itself clearly affected the integrity of muscles. Freezing of fillets with characteristic freezing time of 74 min caused more damage to muscles and hydrolysis of lipids than the other freezing times. Adenosine triphosphatase (ATP) ase activities and Ca²⁺ sensitivity of actomyosin extracts suggested that the freezing process itself, but not the freezing times, caused structural damage to myofibrillar proteins. No difference in the levels of salt‐soluble proteins and sulfhydryl contents in actomyosin extracts was found between the fresh and frozen fillets. Sensory evaluations showed that the cooked frozen fillets were less tender than the cooked fresh ones.

PRACTICAL APPLICATION

In commercial seafood industries, seafoods are frozen at a range of freezing times (rates) that depends mostly on the type of seafood, the type of freezer and freezer's operating conditions. Based on the work reported in the literature, freezing of seafoods at different freezing times may furnish favorable conditions for alterations in muscle structure, muscle proteins and lipids, and textural properties in general. These changes are related to alterations in quality of frozen seafoods and may affect their market. Therefore, knowledge of optimal conditions with respect to freezing rates for freezing commercially important seafoods, as farmed gilthead seabream is, is relevant to the seafood industry. This information can be obtained by experimental studies on changes in the chemical, biochemical, physical and sensory properties of seafoods frozen at different freezing times.

     

Effect of different production typologies on chemical,physical and sensory characteristics of Italian commercial pork

BACKGROUND: Slaughter weight could influence some chemical, physical and sensory characteristics of pork production. The aim was to compare loin quality from pigs slaughtered at 120 kg or at 160 kg live weight, representing two different Italian lines of commercial production. RESULTS: Physical and chemical traits were affected by slaughter weight, but lower values of moisture (P < 0.01) and higher fat content (P < 0.05) were found in heavy pork loin; furthermore, increased slaughter weight resulted in redder, yellower and more intense colour (P < 0.05). Slaughter weight did not influence the purchase intent or consumer preference, except for fresh meat colour (P < 0.05) preferred in light pigs. A selected and trained panel carried out a difference‐from‐control test, showing that heavy pig loin was redder, more marbled, moister, sweeter, saltier, and had a more metallic flavour and lower tenderness than the light one (P < 0.05). The colour difference of raw meat is the only parameter detected by the consumers. CONCLUSION: Different production typologies affected chemical and physical characteristics of loin. Moreover sensory evaluation showed substantial differences between the loin samples. However, the purchase intent and consumer preference were not influenced by these two production typologies. Copyright © 2008 Society of Chemical Industry     

Effect of oil sources and vitamin E levels in the diet on the composition of fatty acids in rooster thigh and chest meat

The aim of this study was to evaluate the inclusion of different oil sources and dietary supplementation with vitamin E on the composition of fatty acids in rooster meat. Two hundred and forty 30‐week‐old White Leghorn roosters were distributed in a completely randomized factorial arrangement of 5 × 2, using five oil sources (sunflower, soybean, canola, linseed and fish) and two levels of antioxidant (30 and 400 mg vitamin E kg^?1 of diet). The intake of fish and canola oil in the diet reduced (P < 0.05) the content of saturated and unsaturated fatty acids in the thigh meat. Amongst the unsaturated fatty acids in the thigh, the fish and canola oil reduced (P < 0.05) the level of ω6 fatty acid, with a consequent decrease in the ratio ω6:ω3. The diet with fish oil increased (P < 0.05) the content of C22:6ω3 in the thigh meat. The use of linseed oil resulted in a significant reduction of the ratio of ω6:ω3 fatty acid in the thigh. The use of soybean oil in the diet increased (P < 0.05) the content of saturated and unsaturated fatty acids in the thigh, specifically in the content of ω6. The inclusion of vitamin E increased the polyunsaturated fatty acids in the chest meat, such as C18:3ω3, C20:5ω3 and C22:6ω3. Copyright © 2004 Society of Chemical Industry     

Structural Characterization and Antifatigue Effect In Vivo of Maca (Lepidium meyenii Walp) Polysaccharide

Maca (Lepidium meyenii Walp) polysaccharides (MP) with purity of 99.2% were obtained to investigate their structural characteristics and antifatigue effect in vivo. The physicochemical properties of MP were analyzed through high‐performance gel filtration chromatography, IR, monosaccharide composition, methylation, GC‐MS, and NMR analyses. The antifatigue effect of MP was evaluated by using a mouse weight‐loaded swimming model. MP is an acidic heteropolysaccharide with an average molecular weight (M_w) of 793.5 kDa. It is composed of D‐GalA: D‐Glc: L‐Ara: D‐Man: D‐Gal: L‐Rha = 35.07:29.98:16.98:13.01:4.21:0.75 (mol, %). The findings revealed that MP contained β‐1,3‐Galp(A), β‐1,3‐Glcp, and α‐1, 3‐Manp linked alternatingly to form a backbone (5:4:1). MP (above mid‐dosage 50 mg/kg bw/d) could effectively elongate swimming durations and accelerate average swimming speeds (within the 1st 5 min) of mice (P < 0.05) and improve the serous biochemical parameters of mice. Compared with the control model, high‐dosage (100 mg/kg bw/d) MP treatment could significantly enhance glutathione peroxidase and creatine kinase activities (P < 0.05) and decreased lactate dehydrogenase activity (P < 0.01). High‐dosage MP could significantly reduce the levels of blood urea nitrogen, lactic acid, and malondialdehyde (P < 0.05). MP is an acidic polysaccharide with a high D‐GalA content, which could be responsible for the antifatigue effect of maca.     

Bacterial Communities of Traditional Salted and Fermented Seafoods from Jeju Island of Korea Using 16S rRNA Gene Clone Library Analysis

Jeotgal, which is widely consumed as a nutritional supplement in Korea, is traditional type of preserved seafood that is prepared by salting and fermenting. Here, we report on the bacterial community structure and diversity of jeotgal obtained from the Korean island of Jeju, which has a subtropical climate. Two samples of Jeotgal were collected from Jeju, made from either damselfish (Chromis notata; jari‐dom‐jeot, J1 and J2) or silver‐stripe round herring (Spratelloides gracilis; ggot‐myulchi‐jeot, K1 and K2). The physical characteristics (pH and salinity) were assessed and the bacterial communities characterized using 16S rRNA gene‐clone library analysis and cultural isolation. No difference was found in the community composition between the J and K fermented seafoods. Both fermented seafoods had relatively high salinity (26% to 33%) and high pH values (pH 6.08 to 6.72). Based on the 16S rRNA gene sequences, the halophilic lactic‐acid bacteria Tetragenococcus halophilus and T. muriaticus were observed to be dominant in the J and K fermented seafoods, accompanied by halophilic bacteria including Halanaerobium spp., Halomonas spp., and Chromohalobacter spp. When compared with 7 other types of fermented seafood from a previous study, the communities of the J and K fermented seafoods were separated by the most influential group, the genus Tetragenococcus. The results suggest that these 2 types of traditional salted fermented seafood from Jeju have distinct communities dominated by Tetragenococcus spp., which are derived from the raw ingredients and are dependent on the physical conditions. This may explain how the seafoods that are made in Jeju may differ from other jeotgals.     

Physiological Factors Influencing Toughness in Cooked Saddletail Snapper (Lutjanus malabaricus)

Saddletail snapper (Lutjanus malabaricus) is a commercially significant tropical species in Australia and has been the subject of consumer complaints of extreme toughness in cooked fillets. Textural and biochemical analyses including collagen and hydroxylysyl pyridinoline (PYD) cross‐links concentrations were conducted on 101 commercially harvested Saddletail snapper to identify causes of toughness. Fish age was found to account for 75.6% of observed variation in cooked muscle texture (work done) of Saddletail snapper. A significant linear relationship (P < 0.001) between PYD content and cooked muscle texture was also identified accounting for 50.3% of observed variation. The concentration ratio of PYD to total collagen (TC) ranged from 0.04 to 0.38 mol PYD per mol of TC. Fish size was also found to be a poor indicator of fish age and therefore a poor indicator of the potential risk of toughness of the cooked muscle.