Tuna Flesh Research Articles

UTILIZING OF DARK MEAT TUNA FISH (Thunnus sp. ) AND TRASH FISH SURIMI IN THE PROCESSING OF FISH BURGER

Trash fish as by-catch includes a wide variety of species caught in shrimp fishing and usually is under utilizied while produced in a great number. Weakness of trash fish are small in measure with bone system, big husk and scale which resulting amount of yield flesh to be utilized relative small. So that, in processing a product require addition of order fish flesh. The objectives of this research were to study the amount of yield of minced fish that can utilizied for fish burger, quality and calory value of the product, and the level of panelists acceptance. Fish burger made from trash fish, used 2 (two) species as gulamah / Silver Pennah Croaker (Argyrosomus amoyensis), senangin / Fourfinger Threadfin (Elentheroma tetradactylum), and dark meat of Tuna (Thunnus sp). Minced fish of these two species was mixed with tuna flesh by ratio 1:1 (gulamah tuna) (A1), 1:2 (senangin tuna) (A2), 1:3 (gulamah tuna) (A3), 1:4 (senangin tuna) (A4), trash minced fish (gulamah senangin) (A5) and dark meat tuna minced fish (A6) as control. Research design applied was Complete Randomized Design with 4 replications. The result showed that amount of yield of minced fish are 47.8 % gulamah), 33.9 % (senangin) and 4.4 % (dark meat of tuna). The quality of fish burger products water content 46.00-53.93 %, protein content 12.78- 20.84%, fat content 12.83-19.52%, ash content 2.32-3.33%, and carbohydrate content 11.61- 17.36% (by-difference). Calory value 253.8-286.9 kcal. Sensory/orgaoleptic test value of this product is 7,04. – 7,93 (aspire). Treatment of minced of gulamah mixed with tuna 1:3 (A3), the fish burger with the best quality as it was by indicated by the water content 50.22%, protein content 20.84% and fat content 12.83%. Keywords : Dark meat tuna, trash fish, minced fish, amount of yield, fish burger

SP0024 Vitamin D and People with RMDS: How Much from Diet?

Vitamin D (vit D) has several roles in the body, including modulation of cell growth, neuromuscular and immune function, and reduction of inflammation. In addition, many genes encoding proteins that...

Influence of physical damage and freezing on histamine concentration and microbiological quality of yellowfin tuna during processing

Yellowfin tuna has a high level of free histidine in their muscle, which can lead to histamine formation by microorganisms if temperature abuse occurs during handling and further processing. The objective of this study was to measure levels of histamine in damaged and undamaged thawed muscle to determine the effect of physical damage on the microbial count and histamine formation during the initial steps of canning processing and to isolate and identify the main histamine-forming microorganisms present in the flesh of yellowfin tuna. Total mesophilic and psicrophilic microorganisms were determined using the standard plate method. The presence of histamine-forming microorganisms was determined in a modified Niven's agar. Strains were further identified using the API 20E kit for enterobacteriaceae and Gram-negative bacilli. Physically damaged tuna did not show higher microbiological contamination than that of undamaged muscle tuna. The most active histamine-forming microorganism present in tuna flesh was Morganella morganii. Other decarboxylating microorganisms present were Enterobacter agglomerans and Enterobacter cloacae. Physical damage of tune during catching and handling did not increase the level of histamine or the amount of microorganisms present in tuna meat during frozen transportation, but they showed a higher risk of histamine-forming microorganism growth during processing.

Optimizing the Enzymatic Hydrolysis of Skipjack Tuna (Katsuwonus pelamis) Dark Flesh Using Alcalase® Enzyme: A Response Surface Approach

The goal of this study was to optimize enzymatic hydrolysis of the dark flesh of skipjack tuna (Katsuwonus pelamis). Alcalase 2.4 L was used as the hydrolytic enzyme at various concentrations (1, 1.5, 2, 2.5 and 3% w/w) at pHs from 6 to 10, temperatures from 35 to 75?C and times of 2 to 6 h. The experiment was performed following a five-level second-order central composite design with six replications at the center points. The high coefficients of determination for degree of hydrolysis (R2 = 0.8909) and free tryptophan content (R2 = 0.9732) indicate the suitability of the design for predicting the responses. The optimum hydrolytic conditions predicted by the response surface methodology were 2% Alcalase at pH 8.86 and 65.4?C for 5.74 h. These conditions resulted in an experimental degree of hydrolysis of 20.74% and free tryptophan content of 102.23 mg kg-1.

Improving the Color Shelf Life of Farmed Southern Bluefin Tuna (Thunnus maccoyii) Flesh with Dietary Supplements of Vitamins E and C and Selenium

ABSTRACT The use of dietary antioxidants to increase the shelf life of farmed southern bluefin tuna (SBT) flesh was examined over a 10-week period using either a standard pellet (Control) or high-vitamin pellet (HV) fortified with vitamin E, vitamin C, and selenium. Following harvest, muscle samples were taken and assessed for antioxidant content. Flesh color shelf life was assessed in muscle stored at 4°C for 8 days. Muscle vitamin levels were significantly higher in the HV group than the Control group for vitamin E (20.4 ± 1.74 vs 9.7 ± 0.89 mg/kg) and vitamin C (29.1 ± 4.36 vs 4.3 ± 0.41 mg.kg–1), but selenium levels were not higher. Muscle samples from the HV group had a slower rate of browning than did those from the Control group, particularly over days 4 to 7 of storage. Results indicated that feeding a diet approximately 10 times higher in dietary antioxidants raised levels of vitamin E and vitamin C, but not selenium, in tuna flesh and increased the shelf life of tuna.

Quantitative measurement of metmyoglobin in tuna flesh via electron paramagnetic resonance

The potential of electron paramagnetic resonance (EPR) spectroscopy in the quantitative determination of metmyoglobin (metMb) in tuna flesh was examined and compared with conventional visible spectrophotometry (VIS). Both fresh and stored tuna samples were directly subjected to EPR measurement at −150 °C without pigment extraction, and their metMb concentrations ([metMb TUNA] EPR) were determined from a calibration curve. A linear calibration curve with good correlation ( R 2 = 0.987) was obtained by a plot between EPR intensities and the known [metMb CALI] VIS concentrations, where [metMb CALI] VIS is the concentration of metMb obtained from visible spectrophotometry for the stock metMb solution. The results show that differences between [metMb TUNA] EPR and [metMb TUNA] VIS for tuna meats are negligible at low concentrations of metMb. However, [metMb TUNA] EPR tends to be higher than [metMb TUNA] VIS at a higher concentration of metMb. This is probably due to incomplete pigment extraction from tuna samples that have been stored for a long period of time. This results in experimental inaccuracy of [metMb TUNA] VIS at higher concentrations of metMb. The overall results suggest that the EPR method is a suitable technique for quantitative measurement of metMb in tuna meat without pigment extraction. Since the EPR method operates at −150 °C, this technique could also be very useful in determining the metMb content in frozen tuna meat during low-temperature storage without thawing.

EFFECT OF HEATING ON RESIDUAL CARBON MONOXIDE CONTENT IN CO-TREATED TUNA AND MYOGLOBIN

Carbon monoxide (CO) can be used by food manufacturers to retain the red color of meat or dark fish prior to vacuum packaging or in the modified atmosphere packaging. Yellowfin tuna steak (c. 1.5 cm) was treated with CO gas, then packaged in a vacuum bag and heated at a constant temperature ranging from 50 to 100C for 30 min. A myoglobin (Mb) solution was prepared from tuna dark muscle and purged with CO gas for comparison. The released CO concentration and the residual CO in the tuna flesh or Mb solution were measured by gas chromatography. The higher level of CO concentration in the vacuum bag from CO-treated tuna was found for conditions with temperatures above 80C. The content of residual CO in the CO-treated tuna steaks after heating was much higher than that in untreated flesh. Regardless of the temperature of heating, a ratio of 58-82% CO was released from Mb solution after heating. This suggested that MbCO was not completely dissociated by heating at temperatures ranging from 50 to 100C.

EFFECT OF FROZEN TEMPERATURE ON AUTOXIDATION AND AGGREGATION OF BLUEFIN TUNA MYOGLOBIN IN SOLUTION

The effect of frozen storage temperatures in the range of -3C to -80C on the autoxidation and aggregation of bluefin tuna oxy- and deoxy-myoglobin (Mb) in solution was examined. Mb solution was kept frozen at various temperatures after prefreezing by dry ice-acetone and examined for autoxidation rate constant and aggregation ratio. The temperature-dependency of these two parameters showed the highest values at -10C with both oxy or deoxy forms. The autoxidation rate constant of deoxyMb was higher than that of oxyMb between -6C and -20C, while the reverse trend was observed at lower temperatures. These results suggest that the structure of Mb was perturbed through freezing resulting in promotion of the autoxidation and aggregation of Mb simultaneously. These results could explain the observation that deoxyMb in the inner portion of tuna flesh discolors faster than oxyMb in the surface portion in the temperature range of -3C and -20C.

A rapid gas chromatographic method for the determination of histamine in fish and fish products

A gas chromatographic (GC) method, which reduced the time for determination of histamine in fish and fish products to less than 20 min, was demonstrated. Contrary to traditional GC method, histamine in sample was initially extracted with alkaline methanol and injected into a GC column (CP-SIL 19CB) for analysis without derivatization. Internal standard used in this protocol was 1,9-nonanediol. Detection limit for histamine by this method was about 5 μg/g. Standard addition test indicated 98–111% (CV: 2.7–7.8%) of recovery for tuna flesh and 99–102% (CV: 2.7–8.9%) for shrimp meat after adding with authentic compound, suggesting that using direct GC analysis for histamine determination was feasible.

Gelatin Prepared from Tuna Skin: A Risk Factor for Fish Allergy or Sensitization?

Background: Although fish gelatin may represent a useful alternative to bovine or porcine gelatins, the clearly recognized high prevalence of fish allergy could increase the risk of anaphylaxis to gelatin. The rationale for investigating tuna gelatin rather than gelatins from more allergenic fishes is the availability of an industrial gelatin under development. The infrequent occurrence of tuna allergy should influence the safety of a derived product. The present study investigated IgE antibodies to tuna-skin-derived gelatin in adults and children with documented fish allergy or sensitization. Methods: Serum samples were taken from 100 consecutive patients with fish allergy or sensitization and tested for IgE antibodies against hydrolyzed or nonhydrolyzed gelatin extracted from tuna skin as compared to extracts from tuna flesh, tuna skin as well as bovine or porcine gelatins. Patients with tuna allergies or sensitization were sensitive to the same tuna species (yellowfin) as that from which the gelatin was obtained. IgE antibodies to these various extracts were analyzed using SDS-PAGE and immunoblotting. Results: Only 3 of the 100 serum samples tested gave evidence of reactivity to gelatin extracted from tuna skin. Cross-reactivity between bovine/porcine and fish gelatins was not observed. Conclusion: The risk of adverse reactions to tuna skin gelatin seems to be significantly lower than the risk of fish allergy. Fish gelatin may represent a valuable alternative to bovine or porcine gelatins.

Pores and physico-chemical characteristics of dried tuna produced by different methods of drying

Information on pore formation and their characteristics in foods during processing is needed for process design, in estimating other properties (i.e. thermal conductivity, moisture diffusivity), and characterizing the quality of a product. In this study the characteristics of pores in dried tuna ( Thunnus tongol) processed by air-, vacuum-, and freeze-drying were measured by mercury porosimetry. Apparent, substance and true densities, porosity and pore size distributions of dried samples were measured to study the pores formed during the drying processes. The apparent density of fresh tuna flesh was 1098 kg/m 3 , while the densities of dried tuna by air-, vacuum-, and freeze-drying were 960, 709 and 317 kg/m 3 , respectively. Porosity of freeze-dried sample was much higher than those the air-dried and vacuum-dried samples. Pores in different samples were characterized as the total intruded volume, total surface area, pore size range and average diameter, and nature of the pore size distribution curves. Peroxide value and color of dried tuna meat were also measured.

Glass Transition of Tuna Flesh at Low Temperature and Effects of Salt and Moisture

ABSTRACTGlass transition of fresh red meat of bigeye tuna (Thunnnas obesus) and its filtrate occurred between —71°C and —68°C, independent of cooling rate from 1 K/min up to 50 K/min. Glass transition at low temperature appeared to occur in the liquid part. Neither dilution nor concentration of the filtrate affected the glass transition temperature (Tg) but the solute concentration of the freeze concentrated phase (Cg) was affected. Addition of salt to the filtrate caused a decrease of ∼20 K in Tg. Results suggested the possibility of qualitative improvement in quality of fish by lowering the storage temperature by 15 K below the present storage temperature (—55°C).

魚肉内における塩類の移動速度 ＩＩ 魚肉内および表皮を通した食塩の移動速度

Penetration and extraction (desalting) of various salts in tuna flesh had been studied under various conditions in our previous paper. In this study, tranfer rates of NaCl have been measured for flesh of river chum (pre-spawning river chum salmon) and ocean chum (pre-spawning chum salmon caught in the North Pacific Ocean), in comparison to tuna flesh and the penetration rates into both salmon flesh through skin have also been evaluated. Observed concentration distributions and amounts of penetrated salt in flesh were explained by FICK's law of diffusion. And for both direction of diffusion, parallel to or perpendicalar to fiber, there were no differences in mechanism and in diffusivities. As flesh, especially in river chum, swelled and shrank in contact with certain concentration of salt solution, the amount of salt per unit volume of swollen flesh in equilibrium were used as surface concentration in the above calculation. And this treatment was certified experimentally in short time penetration. The rates of penetration into both flesh through skin were also expressed by diffusion in composite media and by diffusion accompanied surface resistance. The diffusivity of NaCl in the skin of river chum was larger than the other one, but its over-all resistance through skin was also larger caused by its larger thickness of skin.

Proximate analysis of the flesh and anatomical weight composition of skipjack tuna ( Katsuwonus pelamis)

Skipjack tuna ( K. pelamis) was assessed for its proximate and anatomical compositions with a view to establishing its nutritive and technological usefulness. Analysis of the muscle revealed that it contained between 69·0% and 72·6% moisture, 1·59% and 2·57% lipid, 22·4% and 25·5% protein, 1·53% and 2·42% ash and 0·87% and 3·21% salt. The mean percentage yields of trunk, head and viscera were 69·7%, 23·0% and 7·03%, respectively. On average, a total waste yield (head plus viscera) of about 30% was obtained. The technological implications of this analysis on the development of tuna fisheries in Nigeria are discussed.

Flake Diets and Larval Crustacean Culture

Abstract Initial flake tests were conducted with Macrobrachium rosenbergii to assess larval acceptance and variance at Stages I-X. All formula flakes tested were acceptable to the larvae. Generally, light colored flakes were better accepted than darker flakes. Flake preparations did not totally replace tuna flesh in the larval diets nor did flakes affect total quantity of Artemia required, but these tests indicate a role for such fabricated food particles in larval animal culture systems.

Histamine formation by bacteria isolated from skipjack tuna, Katsuwonus pelamis.

A simplified method for measuring histamine formation in bacterial cultures is described. Histamine production by Proteus morganil, Proteus vulgaris and Hafnia alvei cultures isolated from spoiled skipjack tuna was measured under twelve environmental conditions. The highest histamine concentrations were found at 19°C and 30°C depending on the bacterial species and the environmental parameter. No histamine was formed at 1°C, indicating that the rapid cooling of tuna flesh to freezing temperatures may adequately suppress histamine formation. At 19°C and 30°C, the Proteus organisms at first formed high levels of histamine, much of which was subsequently destroyed; histamine concentrations in these cultures eventually stabilized at 150 to 200mg/100ml. These observations indicate that the concentration of histamine in tuna products may depend on an equilibrium between histamine production and destruction.

EFFECT OF HANDLING AND PROCESSING ON DISCOLORATION OF ALBACORE TUNA

ABSTRACTOccasionally, in the canning of tuna, normal appearing tuna flesh will turn from a desirable white color to an undesirable green color after precooking and prior to retorting. Results demonstrated that the different systems used by the fishermen to hold local albacore tuna prior to delivery to the processor had little influence on the incidence of green discoloration of precooked tuna. Furthermore, frozen storage of local tuna, up to 3 months, did not increase the incidence of green discoloration of precooked tuna.

Rapid Moisture Determination in Meat by Gas Chromatography

Moisture analysis by gas chromatography was performed on tuna flesh, beef, and chicken meat. Weighed quantities of meat were homogenized in anhydrous methanol, ethanol, or isopropanol with an ultrasonic disintegrator. A complete extraction was accomplished by these solvents. The extracts were analyzed by gas chromatography using a Porapack Q column and thermal conductivity detector. The water content was quantitated by calculating the peak areas of water/solvent (A1/A2), and comparing it with a standard plot of A1/A2 for known weight of water. The moisture values obtained by this technique were in good agreement with those of the official AOAC air oven drying procedure. The time required for such analysis was about 5minutes compared to 16-18 hours in AOAC method.

フリルフラマイドの殺菌作用

The bactericidal effect of furylfuramide [2-2(furyl)-3-(5-nitro-2-furyl) acrylamide; FF], a newly permitted food preservative in Japan has been examined. And results obtained may be summarized as follows: 1. Bactericidal effects of FF and nitrofurazone (NFS) were compared each other by the official phenol coefficient method4). S. typhi was killed off with FF at a dilution equivalent 1:10, 000 in 5 minutes which corresponded to 120 in terms of phenol coefficient number. To the contrary, NFS with 1:5, 000 dilution exhibited almost no killing effect on the same test organism in 120 minutes (Tables 1 to 3). 2. Bactericidal activities of FF and NFS against E. coli and Staph. aureus were measured at their growing stage in the nutrient broth containing varying concentrations of each of the drugs and exposed for different period of time. As shown in Fig. 1, E. coli was killed off with more than 0.2 ppm of FF, and Staph. aureus with more than 1.6 ppm of the drug within 6 hours of incubation. To the contrary, no marked killing effect could be seen with NFS even at 200 ppm (Fig. 2). 3. Similar bactericidal effects on the growing stage of E. coli and Staph. aureus were noted with FF which had been added to the tuna flesh infusion, however, the efficacy was slightly lowered as compared with that observed in the nutrient broth (Fig. 3).

The Concentration of Myoglobin and Hemoglobin in Tuna Flesh

SUMMARYAmounts of myoglobin and hemoglobin were determined in light and dark muscle of yellowfin tuna, Neothunnus macropterus. Myoglobin concentration ranged from 0.37 to 1.28 mg/g wet weight in light muscle and from 5.3 to 24.4 mg/g in dark muscle; hemoglobin concentrations ranged from 0.12 to 0.58 mg/g in light muscle and from 0.5 to 3.8 mg/g in dark muscle. The fish were divided into two groups on the basis of means of capture, i.e., taken on hooks from a bait boat, or seined. Average percentage of hemoglobin was slightly, but not significantly, higher in the seined fish. Of the total heme pigments, myoglobin constituted 69–85% in light muscle and 81–95% in dark muscle from bait‐boat fish, and 47–81% in light muscle and 84–98% in dark muscle of seined fish.