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1.
Textural property of surimi products is a prime factor in determining the acceptability of consumer as well as market value. Gelatin is one of the most popular biopolymers widely used in food industry as gelling agent with the unique textural properties. Therefore, the addition of gelatin along with the use of protein cross-linkers could be a means to modify the texture of surimi gel, which can fit the demand of consumers. Surimi from the threadfin bream (Nemipterus bleekeri) was added with bovine gelatin (BG) and bovine/fish gelatin mix (BFGM; 1:1, 2:1, 1:2, 4:1, and 1:4) at 10% protein substitution in combination with and without microbial transglutaminase (MTGase) at 1.2 units/g surimi. Textural properties, whiteness, expressible moisture content, protein pattern, and microstructure and sensory properties of gels were determined. When MTGase at 1.2 units/g surimi was incorporated, the increases in breaking force and deformation were noticeable in both surimi gels, with and without 10% BG added ( p < 0.05). On the other hand, surimi gels added with BFGM at all bovine/fish gelatin ratios had the higher breaking force and deformation, compared with that added with BG, when MTGase was incorporated. Addition of BG or BFGM lowered the expressible moisture content and whiteness of surimi gel ( p < 0.05). Based on SDS-PAGE, band intensity of myosin heavy chain and actin of surimi gel decreased when surimi gel was added with all gelatins, regardless of MTGase addition. The microstructure study revealed that surimi gel network became finer and denser with the addition of MTGase (1.2 units/g surimi), but the coarser and irregular structure was obtained when gelatin was incorporated. Gelatin, especially bovine/fish gelatin mix, at an appropriate level could be used as the protein additive in surumi gel in conjunction with MTGase in order to improve the textural and nutritive properties of the products.  相似文献   

2.
ABSTRACT:   The oxidative stability of lipids from salmon roe and herring roe was compared with those of commercial fish oils originated from sardine and tuna. Both fish roe lipids contained high amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Total EPA and DHA was more than 35% of total fatty acids in both roe lipids. On the basis of oxygen consumption, fish roe lipids showed the higher oxidative stability than both fish oils. This tendency in oxidative stabilities was also confirmed by the determination of propanal formation during oxidation. Analyses of lipid compositions suggested that the higher oxidative stabilities of fish roe lipids would be mainly due to the presence of phospholipids in them. Dietary effects of salmon and herring roe lipids were also determined. Little increase in total cholesterol level was observed in plasma lipids in rats fed salmon and herring roe lipids, although cholesterol content in fish roe lipids were 6.3% and 9.7% of total lipids for salmon roe and herring roe.  相似文献   

3.
Two questions were asked in the present study; does Atlantic salmon taste and discriminate against oxidised feed and are lipid oxidation products absorbed from the intestine. In Experiment 1, a control diet, a medium oxidised diet and a highly oxidised diet were prepared (TBARS levels: 34±5, 61±4 and 76±2 nmol g−1, respectively). The control diet was marked with holmium and the experimental diets with europium. Each of the experimental diets were fed together with the control diet (1:1) to Atlantic salmon in duplicate tanks in one meal to satiation and the stomach contents were analysed for the lanthanides. The fish discriminated slightly against the highly oxidised diet, but not against the medium oxidised diet. In Experiment 2, Atlantic salmon cannulated through the dorsal aorta were fed control and oxidised feed (TBARS: 71±5 and 204±18 nmol g−1) and blood samples were collected regularly over a nine days period. On day 9, the fish were sacrificed, and samples of muscle, liver, intestinal tissue and contents were taken and analysed for oxidation products, and vitamins C and E. Plasma TBARS increased 3-4 fold in response to the oxidised diet and there was a slight increase in muscle and liver TBARS. The data on peroxide value (PV) in the tissues showed large variation, but no differences between the groups were detected. PV and TBARS in the contents of the large intestine increased 7- and 1.6-fold, respectively, in response to oxidised feed. There were no differences in levels of vitamins C and E between the groups. It seems that Atlantic salmon feed quite well on oxidised feed and that aldehydes, here represented by MDA and measured as TBARS, are absorbed from the intestine. The question as to whether lipid hydroperoxides are absorbed is unanswered due to the large variation in tissue PV. On the other hand, animals in general seem to be protected from absorption of lipid hydroperoxides and we hypothesise that similar mechanisms are active in Atlantic salmon. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

4.
Using various chemical analyses, several lipid oxidation products were measured at different stages of oxidation. The oxidation of fish oil (FO), soy oil (SO) and corn oil (CO) mayonnaises was investigated using peroxide value (PV), thiobarbituric acid (TBA), total carbonyl compounds (TCC) and anisidine tests. The results showed that both PV and TCC values increased in FO, SO, and Co mayonnaises during 8 wk of storage at 30ºC, but TBA and anisidine values increased significantly only in fish oil mayonnaise (FOM). Different oxidation products were produced due to inappropriate for SOM and COM. The best analytical tests for early oxidation of FOM are PV and TBA and for later oxidation are TCC and the anisidine test.  相似文献   

5.
Impact of fish gelatin film incorporated without and with palm oil on the quality changes of fried shrimp cracker stored for 15 days at room temperature was investigated, in comparison with nylon/linear low-density polyethylene (nylon/LLDPE) film. The moisture content and water activity of shrimp cracker packaged with all films increased during storage (p < 0.05). The lowest moisture content and water activity were found in the sample packaged with nylon/LLDPE film throughout the storage (p < 0.05). Sample packaged with fish gelatin films incorporated with palm oil generally had lower moisture content than those without oil added during the first 12 days of storage (p < 0.05). During 15 days of storage, shrimp cracker packaged with nylon/LLDPE film generally had the lower PV and TBARS value as well as volatile compounds, except for n-nonanal, than those stored in fish gelatin films, regardless of oil incorporation. The decrease in crispiness and increase in toughness occurred in all samples during the 15 days of storage. Nevertheless, the lower changes were observed in the sample packaged with nylon/LLDPE film. Overall, gelatin film showed excellent oxygen barrier property, which was associated with the retardation of lipid oxidation. The incorporation of oil into gelatin film could lower WVP, but negatively increased oxygen permeability of the resulting film. Thus, the improvement of gelatin film is still required.  相似文献   

6.
Juvenile African catfish, Clarias gariepinus (Burchell), were fed low-tocopherol, practical test-diets containing graded levels of α-tocopheryl acetate (0, 80, 200 and 500 mg kg?1 dry feed) at proportionately 0.02 body weight per day for 70 days. After the feeding period, selected fish tissues were assayed for α-tocopherol and thiobarbituric acid reactive substances (TBARS) concentrations, before and after iron-ascorbate stimulated peroxidation. Results show that tissue accretion of α-tocopherol in muscle, liver and blood plasma increased linearly (R2= 0.83, 0.82 and 0.93, respectively) in response to elevated dietary supplementation of α-tocopheryl acetate within the range of doses under study. In muscle and liver this resulted in a significant decrease (P < 0.05) in basal TBARS and TBARS after stimulated peroxidation, indicating a greater stability against oxidation. Growth indices were not significantly affected (P > 0.05) by dietary α-tocopheryl acetate inclusion. Clarias fed the highest α-tocopheryl acetate dose (500 mg kg?1 dry feed) were observed to have significantly lower (P < 0.05) haematocrit (% packed cell volume) than fish fed the basal diet (0 mg kg?1 dry feed). It was concluded that supplemental α-tocopheryl acetate in practical diets, for Clarias gariepinus, was effective in reducing the degree of tissue-lipid peroxidation under conditions of increased oxidative stress. Thus, the post mortem resistance to oxidation achieved would improve the stability of catfish products destined for human consumption.  相似文献   

7.
The effect of spraying microbial transglutaminase (MTGase) at various levels (1, 4, 7, and 10 units/gram) on the quality of mackerel (Scomber scombrus) fillets was investigated during refrigerated storage. The results of pH and the total volatile base nitrogen (TVB-N) revealed that 7 µ/g MTGase treatment met the best results regarding fish quality. The oxidation was hindered by increasing MTGase concentration, and the lowest totox value was recorded in the fillets treated with 10 µ MTGase. The progress in the total free amino acids was suppressed with the addition of MTGase, and the most effective concentration was found to be 7 µ/g MTGase treatment. Moreover, this concentration was the most promising in inhibition of the total mesophilic aerobic bacteria, the total psychrophilic aerobic bacteria, coliform, and yeast-mold. Panelists preferred the samples treated with 7 µ/g MTGase in terms of odor, texture, and appearance. The addition of MTGase straightened the fish muscle and helped preserve its initial texture. It is important to use the proper concentration of MTGase instead of high concentrations.  相似文献   

8.
ABSTRACT

Microencapsulated fish oil was prepared by spray drying using fish protein hydrolysate, sodium caseinate, maltodextrin, and gum Arabic as wall material. Fish protein hydrolysate was prepared from pink perch meat, and its physical and functional properties were studied. Microencapsulates prepared with a combination of sodium caseinate, maltodextrin, and gum Arabic were kept as control. The encapsulation efficiency and oil release behavior of microencapsulates was evaluated. Surface morphology and thermal properties of microencapsulates were determined by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) analysis, respectively. Fourier-transformed infrared spectroscopy analysis indicated that the spectral pattern of microencapsulates showed a similar structural pattern with a minor band shift for both control and fish protein hydrolysate containing microencapsulates. Oxidative stability of fish oil microencapsulates indicated that the sample stored under was 4°C was more stable than microencapsulates stored under 60°C and 28 ± 2°C temperature conditions. Moreover, microencapsulates containing fish protein hydrolysate had a lower thiobarbituric acid value. Results suggest that the incorporation of fish protein hydrolysate along with other wall material could improve the oxidative stability of microcapsules during storage.  相似文献   

9.
The extent of lipid oxidation and retention of omega (ω)-3 fatty acids in milk protein concentrate (MPC)-added mackerel and salmon mince and nuggets during 4-months frozen storage were investigated in order to develop high ω-3 seafood products. Mechanically deboned fish mince formulated with MPC and other ingredients was formed into batter-breaded nuggets with or without par-frying. The addition of MPC at 4% resulted in significantly lower thiobarbituric acid reactive substances (TBARS) values and helped retain significantly (p < 0.05) higher amounts of docosahexaenoic acid (DHA) in both salmon and mackerel mince and eicosapentaenoic acid (EPA) in the mackerel mince. There were no significant differences in peroxide values (PV) and TBARS values between nugget products with and without par-frying. EPA and DHA were retained less in par-fried than raw nuggets probably due to oil leaching and thermal degradation during frying. The reductions of EPA and DHA in salmon were 67% and 53% for raw and 57% and 39% for par-fried nuggets, while in mackerel they were 63% and 73% for raw and 57% and 56% for par-fried nuggets, respectively. Results suggest that although MPC provided some protection against lipid oxidation, additional measures are needed to improve retention of ω-3 fatty acids in mince-based seafood products during frozen storage.  相似文献   

10.
11.
The fatty acid composition and oxidative stability of fish oil and syrups available in the Turkish retail market were examined in this study. The major saturated fatty acids in capsules and syrups were palmitic acid (16:0) and stearic acid (18:0). The monounsaturated fatty acid contents of fish oil products have very different results (10.71–50.46%). The results show that the label claims for total omega-3, eicosapentaenoic acid, and docosahexaenoic acid presented a reasonable accuracy for the examined products, but it was noted that some of the results showed a considerable difference with the labels.

The free fatty acid level in fish oil products was generally low (0.13–1.95% of oleic acid). Peroxide value of all examined products was below the limit of 10 meq kg?1 oils for edible oil as indicated in Codex (1999). It was detected that the p-Anisidine value of fish oil capsules (5.36–8.90) was considerably lower than for fish oil syrups (21.86–26.74). According to our results, the totox value of fish oil capsules evaluated in this study (7.08–17.35) was within acceptable limits. However, fish oil syrups (34.72–38.06) highly exceeded the upper tolerable limit (26).  相似文献   

12.
The influence of feeding high levels of polyunsaturated fatty acids (PUFA) on muscle fatty acid composition and indices of oxidative damage was examined in Arctic charr, Salvelinus alpinus (L.). All diets contained 100 g kg?1 lipid of dry weight. Two diets contained marine fish oils giving a PUFA level of 250 g kg?1 and 500 g kg?1 of lipid. The remaining two diets contained vegetable oils high in either 18:2n-6 or 18:3n-3, giving a PUFA level of more than 500 g kg?1 of dietary lipid. The charr were maintained at 8°C until their weight doubled, and were then transferred to 0.8°C for 30 days. Growth was similar in all groups. The fatty acid compositions of muscle were influenced by dietary PUFA but were less diverse than those of the diets. The overall pattern of fatty acid compositions indicated preferential desaturation and elongation of n-3 PUFA coupled with selective oxidation of 18:2n-6. Total n-3 PUFA content in TAG was always lowered compared with the diet, suggesting a specific mechanism for the removal of these fatty acids. Subjecting the fish to low temperature increased PUFA content in muscle of charr fed the 250 g kg?1 marine n-3 PUFA diet, but had no effect on the other treatments. For fish at 8°C, no significant differences were found between groups in terms of haematocrit, plasma alanine aminotransferase (ALAT), and plasma and muscle thiobarbituric acid reactive substances (TBARS), although there was a tendency towards increased levels of TBARS in the group receiving 500 g kg?1 marine n-3 PUFA of lipid. Subjecting the muscle to forced oxidative conditions resulted in increases in TBARS in all groups, particularly those fed 500 g kg?1 marine n-3 PUFA. Lowering the environmental temperature corresponded with a further increase in the plasma ALAT and muscle TBARS in this group. It is concluded that feeding diets containing high levels of long-chain n-3 PUFA may be detrimental to the fish's health and flesh quality, particularly at low environmental temperatures.  相似文献   

13.
Lipid peroxidation, specifically polyunsaturated fatty acid (PUFA) oxidation is highly deleterious, resulting in damage to cellular biomembranes, and may be a principal cause of several diseases in fish including jaundice and nutritional muscular dystrophy. Tissue lipid PUFA content and composition are critical factors in lipid peroxidation, as is the level of endogenous antioxidant molecules such as vitamin E. The primary objective of the present study was the characterization of antioxidant systems in a cultured juvenile marine fish, gilthead sea bream (Sparus aurata) with the underlying aim to understand how to avoid oxidation problems that may cause pathologies and disease and so to enhance growth and quality of early ongrowing stages. Juvenile sea bream were fed diets having either high or low levels of fish oil and supplemented or basal levels of vitamin E with PUFA/vitamin E ratios ranging from 117±12 in the diet with low PUFA supplemented with vitamin E to 745±48 in the diet with high PUFA with no additional vitamin E. None of the diets had serious deleterious effects on growth or survival of the fish, but the different dietary regimes were effective in significantly altering the PUFA/vitamin E ratios in the fish livers with values ranging from 5.7±0.4 in fish fed the diet with low PUFA supplemented with vitamin E to 91.1±13.2 in fish fed the diet with high PUFA with no additional vitamin E. This had effects on the peroxidation status of the fish as indicated by the significantly altered levels of in vivo lipid peroxidation products measured in liver, with fish fed the diet rich in PUFA and low in vitamin E showing significantly higher values of thiobarbituric acid reactive substances (TBARS) and isoprostanes. The isoprostane levels generally followed the same pattern as the TBARS levels supporting its value as an indicator of in vivo oxidative stress in fish, as it is in mammals. However, few significant effects on antioxidant enzyme activities were observed suggesting that more severe conditions may be required to affect these activities such as increasing the PUFA/vitamin E ratio or by increasing peroxidative stress through the feeding of oxidized oils.  相似文献   

14.
Freshwater fishes contain long chain omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) of highest nutritional value. PUFAs in fish are susceptible to oxidative damage during processing and subsequent storage. Sardines (Rastrineobola argentea) are an important fish species of Lake Victoria, constituting 72.3% of the total landings by weight on the Tanzanian side of the lake. Fatty acid profiles and lipid oxidation status of sun-dried, deep-fried, and smoked sardines were investigated. Lipid oxidation was assessed by peroxide value, thiobarbituric acid reactive substances (TBARS), and free fatty acids. Fatty acids were analyzed by gas chromatography with flame ionization detector. The three omega-3 PUFAs: docosahexaenoic acid (C22:6n-3), docosapentaenoic acid (C22:5n-3), and eicosapentaenoic acid (C20: 5n-3) contributed 57–60, 63, and 38% of PUFAs in sun-dried, smoked, and deep-fried sardines, respectively. Lipid oxidation reactions were more pronounced in sardines dried on sand and rocks, with TBARS values 97.87 and 84.18 µmolMDA/kg, respectively. The polyene index was significantly lower (p < 0.05) in deep-fried sardines, indicating lower retention of PUFAs in the product. Lake Victoria sardines are a rich source of omega-3 PUFAs. PUFAs in sun-dried sardines are prone to oxidative damage. Smoking resulted in relatively higher retention of omega-3 fatty acids in products.  相似文献   

15.
ABSTRACT

The effects of melanin-free ink (MFI) and pre-emulsification on gel properties and stability of bigeye snapper surimi gel fortified with seabass oil during refrigerated storage of 10 days were studied. Lipid oxidation as determined by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) of surimi gel increased as the level of seabass oil increased (P < 0.05). When MFI was incorporated into surimi gel, lower PV was obtained throughout the storage (P < 0.05). Addition of seabass oil pre-emulsified with soy protein isolate (SPI) in the presence of MFI yielded surimi gel with the highest breaking force and could improve oxidative stability during refrigerated storage (P < 0.05). Slight decrease in whiteness was found in surimi gel added with MFI, while those added with MFI along with pre-emulsified seabass oil showed increased whiteness (< 0.05). Addition of MFI did not affect total viable count and psychrophilic bacterial count in surimi gels. Thus, the incorporation of pre-emulsified seabass oil prepared using SPI in conjunction with MFI could improve quality and oxidative stability of gel from bigeye snapper surimi.  相似文献   

16.
ABSTRACT

Meat products, such as fish meat, are known to be susceptible to undesirable chemical and microbial reactions that characterize spoilage. In this study, the effect of a sodium alginate and chitosan coating incorporated with Mentha piperita, Artemisia dracunculus, and Zataria multiflora essential oils on chemical and microbial attributes of rainbow trout meat was evaluated during storage at 4°C. Chemical and microbial assays were performed on rainbow trout fillets with alginate and chitosan coatings and 0.2% concentration of test essential oils. The results showed that the alginate coating with essential oils significantly decreased production of thiobarbituric acid (TBA) and total volatile basic nitrogen (TVBN) and reduced the growth of foodborne spoilage bacteria during storage at 4ºC. At day 12, the best results were obtained in chitosan coating + Z. multiflora, with 5.96 ± 0.12, 4.93 ± 0.12, and 3.83 ± 0.2 for total viable counts, psychrotrophic bacterial count, and lactic acid bacteria count, respectively. Moreover, the lowest amounts of chemical analysis were observed in chitosan coating + Z. multiflora at the final day (0.54 ± 0.03 and 20.31 ± 0.1 for TBA and TVBN, respectively). Our study revealed that essential oils can be used as effective natural components against undesirable chemical and microbial reactions in fish meat.  相似文献   

17.
The kinetics of astaxanthin degradation and lipid oxidation in shrimp oil from hepatopancreas of Pacific white shrimp (Litopenaeus vannamei) as affected by storage temperature were studied. When shrimp oil was incubated at different temperatures (4, 30, 45 and 60 °C) for 16 h, the rate constants (k) of astaxanthin degradation and lipid oxidation in shrimp oil increased with increasing temperatures (p < 0.05). Thus, astaxanthin degradation and lipid oxidation in shrimp oil were augmented at high temperature. When shrimp oils with different storage conditions (illumination, oxygen availability and temperature) were stored for up to 40 days, astaxanthin contents in all samples decreased throughout storage (p < 0.05). All factors were able to enhance astaxanthin degradation during 40 days of storage. With increasing storage time, the progressive formation of primary and secondary oxidation products were found in all samples as evidenced by the increases in both peroxide values (PV) and thiobarbituric acid reactive substances (TBARS) (p < 0.05). Light, air and temperatures therefore had the marked effect on astaxanthin degradation and lipid oxidation in shrimp oils during the extended storage.  相似文献   

18.
A 3 × 3 factorial experiment was conducted on Labeo rohita fingerlings to evaluate the effect of dietary oxidized oil and vitamin E. Nine experimental diets were made, based on three degrees of oil oxidation (fresh oil, low oil oxidation and high oil oxidation), and each level of oxidation was further supplemented with three levels of vitamin E (0, 100 and 1,000 mg/kg). Weight gain% and specific growth rate (SGR) of fish fed fresh fish oil and low oil oxidation level were significantly higher than highly oxidized oil. Moreover, vitamin E supplemented fish also showed better growth performance. Oil oxidation caused a significant reduction in the concentrations of α‐tocopherol and increase in TBARS level and antioxidant enzyme activities in fish liver and muscles. However, increasing the dietary vitamin E abrogated these effects. Dietary vitamin E supplementation improved the fatty acid, more specifically polyunsaturated fatty acids profile of oxidized oil fed fish. In conclusion, dietary oxidized fish oil increased the oxidative stress condition of fish but supplementation of high dose of vitamin E prevented lipid oxidation, improved growth performance and fatty acid profile of L. rohita.  相似文献   

19.
Antioxidants have been widely used as additives to provide protection against oxidative degradation of foods by free radicals. The effect of thyme essence (Zataria multiflora Boiss) on the rancidity development in cobia (Rachycentron canadum) fillets during frozen storage was studied. Cobia fillets were treated with thyme essence (250 and 500 ppm) and then stored at??18°C for up to 6 months. Rancidity development was measured by several biochemical indices including free fatty acids (FFA), peroxide value (PV), thiobarbituric acid (TBA), and complemented by sensory analysis (flesh odor, consistency, and appearance). Also, pH and expressible moisture were measured during 6-month storage. Proximate composition was also determined in the first day. TBA, PV, and FFA levels increased in all treatments due to lipid oxidation. Thyme essence showed an antioxidative effect in cobia fillets during frozen storage as indicated by TBA, PV, and FFA levels. Results showed that FFA, primary and secondary oxidation products, expressible moisture (EM), and pH of thyme essence treated samples were significantly lower than those of the control samples (p < 0.05). Thyme essence retarded oxidative changes in frozen cobia fillets, and the best oxidation inhibition was obtained using thyme essence at 500 ppm.  相似文献   

20.
Ability of ascorbic acid (vitamin C) to attenuate oxidative damage was evaluated in liver and brain tissues of Oreochromis niloticus (O. niloticus) experimentally exposed to sublethal concentrations of chlorpyrifos (CPF). O. niloticus was exposed to sublethal concentrations of CPF at 12?μg/L (CPF1) and 24?μg/L (CPF2) for 96?h. The fish of vitamin C (Vit C) and CPF2?+?Vit C groups were fed with Vit C supplemented diet (200?mg Vit C/100?g feed). A significant increase in thiobarbituric acid-reactive substances (TBARS) level (P?相似文献   

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