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1.
ABSTRACT

Postmortem biochemical and microbiological changes in loricariid catfish (Pterygoplichthys disjunctivus) muscle were evaluated during ice storage for 20 days. Values of pH remained stable for 15 days (7.4 ± 0.2), and total volatile base-nitrogen (TVB-N) remained under acceptable limits throughout storage, with a final value of 25.2 ± 3.3 mg N/100 g muscle at Day 20. Adenosine-5´-triphosphate (ATP) and derivatives followed a postmortem degradation pattern similar to other species, with the K-value being the best freshness loss indicator. Biochemical and microbiological changes indicated that the shelf life of iced loricariid catfish muscle was 15 days under optimal (0°C) storage conditions.  相似文献   

2.
为探明一定盐度条件下传统鱼露发酵前期挥发性风味物质随时间变化的规律,建立鱼露发酵前期挥发性风味物质的指纹图谱及明确主要风味物质。采用气相色谱—质谱联用(GC-MS)方法分析了180和230两种盐度条件下日本鰒鱼露发酵液的挥发性风味成分。结果显示,有80%的鱼露样品相似度良好,与对照图谱相似度达到了90%;180盐度下发酵150 d的鱼露挥发性风味物质变化较大。盐度180发酵的鱼露样品组有51个共有峰,盐度230有58个共有峰,并在对照图谱中加以标定。通过对指纹图谱共有峰化合物指认,确定了乙醇、丙酮、异戊醛、1-戊烯-3-醇和2-甲基丁酸为鱼露前期发酵液的主要挥发性风味物质。研究表明,盐度180发酵的鱼露更早地进入基础物质转化阶段,有利于鱼露海鲜味的生成;230盐度发酵的鱼露整体发酵进程较为缓慢,但更有利于鱼露中乳酪味和肉香味的形成。在实际生产中可根据需要选择不同的盐度进行发酵。研究结果为揭示鱼露发酵前期主要基础挥发性风味物质及变化规律和鱼露品质控制等提供科学依据。  相似文献   

3.
The commercial value of yellowtail Seriola quinqueradiata meat is often reduced by color deterioration of the dark muscle during storage. The objective of this study was to investigate the effect of simultaneous dietary supplementation of vitamin C (VC) and vitamin E (VE) to cultured yellowtail on color degradation of the dark muscle during storage. Yellowtail were fed for 6 or 11 days on a diet containing 1% VC and 1% VE (vitamin group) or without these vitamins (control group). The amounts of VC and VE in the dark muscle of the vitamin group tended to be higher than those of the control group. During the storage of sliced meat at 23 and 4°C, the decreases in a* value (redness) of the dark muscle of the vitamin group was slower than those of the control group. The formation of metmyoglobin, which can occur along with myoglobin oxidation, in the dark muscle of the vitamin group was slower than that of the control group. These results suggest that simultaneous feeding of high amounts of VC and VE for a short period to yellowtail before harvesting could suppress the color deterioration of the dark muscle during storage.  相似文献   

4.
Dietary fish oil (FO) was replaced by olive oil (OO) in young yellowtail Seriola quinqueradiata to investigate its effects on growth, muscular fatty acid composition and prevention of color deterioration of dark muscle during storage. Yellowtail were fed one of four diets, where FO (80 g/kg diet) was replaced by OO (0, 25, 50 and 100%) for 40 days. No significant difference in growth was seen among the diet groups. In addition, these experimental diets did not affect the proximate compositions of the dorsal muscle, ventral muscle and the liver in these fish. Serum total protein, glucose and total cholesterol levels did not show significant differences; however, serum triglyceride levels were significantly higher in fish fed 50 and 100% OO diets. Fatty acid composition of ventral muscle reflected the composition of the respective diets. Dark muscle discoloration was reduced in fish fed OO diets after 12 to 18 h during storage at 4°C. Furthermore, the redness value of fresh dark muscle increased depending on the extent of FO replacement. These results indicate that the partial or total dietary replacement of FO with OO prevents discoloration of dark muscle without affecting the growth of young yellowtail after 40 days of feeding.  相似文献   

5.
The present study investigated the effects of lipid oxidation on quality deterioration in the ordinary and dark muscles of skipjack tuna Katuwonus pelamis during the early stages of ice storage for 72 h. The lipid hydroperoxide content of the dark muscle was significantly higher (P < 0.01) than that of the ordinary muscle throughout 72 h of ice storage. The metmyoglobin content of the ordinary muscle gradually increased, and was accompanied with darkening in the fish meat color. On the other hand, the addition of sodium ascorbate or 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox®) to the ordinary muscle of skipjack tuna significantly inhibited the formation of lipid hydroperoxide as well as metmyoglobin formation. Thus, a decrease in α-tocopherol content in the ordinary muscle with antioxidant addition was not observed during ice storage period. In conclusion, the rate of lipid oxidation of skipjack tuna ordinary muscle is closely related to metmyoglobin formation, and the addition of antioxidants to fish meat is effective at inhibiting lipid oxidation as well as myoglobin oxidation in post-mortem meat.  相似文献   

6.
选取-20℃、-30℃和-50℃3个冻藏温度,以TVB-N值、肌原纤维蛋白含量、Ca2+-ATPase活性、巯基含量、TBARS值及肌肉组织微观结构为指标,结合感官评分,对比分析90 d内日本枪乌贼(Loligo japonica)的品质变化规律。结果显示,在不同冻藏温度下,随着时间的延长,Ca2+-ATPase活性和感官评分不断下降;肌原纤维蛋白和巯基含量,则先略微上升而后快速下降;TVB-N值和TBARS值呈不断上升的趋势,且温度越高上升速率越快;肌肉组织微观结构分析表明,枪乌贼肌纤维结构在冻藏过程中逐渐变得松散。相比-20℃,-30℃和-50℃冻藏温度条件下更能长久地保持枪乌贼品质,且品质无显著差异。综合分析认为,冻藏温度低于-30℃时,可较好地保持枪乌贼品质。  相似文献   

7.
Myosin was isolated from two types of muscle, ordinary and dark muscles, of three species of fish living in sea water. The compositions of light chains were visualized by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the mechanochemical activity was examined by in vitro motility and ATPase assays. Ordinary muscle myosin of either species had three species of light chain, whereas dark muscle myosin had another two species of light chain judged by SDS-PAGE. Sliding velocity of ordinary muscle myosin was in the range of 4.92–6.89 μm/S, whereas that of dark muscle myosin was in the range of 3.07–4.25 μm/s. Therefore, ordinary muscle myosin showed 1.26–1.95 times higher sliding velocity than dark muscle myosin in either species. The ratios of Vmax of actin-activated Mg2+-ATPase activity of ordinary to dark muscle myosins were correlated quite well to the ratios of sliding velocity. Activity of ordinary muscle myosin was comparable to that of mammalian fast muscle myosin, but that of dark muscle myosin was twice of that of mammalian slow muscle myosin. These results may reflect the essential role of fish dark muscle myosin always used in slow cruising.  相似文献   

8.
We investigated factors that accelerate dimethylamine formation in gadoid dark muscle. The degradation rate of trimethylamine-N-oxide into dimethylamine and formaldehyde during frozen storage was compared between ordinary muscle and dark muscle from walleye pollock, southern blue whiting, and hoki. Dimethylamine was generated faster in dark muscle than in ordinary muscle in each species, and it was produced most abundantly in hoki dark muscle compared with the other two species. We investigated the mechanism that caused dimethylamine to be generated more abundantly in dark muscle during frozen storage, and found that the amount of dark muscle nonheme iron, which catalyzes trimethylamine-N-oxide degradation, was higher than that in ordinary muscle in each species, and hoki dark muscle in particular contained the highest levels of nonheme iron among these three species. Moreover, dark muscle in all three fish species had a higher taurine content (known to accelerate dimethylamine formation) than ordinary muscle. These data suggested two candidate factors, namely nonheme iron and taurine, that may accelerate dimethylamine generation during frozen storage. In addition, gel filtration results suggested that walleye pollock dark muscle contains as yet unidentified low-molecular-weight agents that stably accelerate dimethylamine generation.  相似文献   

9.
ABSTRACT:   C-protein is a myosin-associated protein of vertebrate striated muscle, and its function and properties have been extensively examined. However, there has been no report of C-protein of fish skeletal muscle so far. C-protein was identified in carp skeletal muscle by immunoassay using antibody against chicken C-protein, and the muscle-type specific C-protein was purified from carp ordinary and dark muscles for the first time. Although C-protein could be prepared from crude myosin by the reported procedure, C-protein degraded appreciably during the purification steps. Accordingly, C-protein was selectively extracted from the muscle with 0.15 M K-phosphate buffer (pH 5.8), and purified by ammonium sulfate fractionation, followed by AF-blue chromatography. Myosin free from the accessory proteins was obtained by diethylaminoethyl (DEAE) chromatography and used to assay the binding of C-protein with myosin. Ordinary muscle C-protein bound to ordinary muscle myosin in a saturable manner, but its maximum amount of binding was approximately twice that of dark muscle myosin. Similarly, dark muscle C-protein bound to dark muscle myosin much more than to ordinary muscle myosin. These results suggest that C-protein isoforms specifically bound with myosin isoforms originated from the same type of muscle.  相似文献   

10.
Postmortem changes in blue shrimp (Litopenaeus stylirostris) muscle were studied on the basis of biochemical, chemical, physical, and microbiological changes during an 18 day storage period at 0°C. Adenosine 5′-triphosphate (ATP) content, breakdown products, K-value, pH, trimethylamine nitrogen (TMA-N), total volatile basic nitrogen (TVB-N), water holding capacity (WHC), color, and texture (shear force) changes were examined. Also, total mesophilic and psychrophilic bacterial counts were measured. K-value increased linearly (r2 = 0.98) from an initial value of 1.37 ± 0.59 to 59.42 ± 6.05% at Day 18. Spoilage indicators TVB-N and TMA-N increased from 29.56 ± 1.33 and 0.69 ± 0.25 to 39.04 and 2.04 ± 0.59 mg of N/100 g at Day 18, respectively; meanwhile, the total viable counts of mesophilic and psychrophilic bacteria increased from 3.48 ± 0.44 and 2.61 ± 0.29 log CFU/g to 6.27 ± 0.21 and 7.14 ± 0.39 log CFU/g, respectively, which indicated spoilage at the end of the storage period. The pH, texture, WHC, and color were affected (p < 0.05) during the storage period. Overall, results indicate that blue shrimp muscle quality was maintained for 12 days of storage in ice.  相似文献   

11.
为分析青海湖裸鲤(Gymnocypris przewalskii)特征挥发性成分,以体重为20g的青海湖裸鲤作为研究对象,剖取肌肉后采用固相微萃取(SPME)结合气相色谱-质谱联用(GC-MS)对裸鲤肌肉挥发性成分进行分离鉴定。结果表明,在青海湖裸鲤肌肉中检测出60种化合物,包括8种醇类化合物、9种醛类化合物、5种酮类化合物、2种酸类化合物、8种酯类化合物、12种烃类化合物、12种芳香族化合物及4种其他类物质,其中芳香族化合物含量最高。结合气味活度值(OVA)分析,青海湖裸鲤肌肉挥发性气味的主要贡献化合物为1-辛烯-3-醇、己醛、辛醛、壬醛、2-癸烯醛及2,4-癸二烯醛。  相似文献   

12.
The effects of storage temperature and time on raw pink salmon by-products were evaluated in relation to the fishmeal produced. Chemical analyses were performed on the raw and processed by‐products at two temperatures. Total volatile base nitrogen values indicated substantial spoilage by day 2 at 15.4 ± 1.4°C and day 6 at 6.0 ± 0.8°C. For most biogenic amines in raw by-products stored at 15.4°C, there were many significant differences from the fresh by-products by day 2. For by-products stored at 6.0°C, significant changes in biogenic amine were evident by day 2 and continued to increase. The thiobarbituric acid reactive substances (TBARS) values of the raw material stored at 15.4°C started showing significant changes from fresh on day 3 and at 6.0°C on day 4. The lipid oxidation (TBARS) was significantly different from fresh by day 2. Biogenic amines in fishmeals suggested some changes occurred between day 0 and day 3 at 15.4°C and by day 7 at 6.0°C.  相似文献   

13.
ABSTRACT

Fish is one of the most common sources of food allergens, and grass carp is among the most popular freshwater fish. The objective of this study was to investigate the effects of heat treatment on the antigenicity and allergenicity of white and dark muscle of grass carp. The results showed that the antigenicity of heated white muscle was higher than that of unheated white muscle, while the allergenicity of white muscle was lower than that of unheated muscle when heated at 65°C, and the lowest value was 44.6%. Furthermore, the allergenicity of dark muscle increased for the first 30 min when heated at 65°C, and it increased for the first 60 min and then decreased with the increasing heating time thereafter when heated at 80 and 100°C. In addition, the lowest antigenicity and allergenicity of dark muscle were obtained at 100°C, and the values were 0.447 mg mL?1 and 47.0%, respectively. Thus, to decrease the antigenicity and allergenicity of grass carp muscles, it is suggested that heating at 65°C is better than 80 or 100°C for the white muscle, while 100°C is an appropriate heating temperature for the dark muscle.  相似文献   

14.
Changes in biochemical and sensory attributes of chub mackerel (Scomber japonicus) fillets during storage treated by immersion in a 12% NaCl brine with or without 0.2% liquid smoke were investigated. Brine-treated chub mackerel fillets were packaged in modified atmosphere or under vacuum and were stored at 4°C. The brined fillets were stored and evaluated raw and after heat treatment as cooked samples. Fish fillets were assessed organoleptically to determine acceptability and by measuring the pH, oxidation levels (TBARS test), and total volatile basic nitrogen (TVBN). Fillets treated in brine with liquid smoke exhibited similar pH and significantly lower TBARS and TVBN values (p < 0.05). The combination of the use of brines containing liquid smoke and subsequent vacuum packaging produced the lowest TBARS and TVBN values and resulted in extended acceptability.  相似文献   

15.
ABSTRACT

Effects of various heat pump drying parameters (temperature, air velocity, bypass air ratio, and drying time) on the volatile compounds in silver carp (Hypophthalmichthys molitrix) were studied. These parameters determined the drying rate and influenced the formation of the volatile flavor compounds. High temperatures strongly promoted the volatile flavor compounds’ formation. Temperature increase from 5 to 35°C induced increase in the total various volatile compounds (including alcohols, aldehydes, ketones, and acids) content, total volatile basic nitrogen (TVB-N), and thiobarbituric acid-reactive substances (TBARS). However, high temperatures (> 35°C) led to many unpleasant volatile odors. Increase in the air velocity (0.35–1.65 m s?1) and bypass ratio (0.2:1.0) led to increases in the volatile compound contents but decreases in the TVB-N and TBARS values. The TVB-N content was the lowest in all the samples when the bypass air ratio value was 0.6. The drying time had negative effects both on the generation of volatile flavor compounds and TVB-N and TBARS. We found that the optimal temperature, velocity, bypass ratio, and time for our process were 20°C, 1.65 m s?1, 0.6, and 36 h, respectively.  相似文献   

16.
Quality changes of vacuum-packed Atlantic mackerel (Scomber scombrus) fillets during 12 months’ frozen storage at ?27°C and 9 days’ chilled storage at +4°C were evaluated. Freezing at ?27°C preserved the long chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs), both in light and dark muscle, vitamin D, and the low molecular weight metabolites (LMW) (studied by high resolution nuclear magnetic resonance spectroscopy, HR NMR). Protein oxidation took place, especially between 1 and 7 months, decreasing water holding capacity and protein extractability. During chilled storage, no lipid or protein oxidation was observed, but lipolysis increased, and several LMW metabolites relevant for sensory and nutritional quality degraded into non-favorable compounds. The content of biogenic amines was high at day 9 (e.g., 18 mg histamine/100 g), jeopardizing safety. Preservation of mackerel fillets by freezing at ?27°C is thus a better option compared to prolonged chilled storage at +4°C; the quality was well preserved for 12 months’ frozen storage.  相似文献   

17.
为探究池塘循环水槽(In-pond raceway system,以下简称IPRS)养殖模式下斑点叉尾鮰(Letaurus punetaus,以下简称鮰)肌肉中特征挥发性风味成分;以传统大池塘养殖(Traditional pond system,以下简称TPS)为对照,利用GC-MS技术对两种模式下的鮰肌肉的挥发性成分进行了萃取和分离鉴定,并结合ROAV确定了不同模式下特征挥发性风味成分;结果显示,IPRS及TPS下分别检测出50种及51种挥发性风味成分,主要由醛类、烃类、醇类及酯类等四大类组成,IPRS鮰肌肉醇类、酮类物质均高于TPS,IPRS下1-戊醇、1-戊烯-3-醇、乙酸乙烯酯、2-壬酮、2,3-辛二酮、1,3-戊二烯、十五烷等物质相对含量显著或极显著高于TPS(P＜0.05或P＜0.01),己醛等部分醛类物质在含量较高时易呈现令人不愉快的气味,IPRS下优势显著。IPRS下特征挥发性风味成分主要包括1-辛烯-3-醇、己醛、庚醛、辛醛、壬醛、2,6-壬二烯醛、癸醛、2,4-癸二烯醛及(E,E)-2,4-壬二烯醛,其中庚醛、2,6-壬二烯醛为TPRS特有的特征挥发性风味成分。结论显示,养殖模式对鮰肌肉挥发性风味成分及相对含量具有较大影响,IPRS下挥发性风味物质构成优于TPS,适合鮰集约化、高密度养殖。  相似文献   

18.
The effects of fasting on the quality of the dorsal and ventral ordinary muscles from cultured Pacific bluefin tuna (Thunnus orientalis) during chilled storage were investigated. Tuna were subjected to fasting for 2 days in the summer or 6 days in the winter prior to harvesting. The breaking strength of the dorsal ordinary muscle sampled in the summer increased until 24 h and then decreased. There were no significant differences in the lipid and glycogen content of the ordinary muscle after 9 h of storage between the controls and either fasting group. The pH of the ordinary muscle subjected to summer and winter fasting was higher than in the controls after 24–48 h of storage. However, the relationship between the pH and glycogen content was unclear. The metmyoglobin content during chilled storage was lower in the ordinary muscles from either fasting group than in the controls. In conclusion, fasting for 6 days in the winter improved the color stability of the ordinary muscle without a decline in its lipid content.  相似文献   

19.
咸鱼中的挥发性风味成分   总被引：3，自引：2，他引：1  
为了探明咸鱼挥发性气味特征物质,采用顶空固相微萃取和气相色谱—质谱联用分析技术,对柳叶鱼、红牙、小黄鱼以及带鱼等4种常见鱼的咸鱼进行萃取和分离鉴定。结果表明,这4种咸鱼的挥发性风味成分的组成和种类各不相同,分别得到105种、89种、88种以及72种挥发性风味物质(匹配度超过80%),以醛类、醇类以及烃类物质为主,总量分别占了这4种鱼的49.99%、53.09%、60.54%以及86.18%。研究表明,咸鱼的特征香气以鱼腥味、青草味-脂肪味为主;咸鱼特征风味物质是3-甲基丁醛、己醛、(z)-4-庚醛、庚醛、苯甲醛、辛醛、壬醛、1-戊烯-3-醇、3-甲基丁醇、1-辛烯-3-醇、庚醇、三甲胺。  相似文献   

20.
Beneficial utilization of yuzu (Citrus junos) peel was investigated to improve the commercial value of cultured yellowtail fish. The antioxidant effects of grated yuzu peel from pomace (yuzu paste) on prevention of dark muscle discoloration during storage in sliced yellowtail fish were tested. Four diets were prepared, containing 0, 10, 50, and 100 g yuzu paste in a 1,450-g diet (wet basis). Fish were fed one of the four diets for 10 weeks. Growth performance was not significantly different among the dietary groups, but fish fed a diet containing 100-g yuzu paste showed the least average body weight and a significant increase in fecal amount and fat levels in the feces, which suggest low digestibility and low absorption. Dark muscle discoloration was significantly reduced in all yuzu dietary groups compared to the control group during storage at 4°C. The optimal supplementation of yuzu paste in the fish diet is very effective at maintaining fish flesh freshness as a finishing diet without causing additional phosphorus or nitrogen pollution of the sea and inhibiting fish growth. This study provides a new way to utilize waste yuzu peel, which also helps reduce waste from yuzu processing.  相似文献   

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