野生与人工养殖的虎斑乌贼肌肉营养成分比较

分析研究人工养殖和野生条件下虎斑乌贼（Sepia pharaonis）肌肉的一般营养成分、氨基酸和脂肪酸的组成。结果表明：人工养殖和野生虎斑乌贼的蛋白质含量差异较小,分别为20.24%和20.15%;野生型与人工养殖的虎斑乌贼的脂肪含量分别为0.81%和0.97%,人工养殖条件下,脂肪含量略有提高。不饱和脂肪酸的总含量两者相似,其中二十碳五烯酸（eicosapentaenoic acid,EPA）和二十二碳六稀酸（docosahexaenoic acid,DHA）的总含量分别为37.13%和33.63%。在氨基酸种类和含量方面,人工养殖和野生虎斑乌贼都测得17 种氨基酸,鲜样中总含量分别是18.84%和18.07%,其中必需氨基酸/总氨基酸分别为42.83%和42.00%。     

The effects of industrial pre-frying and domestic cooking methods on the nutritional compositions and fatty acid profiles of two different frozen breaded foods

This study was carried out to determine the effects of manufacturer pre-frying in olive and sunflower oil, as well as domestic cooking methods (deep-frying in olive and sunflower oil and baking) on the proximate compositions and fatty acid profiles of tuna pasties and ham nuggets. The pre-frying processes reduced moisture and carbohydrates and increased ash, fat and protein content in both pre-fried products. During cooking, the frying processes caused a reduction in moisture content and an increase in fat content in relation to pre-fried samples, while baking did not modify the proximate composition. The fatty acid profiles of products during both the pre-frying and frying processes became similar to those of the culinary fat used. Thus, the frying processes reduced the proportion of saturated fatty acids (SFA) and increased the proportion of monounsaturated fatty acids (MUFA) in the foods when olive oil was used, whereas increased the proportion of polyunsaturated fatty acids (PUFA) in products fried in sunflower oil. The fatty acid profiles of fried samples tended to be more similar to the frying fat than to the pre-frying fat, whereas the fatty acid profiles identified during the pre-frying process for baked products were not significantly modified. Thus, samples pre-fried in olive oil and subsequently baked showed the best proportion of fat content and PUFA/SFA, MUFA + PUFA/SFA and n-6/n-3 ratios of the tested products.     

Nutrients in Wild and Farmed Fish and Shellfish

Wild and cultivated channel catfish, rainbow trout, coho salmon, red swamp crayfish, white river crayfish and Eastern oysters were analyzed raw and cooked for proximate composition and ten vitamins. Cultivated catfish had 5 and salmon 2 1/2 times more fat than their wild counterparts. In all other species wild and cultivated samples had similar nutrient content. Cholesterol was independent of fat content and similar in wild and cultivated samples. Vitamin B12 in 100g met or exceeded the 1989 Recommended Dietary Allowance (RDA) for adults of 2 μg/day in all species. Other B vitamines seldom exceeded 10% of the RDA except for niacin in finfish. Vitamin A, ascorbic acid and folic acid levels were negligible.     

Nutritional quality of red shrimp,Aristeus antennatus (Risso), pink shrimp,Parapenaeus longirostris (Lucas), and Norway lobster,Nephrops norvegicus (Linnaeus)

The proximate composition, amino acid and fatty acid profiles, lipid classes and cholesterol and glycogen contents were determined in the edible part of red shrimp, Aristeus antennatus (Risso), pink shrimp, Parapenaeus longirostris (Lucas), and Norway lobster, Nephrops norvegicus (Linnaeus), in two distinct periods of the year. The proximate composition did not vary significantly between species or between periods of sampling. Significant differences in glycogen content were obtained between winter and summer; the lowest values were attained in winter (1.2, 1.1 and 1.0% wet weight for red shrimp, pink shrimp and Norway lobster respectively). With the exception of Norway lobster, an opposite trend was obtained for cholesterol content, ie lower values in summer (60.8 and 57.8 mg per 100 g wet weight for red shrimp and pink shrimp respectively). The major essential amino acids (EAA) were arginine, lysine and leucine and the limiting amino acid was methionine in all three crustacean species. The most important non‐essential amino acids (NEAA) were glutamic acid, aspartic acid, proline and glycine. In respect to lipid classes, phospholipids and free cholesterol predominated. The major fatty acids were 16:0, 18:1n‐9, 20:5n‐3 and 22:6n‐3. The polyunsaturated fraction was dominant (42.1–48.4%), followed by the monounsaturated (26.3–34.6%) and saturated (22.9–27.4%) fatty acids. In conclusion, the nutritional quality of these shellfish species is similar, they are valuable protein and lipid sources for the human diet and are adequate elements of the traditional Portuguese diet. Copyright © 2003 Society of Chemical Industry     

Seasonal changes of proximate composition and fatty acids of farmed dusky grouper (Epinephelus marginatus Lowe, 1834)

The aim of this work was to determine the seasonality of nutrient profiles of dusky grouper (Epinephelus marginatus Lowe, 1834) cultured in a cage to improve knowledge on its nutritional composition. Fish (n = 735) were reared in a circular polyethylene floating cage for a 19‐month experimental period and provided a commercial pelleted feed once a day with a total daily ration of 1% wet body weight. Fish were sampled every 3–4 months, and biometric parameters as well as muscle composition were determined. The edible proportion of fish increased slightly with culture time. The flesh showed low lipid content, similar to those reported for wild grouper. Biometric indices, muscle proximate composition and fatty acid profiles were significantly affected by seasonality, that is lipids and monounsaturated fatty acids increased during summer, in parallel with the decline of polyunsaturated fatty acids.     

Influence of Commercial Diets on Quality Aspects of Cultured Gulf of Mexico Surgeon (Ancipenser oxyrinchus desotoi)

ABSTRACT: Cultured sturgeons were fed commercially available diets formulated for hybrid bass, catfish, and trout. The impact of these diets in the quality of the edible muscle was investigated through determination of processing yields, proximate compositions, fatty acid profiles, muscle color, and sensory characteristics. Sturgeon fed the catfish diet were significantly smaller but dressed fillets (percent live weight) were similar for all feeds. Consumer visual acceptability scores were highest for fillets from fish fed the catfish diet, and color differences were determined. Sturgeon fillets from fish fed the trout diet presented a yellowish orange coloration instead of a pale pink coloration. Results show that the diets tested had no detrimental impact in the composition of sturgeon fillets.     

Comparison of wild and cultured sea bass (Dicentrarchus labrax) quality

Chemical composition, nutritional value and other physico-chemical parameters of sea bass from two different geographical areas (Greece and Spain) and from aquaculture and wild origin were studied. Farmed and wild fish differ in proximate composition, colour, and especially in texture, fatty acids and free amino acids (FAAs) profiles. Flesh of wild fish was firmer, which could be attributed to their lower fat content and higher level of activity. Cultured fish showed a higher content of monounsaturated fatty acids and lower of saturated and polyunsaturated fatty acids (PUFAs). Within the PUFA group, n−3 fatty acids were predominant in wild sea bass, while n−6 were more abundant in farmed fish. Some FAAs related to the characteristic flavour of fish, such as glutamic acid, aspartic acid, alanine, and glycine were more abundant in cultured sea bass. No differences between fish from both farms were found, due to the similar composition of the feed used.     

Influence of Phospholipid Content and Fatty Acid Composition of Individual Phospholipids in Muscle from Bison, Hereford and Brahman Steers on Flavor

Neutral lipid (NL) and phospholipid (PL) fractions and their corresponding fatty acid profiles from the L. dorsi of Bison, Hereford, and Brahman steers of similar age finished on identical diets were determined. Compositional differences were related to sensory characteristics of the samples. Phosphatidylcholine + lysophosphatidylethanolamine (PC + LPE) existed in the highest concentration in all samples evaluated followed by lysophosphatidylcholine (LPC), phosphatidylethanolamine (PE), sphingomyelin (SPH), fraction one and phosphatidylserine (PS). Bison contained more total PL, particularly PC + LPE and LPC, than the other two bovine species. Polyunsaturated fatty acid (PUFA) composition of these PL was greater for Bison. Off-flavor and aftertaste increased with increasing levels of PC + LPE and LPC due to their greater composition of PUFA.     

Physicochemical and fatty acid characteristics of stewed pork as affected by cooking method and time

This study was designed to investigate the effects of cooking on physicochemical and fatty acid characteristics of stewed pork. Pre‐fried or raw pork belly cubes were stewed for 60, 90, 120, 150 or 180 min. After cooking, proximate chemical composition, texture, sensory evaluation, lipid oxidation, fatty acid profiles and cholesterol content were determined. Prolonged cooking time resulted in higher percentages of dry matter, fat and fat loss in stewed cubes (P < 0.01), and pre‐frying also increased fat loss. Tenderness and elasticity values of texture profile analysis and sensory scores were the highest for the cubes stewed for 180 min or by pre‐frying combined with stewing for 150 min. Pre‐frying and extended cooking time significantly increased lipid oxidation (P < 0.01). Cooking modified fatty acid profiles which altered the derived cardiovascular indices, and reduced cholesterol content. Prolonged stewing improved eating quality and most nutritional values of pork belly.     

Rancid Flavor of Milk: Relationship of Acid Degree Value, Free Fatty Acids, and Sensory Perception

Acid degree value (ADV) as determined by the standard method, free fatty acid profile, and sensory analyses by a trained panel (n = 5) using magnitude estimation were used as measures of intensity of rancid flavor in milk. The correlation between ADV and rancidity scores was 0.13 (p = 0.16). Laboratory-prepared rancid samples were assigned higher rancidity scores than farm-collected milk samples with similar ADV. Rancidity scores and ADV increased with storage time. Major free fatty acid concentrations increased as ADV increased (r = 0.93, p = 0.0001) for farm milk samples but correlation was low (r = 0.27, p = 0.40) for laboratory-prepared rancid samples.     

Fatty acid profile of wild and farmed gilthead sea bream (Sparus aurata)

Historically farmed fish were frequently found to exhibit a lower ratio of n3/n6 fatty acids compared to wild fish. This study compares the proximate and fatty acid composition of wild and cultured gilthead sea bream fish from a lagoon in NW Greece. Wild fish contained less fat and showed different fatty acid profiles. Farmed fish exhibited threefold higher concentrations of linoleic acid (C18:2n-6) in muscle and twofold in visceral fat. Their muscle tissue contained higher levels of saturated fatty acids and higher ratios of eicosapentaenoic acid/docosahexaenoic acid (0.49?±?0.04 vs. 0.03?±?0.01; ???<?0.001). Wild fish exhibited lower levels of muscle n-3 fatty acids (15.87?±?0.82 vs. 19.89?±?1.06; P?<?0.001) but a higher ratio of n-3/n-6 (2.22?±?0.14 vs. 1.64?±?0.10, ???<?0.001). These results emphasize the need to further explore dietary manipulation of fatty acid content as a method of improving the fatty acid profile and maximise the health benefits of consuming farmed fish.     

Feeding interruption and quality of cultured gilthead sea bream

Proximate composition, fatty acid and amino acid profiles and sensory attributes of semi-intensive cultured gilthead sea bream were determined without feeding interruption and with feeding interruption from 1 to 13 days. Average proximate composition was protein: 19.4–19.9%, fat 14.1–15.4%, moisture: 64.1–65.3%, and ash: 1.3%. The monounsaturated fatty acids (MUFA) were dominant: 43%, followed by polyunsaturated fatty acids (PUFA): 32% and saturated fatty acids (SFA) 25%. For each fatty acid class the major compounds were palmitic acid (SFA), vaccenic and oleic acid (MUFA) and docosahexaenoic acid (PUFA). Regarding the feeding interruption, it appears that the perivisceral fat can supply the required energy for up to 13 days of starvation.     

Effect of gamma radiation and cold storage on chemical and organoleptic properties and microbiological status of liquid egg white and yolk

This investigation aims to establish a feasible radiation dose for treating liquid egg white (LEW) and yolk (LEY) at room temperature to improve their microbial safety. Samples of LEW and LEY were subjected to gamma irradiation doses of 0,1,2,3 and 4 kGy at room temperature followed by storage at 4 ± 1 °C. Then the effects of irradiation and cold storage on proximate composition, pH, soluble protein and free sulfhydryl content (SH) were determined for LEW and LEY in addition to the contents of total carotenoids in LEY. Moreover, free fatty acids (FFA) and peroxide value (PV) were determined for lipids of LEY.The microbial safety of LEW and LEY was established during storage throughout the enumeration of the total plate count, enterobacteriaceae, Staphylococcus aureus as well as the detection of Salmonella. The effects of irradiation at 3 kGy dose, which was enough for improving the microbial safety of samples, on amino acid composition of LEW and LEY and fatty acid profiles of LEY lipids were studied. In addition, sensory evaluation was carried out for liquid and scrambled egg white and egg yolk samples. The results showed that gamma irradiation and refrigerated storage had no significant effects on proximate composition and pH of liquid egg samples, while significantly decreased the contents of total carotenoids in LEY samples. Furthermore, gamma irradiation had no significant effects on protein solubility and the contents of free SH in LEW, while induced significant slight decreases in protein solubility and the contents of free SH in LEY. Cold storage, however, showed no significant effects on protein solubility and free SH in all liquid egg samples. FFA contents and PV of LEY lipids significantly increased post irradiation treatments and during storage, but the observed values were relatively low and acceptable. In addition, gamma irradiation at 3 kGy dose had no significant effects neither on the amino acid composition of LEW and LEY nor on fatty acid profiles of LEY lipids. The sensory preference did not alter neither for the liquid egg samples nor for scrambled egg samples that prepared from irradiated liquid egg products. Finally, gamma irradiation at 3 kGy dose appeared to be the optimum for treating LEW and LEY at room temperature followed by cold storage at 4 ± 1 °C.     

Proximate Composition, Mineral Content, and Fatty Acids of Catfish (Ictalurus punctatus, Rafinesque) for Different Seasons and Cooking Methods

The effect of conventional cooking methods and the influence of season upon proximate composition, mineral, and fatty acid profile was studied in catfish (Ictalurus punctatus, Rafinesque) fillets. Seasonal (August, December, and April purchased fillets) influences were minimal. As expected, fried catfish fillets had significantly altered (P ≤ 0.05) fatty acid profiles compared to the raw and baked fillets. All three cooking treatments resulted in significant differences (P ≤ 0.05) in proximate composition and in the levels of potassium, phosphorus, magnesium, and iron. The information presented would be useful for nutrient data banks when dietary intake of such items is of interest.     

Variations in proximate composition and fatty acid profiles of Baltic sprat (Sprattus sprattus balticus)

The variability of the proximate composition and fatty acid profiles in samples of sprat (Sprattus sprattus balticus) from the southern Baltic Sea were studied in relation to the catch season and location, individual fish size, and sex. Fatty acid profiles depended on such features as fish size and lipid content, which depend on the season of the year in which the fish were caught. No differences in fatty acid profiles were noted between the sexes in the individuals examined. Studies on fish lipids are necessary as fish lipids are important in the prevention of cardiac disease. One of the chief advantages of fish lipids that is relevant to the prevention of cardiac disease is their n−3 to n−6 fatty acid ratio. The most advantageous ratio of these fatty acids was noted in sprat that were the smallest in length.     

Flavour profiling by gas chromatography–mass spectrometry and sensory analysis of yoghurt derived from ultrasonicated and homogenised milk

The odour, flavour, taste, sensory and volatile components profile of yoghurt, derived from milk homogenised by ultrasound or pressure were compared. The ultrasonication of milk led to yoghurts with lower degree of likeness (DOL) and off-flavours compared with those of yoghurts from pressure treated milk; also, burned, pungent and fatty flavour characteristics were more intense. The volatile components were identified by solid phase microextraction–gas chromatography–mass spectrometry (SPME–GC–MS). Both homogenisation treatments lead to chromatograms with similar peak areas of 2,3-butadione, 3-hydroxy-2-butanone, delta-decalactone, while the chromatogram peak areas of acetone, 2-butanone, 2-heptanone, bicyclo[2,2,1]-heptan-2-one, 2-nonanone, 2-undecanone, butanoic acid, hexanoic acid, octanoic acid, n-decanoic acid, hexadecanoic acid, acetaldehyde, hexanal, 1-buten-3-yne, heptane and dimethylsulphide were higher for the ultrasonicated samples. Sensory characteristics and GC–MS profiles were correlated with DOL and two models created with PLS regression. Both models included the appropriate variables and showed adequate ability to describe DOL by sensory characteristics or volatile components.     

Comparative assessment of proximate composition,physicochemical parameters,fatty acid profile and mineral content in farmed and wild rainbow trout (Oncorhynchus mykiss)

This study was conducted to determine differences between farmed and wild rainbow trout in terms of proximate and fatty acid composition, physicochemical parameters and mineral content. Fat content of farmed fish fillets was higher, while moisture content was lower than wild fish. However, wild fish had higher pH value and water‐holding capacity comparing to farmed fish. The muscle lipids of farmed fish contained higher proportions of 20:0, 18:1n‐9 and 20:1n‐9; and lower proportions of 18:2n‐6, 20:2cis, 18:3n‐3, 20:3n‐6, 20:4n‐6, 20:5n‐3 and 22:6n‐3 fatty acids than wild fish. The percentage of total saturated fatty acids (SFAs) was similar in both fish. Total polyunsaturated fatty acids (PUFAs), n‐3 PUFAs and n‐3/n‐6 PUFAs ratio were higher in the wild fish comparing to farmed fish, whereas its total monounsaturated fatty acids (MUFAs) and n‐6 PUFAs contents were lower. Among the seventeen minerals analysed in fish flesh, differences existed between farmed and wild rainbow trout in Ca and Fe contents. Moreover, toxic trace minerals (As, Cd, Pb and Hg) were all present in amounts below their toxic levels. The differences observed between farmed and wild fish may be attributed to the diet constituents and environmental conditions of the fish.     

Nutrients and Chemical Residues in One- to Two-Pound Mississippi Farm-raised Channel Catfish (Ictalurus punctatus)

Composite samples of Mississippi farm-raised channel catfish (FRCC) fillets were analyzed at four different seasons for the following: proximate composition, cholesterol, fatty acids, eight vitamins, eleven minerals, four heavy metals and eight chemical residues. Nutrients and other compounds did not vary appreciably with season. Mississippi FRCC were higher in fat, calories and thiamin compared with USDA and wild catfish data and had much less cholesterol than previously reported. Monounsaturates comprised over half the fatty acids in FRCC and omega-3 fatty acid content was low. Chemical residues were not detectable or present in extremely small amounts.