Effect of Different Cooking Methods on Minerals,Vitamins, and Nutritional Quality Indices of Rainbow Trout (Oncorhynchus mykiss)

In this study, the influence of four cooking methods (baking, boiling, microwaving, and frying) on the nutritional value of rainbow trout was determined. Proximate, fatty acid composition, vitamin, mineral contents, and nutritional quality indices of rainbow trout were investigated (i.e., before and after cooking treatments). In all samples, there was reduction of total n-3 than raw fish fillets. Considering overall nutritional quality indices, vitamin, and mineral contents; baking and boiling were the best cooking methods among other methods used in this study.     

Lipid characteristics in cooked, chill-reheated fillets of Indo-Pacific king mackerel (Scomberomorous guttatus)

Slices of Scomberomorous guttatus cooked by four different methods (microwave cooking, grilling, steaming and shallow fat frying) were kept chilled at 5 °C for 2 days, reheated by microwave and then evaluated for the changes in the lipid characteristics. The total lipid content for raw sample was 6.0 g/100 g which consist of 49.4 g/100 g saturated (SFA), 6.9 g/100 g monounsaturated (MUFA) and 43.8 g/100 g polyunsaturated fatty acids (PUFA). Upon cooking, the total lipids changed to about 7 (microwave), 11 (grilling), 5 (steaming) and 10 g/100 g (shallow fat frying). These changes are significant, with the exception of steam cooking. Cooking did not significantly affect the percentage of NPL, PL, SFA, MUFA and PUFA in the samples. Frying resulted in the change of the SFA/PUFA ratio more than other cooking methods. A significant (P < 0.05) decrease in the content of EPA was only found in the fried samples. A significant (P < 0.05) decrease in the content of DHA in all cooked samples were also obtained. The n-6/n-3 ratio did not change significantly in all cooked and reheated samples, except for shallow fat fried. Reheating did not significantly affect the NPL and PL contents of the fillets, except for microwave cooked samples. Cooking increases the FFA, PV and TBA of samples; reheating enhances the increase.     

Change in proximate, amino acid and fatty acid contents in muscle tissue of rainbow trout (Oncorhynchus mykiss) after cooking

Changes in proximate, amino acid and fatty acid composition of farmed, commercially important rainbow trout (Oncorhynchus mykiss) after conventional and microwave cooking were analysed. Rainbow trouts cooked in microwave ovens had statistically significant higher total protein, total fat, and ash than electrical oven‐cooked samples. The amounts of essential and nonessential amino acids were not different between cooking methods, but the difference between raw and cooked samples was significant. Lysine, leusine, methionine, threonine, valine, arginine and histidine were found most in microwave‐cooked rainbow trouts whereas isoleucine, tyrosine and phenylalanine were found most in electrical oven‐cooked samples. As total saturated fatty acid and total monounsaturated fatty acids amount were not statistically different between the cooking methods, the difference between raw and cooked fillets was found statistically significant (P < 0.05). There was no statistically significant difference between raw and cooked fillets in total n‐3 and n‐6 contents.     

Comparison of the effects of four cooking methods on fatty acid profiles and nutritional composition of red mullet (Mullus barbatus) muscle

This study was performed to examine the effects of different cooking methods (frying, steaming, oven cooking, and microwave cooking) on proximate chemical composition, mineral contents, and fatty acids profiles of red mullet (Mullus barbatus) fillets. The frying process caused a significant increase in fat content (from 13.37±0.04 to 34.44±0.20 g/100 g d.w.) and reduced the proportion of the palmitic acid of 50.73% and saturated fatty acids of 56.9%. While, the proportion of polyunsaturated fatty acids (PUFA) increased from 4.04% of total fatty acids for raw fillet to 49.17% of total fatty acids for fried fillets. The steamed, oven-cooked, and microwave-cooked fillets showed the best proportion of fat content, PUFA, and ω-6/ω-3 ratio as compared with fried red mullet fillets. Na, Mg, and Zn contents of cooked fish fillets significantly decreased.     

Effects of Four Cooking Methods on the Proximate, Mineral and Fatty Acid Composition of Fish Fillets

The effects of baking, broiling, deep frying and cooking in a microwave oven on the proximate, mineral and fatty acid composition of grouper (Epinephelus morio), red snapper (Lutjanus campechanus), Florida pompano (Trachinotus carolinus) and Spanish mackerel (Scomberomorus maculatus) were determined. The lipid content of low fat species was not significantly changed by cooking, but lipid was lost from fatty fillets during cooking. The fatty acid composition of all fillets was not significantly changed by baking, broiling or microwave cooking. Deep fried fillets absorbed the major fatty acids in the cooking medium, and as the fillet lipid content increased the extent of absorption of fatty acids from the cooking medium decreased. Sodium, potassium and magnesium levels were decreased when low fat species were cooked, but these minerals were not lost when raw fillets containing higher lipid levels were cooked. Cooking did not significantly affect the concentration of the microelements, zinc, copper, iron and manganese.     

Effect of different precooking methods on chemical composition and lipid damage of silver carp (Hypophthalmichthys molitrix) muscle

The influence of three precooking methods (steaming, oven‐baking and microwave‐cooking) on the chemical composition and lipid quality of silver carp fillets was evaluated. The changes in protein, fat and moisture were found to be significant for all the treatments (P ≤ 0.05). The iron content in the samples subjected to steam‐cooking increased; however, the other precooking methods did not change the mineral contents (P ≥ 0.05). The free fatty acid content of the fillets did not change by the different precooking methods, while thiobarbituric acid (TBA) values increased for oven‐ and microwave‐cooked fillets and remained constant in the steam‐cooked samples. Conjugated diene and browning colour formation levels significantly increased in the oven‐baked fillets. Oven‐baking and microwave‐cooking marginally affected the fatty acid composition of the silver carp. On comparing the raw and precooked fillets, steam‐cooking was found to be the best precooking method on retaining nutritional constituents.     

鱼香肉丝在烹饪前后营养成分的评价

为系统评价中国传统菜肴鱼香肉丝的营养品质以及烹饪前后的营养成分变化,将用于制作鱼香肉丝的原材料平均分成2组,每组3份,分别是生原料组和成品组。对其22种营养素指标进行检测,并分别对常规营养素、氨基酸、脂肪酸、矿质元素以及维生素进行营养评价。结果表明,在烹饪后鱼香肉丝的蛋白质显著升高(P<0.05),脂肪、磷、和铁的含量极显著升高(P<0.01),但氨基酸组成和脂肪酸总量无显著变化,维生素B₁显著降低(P<0.01)。蛋白质的氨基酸组成合理,必需氨基酸指数达到了85.91%;且多不饱和脂肪酸含量丰富,占总脂肪酸的58.36%。此外,矿质元素的营养质量指数均大于1(除钙以外),基本满足人体需求,但鱼香肉丝的维生素A和维生D含量较为缺乏,B族维生素(B₁、B₃、B₁₂)含量也低于中国居民膳食营养素摄入量的推荐值。综上,鱼香肉丝是一道营养丰富、均衡的菜肴,它具有优质的蛋白质、脂肪酸和丰富的矿质元素。烹饪会造成其维生素B₁的损失,而大大增加铁元素的含量,并且蛋白质和脂肪的含量会升高。本研究为膳食记录提供了更为准确的营养数据。     

The effect of cooking methods on mineral and vitamin contents of African catfish

Proximate composition, mineral and vitamin contents (A, E, B₁, B₂, niacin and B₆) were investigated in cooked African catfish. Different cooking treatments were used (baking, grilling, microwaving and frying). The protein and ash contents increased in all cooked fish. The fat content increased only in fried fillets. The moisture content of cooked fish decreased. Mineral levels were affected by cooking methods, except for Cu Although the vitamin A content significantly increased in grilled and fried fish, vitamin E increased in all cooked fish. Vitamin B₁ content of cooked fish significantly decreased. Vitamin B₂ and niacin contents of grilled fish increased significantly. B₆ content of cooked fish significantly decreased but this did not occur for the grilled fish. High levels of vitamin and mineral contents were found in grilled catfish.     

Effect of a linseed diet on lipid oxidation, fatty acid composition of muscle, perirenal fat, and raw and cooked rabbit meat

Forty Californian×New Zealand rabbits (1kg initial body weight) were fed a control or a linseed isoenergetic diet containing 30g of extruded linseed/kg. Twenty rabbits for each dietary treatment were slaughtered at 11 weeks of age, at 35 days after the start of the experiment. Feeding the linseed diet increased (P<0.005) the content of 18:2n-3 in muscles, perirenal fat, and raw and cooked meat. The long chain n-3 polyunsaturated fatty acid (PUFA) contents were also increased (P<0.01) in the meat. The linseed diet produced a robust decrease in the n-6/n-3 ratio. Cooking did not alter n-3 PUFA more than saturated fatty acids (SFA) or monounsaturated fatty acids (MUFA). However, n-6 PUFA were altered by cooking. The oxidative stability of Longissimus dorsi was not affected by the linseed diet, even after 300min of forced-oxidation. Inclusion of linseed in rabbit diets is a valid method of improving the nutritional value of rabbit meat.     

Domestic Cooking of Muscle Foods: Impact on Composition of Nutrients and Contaminants

Meat and fish are muscle foods rich in valuable nutrients, such as high‐quality proteins, vitamins, and minerals, and, in the case of fish, also unsaturated fatty acids. The escalation of meat and fish production has increased the occurrence of pesticide and antibiotic residues, as result of pest control on feed crops, and antibiotics used to fight infections in animals. Meat and fish are usually cooked to enrich taste, soften texture, increase safety, and improve nutrient digestibility. However, the impact of cooking on nutritional properties and formation of deleterious compounds must be understood. This review summarizes studies, published in the last decade, that have focused on how domestic cooking affects: (i) composition of nutrients (protein, fatty acids, vitamins, and minerals); (ii) antibiotic and pesticide residue contents; and (iii) the formation of cooking‐induced contaminants (heterocyclic aromatic amines, polycyclic aromatic hydrocarbons, and thermal degradation products of antibiotics and pesticides). Cooking affects the nutritional composition of meat and fish; frying is the cooking method that causes the greatest impact. Cooking may reduce the pesticide and antibiotic residues present in contaminated raw meat and fish; however, it may result in the formation of degradation products of unknown identity and toxicity. Control of cooking time and temperature, use of antioxidant‐rich marinades, and avoiding the dripping of fat during charcoal grilling can reduce the formation of cooking‐induced contaminants.     

Retention of health-related beneficial components during household preparation of selenium-enriched African catfish (Clarias gariepinus) fillets

Industrial processing and heat treatment of fish muscle generally lead to losses of water-soluble components, some of which may have beneficial health effects. The aim of this work was to determine the retention of taurine, selenium and n-3 polyunsaturated fatty acids when preparing African catfish by three traditional household techniques: boiling in pouches, deep-frying and baking. Cooking did not significantly reduce the content of selenium, having retention between 91and 104%. Deep-frying resulted in a taurine loss of 40%, which was significantly higher than in baking where losses were 25% The fatty acid profiles were similar for baked and boiled fillets, but were significantly different from deep-fried fillets, due to absorption of vegetable frying oil. Baking was the best preparation technique with regard to retention of 20:5n-3 (eicosapentaenoic acid; EPA) and 22:6n-3 (docosahexaenoic acid, DHA), retaining above 80% for both fatty acids, whereas boiling and deep-frying were able to retain only approximately 54 and 65% of each, respectively.     

Nutritional Quality of Rabbit Meat as Affected by Cooking Procedure and Dietary Vitamin E

ABSTRACT: The effect of two dietary treatments (50 as opposed to 200 mg kg^-1 of α-tocopheryl acetate) on rabbit meat, cooked by different procedures (boiling, frying, roasting), was evaluated. Cooking caused an increase of pH, shear force, lightness, hue and chroma, and a decrease of water holding capacity. The change in nutritional value was slight but lipid oxidation was increased and the fat quality worsened. Boiled meat had the lowest nutrient retention and the highest TBARS values. Supplemental vitamin E was effective in reducing oxidative processes and increasing the amount of n-3 polyunsaturated fatty acids also during cooking.     

Nutritional value and flavor of turbot (Scophthalmus maximus) muscle as affected by cooking methods

In this study, the effects of five cooking methods on nutritional value and flavor of turbot muscle were evaluated. Chemical compositions of samples were determined using AOAC methods, and the fatty-acid composition was determined by gas chromatography–mass spectrometry (GC–MS). Flavors of samples cooked using different methods were characterized by electronic nose. Volatile compounds were determined using solid-phase microextraction (SPME) followed by gas GC–MS. All the samples were investigated before/after cooking. The results showed that the fatty acids found in abundance in the raw sample were C22:6n-3, C16:0, C18:1n-7, and C20:5n-3. All of the fatty acids were detected in steamed samples, while some of the fatty acids were degraded in other cooking methods. Electronic nose can be used to distinguish samples cooked differently. 20, 17, 34, 20, and 23 compounds were detected in samples cooked by frying, baking, microwave heating, boiling in vacuum-sealed bag (BIVSB) and steaming, respectively. Aldehydes, ketones, alcohols, acids, and hydrocarbons were the main volatile components detected. In summary, steaming preserves water, protein, lipids and fatty acids the best in cooked samples while generates desirable flavor, it is recommended as the choice of cooking for turbot.     

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.     

Effects of cooking methods on the proximate,mineral and fatty acid composition of European eel (Anguilla anguilla)

The influence of microwave cooking and traditional cooking methods such as baking, grilling and frying on the nutritional composition of eels (Anguilla anguilla) was studied. All methods reduced moisture and increased the protein and fat content. Although the potassium and sodium content of fish cooked by different methods decreased significantly (P = 0.000), the calcium and magnesium content increased. The zinc content of the fish was not affected by cooking. The manganese and iron content significantly increased only in fried fish. The copper content was increased by grilling and microwave cooking. The proportion of saturated fatty acids and monounsaturated fatty acids in cooked fish decreased. Omega‐3 polyunsaturated fatty acids were increased by all cooking methods. The grilling and microwave‐cooking methods were the most suitable considering the n3/n6 ratio and eicosapentaenoic acid levels. The increase in the docosahexaenoic acid level of fried fish enhanced its nutritional value.     

Effect of High Dietary Vitamin E on Lipid Stability of Oven-cooked and Hot-smoked Trout Fillets

ABSTRACT: Supplementing α-tocopheryl acetate (300 and 5000 mg/kg diet) in a trout finishing diet was done to minimize lipid oxidation in oven-cooked fillets and hot-smoked products. Hot-smoked processing did not affect α-tocopherol content of finished products compared with raw fillets. Feeding diets containing 5000 mg vitamin E/kg increased muscle α-tocopherol content that minimized lipid oxidation in (1) oven-cooked fillets produced from fresh and 7-d refrigerated fillets and (2) hot-smoked products following refrigerated storage for 8 wk. Dietary vitamin E did not affect fatty acid composition of products from either cooking method. Oven-cooked fillets produced from 7-d refrigerated, raw fillets and refrigerated, smoked products had lower percentages of omega-6 fatty acids and lower omega-3 fatty acids:omega-6 fatty acids ratios compared with fresh, raw samples.     

Effects of cooking and reheating methods on the fatty acid profile of sea bream treated with rosemary extract

BACKGROUND: The effects of rosemary extract on the fatty acid profile of sea bream fillets cooked by different methods (oven baking, grilling and pan frying) as well as the effects of different reheating methods (microwave and conventional oven) on the fatty acid composition of fish after frozen storage for 4 months were investigated. RESULTS: The proportion of saturated fatty acids increased only slightly in fried samples but significantly in oven‐baked and grilled samples, while the proportion of polyunsaturated fatty acids (PUFAs) increased significantly in fried samples but only slightly in oven‐baked and grilled samples. The proportion of monounsaturated fatty acids remained relatively constant after cooking. Of the fatty acids analysed, the most significant increases (P < 0.05) were observed in C18:1n‐9 and C18:2n‐6 and the most significant decreases (P < 0.05) in C14:0, C16:1, C20:5n‐3 and C22:6n‐3. Although sea bream fillets fried in sunflower oil showed an increase in PUFAs, the lowest eicosapentaenoic and docosahexaenoic acid contents were found in fried samples. CONCLUSION: Sea bream fillets treated with rosemary extract showed slower oxidation than untreated fish. Neither conventional nor microwave reheating after frozen storage for 4 months had a detrimental effect on the fatty acid profile and its stability. Copyright © 2009 Society of Chemical Industry     

Yield and Comparison of Nutritive and Energy Values: Selected Variety Pork Products

Eight raw and cooked pork products were compared for yield and physiologic energy values, nutrient composition and protein quality. Cracklings were not cooked. Cooking resulted in some significant changes (wet basis) in parameter values. Knuckles and ham hocks had similar parameter values. All products, except skin, had a cooking loss. Skin had a 15.3 g/kg gain, apparently due to an exceptional moisture increase. The fat composition showed a very low ratio of polyunsaturated to total saturated fats. There were no differences between the calculated PERs of each raw and cooked product. These data indicated that the chemical score and the PER values of these products were generally directly proportional to the total quantity of essential amino acids present.     

烹调方式对猪肉肌内脂肪中脂肪酸组成的影响

不同的烹调方式使猪肉中的脂肪含量和脂肪酸组成发生变化。以猪背最长肌为原料,通过4种常见的烹调方式:蒸、煮、微波、烤,探究脂肪酸的变化规律,进而指导人们的烹调方式。采用改进的Folch法提取烹调后猪肉中的脂肪,用氨丙基硅胶固相萃取小柱分离脂肪中的甘油三酯和磷脂,并采用气相色谱,以十三烷酸甲酯为内标定量分析总脂、甘油三酯及磷脂的脂肪酸组成。结果表明,与对照组相比,蒸、微波、煮和烤对猪肉脂肪中甘油三酯的脂肪酸组成无显著影响。而微波、煮和烤均使磷脂的脂肪酸组成发生显著性变化,其中饱和脂肪酸(SFA)和反式脂肪酸(TFA)的含量均显著增加,而单不饱和脂肪酸(MUFA)与多不饱和脂肪酸(PUFA)的含量明显减少,变化最明显的为烤制;蒸制对磷脂的脂肪酸组成影响最小,仅SFA和PUFA发生一定程度的变化;总脂肪酸组成差异显著,其含量变化主要是由磷脂的变化引起的。结论:烹调对磷脂影响显著;蒸制对猪肉脂肪的脂肪酸保护效果最好,烤制易破坏脂肪酸,从而降低营养价值。