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.     

Determination of acrylamide content of food products in Korea

Acrylamide (AA) contents of commercial market‐purchased foods and of traditional home‐cooked Korean foods were investigated. The effect of cooking method on AA amount in potatoes was also studied. AA contents of roasted barley and corn ranged from 116 to 449 µg kg^?1 and of chips ranged from 12 to 3241 µg kg^?1, representing a very high variation in AA contents among tested samples. Lower levels of AA were found in wheat flour chips compared to potato chips. AA contents of ramen noodles were below 37 µg kg^?1, whether they contained potato starch or not. The AA contents of Korean home‐cooked oil fried foods increased in the following order: yakwa < whole deep‐fried sea tangle < ground and deep‐fried lotus root < ground and pan‐fried lotus root < French fries < ground and pan‐fried potato. Lotus root and garlic also had the potential to produce AA during cooking. Pre‐treatment such as grinding, boiling, freezing and thawing increased the AA formation in oil‐fried potato. Temperature was more influential than time on AA formation during deep‐oil frying. Removing water‐soluble fractions reduced AA content of cooked potatoes. Copyright © 2006 Society of Chemical Industry     

Effect of different cooking methods on lipid oxidation and formation of volatile compounds in foal meat

The influence of four different cooking methods (roasting, grilling, microwaving and frying) on cooking loss, lipid oxidation and volatile profile of foal meat was studied. Cooking loss were significantly (P < 0.001) affected by thermal treatment, being higher (32.5%) after microwaving and lower after grilling (22.5%) and frying (23.8%). As expected, all the cooking methods increased TBARs content, since high temperature during cooking causes increased oxidation in foal steaks, this increase was significantly (P < 0.001) higher when foal steaks were microwaved or roasted.     

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     

家庭烹调对鲟鱼中脂肪酸和胆固醇的影响

对杂交鲟鱼（Acipenser baerii×A. schrenckii）进行了清蒸、油煎、微波、微波烤、烤箱烤和压力锅煎6 种家庭烹调处理,测定其脂肪和胆固醇含量、脂肪氧化指标和各脂肪酸含量的变化。结果表明,所有烹调方法均降低了n-3/n-6多不饱和脂肪酸含量的比值,其中压力烹调比值最高（0.85）,清蒸次之（0.83）,而烤箱烤最低（0.73）。胆固醇保存率以清蒸和压力锅煎最高,两种处理间无显著差异。烹调后样品酸价和硫代巴比妥酸值上升而过氧化值下降,并与样品的胆固醇含量相关。清蒸和压力烹调中脂肪酸和胆固醇变化相对较少,可能与其密闭烹调条件造成氧化程度较低有关。     

Effects of different cooking methods on the mineral contents of wild and farmed sea bream (Sparus aurata)

The effects of different cooking methods (steaming, boiling, oven cooking, grilling, frying in olive oil, frying in soybean oil, frying in corn oil and frying in sunflower oil) on mineral contents (Ca, Mg, K, Na, Fe, Zn, Cu and Mn) of wild and farmed sea bream (Sparus aurata) were determined. The moisture rate decreased significantly (P < 0.05) after boiling, grilling, oven cooking and frying but remains stable after steaming. The fat content increased with different frying treatments. The Ca, Mg, Na, K and Zn contents of wild and farmed sea bream cooked by almost all methods significantly decreased (P < 0.05). The Cu content in grilled wild and farmed sea bream increased significantly (P < 0.05). Losses of mineral content in fried sea bream were higher than those of fish cooked by other methods. On comparing the raw and cooked fish, the results indicated that cooking had considerable effect on the mineral contents.     

Dietary evaluation of Mediterranean fish and molluscs pan‐fried in virgin olive oil

The effect of domestic pan‐frying in virgin olive oil (VOO) on the proximate composition, energy content, cholesterol, squalene and fatty acids in the edible portion of six species of finfish, common squid and mussels just caught from several regions of the Aegean Sea (Mediterranean Sea) was investigated. The species selected are traditionally consumed pan‐fried in VOO by the Greeks. On a fresh weight basis, pan‐frying caused significant water loss and increase of total fat, crude protein and energy content. The amount of VOO absorbed during frying ranged from 4.5 to 14.2% of fresh matter, showing a non‐linear negative correlation with initial fat, fish length and fish weight. Cholesterol content increased from 25 to 106 mg 100 g^?1 fresh weight (fw) to 33–130 mg 100 g^?1 fw after frying. VOO absorbed during frying resulted in a 20–78 times increase of squalene content and in significant alteration of fatty acid composition, the major change being the increase of monounsaturated fatty acids which became predominant in all fried samples. The intakes of fat and major fatty acid classes by consuming the pan‐fried seafood were comparable with the respective average Greek values. Frying in VOO resulted in a two to three times decrease of the atherogenic index and a slightly less decrease of the thrombogenic index. Both indices remained lower than 0.45 in all fried samples. The cholesterol‐saturated fat index and the cholesterol index increased up to twice after frying, ranging between 3.4–9.9 and 2.9–9.3, respectively. From the results obtained it is concluded that fish and shellfish pan‐fried in VOO present a healthy lipid profile in terms of the n‐6/n‐3 ratio, major fatty acid classes and total fat content. Copyright © 2004 Society of Chemical Industry     

Aroma profile and consumer liking of salted and dried chicken meat: Effects of desalting and cooking methods

Twenty-four dried and salted broiler breasts, a chicken charqui–like muscle food, were submitted to desalting in cold water and different cooking methods (grilling, roasting, frying with olive oil, and sous-vide cooking). Samples were assessed by levels of thiobarbituric acid reactive substances, volatile compounds, and odor-liking analysis. Desalted and sous-vide cooked samples presented the highest levels of thiobarbituric acid reactive substances and volatile compounds derived from lipid oxidation. Grilling, roasting, and frying promoted an increase of Maillard-derived volatiles in dried salted broiler meat. This difference in aromatic profile led to a high odor acceptability of samples submitted to more intense thermal treatments such as grilling, roasting, and frying. In contrast, prolonged cooking (sous-vide technique) and desalting in cold water led to a marked decline in consumers’ liking due the rise in volatile compounds derived from lipid oxidation. In conclusion, based on the results, it seemed to be reasonable to hypothesize that dried and salted broiler meat submitted to high temperatures during cooking (≈180–200°C) tended to generate high Maillard-derived volatiles, while long cooking times led to a great thermal degradation/oxidation of lipids, which generates high content of lipid-derived volatile components.     

Influence of thermal treatment on formation of volatile compounds,cooking loss and lipid oxidation in foal meat

The influence of four different cooking methods (roasting, grilling, microwaving baking and frying with olive oil) on volatile compounds profile (using solid phase microextraction coupled to GC–MS), lipid oxidation (by TBARs measurement) and cooking loss of foal meat was studied. Cooking losses were significantly (P < 0.001) affected by thermal treatment, being higher (29.9%) after microwaving and lower after grilling (19.1%) treatments. As expected, all the cooking methods increased TBARs content, since high temperature during cooking seems to cause an increase of the oxidation processes in foal steaks, being this increment significantly (P < 0.001) higher when foal steaks were roasted or microwaved.     

Influence of Various Cooking Methods on the Concentrations of Volatile N‐Nitrosamines and Biogenic Amines in Dry‐Cured Sausages

Abstract: N‐nitrosamines, biogenic amines, and residual nitrites are harmful substances and are often present in cured meats. The effects of different cooking methods (boiling, pan‐frying, deep‐frying, and microwave) were investigated on their contents in dry‐cured sausage. The various N‐nitrosamines were isolated by a steam distillation method and analyzed by gas chromatography mass spectrometry (GC‐MS). The biogenic amines were determined after extraction with perchloric acid as dansyl derivatives by high‐performance liquid chromatography (HPLC) method. The results showed that initial dry‐cured raw sausage contained 5.31 μg/kg of total N‐nitrosamines. Cooking by deep‐frying or pan‐frying resulted in products having the highest (P < 0.05) contents, compared with boiling or microwave treatments, which were not different from the raw. Although frying increased the content of N‐nitrosodimethylamine (NDMA), N‐nitrosodiethylamine (NDEA), and N‐nitrosopyrrolidine (NPYR), it decreased the contents of histamine and cadaverine. Boiling and microwave treatments decreased the total biogenic amines significantly (P < 0.05). Residual nitrite was significantly reduced by cooking treatments. The results suggest that boiling and microwave treatments were more suitable methods for cured meat. Practical Application: N‐nitrosamines and biogenic amines are considered potentially harmful substances to humans and often present in dry‐cured sausage. Different cooking methods may effect the content of these harmful substances. However, little information exists on the different cooking methods on dry‐cured meats.     

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.     

烹制方法对猪肉脂质氧化和挥发性风味物质的作用研究

研究对比了4种烹制方法(煮制、烤制、微波及油炸制(大豆油、花生油和葵花油))对猪肉脂质氧化及挥发性风味成分的影响。结果表明:烹制能够促进猪肉的脂质氧化,经不同方式烹制后,熟制猪肉的过氧化值(POV)和硫代巴比妥酸值(TBA)显著增加(P0.05)。不同熟制猪肉之间脂质氧化程度存在显著性差异(P0.05),其中烤制猪肉的脂质氧化程度最高,其次为微波和水煮,而炸制猪肉的氧化程度最低。气相色谱-质谱(GC-MS)联用技术从熟制猪肉中共分离鉴定出68种挥发性风味成分,主要包括醛类、脂肪烃类、醇类、酮类、酯类等,总挥发性风味化合物含量在221.09(大豆油炸制猪肉)-1084.61 AU×106/g(煮制猪肉)之间。醛类是主要的化合物,占总挥发性风味成分的73.78(葵花油炸制猪肉)-78.79%(烤制猪肉),而己醛是最主要的醛类物质。TBA值与醛类、醇类及总挥发性风味物质呈显著正相关(p0.05),而POV值与挥发性风味物质的相关性不显著(p0.05)。主成分分析法(PCA)能够很好地区分经不同烹制方法得到的熟猪肉。     

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.     

Effect of Fish and Oil Nature on Frying Process and Nutritional Product Quality

ABSTRACT: The modifications on a lean fish (cod—Gadus morhua) and a fatty fish (farmed salmon—Salmo salar) after the application of pan-frying using 2 types of oil with different lipid profile (extra virgin olive oil and sunflower oil) was the aim of this study. Fat content and total energetic value increased significantly after the frying process only in the lean fish, without relevant changes in the fatty fish. Extra virgin olive oil led to a higher fat absorption rate than sunflower oil in both fish. Frying hardly affected the lipid profile of farmed salmon regardless the oil used, however it drastically changed in fried cod compared to raw cod. Omega-6/omega-3 ratio increased from 0.08 in raw cod to 1.01 and 6.63 in fried cod with olive oil and sunflower oil, respectively. In farmed salmon, the omega-6/omega-3 ratio was 0.38 (raw), and 0.39 to 0.58 in fried salmon. The amount of EPA + DHA slightly decreased with frying in salmon, and increased in cod. The type of oil has more influence in the nutritional fish quality for the lean fish compared to that of the fatty fish. The use of extra virgin olive oil was efficient to avoid a significant increase of the lipid oxidation intensity during frying in cod but not in salmon. Practical Application: Food modifies its composition and nutritional value with the application of cooking technologies. As most food table composition tables are based on raw food products, this article contributes with interesting data on pan-fried fish composition, which may improve the approach to achieve a real intake of healthy nutrients as omega 3 fatty acids.     

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.     

A Kinetic Study of Furan Formation in Wheat Flour‐Based Model Systems during Frying

Furan is a possible human carcinogen, which is formed in worldwide highly consumed fried starchy foods. In order to elucidate the mechanisms responsible for its occurrence in this food category and propose techniques for its mitigation, the kinetics of furan formation, oil absorption, lipid oxidation, and color change were studied in wheat flour‐based model systems during frying at 160, 170, 180, and 190 °C up to 13 min and data were fitted to mathematical models. Additionally, an Arrhenius‐type dependency with temperature was evaluated for all studied responses. More drastic frying conditions increased significantly (P ≤ 0.05) the furan content of fried samples. Furan formation followed a sigmoid trend with frying time only for frying temperature of 190 °C (RMS_190°C: 7.6%). At lower temperatures, furan generation did not reach the asymptotic concentration level. Color change, lipid oxidation, and oil absorption increased with frying temperature and followed asymptotic relationships with frying time. For all evaluated temperatures, color change (RMS: 4.4% to 12.5%) and polar compound generation (RMS: 2.6% to 7.4%) presented good fit to a first‐order kinetic model. Oil absorption was successfully fit to a mass balance‐based model (RMS: 10.0% to 19.8%). Under the experimental conditions studied, only color change (E_A: 15.47 kJ/mol), lipid oxidation (E_A: 6.67 kJ/mol), and oil absorption (E_A: 76.98 kJ/mol) presented good fit (RMS: 0.7% to 6.3%) to an Arrhenius‐type equation. Based on our results, the keeping of frying temperature below 180 °C and the reduction of the frying time would contribute to reduce not only the final furan occurrence in fried foods but also their oil content.     

Effect of different cooking methods on the oxidation,proximate and fatty acid composition of silver catfish (Rhamdia quelen) fillets

The influence of seven cooking methods (boiling, conventional baking, microwave baking, grilling, deep-frying in soybean oil, canola oil, or partially hydrogenated vegetable oil) on the oxidation, proximate and fatty acid composition of silver catfish (Rhamdia quelen) fillets was evaluated. All the treatments reduced moisture and increased the protein content. The free fatty acid content of the fillets was significantly reduced by the different cooking methods, while conjugated diene levels and peroxide values decreased for all fried samples, but remained constant in the samples subjected to the other cooking methods. Boiling and baking increased thiobarbituric acid reactive substances (TBARS), while grilling and frying did not change TBARS. Boiling, baking, and grilling did not affect the silver catfish fillets fatty acid composition. Frying in canola oil increased n−3/n−6 ratio, while frying in soybean oil increased the general polyunsaturated fatty acid content, and frying in hydrogenated vegetable oil incorporated trans fatty acids in the fillets.     

Effects of different cooking methods on the formation of food mutagens in meat

Hamburgers and chicken fillets were cooked in convection ovens, deep‐fried or contact fried and analysed for mutagenic activity using the Ames test. For the three different convection ovens, the cooking parameters studied included the presence of steam, air velocity, air temperature and holding time. For deep‐frying and contact frying, the cooking parameters included cooking temperature and cooking time. In cooked hamburgers, mutagenic activity was only detected in those that had been deep‐fried. In chicken fillets, mutagenic activity was detected in samples prepared with all cooking methods, being highest in the deep‐fried samples. Factorial analysis indicated that heat transfer was the most important factor affecting mutagenic activity. High temperature and high air velocity in the convection ovens enhanced mutagenic activity. The presence of steam reduced the mutagenic activity, except when high temperature was used in combination with high air velocity. In chicken fillets, high mutagenic activity correlated to high weight loss during cooking. Pan‐fried chicken fillets were analysed using high performance liquid chromatography (HPLC) and the mutagenic/carcinogenic heterocyclic amines 2‐amino‐3,8‐dimethylimidazo[4,5‐f ]‐quinoxaline (MeIQx), 2‐amino‐1‐methyl‐6‐phenylimidazo‐[4,5‐b]‐pyridine (PhIP) and the co‐mutagenic heterocyclic amine Norharman (9H‐pyrido[3,4‐b]‐indole) were identified. The HPLC fractions were tested for mutagenic activity and, apart from the mutagenic fractions corresponding to MeIQx and PhIP, several mutagenic fractions were detected that did not correspond to known heterocyclic amines.     

Effect of cooking method on the fatty acid profile of New Zealand King Salmon (Oncorhynchus tshawytscha)

Farmed New Zealand King Salmon (Oncorhynchus tshawytscha) was prepared according to common consumer techniques; raw, poached, steamed, microwaved, pan fried (no added oil), oven baked (no added oil) and deep fried (in sunflower oil). The fatty acid profile was investigated to determine the optimal preparation techniques to achieve both optimal sensory and nutritional qualities, in particular the levels of long chain polyunsaturated omega-3 fatty acids. The modified Bligh and Dyer method was used for lipid extraction and the Hartman and Lago method for FAMES preparation. Fatty acid composition was determined by gas chromatography. There were moisture and lipid losses during cooking amongst the different methods. The fatty acid profile showed only minor differences between the methods apart from an increase in PUFA in the deep fried salmon due to linoleic acid uptake from the frying oil. In all the cooking methods the omega-3 fatty acids were well preserved. However, deep fried showed the lowest amounts of omega-3 fatty acids. As the results showed good preservation of omega-3 fatty acids regardless of cooking method, there may be possible “internal protection” of omega-3 fatty acids in King Salmon that warrants future research.     

Optimising the frying temperature of gluten balls using response surface methodology

The continuous frying process of gluten balls involved three consecutive deep frying pans. The effects of the temperatures of the first and the second deep frying pans on the quality indices of the obtained fried gluten balls, including expansion volume, expansion ratio, measured value of textural property, Hunter colour b value, and sensory evaluation score, were investigated using response surface methodology while fixing the temperature of the third deep frying pan at 195±3°C. Based on the obtained sensory evaluation scores, the peak force and brittleness breakdown of textural properties, as well as Hunter colour b value of the fried gluten balls, it was found that the optimum temperature ranges for the first and the second deep frying pans were 130–143°C and 155–161°C, respectively. © 1998 SCI.