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Frying
Kinds of Frying Terms modified by Frying Selected AbstractsKINETICS OF ACRYLAMIDE FORMATION DURING TRADITIONAL AND VACUUM FRYING OF POTATO CHIPSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2005CLAUDIA GRANDA ABSTRACT Acrylamide is considered a carcinogen in animals and a possible carcinogen in humans. It has been found in starch-rich foods cooked at high temperatures. Vacuum frying (10 Torr) was investigated as a possible alternative to reduce acrylamide formation in potato chips. The cultivar Atlantic was used to determine the kinetics of acrylamide formation during traditional and vacuum frying at different temperatures. There was a 94% decrease in acrylamide content when potatoes were fried to the same final moisture content (1.5% ± 0.3% w.b.) under vacuum compared to those fried under atmospheric conditions. Acrylamide accumulation under vacuum frying was modeled using first-order kinetics (during traditional frying, the logistic kinetic model was used). The behavior of the kinetics of acrylamide content in potato chips fried under the two processes was different mainly because of the different temperatures used. During traditional frying, higher temperatures are used (150 to 180C) and acrylamide after some time is produced but starts degrading, producing a constant level of acrylamide content at longer times. During vacuum frying (10 Torr), acrylamide increased exponentially (but at lower levels) for all frying times. [source] Cyclic fatty acids in sunflower oils during frying of frozen foods with oil replenishment,EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2007Antonio Romero Abstract Frying of frozen foods has become popular because it considerably reduces cooking time. Polymers and cyclic fatty acid monomers (CFAM) formed during frying are potentially toxic and therefore their production should be minimized. Twenty discontinuous fryings of different frozen foods were carried out over ten consecutive days, in sunflower oil (SO) and in high-oleic acid sunflower oil (HOSO), by adding fresh oil after each frying to bring the volume of the fryer oil back to 3,L. CFAM methyl ester derivates were hydrogenated, isolated, concentrated and quantified by HPLC using a reverse-phase column, followed by gas chromatography. After 20,fryings, significantly higher contents of polar material, polymers and CFAM (all p,<0.001) were found in SO than in HOSO. Bicyclic compound formation was four times higher in SO (p,<0.001). The fat from the fried potatoes presented a polymer content very similar to that of their corresponding oils. The 100-g rations of the SO-fried potatoes from the 20th frying supply 49 or 15%, respectively, more polymers and CFAM and 1,mg more bicyclic fatty acids than the 100-g rations of HOSO-fried potatoes. Because digestion and absorption of polar material, polymers and CFAM occur, the data clearly show the advantageousness and advisability of frying with HOSO rather than SO. [source] Magnetic Resonance Temperature Mapping of Microwave-Fried Chicken FingersJOURNAL OF FOOD SCIENCE, Issue 5 2009Isil Barutcu ABSTRACT:, The main objective of this study was to compare the heating patterns of chicken fingers deep-fried conventionally and using a microwave. Two dimensional internal temperature maps of fried chicken fingers with rectangular geometry were measured post frying using magnetic resonance imaging (MRI). Frying was performed in a microwave oven at 365 W power level for 0.5 and 1.5 min after bringing the oil temperature to 180 ± 1 °C. Samples were also fried in a conventional fryer at 180 °C for 2 and 5 min for comparison. Variations in internal temperature distribution increased proportionally to frying time in both microwave and conventional frying. Internal thermal equilibrium is reached in all samples after 13 min of holding time. Internal structural changes, void formation, were also visualized in the images. Void formation did not significantly impact cooling rates. [source] Kinetics of Potato Color and Texture Development during Baking, Frying, and Microwaving with the Addition of Liquid SmokeJOURNAL OF FOOD SCIENCE, Issue 9 2006M. Yost ABSTRACT:, The rate of color and texture development in par-fried French fries coated with liquid smoke and thermally processed was determined. Liquid smoke containing 8% to 11% carbonyls was diluted to 30% and applied to 1 side of French fries at 0%, 1%, 3%, or 5% by weight. The fries were immersion fried at 190.6 °C for 4 min, microwaved (900 watts) for 4 min, or baked at 190.6 °C for 20 min. Color and texture measurements were recorded at intervals during processing. Liquid smoke increased the rate of browning in French fries. Browning followed pseudo zero-order kinetics, with the a value, Browning index, and total change in color (,E) showing the best fit. When liquid smoke was added in high concentrations the reaction rate did not increase as more liquid smoke was added because the carbonyls were no longer limiting the rate of Maillard browning. The rate of color development in French fries was also affected by the thermal processing method. Frying developed color at the fastest rate, followed by microwaving and baking. Although liquid smoke increased the rate of color development in French fries, it did not affect French fry texture. Through sensory testing, it was determined that liquid smoke can be used to improve the color of microwaveable French fries without affecting French fry flavor or texture. [source] The Effect of Edible Coatings and Pressure Frying Using Nitrogen Gas on the Quality of Breaded Fried Chicken NuggetsJOURNAL OF FOOD SCIENCE, Issue 3 2006Tameshia S. Ballard ABSTRACT: The effects of 2 edible coatings, methylcellulose (MC) and whey protein isolate (WPI), and 2 pressure sources (nitrogen gas and steam) on the quality attributes (crispness, moisture and fat content, juiciness, color, and texture) of breaded fried chicken nuggets were evaluated. MC or WPI was incorporated into either the pre-dust or the batter before frying. Chicken nuggets were fried in a modified restaurant-type pressure fryer under a constant pressure of 163 kPa at 175°C for 240 s. Samples were held under a heat lamp at 60°C for 0-, 10-, 20-, and 30-min time intervals. Crispness was evaluated using a nondestructive ultrasonic technique. Coating type and pressure source had a significant effect (P < 0.05) on all quality attributes. Chicken nuggets fried using nitrogen gas were crispier (P < 0.05) than those fried with steam. The treatment combination of MC incorporated into the pre-dust and frying with nitrogen gas was the most effective at maintaining product crispness. [source] Reduction of Acrylamide Formation in Potato Chips by Low-temperature Vacuum FryingJOURNAL OF FOOD SCIENCE, Issue 8 2004C. Granda ABSTRACT: Potatoes and other foods that have a high content of the amino acid asparagine and a high accumulation of reducing sugars are subject to the formation of acrylamide upon frying. The objectives of this research were (1) to analyze the level of acrylamide formed during deep-fat frying of potato chips and (2) to evaluate means of reducing acrylamide in potato chips by using different potato cultivars and vacuum frying. Several potato cultivars were used in this research, including Innovator (I), NDTX 4930,5W (N), ATX 854 04,8W (ATw), Atlantic (A), Shepody (S), ATX847806,2Ru (ATr), and White-Rose (W). An electric bench-top (atmospheric conditions)-type fryer was used to fry the potatoes. Three temperatures were used: 150 °C, 165 °C, and 180 °C. The vacuum frying experiments were performed at 118 °C, 125 °C, and 140 °C and a vacuum pressure of 10 Torr. The potatoes were sliced (1.5-mm thick) and fried for different lengths of times. For potatoes fried at 165 °C (for 4 min) at atmospheric conditions, the acrylamide contents were 5021 ± 55 ppb (W), 552 ± 25 ppb (I), 358 ± 50 ppb (N), 397 ± 25 ppb (ATw), 646 ± 55 ppb (A), 466 ± 15 ppb(S), and 537 ± 14 ppb (ATr). Vacuum frying reduced acrylamide formation by 94%. Results showed that both cultivar and modified frying systems can play an important role in reducing acrylamide formation in fried potatoes. As the frying temperature decreased from 180 °C to 165 °C, acrylamide content in potato chips reduced by 51% during traditional frying and by 63% as the temperature decreased from 140 °C to 125 °C in vacuum frying. Increased frying time increased acrylamide formation during traditional frying for all temperatures and frying methods analyzed. However, the effect on acrylamide concentration was greater for the traditional frying than the vacuum frying. Keywords: acrylamide, vacuum, frying, potato, temperature [source] Oxidative Stability of Soybean and Sesame Oil Mixture during Frying of Flour DoughJOURNAL OF FOOD SCIENCE, Issue 7 2004J. Chung ABSTRACT: Effects of roasted sesame seed oil on the oxidative stability of soybean oil during frying of flour dough at 160 °C were studied by determining fatty acid composition and conjugated dienoic acid (CDA), p -anisidine (PA), and free fatty acid (FFA) values. Concentration of sesame oil in frying oil was 0%, 10%, 20%, or 30% (v/v). Tocopherols and lignan compounds in the frying oil were also determined by high-performance liquid chromatography. As the number of fryings performed by the oil increased, linolenic acid content in frying oil decreased, and the decreasing rate was lower in frying oil containing sesame oil than in the oil containing no sesame oil. CDA and FFA values of frying oil increased during frying and their relative values to the initial value were lower in frying oil containing sesame oil than in the oil containing no sesame oil. This indicates that the addition of sesame oil improved thermooxidative stability of frying oil, possibly due to the presence of lignan compounds in sesame oil. Tocopherols and lignan compounds in frying oil decreased during frying. As the amount of sesame oil in frying oil increased, degradation of tocopherols increased and lignan compounds degradation decreased. Tocopherols were suggested to protect lignan compounds in sesame oil from decomposition during frying. [source] Structure Oil-Absorption Relationships During Deep-Fat FryingJOURNAL OF FOOD SCIENCE, Issue 9 2003P. B OUCHON ABSTRACT Analysis of the oil-absorption process in deep-fat fried potato cylinders (frying temperatures of 155°C, 170°C, and 185°C) allowed to distinguish 3 oil fractions: structural oil (absorbed during frying), penetrated surface oil (suctioned during cooling), and surface oil. Results showed that a small amount of oil penetrates during frying because most of the oil was picked up at the end of the process, suggesting that oil uptake and water removal are not synchronous phenomena. After cooling, oil was located either on the surface of the chip or suctioned into the porous crust microstructure, with an inverse relationship between them for increasing frying times. [source] Chlorpyrifos Residues Before and After Cooking of Catfish FilletsJOURNAL OF FOOD SCIENCE, Issue 1 2003P. Wan ABSTRACT :In this paper, chlorpyrifos residues were compared before and after frying, smoking or baking and quantified using GC/ECD (gas chromatography/electron capture detector) and ELISA (enzyme-linked immunosorbent assay) methods. All cooking methods reduced chlorpyrifos by 8 to 52% on a dry basis or 12 to 56% on a fat basis. Frying, which reduced chlorpyrifos residue by 56% on a fat basis was shown to provide the greatest reduction when compared to baking (22%) and smoking (12%). Statistical analysis showed that results from the GC/ ECD and ELISA methods were not significantly different (p= 0.05). [source] The Dielectric Property of Soybean Oil in Deep-Fat Frying and the Effect of FrequencyJOURNAL OF FOOD SCIENCE, Issue 3 2002C. Inoue ABSTRACT: : Suitability of the dielectric constant for real time and continuous evaluation of frying oil was investigated. Measurements of the dielectric capacitance, in the frequency range 1 kHz to 100 kHz, were made on soybean oil heated at several temperatures (180, 200, 220, and 240 °C) for a few d. Frequency dependence was also measured between 50 Hz and 30 MHz. The dielectric constant of the soybean oil increased with increase in the heating time, and was well correlated with acid value, density, and relative viscosity. Our equipment for measuring capacitance would be available for real time and continuous evaluation of frying oil quality in the food industry. [source] Common edible insects and their utilization in ChinaENTOMOLOGICAL RESEARCH, Issue 5 2009Xiaoming CHEN Abstract This paper reviews the common edible insects and their use in China. One-hundred and seventy-eight insect species from 96 genera, 53 families and 11 orders are commonly eaten in China. Preparation of edible insects includes frying, braising, stewing, stewing after frying, boiling and roasting. The insect forms eaten range from eggs to adults; however, in restaurants most are larvae and pupae. More than 50 species have been analyzed for their nutritive elements and nutritional value and these data are reviewed here. Insect health foods sold in the Chinese market are also briefly discussed. [source] Cyclic fatty acids in sunflower oils during frying of frozen foods with oil replenishment,EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2007Antonio Romero Abstract Frying of frozen foods has become popular because it considerably reduces cooking time. Polymers and cyclic fatty acid monomers (CFAM) formed during frying are potentially toxic and therefore their production should be minimized. Twenty discontinuous fryings of different frozen foods were carried out over ten consecutive days, in sunflower oil (SO) and in high-oleic acid sunflower oil (HOSO), by adding fresh oil after each frying to bring the volume of the fryer oil back to 3,L. CFAM methyl ester derivates were hydrogenated, isolated, concentrated and quantified by HPLC using a reverse-phase column, followed by gas chromatography. After 20,fryings, significantly higher contents of polar material, polymers and CFAM (all p,<0.001) were found in SO than in HOSO. Bicyclic compound formation was four times higher in SO (p,<0.001). The fat from the fried potatoes presented a polymer content very similar to that of their corresponding oils. The 100-g rations of the SO-fried potatoes from the 20th frying supply 49 or 15%, respectively, more polymers and CFAM and 1,mg more bicyclic fatty acids than the 100-g rations of HOSO-fried potatoes. Because digestion and absorption of polar material, polymers and CFAM occur, the data clearly show the advantageousness and advisability of frying with HOSO rather than SO. [source] Correlation between physicochemical analysis and radical-scavenging activity of vegetable oil blends as affected by frying of French friesEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2006Mohamed Fawzy Ramadan Abstract The main goal of the present work was to compare and correlate the results of physicochemical parameters and antiradical performance of some oil blends during deep-frying, which will be an initial indicator for applying antiradical tests for monitoring deep-frying oils. Two oil blends were prepared. The first blend was a mixture (1,:,1, wt/wt) of sunflower seed oil and palm olein (SO/PO) and the second was a mixture (1,:,1, wt/wt) of cottonseed oil and palm olein (CO/PO). The oil blends were evaluated during intermittent frying of French fries on two consecutive days for 16,h, with oil replenishing after 8,h. Changes in the fatty acid profile and some physicochemical parameters (peroxide value, color index, viscosity, total polar compounds and UV absorbance at 232 and 270,nm) were used to evaluate the alterations during frying. A quick spectrophotometric method was developed to assess deep-frying oil quality. With the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, the neutralization of the stable radical DPPH by antioxidants present in the oil during frying was measured. Radical-scavenging activity (RSA) of both oil blends was recorded during frying, wherein the results showed that the SO/PO blend had the highest RSA. It was evident from the results that a proportional correlation and positive relationship existed between the levels of fatty acids and the physicochemical characteristics of the vegetable oil blends and their RSA. The initial results obtained allow us to suggest that antiradical measurements could be used to quantify the oxidative and hydrolytic deterioration of vegetable oils upon frying. [source] Effect of deep-fat frying of potato chips and chicken on the quality of soybean oilINTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 4 2000Daya Goburdhun Abstract The type of products may affect the quality of oil during deep-fat frying. The quality changes in pure soybean oil during frying of potato chips and chicken drumsticks were evaluated and compared. The oil was subjected to continuous frying at 180°C for a period of 315 min. The parameters used to assess the oil quality were peroxide value (PV), iodine value (IV), free fatty acids (FFA), refractive index (RI) and colour. The percentage of oil absorbed by the two products was determined. The oil was also assessed visually for any change in colour, viscosity, turbidity, flavour and deposit. Results showed that, for both products, PV, IV, FFA, RI and colour changed significantly with time (P < 0.05). Potato absorbed oil during frying (6.9%), whereas chicken released fat into the frying medium (2.4%). When the rates of change of the various parameters in the oils were compared for the two products, significant differences (P < 0.05) were noted for PV and colour only. The oil used during the frying of chicken appeared visually to be at a more advanced stage of deterioration. [source] Effect of different cooking methods on the antioxidant activity of some vegetables from PakistanINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2008Bushra Sultana Summary The effects of different cooking methods (boiling, frying and microwave cooking) on the antioxidant activity of some selected vegetables (peas, carrot, spinach, cabbage, cauliflower, yellow turnip and white turnip) were assessed by measuring the total phenolic contents (TPC), reducing power and percentage inhibition in linoleic acid system. TPC (gallic acid equivalents g/100 g of dry weight) and reducing power of the methanolic extracts of raw-, microwaved-, boiled- and fried vegetables ranged 0.333,2.97, 0.52,2.68, 0.48,2.08, 1.00,2.02 and 0.391,2.24, 0.822,1.10, 0.547,1.16, 0.910,4.07, respectively. The level of inhibition of peroxidation ranged 71.4,89.0, 66.4,87.3, 73.2,89.2 and 77.4,91.3%, respectively. Antioxidant activity of the vegetables examined was appreciably affected because of varying cooking treatments. TPC of vegetables, generally, decreased by boiling, frying and microwave cooking. There was a significant (P < 0.05) increase in reducing power as a result of frying. However, boiling and microwave cooking did not affect reducing power. Inhibition of peroxidation increased by boiling and frying, whereas, in contrast it was decreased by microwave cooking. The results of the present investigation showed that all the cooking methods affected the antioxidant properties of the vegetables; however, microwave treatment exhibited more deleterious effects when compared with those of other treatments. Thus an appropriate method might be sought for the processing of such vegetables to retain their antioxidant components at maximum level. [source] The optimization of vacuum frying to dehydrate carrot chipsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2005Liu-ping Fan Summary The effects of pretreatment and processing conditions, such as frying temperature, absolute vacuum pressure and frying time; on the properties of fried carrot chips were studied. Statistical analysis with response surface regression showed that moisture content, fat content and breaking force of carrot chips were significantly (P < 0.05) correlated with frying temperature, vacuum absolute pressure and frying time. The optimum conditions were a vacuum frying temperature of 100,110 °C, a vacuum absolute pressure of 0.010,0.020 MPa and a frying time of 15 min. [source] The performance of a methyl cellulose-treated coating during the frying of a poultry productINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2005Mohamad Y. Maskat Summary The performance of coatings treated with a range of methyl cellulose (MC) concentrations during the frying of coated chicken breasts was investigated. Chicken breasts were immersed in 0, 1 and 2.5% MC solution and then coated with a commercial coating mix. The coated chicken breasts were then fried at an initial temperature of 190 °C. Parameters measured included coating pickup, coating loss, cooked yield and frying loss. Results showed a significant increase in coating pickup with the use of 1 and 2.5% MC, which may have been due to the higher viscosity and binding ability of the MC layer. The use of 2.5% MC produced lower coating loss and frying loss and also a higher cooked yield. [source] An oil dilution technique used in small-scale frying to reduce oil expenditureINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2004Emin Yilmaz Summary An oil dilution technique was developed and it saved oil expenditure in doughnut frying by about 30% without any compromise in doughnut quality compared with standard small-scale control frying. Doughnut quality as evaluated by a sensory panel and absorbed fat content measurements, also supported the main findings. In addition, either the oil density, acid value or alkaline contaminant materials can be effectively used to monitor oil quality changes during frying. [source] Structural changes and shrinkage of potato during fryingINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2001Rui M. Costa Summary Light microscopy was used to study changes in cell size, blister formation and crust evolution during potato frying. Frying experiments with both French fries and crisps of different thickness (1,5 mm) were performed at temperatures of 140 and 180 °C. Thickness, volume and density changes were also measured. The formation of crust in French fries starts after the potato surface reached approximately 103 °C, and then the crust thickness increased linearly with the square root of frying time, this increase being faster at 180 °C. The potato volume decreased during frying, although in the late stages the volume may increase because of oil uptake and cell separation caused by entrapped water vapour. Shrinkage was adequately described by the Weibull model with a residual value, with shrinkage rate increasing with temperature and decreasing with potato thickness. The residual volume was not affected by temperature (65% for French fries and 59,30 for crisps, depending on thickness). Volume appeared to decrease mainly as the result of water loss, except for very low water content, and thus potato density changes were very small. [source] Taurine concentrations in animal feed ingredients; cooking influences taurine contentJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 7-8 2003A. R. Spitze Summary The aim of this study was to determine the taurine content in a variety of animal feeds. There is very little information on the taurine content of ingredients used in home-prepared diets for dogs and cats, and foods fed to wild animals in captivity. This study reports the taurine content of both common and alternative feed ingredients, and compares taurine loss as a result of different methods of food preparation. Foods were selected based on their use in commercial and home-prepared diets. Animal muscle tissue, particularly marine, contained high taurine concentrations. Plant products contained either low or undetectable amounts of taurine. The amount of taurine that remained in a feed ingredient after cooking depended upon the method of food preparation. When an ingredient was constantly surrounded by water during the cooking process, such as in boiling or basting, more taurine was lost. Food preparation methods that minimized water loss, such as baking or frying, had higher rates of taurine retention. [source] ANALYSIS AND FORMATION OF ACRYLAMIDE IN FRENCH FRIES AND CHICKEN LEGS DURING FRYINGJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2006W.H. CHUANG ABSTRACT The analysis and formation of acrylamide in French fries and chicken legs during frying were studied. Results showed that the most appropriate extraction solvent was ethyl acetate, with C-18 cartridge for purification and 5-mL deionized water as elution solvent. Dibromination of acrylamide followed by dehydrobromination to 2-bromopropionamide in the presence of triethylamine was necessary for subsequent analysis by gas chromatography,mass spectrometry. The most appropriate temperature programming condition was as follows: 70C in the beginning, raised to 150C at a rate of 10C/min, maintained for 1 min and to 240C at a rate of 30C/min, maintained for 5 min. Detection was carried out using selected-ion monitoring mode, and N,N -dimethylacrylamide was used as internal standard for quantification. French fries and the outer flour portion of chicken legs fried at 180C generated a higher level of acrylamide than at 160C. Compared to soybean oil and palm oil, a lower amount of acrylamide was produced in French fries and the outer flour portion of chicken legs fried in lard. However, no acrylamide was detected in the inner meat portion of fried chicken legs. [source] OPTIMIZATION OF PRE-FRY DRYING OF YAM SLICES USING RESPONSE SURFACE METHODOLOGYJOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2010OLAJIDE PHILIP SOBUKOLA ABSTRACT The effect of convective hot-air drying pretreatment and frying time at a frying temperature of 170 ± 1C on moisture and oil contents, breaking force (crispness) and color parameters of yam chips was investigated. Response surface methodology technique was used to develop models for the responses as a result of variation in levels of drying temperature (60,80C), drying time (1,5°min) and frying time (2,6°min). Drying pretreatment had a significant effect on oil and moisture contents, breaking force and color parameters of yam chips, with water removal exhibiting a typical drying profile. Response surface regression analysis shows that responses were significantly (P < 0.05) correlated with drying temperature and time and frying time. The optimum pre-fry drying condition observed was a drying temperature of 70,75C for about 3,4 min while frying for 4,5 min. PRACTICAL APPLICATIONS Deep-fat frying is a very important cooking method and a lot of effort has been devoted to manufacturing fried products with lower oil content and acceptable quality parameters. The information provided in this work will be very useful in manufacturing fried yam chips of acceptable quality attributes through the combination of drying pretreatment conditions. The result is very useful in considering different processing variables and responses at the same time as compared with single factor experiment common in the literature. [source] KINETICS OF ACRYLAMIDE FORMATION DURING TRADITIONAL AND VACUUM FRYING OF POTATO CHIPSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2005CLAUDIA GRANDA ABSTRACT Acrylamide is considered a carcinogen in animals and a possible carcinogen in humans. It has been found in starch-rich foods cooked at high temperatures. Vacuum frying (10 Torr) was investigated as a possible alternative to reduce acrylamide formation in potato chips. The cultivar Atlantic was used to determine the kinetics of acrylamide formation during traditional and vacuum frying at different temperatures. There was a 94% decrease in acrylamide content when potatoes were fried to the same final moisture content (1.5% ± 0.3% w.b.) under vacuum compared to those fried under atmospheric conditions. Acrylamide accumulation under vacuum frying was modeled using first-order kinetics (during traditional frying, the logistic kinetic model was used). The behavior of the kinetics of acrylamide content in potato chips fried under the two processes was different mainly because of the different temperatures used. During traditional frying, higher temperatures are used (150 to 180C) and acrylamide after some time is produced but starts degrading, producing a constant level of acrylamide content at longer times. During vacuum frying (10 Torr), acrylamide increased exponentially (but at lower levels) for all frying times. [source] KINETICS of QUALITY CHANGE DURING COOKING and FRYING of POTATOES: PART I. TEXTUREJOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2003F. NOURIAN ABSTRACT Kinetics of texture change during cooking and frying of potatoes were evaluated in this study. Potatoes were cut into cylinders (diameter × height: 20 mm × 20 mm for cooking, and 10 mm × 20 mm for frying) and cooked in a temperature controlled water bath at 80,100C or fried in a commercial fryer at 160,190C for selected times. the cooked samples were water cooled while the fried samples were air cooled immediately after the treatment. Test samples were then subjected to a single cycle compression test in a computer interfaced Universal Testing Machine and three textural properties (hardness, stiffness and firmness) were derived from the resulting force-deformation curves. Texture parameters of cooked potatoes decreased with progress of cooking time and the rate of texture changes associated with each temperature was found to be consistent with two pseudo first-order kinetic mechanisms, one more rapid than the other. Textural values of fried potatoes were found to increase with frying time and also followed a first order kinetic model. Temperature sensitivity of rate constants was adequately described by Arrhenius and z-value models. [source] THERMAL PROPERTIES OF SHRIMPS, FRENCH TOASTS AND BREADINGJOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2000M.O. NGADI ABSTRACT Thermal properties of fried products namely butterfly and popcorn shrimp, French toast and breading were determined for a wide range of temperature (20 to 140C), moisture content (3.3 to 87.4% w.b.) and fat content (0.005 to 0.618 kg/kg dry weight) typically encountered during deep-fat frying. Solid density of the products ranged from 1034 to 1508 kg/m3. Solid density increased with decreasing moisture content of product. Thermal conductivity ranged from 0.03 to 0.85 W/mC. Specific heat ranged from 1.51 to 4.67 kJ/kgC. The results were in the range of published data for similar products. Temperature, moisture and fat content affected variations of thermal conductivity and specific heat. Regression equations were used to fit experimental data. [source] EFFECTS OF COOKED TEMPERATURES AND ADDITION OF ANTIOXIDANTS ON FORMATION OF HETEROCYCLIC AROMATIC AMINES IN PORK FLOSSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2009GUOZHOU LIAO ABSTRACT Heterocyclic aromatic amines (HAAs) are an important class of food mutagens and carcinogens produced in meats cooked at high temperature. The formation of HAAs in pork floss during processing and the effect of vitamin C and vitamin E on HAAs formation in pork floss were studied. Pork floss was prepared by steaming of raw pork, followed by pressing, tearing, adding various additives, and then the cooked pork was subjected to stir frying. The various HAAs in pork floss were isolated by solid phase extraction and analyzed by high-performance liquid chromatography (HPLC). Results showed that the type and level of HAAs increased with increasing processing temperature. Up to seven HAAs, 9H-pyrido[4,3-b]indole (Norharman), 1-methyl-9H-pyrido[4,3-b]indole (Harman), 2-amino-1- methyl-6-phenylimidazo[4,5-f]pyridine (PhIP), 2-amino-dipyrido[1,2-a: 3,,2,-d]imidazole (Glu-P-2), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-9H-pyrido[2,3-b]indole (AaC) and 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAaC) were detected in pork floss when stir fried at 150C. Color development increased with cooking temperatures, and was correlated with HAAs formation. The addition of vitamin C at various levels was not effective toward HAAs inhibition. However, the incorporation of 0.1% vitamin E reduced Norharman, PhIP, AaC and MeAaC concentrations in the pork floss. PRACTICAL APPLICATION The formation of heterocyclic aromatic amines (HAAs) is one of the most unfavorable changes during the cooking of food. Since the connection between the consumption of dietary carcinogens and cancer risks in human has been established, interest in this matter has been growing. However, the processing methods and conditions of Chinese traditional food are different from Western, and to date, little is known about HAAs content in the traditional meat products of China. The information derived from this study serves as an essential base of knowledge from a public health standpoint, and contributes to a repository of HAAs information relevant to Chinese cooking; it also can provide clues to understanding the factors that affect HAAs formation and can indicate means of reducing or eliminating these compounds. [source] PHYSICAL-CHEMICAL AND SENSORY QUALITY EVALUATION OF POTATO VARIETIES (SOLANUM TUBEROSUM L.)JOURNAL OF FOOD QUALITY, Issue 2 2000J.E. PARDO ABSTRACT Seven table potato varieties were studied for pH, soluble solids content, moisture, firmness, color, external appearance of raw tubers and flavor and texture of the fried and boiled product. Monalisa was the most appreciated variety regarding external appearance, Bartina was preferred for the flavor of the fried product while Victoria and Desiree were the best for flavor and texture of boiled potatoes. The different scores by variety depending on frying or boiling suggest a specific use for each variety. Soluble solids content, pH, and moisture determinations showed minimal differences between varieties. Firmness was highest in the two varieties with the least moisture (Desiree and Victoria) and lowest in varieties with a high degree of moisture (Bartina and Caesar); fresh potato firmness had a positive correlation with these sensorial parameters when the product was boiled. All colorimetric parameters were useful to discriminate red skin from yellow-white skin varieties. [source] Process Optimization and Consumer Acceptability of Salted Ground Beef Patties Cooked and Held Hot in Flavored MarinadeJOURNAL OF FOOD SCIENCE, Issue 7 2010Subash Shrestha Abstract:, Food safety is paramount for cooking hamburger. The center must reach 71 °C (or 68 °C for 15 s) to assure destruction of,E. coli,O157:H7 and other food pathogens. This is difficult to achieve during grilling or frying of thick burgers without overcooking the surface. Thus, the feasibility of partially or completely cooking frozen patties in liquid (93 °C water) together with hot holding in liquid was investigated. Initial studies demonstrated that compared to frying, liquid cooking decreased (P,< 0.05) patty diameter (98 compared with 93 mm) and increased (P,< 0.05) thickness (18.1 compared with 15.6 mm). Liquid cooked patties had greater weight loss (P,< 0.05) immediately after cooking (29 compared with 21%), but reabsorbed moisture and were not different from fried patties after 1 h hot water holding (61 °C). Protein and fat content were not affected by cooking method. However, liquid cooked patties were rated lower (P,< 0.05) than fried patties for appearance (5.7 compared with 7.5) and flavor (5.9 compared with 7.5). An 8-member focus group then evaluated methods to improve both appearance and flavor. Salted, grill-marked patties were preferred, and caramel coloring was needed in the marinade to obtain acceptable flavor and color during liquid cooking or hot holding. Patties with 0.75% salt that were grill-marked and then finish-cooked in hot marinade (0.75% salt, 0.3% caramel color) were rated acceptable (P,< 0.05) by consumers for up to 4 h hot holding in marinade, with mean hedonic panel ratings > 7.0 (like moderately) for appearance, juiciness, flavor, and texture. Practical Application: Grill-marked and marinade-cooked ground beef patties reached a safe internal cooking temperature without overcooking the surface. Burgers cooked using this method maintained high consumer acceptability right after cooking and for up to 4 h of hot holding. Consumers and foodservice operations could use this method without specialized equipment, and instead use inexpensive and common equipment such as a soup pot or a restaurant steam table. Use of marinades (salt/caramel color or others) in this cooking and holding method provides a nearly endless culinary flavoring opportunity. [source] Magnetic Resonance Temperature Mapping of Microwave-Fried Chicken FingersJOURNAL OF FOOD SCIENCE, Issue 5 2009Isil Barutcu ABSTRACT:, The main objective of this study was to compare the heating patterns of chicken fingers deep-fried conventionally and using a microwave. Two dimensional internal temperature maps of fried chicken fingers with rectangular geometry were measured post frying using magnetic resonance imaging (MRI). Frying was performed in a microwave oven at 365 W power level for 0.5 and 1.5 min after bringing the oil temperature to 180 ± 1 °C. Samples were also fried in a conventional fryer at 180 °C for 2 and 5 min for comparison. Variations in internal temperature distribution increased proportionally to frying time in both microwave and conventional frying. Internal thermal equilibrium is reached in all samples after 13 min of holding time. Internal structural changes, void formation, were also visualized in the images. Void formation did not significantly impact cooling rates. [source] Influence of Cooking Methods on Antioxidant Activity of VegetablesJOURNAL OF FOOD SCIENCE, Issue 3 2009A. M. Jiménez-Monreal ABSTRACT:, The influence of home cooking methods (boiling, microwaving, pressure-cooking, griddling, frying, and baking) on the antioxidant activity of vegetables has been evaluated in 20 vegetables, using different antioxidant activity assays (lipoperoxyl and hydroxyl radicals scavenging and TEAC). Artichoke was the only vegetable that kept its very high scavenging-lipoperoxyl radical capacity in all the cooking methods. The highest losses of LOO· scavenging capacity were observed in cauliflower after boiling and microwaving, pea after boiling, and zucchini after boiling and frying. Beetroot, green bean, and garlic kept their antioxidant activity after most cooking treatments. Swiss chard and pepper lost OH· scavenging capacity in all the processes. Celery increased its antioxidant capacity in all the cooking methods, except boiling when it lost 14%. Analysis of the ABTS radical scavenging capacity of the different vegetables showed that the highest losses occurred in garlic with all the methods, except microwaving. Among the vegetables that increased their TEAC values were green bean, celery, and carrot after all cooking methods (except green bean after boiling). These 3 types of vegetables showed a low ABTS radical scavenging capacity. ccording to the method of analysis chosen, griddling, microwave cooking, and baking alternately produce the lowest losses, while pressure-cooking and boiling lead to the greatest losses; frying occupies an intermediate position. In short, water is not the cook's best friend when it comes to preparing vegetables. [source] | |||||||||||||