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Frying Temperatures (frying + temperature)
Selected AbstractsCarotenoid Content and Physicochemical and Sensory Characteristics of Carrot Chips Deep-Fried in Different Oils at Several TemperaturesJOURNAL OF FOOD SCIENCE, Issue 9 2001A. Sulaeman ABSTRACT: The influence of deep-frying using different oils and temperatures on carotenoid content and physicochemical and sensory characteristics of carrot chips was investigated. Sliced carrots were steam-blanched, cooled, soaked in 0.2% sodium metabisulfite, and deep-fried in canola, palm, or partially hydrogenated soybean oil (PHSO) at 165, 175, or 185 °C. Frying temperature, but not oil, significantly (P < 0.05) affected the ,-carotene, ,-carotene, and total carotenoid contents. Oil type significantly (P < 0.05) influenced all color values. Increasing temperature lowered the redness value, which correlated with decreased carotenoid content, color darkening, and decreased hardness value. Trained panelists detected no differences among oil types in crispness, sweetness, odor, and acceptability. The best carrot-chip product was that fried in PHSO at 165 °C. [source] Thermostability of genetically modified sunflower oils differing in fatty acid and tocopherol compositionsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2008Susana Marmesat Abstract The objective of the study was to investigate the performance at frying temperature of a new sunflower oil with high content of oleic and palmitic acid (HOHPSO) and containing ,-tocopherol as the most abundant natural antioxidant. HOHPSO either containing ,- or ,-tocopherol (HOHPSO-, and HOHPSO-,, respectively) were obtained from genetically modified sunflower seeds and refined under identical conditions. The oil stability against oxidation, as measured by Rancimat at 120,°C, was much higher for the oil containing ,-tocopherol, suggesting the higher effectiveness of ,-tocopherol as compared to ,-tocopherol to delay oxidation. Experiments at high temperature (180,°C) simulating the conditions applied in the frying process clearly demonstrated that, for the same periods of heating, the oil degradation and the loss of natural tocopherol were significantly lower for the oil containing ,-tocopherol. Comparison of different genetically modified sunflower oils with different fatty acid compositions confirmed that oil degradation depended on the fatty acid composition, being higher at a higher degree of unsaturation. However, the loss of tocopherol for a similar level of oil degradation was higher as the degree of unsaturation decreased. Overall, the results showed that HOHPSO-, had a very high stability at frying temperatures and that mixtures of HOHPSO-, and HOHPSO-, would be an excellent alternative to fulfill the frying performance required by the processors and the vitamin,E content claimed by the consumers. [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] 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] Thermostability of genetically modified sunflower oils differing in fatty acid and tocopherol compositionsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2008Susana Marmesat Abstract The objective of the study was to investigate the performance at frying temperature of a new sunflower oil with high content of oleic and palmitic acid (HOHPSO) and containing ,-tocopherol as the most abundant natural antioxidant. HOHPSO either containing ,- or ,-tocopherol (HOHPSO-, and HOHPSO-,, respectively) were obtained from genetically modified sunflower seeds and refined under identical conditions. The oil stability against oxidation, as measured by Rancimat at 120,°C, was much higher for the oil containing ,-tocopherol, suggesting the higher effectiveness of ,-tocopherol as compared to ,-tocopherol to delay oxidation. Experiments at high temperature (180,°C) simulating the conditions applied in the frying process clearly demonstrated that, for the same periods of heating, the oil degradation and the loss of natural tocopherol were significantly lower for the oil containing ,-tocopherol. Comparison of different genetically modified sunflower oils with different fatty acid compositions confirmed that oil degradation depended on the fatty acid composition, being higher at a higher degree of unsaturation. However, the loss of tocopherol for a similar level of oil degradation was higher as the degree of unsaturation decreased. Overall, the results showed that HOHPSO-, had a very high stability at frying temperatures and that mixtures of HOHPSO-, and HOHPSO-, would be an excellent alternative to fulfill the frying performance required by the processors and the vitamin,E content claimed by the consumers. [source] Comparison of near-infrared emission spectroscopy and the Rancimat method for the determination of oxidative stabilityEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 1 2007Fabiano B. Gonzaga Abstract This work presents a comparison between a new method for the determination of the oxidative stability of edible oils at frying temperatures, based on near-infrared emission spectroscopy (NIRES), and the Rancimat method at 110,,°C. In the NIRES-based method, the induction time (IT) is determined by means of the variation of the emission band at 2900,nm during heating at 160,,°C. The comparison between the IT values obtained with the two methods for 12,samples of edible oils shows some correlation for samples of the same type once there is an agreement on the sequence of highest to lowest IT values between the methods, but a poor correlation considering all samples (correlation coefficient of 0.78). This lack of correlation demonstrates that the results obtained with the Rancimat method cannot be used as an indication of the oxidative stability, or the resistance to degradation, of edible oils at frying temperatures. The difference in the heating temperatures used in the two methods leads to 20,36,times higher IT values for the Rancimat method in relation to the NIRES-based method, but with similar repeatabilities (2.0 and 2.8%, respectively). [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] The influence of oil type and frying temperatures on the texture and oil content of French friesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2005Agnieszka Kita Abstract The purpose of the present study was to determine the effects of the frying medium and temperatures on fat content and texture of French fries. The material taken for the study consisted of seven types of vegetable oil: refined sunflower, rape, soy, olive oil, palm, partially hydrogenated rape oil (modified oil I) and a blend of vegetable oils (modified oil II). The French fries prepared from Asterix potato variety were fried at oils heated to 150, 160, 170, 180 and 190 °C. The length of frying (12, 10, 8, 6.5 and 4.5 min, respectively) depended on oil temperature. Fat content and the texture of French fries were determined. The type of frying medium significantly affects the texture of French fries. Temperature influenced both the fat content and texture of product. The increase of frying temperature decreased fat uptake and hardness of French fries. French fries fried in rape oil exhibited the most delicate texture and the lowest oil absorption when compared with French fries fried in other types of oil under investigation. Copyright © 2005 Society of Chemical Industry [source] Loss of tocopherols and formation of degradation compounds at frying temperatures in oils differing in degree of unsaturation and natural antioxidant contentJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2002Daniel Barrera-Arellano Abstract Samples of oils of different degrees of unsaturation, namely palm olein, olive oil, high-linoleic sunflower oil, high-oleic sunflower oil, rapeseed oil and soybean oil, were heated at 180,°C for 2, 4, 6, 8 and 10,h in the presence or absence of their natural antioxidants. Also, tocopherol-stripped oils were supplemented with ,-tocopherol (500,mg,kg,1), ,-tocopherol (500,mg,kg,1) or a mixture of ,-, ,-, ,- and ,-tocopherols (250,mg,kg,1 each) and heated under the same conditions. Losses of tocopherols and formation of polymeric triacylglycerols were followed. Total polar compounds were also evaluated after 10,h of heating. Results demonstrated that tocopherols were lost very rapidly, in the expected order, with ,-tocopherol being the least stable. Polymeric and polar compound formation during heating was inhibited to a variable extent, being more dependent on the natural content and type of tocopherols than on the degree of unsaturation of the oil. For example, polymeric and polar compound contents in soybean oil were significantly lower than those found in high-linoleic sunflower oil. However, the expected influence of the degree of unsaturation was evident when oils were unprotected or possessed identical initial antioxidant contents. Finally, levels of degradation compounds after 10,h of heating were not dependent on the remaining content of antioxidants. © 2002 Society of Chemical Industry [source] The Risks of Everyday Life: Fat content of chips, quality of frying fat and deep-frying practices in New Zealand fast food outletsAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2 2002Judith Morley-John Objectives:To collect baseline data on the fat content of hot chips, quality (degradation) of cooking fat, deep-frying practices and related attitudes in fast food outlets in New Zealand. To identify the key determinants of the fat content of chips and quality of cooking fat. Methods:A nationally representative sample of fast food outlets (n=150, response rate 80%) was surveyed between September 1998 and March 1999. Data collected included a questionnaire, observation of cooking practices and analysis of cooked chips and frying fat. Results:Only 8% of independent operators had formal training in deep frying practices compared with 93% of chain operators. There was a wide range of fat content of chips (5%-20%, mean 11.5%). The use of thinner chips, crinkle cut chips and lower fryer fat temperature were associated with higher chip fat content. Eighty-nine per cent of chain outlets used 6,10 mm chips compared with 83% of independent outlets that used chips ,12 mm. A wide range of frying temperatures was recorded (136,233°C) with 58% of outlets frying outside the reference range (175,190°C). As indices of fat degradation, fat acid and polar compound values above the recommended levels occurred in 54% and 5% of outlets respectively. Operators seemed willing to learn more about best practice techniques, with lack of knowledge being the main barrier to change. Conclusions and implications:Deep frying practices could be improved through operator training and certification options. Even a small decrease in the mean fat content of chips would reduce the obesogenic impact of this popular food. [source] | ||||||||||