The Experts below are selected from a list of 1743 Experts worldwide ranked by ideXlab platform
G S Mittal - One of the best experts on this subject based on the ideXlab platform.
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single sided Pan Frying of frozen hamburgers with flippings for microbial safety using modeling and simulation
Journal of Food Engineering, 2007Co-Authors: G S MittalAbstract:Mathematical heat and mass (moisture and fat) transfer models for the single-sided Pan-Frying of frozen hamburger patties were developed and validated against experimental data. The slowest microbial inactivation point within a patty was predicted using transport and microbial inactivation models. The simulation results demonstrated the inactivation of Escherichia coli O157:H7, Listeria innocua, and Salmonella serotypes within patties during cooking. The effects of various turning intervals, patty thickness, initial patty temperature and D (thermal death time) values on safe process time were analyzed. Increasing the number of overturns by reducing flipping interval reduced the process time considerably at lower Pan temperature. Small variations of D had significant differences on process time also at lower Pan temperature. E. coli can be satisfactorily inactivated at required final cooking temperature but not Salmonella and Listeria where higher process times are needed for the same temperature.
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double sided Pan Frying of unfrozen frozen hamburgers for microbial safety using modelling and simulation
Food Research International, 2006Co-Authors: G S MittalAbstract:Abstract The predictive mathematical heat and mass (water and fat) transfer models for the double-sided Pan-Frying of unfrozen and frozen hamburger patties were developed and validated against experimental data. The simulation results demonstrated the inactivation of Escherichia coli O157:H7, Listeria innocua, and Salmonella serotypes within patties during cooking. The effects of various patty thickness and Pan temperature on safe process time were analyzed. For a safe patty, double-sided Pan-Frying with 160 °C Pan temperature is recommended due to its faster cooking and better microbial safety. The cooking times for double-sided Pan-Frying of frozen and unfrozen patties are approximately 293 and 115 s, respectively. The increase in heating temperature resulted in higher rates of patty centre temperature increase and water and fat losses, and decreased the process time for 12 log reductions of microorganisms. An increase in the thickness of the patty resulted in an increased process time.
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Double-sided Pan-Frying of unfrozen/frozen hamburgers for microbial safety using modelling and simulation
Food Research International, 2006Co-Authors: G S MittalAbstract:Abstract The predictive mathematical heat and mass (water and fat) transfer models for the double-sided Pan-Frying of unfrozen and frozen hamburger patties were developed and validated against experimental data. The simulation results demonstrated the inactivation of Escherichia coli O157:H7, Listeria innocua, and Salmonella serotypes within patties during cooking. The effects of various patty thickness and Pan temperature on safe process time were analyzed. For a safe patty, double-sided Pan-Frying with 160 °C Pan temperature is recommended due to its faster cooking and better microbial safety. The cooking times for double-sided Pan-Frying of frozen and unfrozen patties are approximately 293 and 115 s, respectively. The increase in heating temperature resulted in higher rates of patty centre temperature increase and water and fat losses, and decreased the process time for 12 log reductions of microorganisms. An increase in the thickness of the patty resulted in an increased process time.
Nikolaos K Andrikopoulos - One of the best experts on this subject based on the ideXlab platform.
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Distribution and retention of phytosterols in Frying oils and fried potatoes during repeated deep and Pan Frying
European Food Research and Technology, 2007Co-Authors: Fotini N. Salta, Nick Kalogeropoulos, Nausika Karavanou, Nikolaos K AndrikopoulosAbstract:The retention and distribution of phytosterols in fried oils and French-fries during eight successive Pan- and deep-Frying sessions of pre-fried potatoes in sunflower oil, palm oil, cottonseed oil, virgin olive oil and a vegetable shortening were evaluated. Phytosterols (β-sitosterol, campesterol, stigmasterol, Δ5-avenasterol) were determined in the unsaponifiable fraction of Frying oils and lipids extracted from French-fries by GC/FID after derivatization to trimethylsilyl ethers. French-fries were enriched with phytosterols due to the absorption of Frying oil, with β-sitosterol predominating in both fried oils and potatoes. The amount of phytosterols decreased during Frying, their overall retentions reaching 9.5–22.8% and 29.4–51.2% after eight successive Pan- and deep-Frying sessions, respectively, while their deterioration was found to be affected by Frying time, Frying technique, being more prolonged during Pan-Frying, and by the oils’ unsaturation, being more extended in polyunsaturated oils. Phytosterols were more or less uniformly distributed between the fried oil and the fried potatoes. The phytosterols dietary intake by consuming potatoes fried in the oils tested is discussed.
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formation and distribution of oxidized fatty acids during deep and Pan Frying of potatoes
European Journal of Lipid Science and Technology, 2007Co-Authors: Nick Kalogeropoulos, Fotini N. Salta, Antonia Chiou, Nikolaos K AndrikopoulosAbstract:The formation of cis-9,10-epoxystearate, trans-9,10-epoxystearate, cis-9,10-epoxyoleate, cis-12,13-epoxyoleate, trans-9,10-epoxyoleate, trans-12,13-epoxyoleate and the co-eluting 9- and 10-ketostearates during eight successive Pan- and deep-Frying sessions of pre-fried potatoes in five different types of vegetable oils - namely cottonseed oil, sunflower oil, vegetable shortening, palm oil and virgin olive oil - was followed and quantified both in fried oils and in fried potatoes by GC/MS after derivatization to methyl esters. These oxidized fatty acids were present at relatively low concentrations in the fresh oils and pre-fried potatoes while they increased linearly with Frying time, reaching up to 1140.8 μg/g in virgin olive oil (VOO) and 186.9 μg/g in potatoes Pan-fried in VOO after eight Pan-Frying sessions, with trans-9,10-epoxystearate predominating in all cases. The formation of polymerized triacylglycerols (PTG) was also quantified in Frying oils by size exclusion HPLC. Pan-Frying caused higher oxidized fatty acid and PTG formation compared to deep-Frying. Epoxyoleates and PTG concentrations were increased after Frying in polyunsaturated oils, while epoxystearate and 9- and 10-ketostearate concentrations were increased after Frying in monounsaturated oils. No specific absorption of the oxidized fatty acids by the fried potatoes seems to occur. The dietary intake of oxidized fatty acids and PTG by the consumption of fried potatoes was discussed.
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Retention and distribution of polyphenols after Pan-Frying of French fries in oils enriched with olive leaf extract
Journal of Food Science, 2007Co-Authors: Fotini N. Salta, I. Ntalla, Anastasia Mylona, Nick Kalogeropoulos, Nikolaos K AndrikopoulosAbstract:Palm oil, olive oil, and sunflower oil were supplemented with an extract rich in polyphenols obtained from olive tree (Olea europaea) leaves at levels of 120 and 240 mg total polyphenols per kilogram of oil. Pan-Frying of potatoes was performed in both the enriched and the nonsupplemented oils under domestic Frying conditions. Total polyphenol content was estimated by the Folin-Ciocalteau assay, oleuropein was determined by HPLC analysis, while other individual polyphenols by GC/MS analysis. Fourteen polyphenol species were identified in the olive leaf extract, among which oleuropein predominated (1.25 g/kg olive leaves). All the enriched oils contained oleuropein before and after Frying. Oleuropein as well as other polyphenol species were detected in all French fries cooked in enriched oils. Polyphenol intake by consuming French fries Pan-fried in the enriched oils was calculated to be 6 to 31 times higher than that in the case of French fries fried in commercial oils, being dependent on the Frying oil type.
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Formation and distribution of oxidized fatty acids during deep‐ and Pan‐Frying of potatoes
European Journal of Lipid Science and Technology, 2007Co-Authors: Nick Kalogeropoulos, Fotini N. Salta, Antonia Chiou, Nikolaos K AndrikopoulosAbstract:The formation of cis-9,10-epoxystearate, trans-9,10-epoxystearate, cis-9,10-epoxyoleate, cis-12,13-epoxyoleate, trans-9,10-epoxyoleate, trans-12,13-epoxyoleate and the co-eluting 9- and 10-ketostearates during eight successive Pan- and deep-Frying sessions of pre-fried potatoes in five different types of vegetable oils - namely cottonseed oil, sunflower oil, vegetable shortening, palm oil and virgin olive oil - was followed and quantified both in fried oils and in fried potatoes by GC/MS after derivatization to methyl esters. These oxidized fatty acids were present at relatively low concentrations in the fresh oils and pre-fried potatoes while they increased linearly with Frying time, reaching up to 1140.8 μg/g in virgin olive oil (VOO) and 186.9 μg/g in potatoes Pan-fried in VOO after eight Pan-Frying sessions, with trans-9,10-epoxystearate predominating in all cases. The formation of polymerized triacylglycerols (PTG) was also quantified in Frying oils by size exclusion HPLC. Pan-Frying caused higher oxidized fatty acid and PTG formation compared to deep-Frying. Epoxyoleates and PTG concentrations were increased after Frying in polyunsaturated oils, while epoxystearate and 9- and 10-ketostearate concentrations were increased after Frying in monounsaturated oils. No specific absorption of the oxidized fatty acids by the fried potatoes seems to occur. The dietary intake of oxidized fatty acids and PTG by the consumption of fried potatoes was discussed.
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recovery and distribution of natural antioxidants α tocopherol polyphenols and terpenic acids after Pan Frying of mediterranean finfish in virgin olive oil
Food Chemistry, 2007Co-Authors: Nick Kalogeropoulos, Anastasia Mylona, Antonia Chiou, Maria S Ioannou, Nikolaos K AndrikopoulosAbstract:Abstract Samples of eight finfish representing the most popular fish species in Greece were Pan-fried in virgin olive oil according to the Greek traditional culinary practice. Analyses for polyphenols, hydroxy pentacyclic triterpene acids (HPTA) and α-tocopherol were performed in the fresh and fried oils and fish. Polyphenols and HPTA were determined by GC/MS and α-tocopherol by HPLC. Nine polyphenols were determined in the Frying oil samples; six of them were also found in fried fish. The terpenic acids oleanolic, maslinic and ursolic were also determined in Frying oils and fried fish. No polyphenols and no HPTA were detectable in raw fish, while α-tocopherol was present in all samples. Besides water loss and oil absorption, Pan Frying caused the partial loss of all the antioxidants studied in the fried oils, as well as their enrichment in the fried fish. The overall retention of α-tocopherol in the fried oil and fish ranged from 30% to 80%, the respective values for polpyphenols and HPTA ranging between 51–87% and 46–88%. The polarity of the antioxidants studied, seems to affect to some extent their partition between the Frying oil and the water-containing fish.
Mieke Uyttendaele - One of the best experts on this subject based on the ideXlab platform.
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Growth and inactivation of Salmonella enterica and Listeria monocytogenes in broth and validation in ground pork meat during simulated home storage abusive temperature and home Pan-Frying.
Frontiers in microbiology, 2015Co-Authors: Xiang Wang, Elien De Boeck, Frank Devlieghere, Evy Lahou, Annemie Geeraerd, Mieke UyttendaeleAbstract:Ground pork meat with natural microbiota and inoculated with low initial densities (1-10 or 10-100 CFU/g) of Salmonella enterica or Listeria monocytogenes was stored under abusive temperature at 10°C and thermally treated by a simulated home Pan-Frying procedure. The growth and inactivation characteristics were also evaluated in broth. In ground pork meat, the population of S. enterica increased by less than one log after 12-days of storage at 10°C, whereas L. monocytogenes increased by 2.3 to 2.8 log units. No unusual intrinsic heat resistance of the pathogens was noted when tested in broth at 60°C although shoulders were observed on the inactivation curves of L. monocytogenes. After growth of S. enterica and L. monocytogenes at 10°C for 5 days to levels of 1.95 log CFU/g and 3.10 log CFU/g, respectively, in ground pork meat, their inactivation in the burger subjected to a simulated home Pan-Frying was studied. After thermal treatment S. enterica was undetectable but L. monocytogenes was recovered in three out of six of the 25 g burger samples. Overall, the present study shows that data on growth and inactivation of broths are indicative but may underestimate as well as overestimate behavior of pathogens and thus need confirmation in food matrix conditions to assess food safety in reasonably foreseen abusive conditions of storage and usual home Pan-Frying of of meat burgers in Belgium.
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effectiveness of inactivation of foodborne pathogens during simulated home Pan Frying of steak hamburger or meat strips
International Journal of Food Microbiology, 2015Co-Authors: Evy Lahou, Elien De Boeck, Elien Verguldt, Xiang Wang, Frank Devlieghere, Annemie Geeraerd, Mieke UyttendaeleAbstract:Abstract In order to evaluate the effect of simulated home Pan Frying of raw meat and meat preparations of different animal species on the thermal inactivation of pathogens, the heat resistance (D-value) of three strains of Campylobacter jejuni, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and two strains of generic E. coli was validated in BHI and adjusted BHI (i.e. pH 5.6 and 1.5% NaCl) at 60 °C. The D-values were obtained of the linear phase of the survivor curves created in GInaFiT, a freeware tool to fit models to experimental data. The obtained D-values corresponded to those previously published in literature and confirmed L. monocytogenes to be the most heat resistant pathogen among them. Heat treatment in adjusted BHI significantly increased heat-resistance of E. coli O157:H7 and generic E. coli. Subsequently, the thermal inactivation of L. monocytogenes, Salmonella spp., C. jejuni and E. coli O157:H7 was evaluated using a standardized procedure simulating commonly used home Pan Frying of various types of meat including steaks or filets, hamburgers and meat strips from various animal species such as pork, beef, chicken, lamb and some turkey, horse, kangaroo and crocodile meat. Corresponding F70-values were calculated based upon measured core time/temperature profiles. It was noted that a core temperature of 70 °C was not always achieved and, moreover, a heat treatment equivalent to 2 min at 70 °C was also not always obtained. This was in particular noted in hamburgers although the meat was visually judged well done. On several occasions, residual survivors of the initial inoculated (4 log CFU/g) food borne pathogens could be recovered either by enumeration (limit of detection 1 log CFU/g) or by the presence/absence testing per 25 g. Pan Frying of hamburgers yielded the highest number of surviving pathogenic bacteria (46%), followed by well-done filets and steaks (13%) and meat strips (12%). Taking only steaks (beef, horse, kangaroo, crocodile and turkey) into account, residual detection of pathogens occurred for all levels of doneness: 18% for well-done, 71% for medium and even 90% for rare steaks. Numbers of L. monocytogenes recovered after heat treatment ranged from
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Effectiveness of inactivation of foodborne pathogens during simulated home Pan Frying of steak, hamburger or meat strips.
International journal of food microbiology, 2015Co-Authors: Evy Lahou, Elien De Boeck, Elien Verguldt, Xiang Wang, Frank Devlieghere, Annemie Geeraerd, Mieke UyttendaeleAbstract:Abstract In order to evaluate the effect of simulated home Pan Frying of raw meat and meat preparations of different animal species on the thermal inactivation of pathogens, the heat resistance (D-value) of three strains of Campylobacter jejuni, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and two strains of generic E. coli was validated in BHI and adjusted BHI (i.e. pH 5.6 and 1.5% NaCl) at 60 °C. The D-values were obtained of the linear phase of the survivor curves created in GInaFiT, a freeware tool to fit models to experimental data. The obtained D-values corresponded to those previously published in literature and confirmed L. monocytogenes to be the most heat resistant pathogen among them. Heat treatment in adjusted BHI significantly increased heat-resistance of E. coli O157:H7 and generic E. coli. Subsequently, the thermal inactivation of L. monocytogenes, Salmonella spp., C. jejuni and E. coli O157:H7 was evaluated using a standardized procedure simulating commonly used home Pan Frying of various types of meat including steaks or filets, hamburgers and meat strips from various animal species such as pork, beef, chicken, lamb and some turkey, horse, kangaroo and crocodile meat. Corresponding F70-values were calculated based upon measured core time/temperature profiles. It was noted that a core temperature of 70 °C was not always achieved and, moreover, a heat treatment equivalent to 2 min at 70 °C was also not always obtained. This was in particular noted in hamburgers although the meat was visually judged well done. On several occasions, residual survivors of the initial inoculated (4 log CFU/g) food borne pathogens could be recovered either by enumeration (limit of detection 1 log CFU/g) or by the presence/absence testing per 25 g. Pan Frying of hamburgers yielded the highest number of surviving pathogenic bacteria (46%), followed by well-done filets and steaks (13%) and meat strips (12%). Taking only steaks (beef, horse, kangaroo, crocodile and turkey) into account, residual detection of pathogens occurred for all levels of doneness: 18% for well-done, 71% for medium and even 90% for rare steaks. Numbers of L. monocytogenes recovered after heat treatment ranged from
Nick Kalogeropoulos - One of the best experts on this subject based on the ideXlab platform.
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heavy metals in raw fried and grilled mediterranean finfish and shellfish
Food and Chemical Toxicology, 2012Co-Authors: Nick Kalogeropoulos, Sotirios Karavoltsos, Aikaterini Sakellari, Stella Avramidou, Manos Dassenakis, Michael ScoullosAbstract:The effect of domestic Pan-Frying and grilling on Cd, Cr, Cu, Fe, Hg, Ni, Pb and Zn content of popular small Mediterranean finfish and shellfish was studied. The species selected -namely anchovy, bogue, hake, picarel, sardine, sand smelt, stripped mullet, Mediterranean mussel, shrimp and squid- are among the most commonly marketed and consumed in Greece and most of the Mediterranean countries. Both culinary practices examined resulted in increased metals concentrations compared to those of raw samples, the increment being inversely related to fish size and -in most cases- being more extended in Pan-Frying. The consumption of cooked seafood is expected to provide significant amounts of Fe and Zn followed, in decreasing order, by Cr, Cu and Ni. In addition, the estimation of (a) weekly intakes and (b) target hazard quotients for the toxic elements Cd, Hg and Pb revealed that the cooked fish and shellfish do not pose any health risk for the consumers.
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Recovery and Distribution of Macro- and Selected Microconstituents after Pan-Frying of Mediterranean Fish in Virgin Olive Oil
Olives and Olive Oil in Health and Disease Prevention, 2010Co-Authors: Nick Kalogeropoulos, Antonia ChiouAbstract:Publisher Summary Domestic Pan-Frying of Mediterranean fish in virgin olive oil (VOO) causes significant changes in their crude composition, i.e., water loss and increased fat, protein and energy content. The use of VOO for Frying fish is beneficial for the fatty acid profile of fried products, as they contain less saturated fatty acid (SFA) and more monounsaturated fatty acids (MUFA), while still providing significant amounts of n-3 polyunsaturated fatty acids (PUFA), having n-6/n-3 ratios close to 1. Virgin olive oil absorption by fried fish enriches it with health-promoting microconstituents like squalene and phytosterols, together with natural antioxidants (tocopherols, polyphenols, and terpenic acids), a significant fraction of which survives Frying, thus becoming part of our diet. Differences in the antioxidant's polarity seem to govern, to some extent, their distribution between the Frying oil and the water-rich fish. Pan-fried fish do not overload the consumer with cholesterol, while part of the fish cholesterol seems to leach into the Frying oil, remaining in the fryer. A serving of fish Pan-fried in VOO provides a significant portion of the daily intakes of protein, oleic acid, n-3 PUFA, vitamin E, polyphenols, terpenic acids, squalene, and plant sterols. Based on the above, Pan-fried fish—as part of a balanced diet—has a place in our diets, assuming that Frying is performed in unused VOO.
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Recovery and Distribution of Macro- and Selected Microconstituents after Pan-Frying of Vegetables in Virgin Olive Oil
Olives and Olive Oil in Health and Disease Prevention, 2010Co-Authors: Nick KalogeropoulosAbstract:Publisher Summary Pan-Frying of vegetables (like potatoes, green peppers, zucchinis, and eggplants) in olive oil is a common practice in the Mediterranean olive-oil-producing countries. Vegetables are normally fried uncoated or coated with flour or batter and the fried products are either served as starters or used as ingredients of other Mediterranean recipes. The major process contributing to the instability of olive oil when heated is lipid oxidation, which can lead to significant changes in the oil composition that affect its biological properties, as lipid peroxidation products have been linked to cancer and cardiovascular disease. Although antioxidants protect olive oil from thermal degradation, Frying reduces the oil antioxidative capa-city, a particularly important fact when the same oil is used repeatedly. Comparing Frying oils and Frying techniques, the combination of virgin olive oil and deep-Frying has been shown to be the better choice, as olive oil has a relatively long deep-fat Frying “shelf life” and is comparatively more stable than other oils for repeated Frying. Deep Frying is considered less stressful for the oil and food, as contact with atmospheric oxygen is minimized, and it is preferably used for commercial Frying. However, as the oil is re-used several times, accumulation of polymeric compounds occurs as the oil antioxidant capacity is reduced. Therefore, it seems that the traditional Mediterranean practice of Pan-Frying in virgin olive oil that has not been used for more than 1 or 2 times, appears more reasonable for domestic cooking.
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Distribution and retention of phytosterols in Frying oils and fried potatoes during repeated deep and Pan Frying
European Food Research and Technology, 2007Co-Authors: Fotini N. Salta, Nick Kalogeropoulos, Nausika Karavanou, Nikolaos K AndrikopoulosAbstract:The retention and distribution of phytosterols in fried oils and French-fries during eight successive Pan- and deep-Frying sessions of pre-fried potatoes in sunflower oil, palm oil, cottonseed oil, virgin olive oil and a vegetable shortening were evaluated. Phytosterols (β-sitosterol, campesterol, stigmasterol, Δ5-avenasterol) were determined in the unsaponifiable fraction of Frying oils and lipids extracted from French-fries by GC/FID after derivatization to trimethylsilyl ethers. French-fries were enriched with phytosterols due to the absorption of Frying oil, with β-sitosterol predominating in both fried oils and potatoes. The amount of phytosterols decreased during Frying, their overall retentions reaching 9.5–22.8% and 29.4–51.2% after eight successive Pan- and deep-Frying sessions, respectively, while their deterioration was found to be affected by Frying time, Frying technique, being more prolonged during Pan-Frying, and by the oils’ unsaturation, being more extended in polyunsaturated oils. Phytosterols were more or less uniformly distributed between the fried oil and the fried potatoes. The phytosterols dietary intake by consuming potatoes fried in the oils tested is discussed.
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formation and distribution of oxidized fatty acids during deep and Pan Frying of potatoes
European Journal of Lipid Science and Technology, 2007Co-Authors: Nick Kalogeropoulos, Fotini N. Salta, Antonia Chiou, Nikolaos K AndrikopoulosAbstract:The formation of cis-9,10-epoxystearate, trans-9,10-epoxystearate, cis-9,10-epoxyoleate, cis-12,13-epoxyoleate, trans-9,10-epoxyoleate, trans-12,13-epoxyoleate and the co-eluting 9- and 10-ketostearates during eight successive Pan- and deep-Frying sessions of pre-fried potatoes in five different types of vegetable oils - namely cottonseed oil, sunflower oil, vegetable shortening, palm oil and virgin olive oil - was followed and quantified both in fried oils and in fried potatoes by GC/MS after derivatization to methyl esters. These oxidized fatty acids were present at relatively low concentrations in the fresh oils and pre-fried potatoes while they increased linearly with Frying time, reaching up to 1140.8 μg/g in virgin olive oil (VOO) and 186.9 μg/g in potatoes Pan-fried in VOO after eight Pan-Frying sessions, with trans-9,10-epoxystearate predominating in all cases. The formation of polymerized triacylglycerols (PTG) was also quantified in Frying oils by size exclusion HPLC. Pan-Frying caused higher oxidized fatty acid and PTG formation compared to deep-Frying. Epoxyoleates and PTG concentrations were increased after Frying in polyunsaturated oils, while epoxystearate and 9- and 10-ketostearate concentrations were increased after Frying in monounsaturated oils. No specific absorption of the oxidized fatty acids by the fried potatoes seems to occur. The dietary intake of oxidized fatty acids and PTG by the consumption of fried potatoes was discussed.
Evy Lahou - One of the best experts on this subject based on the ideXlab platform.
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Growth and inactivation of Salmonella enterica and Listeria monocytogenes in broth and validation in ground pork meat during simulated home storage abusive temperature and home Pan-Frying.
Frontiers in microbiology, 2015Co-Authors: Xiang Wang, Elien De Boeck, Frank Devlieghere, Evy Lahou, Annemie Geeraerd, Mieke UyttendaeleAbstract:Ground pork meat with natural microbiota and inoculated with low initial densities (1-10 or 10-100 CFU/g) of Salmonella enterica or Listeria monocytogenes was stored under abusive temperature at 10°C and thermally treated by a simulated home Pan-Frying procedure. The growth and inactivation characteristics were also evaluated in broth. In ground pork meat, the population of S. enterica increased by less than one log after 12-days of storage at 10°C, whereas L. monocytogenes increased by 2.3 to 2.8 log units. No unusual intrinsic heat resistance of the pathogens was noted when tested in broth at 60°C although shoulders were observed on the inactivation curves of L. monocytogenes. After growth of S. enterica and L. monocytogenes at 10°C for 5 days to levels of 1.95 log CFU/g and 3.10 log CFU/g, respectively, in ground pork meat, their inactivation in the burger subjected to a simulated home Pan-Frying was studied. After thermal treatment S. enterica was undetectable but L. monocytogenes was recovered in three out of six of the 25 g burger samples. Overall, the present study shows that data on growth and inactivation of broths are indicative but may underestimate as well as overestimate behavior of pathogens and thus need confirmation in food matrix conditions to assess food safety in reasonably foreseen abusive conditions of storage and usual home Pan-Frying of of meat burgers in Belgium.
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effectiveness of inactivation of foodborne pathogens during simulated home Pan Frying of steak hamburger or meat strips
International Journal of Food Microbiology, 2015Co-Authors: Evy Lahou, Elien De Boeck, Elien Verguldt, Xiang Wang, Frank Devlieghere, Annemie Geeraerd, Mieke UyttendaeleAbstract:Abstract In order to evaluate the effect of simulated home Pan Frying of raw meat and meat preparations of different animal species on the thermal inactivation of pathogens, the heat resistance (D-value) of three strains of Campylobacter jejuni, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and two strains of generic E. coli was validated in BHI and adjusted BHI (i.e. pH 5.6 and 1.5% NaCl) at 60 °C. The D-values were obtained of the linear phase of the survivor curves created in GInaFiT, a freeware tool to fit models to experimental data. The obtained D-values corresponded to those previously published in literature and confirmed L. monocytogenes to be the most heat resistant pathogen among them. Heat treatment in adjusted BHI significantly increased heat-resistance of E. coli O157:H7 and generic E. coli. Subsequently, the thermal inactivation of L. monocytogenes, Salmonella spp., C. jejuni and E. coli O157:H7 was evaluated using a standardized procedure simulating commonly used home Pan Frying of various types of meat including steaks or filets, hamburgers and meat strips from various animal species such as pork, beef, chicken, lamb and some turkey, horse, kangaroo and crocodile meat. Corresponding F70-values were calculated based upon measured core time/temperature profiles. It was noted that a core temperature of 70 °C was not always achieved and, moreover, a heat treatment equivalent to 2 min at 70 °C was also not always obtained. This was in particular noted in hamburgers although the meat was visually judged well done. On several occasions, residual survivors of the initial inoculated (4 log CFU/g) food borne pathogens could be recovered either by enumeration (limit of detection 1 log CFU/g) or by the presence/absence testing per 25 g. Pan Frying of hamburgers yielded the highest number of surviving pathogenic bacteria (46%), followed by well-done filets and steaks (13%) and meat strips (12%). Taking only steaks (beef, horse, kangaroo, crocodile and turkey) into account, residual detection of pathogens occurred for all levels of doneness: 18% for well-done, 71% for medium and even 90% for rare steaks. Numbers of L. monocytogenes recovered after heat treatment ranged from
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Effectiveness of inactivation of foodborne pathogens during simulated home Pan Frying of steak, hamburger or meat strips.
International journal of food microbiology, 2015Co-Authors: Evy Lahou, Elien De Boeck, Elien Verguldt, Xiang Wang, Frank Devlieghere, Annemie Geeraerd, Mieke UyttendaeleAbstract:Abstract In order to evaluate the effect of simulated home Pan Frying of raw meat and meat preparations of different animal species on the thermal inactivation of pathogens, the heat resistance (D-value) of three strains of Campylobacter jejuni, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and two strains of generic E. coli was validated in BHI and adjusted BHI (i.e. pH 5.6 and 1.5% NaCl) at 60 °C. The D-values were obtained of the linear phase of the survivor curves created in GInaFiT, a freeware tool to fit models to experimental data. The obtained D-values corresponded to those previously published in literature and confirmed L. monocytogenes to be the most heat resistant pathogen among them. Heat treatment in adjusted BHI significantly increased heat-resistance of E. coli O157:H7 and generic E. coli. Subsequently, the thermal inactivation of L. monocytogenes, Salmonella spp., C. jejuni and E. coli O157:H7 was evaluated using a standardized procedure simulating commonly used home Pan Frying of various types of meat including steaks or filets, hamburgers and meat strips from various animal species such as pork, beef, chicken, lamb and some turkey, horse, kangaroo and crocodile meat. Corresponding F70-values were calculated based upon measured core time/temperature profiles. It was noted that a core temperature of 70 °C was not always achieved and, moreover, a heat treatment equivalent to 2 min at 70 °C was also not always obtained. This was in particular noted in hamburgers although the meat was visually judged well done. On several occasions, residual survivors of the initial inoculated (4 log CFU/g) food borne pathogens could be recovered either by enumeration (limit of detection 1 log CFU/g) or by the presence/absence testing per 25 g. Pan Frying of hamburgers yielded the highest number of surviving pathogenic bacteria (46%), followed by well-done filets and steaks (13%) and meat strips (12%). Taking only steaks (beef, horse, kangaroo, crocodile and turkey) into account, residual detection of pathogens occurred for all levels of doneness: 18% for well-done, 71% for medium and even 90% for rare steaks. Numbers of L. monocytogenes recovered after heat treatment ranged from
