Pan Frying Research Articles

Volatile fingerprints of beef cooking methods using sol–gel‐based solid‐phase microextraction (SPME) and direct analysis in real‐time mass spectrometry (DART‐MS)

RationaleThe aroma profile of food is a complex mixture of volatile compounds that constitutes a major component of the overall eating experience. The food service industry and chefs therefore constantly seek ways to investigate and thereby enhance the aroma profile. Oven cooking, sous vide and pan fry are three cooking methods of beef commonly practised by chefs. Near real‐time analysis of volatile compounds from these three cooking methods will provide insight into respective volatile fingerprints and help improve cooking techniques.MethodsVolatile compounds from three beef cooking methods were captured using an in‐house sol–gel based solid phase microextraction (SPME) method and analysed using direct analysis in real‐time mass spectrometry (DART‐MS). A volatile organic compound (VOC) standard was used to demonstrate successful implementation of the sol–gel coating technique. Volatile features discriminating the three cooking methods were shortlisted and statistically assessed by univariate and multivariate analyses.ResultsThe VOC standard was successfully adsorbed by the sol–gel method and detected by DART‐MS. Hierarchical cluster analysis clearly demarcated three beef cooking methods based on their volatile fingerprints. Out of 65 significant features differentiating the cooking methods, 50 were at highest concentrations from pan‐fry cooking only, followed by 14 with highest concentrations from oven cooking followed by pan frying. Sous vide followed by pan frying showed lowest concentrations of almost all volatile features.ConclusionsThe sol–gel‐based solid‐phase microextraction technique combined with DART‐MS was successful in differentiating beef cooking methods based on their volatile fingerprints. A workflow for rapid assessment of the volatile profile from beef cooking methods was established, providing a baseline to further explore volatile profiles from other key ingredients.

The effects of different cooking methods and spices on the formation of 11 HCAs in chicken wing and pork belly

Heterocyclic amines (HCAs) are mutagenic and carcinogenic compounds formed when cooking meats, such as chicken and pork. In this study, the effect of different cooking methods (air frying, infrared cooker, pan frying, and electric oven) and spices (rosemary, turmeric, and garlic) on the formation of 11 HCAs (IQ, MelQ, MelQx, 4,8-DiMelQx, PhIP, AαC, MeAαC, Trp-P-1, Trp-P-2, Harman, and Norharman) in chicken wing and pork belly were determined by ultra-high-performance liquid chromatography−triple quadrupole mass spectrometry, and the physicochemical characteristics of the cooked meats were compared. The effect of air frying temperatures and times on the 11 HCAs formation was also investigated. Pan-fried chicken wing and pork belly lost less moisture and weight than the other samples. Air frying resulted in the lowest contents of 11 HCAs compared to pan frying, cooking in an electric oven, and infrared cooking, regardless of meat type. For example, 11 HCAs levels in air-fried chicken wings were 4.35 μg/kg, with the inhibition rate of 75.29% comparing with pan-fried chicken wings (17.61 μg/kg). HCAs formation depended on air frying temperatures and times. For example, the HCAs contents in chicken wing air-fried at 200 °C for 20 min (2.98 μg/kg) increased by 2.8 times compared to chicken wing air-fried at 140 °C for 50 min (1.08 μg/kg). Additionally, all spices showed an inhibitory effect on HCA formation. Especially, turmeric exhibited the highest inhibitory effect on the formation of HCAs by 50.67%. These results indicate that air frying and spices could inhibit the formation of HCAs during the thermal preparation of meats.

Impact of cooking method on properties of beef and plant-based burgers: Appearance, texture, thermal properties, and shrinkage

Consumers are increasingly adopting plant-based diets because of environmental, health, and animal welfare concerns. Ideally, the cooking behavior of plant-based meat analogs should accurately mimic that of real meat products so consumers can easily adopt them. In the current study, we characterized the impact of different cooking procedures (pan frying, air frying, and oven baking) on the physicochemical properties of beef and plant-based patties. We examined the influence of cooking temperature and time on the appearance, texture, cooking loss, and shrinkage of the two kinds of product. Moreover, the thermal properties of the beef and plant-based burgers were characterized using thermogravimetric and differential scanning calorimetric analysis to provide insights in the key temperatures where molecular changes occurred during cooking. A significant difference was observed in the physicochemical attributes of beef and plant-based patties but cooking method did not have a major influence on their final properties. After cooking, the plant-based patties had a higher water holding capacity, exhibited less shrinkage, and were softer (lower hardness, cohesiveness, springiness, resilience, and chewiness) than beef patties. However, thermal analysis suggested they exhibited a quite similar mass loss during cooking. Our results demonstrate important differences between the cookability of beef and plant-based patties, which highlights the need for further research on the physiochemical basis of the properties of plant-based foods that more accurately simulate the behavior of real meat products. • Three common cooking methods (pan frying, air frying, and oven baking) were used. • Impacts of cooking temperature/time were investigated. • Cooked PB patties had a higher water holding capacity, less shrinkage, and were softer than beef ones. • Cooking method did not have a major influence on patties' final properties. • Thermal analysis suggested PB and beef patties have similar mass loss during a cooking.

Parsley (Petroselinum crispum Mill.): A source of bioactive compounds as a domestic strategy to minimize cholesterol oxidation during the thermal preparation of omelets

This study evaluated the protective effect of parsley (Petroselinum crispum Mill.) against lipid and cholesterol oxidation in omelets prepared by air frying, pan frying, and microwaving. The bioactive composition and in vitro antioxidant capacity of parsley extract was characterized. Compounds such as phenolic acids and their derivatives (p-coumaric acid, p-coumaric acid 4-O-hexoside) and flavonoids (apigenin 7-glucoside, quercetin-O-pentosyl-hexoside) were identified in parsley by UHPLC-ESI-MS. Moreover, the presence of these bioactive constituents was investigated in omelets. Cooking induced lipid oxidation and increased the level of cholesterol oxidation products (COPs) in control omelets, which was more pronounced after air frying and microwaving. The total content of COPs increased from 40.69 ± 2.26 μg/g (raw) to 821.05 ± 13.77 μg/g (air frying), 805.21 ± 14.50 μg/g (microwaving), and 311.07 ± 13.84 μg/g (pan frying). The addition of parsley proved to be effective reducing COPs formation, mainly in air-fried samples with 0.75% parsley (81.73% of protection). Chromatographic analyses revealed the thermo-degradation of parsley compounds, since only two flavonoids detected in parsley were found in omelets containing the herb after cooking. Nonetheless, these findings indicate the potential application of parsley as a natural inhibitor of cholesterol and lipid oxidation in food systems such as omelets.

Effect of Three Cooking Techniques on Nile Tilapia (Oreochromis niloticus) Burgers Quality Attributes تأثير ثلاث تقنيات للطهي على خصائص جودة برجرسمک البلطي النيلي(Oreochromis niloticus)

Three cooking techniques (pan frying in corn oil, roasting in a Halogen convection oven, and grilling in a double jacket electric grill) were evaluated for their effect on the quality attributes (cooking characteristics, chemical composition, fatty acids, amino acids, physicochemical properties, microbiological activity, sensory evaluation, and cost-profit analysis) of the Nile tilapia (Oreochromis niloticus) burgers. The Nile tilapia weighed an average of 500 grams and contained 52.13% edible flesh. There were no significant (p ≤ 0.05) differences in the proximate chemical composition of roasted and grilled burgers. While, the frying technique and both other cooking techniques differs significantly (p ≤ 0.05). In terms of pH, total volatile base nitrogen, and thiobarbituric acid reactive substances values, there were no significant differences (p ≤ 0.05) between the three cooking techniques. During the frying process, the fatty acids and amino acids content of the fish burgers was considerably influenced. The results of the sensory evaluation of fish burgers revealed that fried and grilled burgers had better color, odor, appearance, and overall acceptability than roasted burgers. The Nile tilapia burgers were proven to be good for human eating, roasted and grilled as cooking methods for a healthy diet. The current research paves the way for optimal use of this product with profit margin 83.33%, especially during the peak of fishing season.

Fatty acid profile and health lipid indicies of goose meat in relation to various types of heat treatment

The effect of water bath cooking (WBC), oven convection roasting (OCR), grilling (G), pan-frying (PF) on the fatty acid profile and health lipid indices of goose meat was investigated in this study. The experimental material covered 80 breast muscles (40 with skin and subcutaneous fat and 40 without skin) cut from carcasses of 17-week-old “Polish oat geese”. The fatty acid profile of meat was determined by gas chromatography and health lipid indices were calculated. It was stated that the kind of heat treatment as well as the type of goose meat (muscles with and without skin) affected the fatty acid profile and health lipid indices. The sum of SFA was significantly higher in cooked samples for both kinds of meat than in raw ones. The cooked samples with skin had a lower increase in Ʃ SFA than the skinless meat. Boiling (meat without skin) and pan-frying (both kinds of meat) caused a slight decrease, while grilling and oven convection roasting (both kinds of meat) caused an increase of Ʃ MUFA in comparison to raw samples. Moreover, meat with skin is characterized by a higher value of Ʃ MUFA than meat without skin for all cooking methods. The Ʃ PUFA was lower in all cooked samples than in raw meat, wherein this decline was usually higher for skinned meat. The G meat was the lowest and PF the highest in Σ PUFA for both kinds of meat after heat treatment. The highest loss showed C20:4 n-6 in OCR samples and the lowest C18:2 n-6 in PF (both kinds of meat). Heat treatment caused an increase in the Σ PUFA n-6/n-3 ratio, wherein the lowest value was shown by the WBC samples without skin, and the highest by OCR with skin. Water bath cooking of meat was more beneficial for consumers in terms of AI, TI, Σ DFA/Σ OFA, Σ PUFA/Σ SFA, Σ UFA/Σ SFA indexes and Σ SFA, Σ OFA values than the remaining methods.

The selected goose meat quality traits in relation to various types of heat treatment

The effect of water bath cooking (WBC), oven convection roasting (OCR), grilling (G), pan frying (PF) on selected physical properties of goose meat was compared in this study. A measurement of cooking loss, texture, color parameters, and sensory evaluation was carried out. The experimental material covered 96 breast muscles cut from carcasses of 17-week-old “Polish oat geese.” The kind of goose meat (with and without skin) and the type of heat treatment affected cooking loss, shear force (SF), and rheological parameters (hardness, cohesiveness, gumminess, and chewiness). The water bath–cooked and pan-fried samples for both kinds of meat were characterized by lower cooking loss than other ones. Goose meat with skin and subcutaneous fat showed higher cooking loss and lower SF value, hardness, gumminess, and chewiness than that without skin for all methods. The water bath–cooked samples were characterized by the lowest SF value, hardness, and chewiness for both kinds of meat. They had the highest value of L∗ parameter and were characterized by a lighter color among others, too. Pan-fried meat showed the highest value of a∗ and lowest of ho parameters; the color of these samples was redder. Moreover, the lower C values of oven convection-roasted and grilled samples showed that they were brighter. According to the Comission Internationale de l’Eclairage classification, the ΔE parameter only for G and OCR indicated noticeable color differences (<2), whereas other pairs had visible differences. The method of cooking affected sensory descriptors such as the intensity of flavor and aroma, tenderness, juiciness, springiness, cohesiveness, and overall palatability of goose meat. The goose samples of PF, G, and OCR were characterized as very good and WBC as extremely desirable overall palatability. However, in the next stage of research, there is a need to study changes in the chemical composition, the degree of lipid oxidation, and the nutritional value of this meat that underwent different methods of cooking. Only then it will be possibly to clearly determine which method of the heat treatment of goose meat is optimal.

Carnosine and anserine in chicken can quench toxic acrylamide under cooking conditions: Mass spectrometric studies on adduct formation and characterization

Acrylamide (AA) is a toxic industrial chemical but is also found in heated potato foods such as French fries due to the Maillard reaction between amino acids and reducing sugars. However, high-temperature cooking is often required for flavoring, browning, and sterilizing of raw ingredients. Imidazole dipeptides, such as carnosine (β-alanyl-l-histidine, CAR) and anserine (β-alanyl-Nπ-methyl-l-histidine, ANS), are present in high concentrations in meat and are known to scavenge radical species and toxic aldehydes. Here, we investigated the reaction between CAR/ANS and AA under several conditions expected to detoxify AA by cooking with meat. The reaction products were characterized by LC–ESI-MS/MS as CAR/ANS-AA adducts at the N-terminus, and His-Nτ/Nπ. The reactivity of CAR sites toward AA were in the order N-terminus > Nτ > Nπ. A selective LC–ESI-SRM/MS method was also developed and confirmed the formation of CAR/ANS-AA adducts during pan frying of minced potato and chicken breast.

Relationships Between Loin Color, Cut Thickness, Cooking Method, Water-Holding Capacity and Tenderness for Pork Cooked to 62.8°C

ObjectivesConsumer research has consistently shown that consumers over-cook pork creating a subpar eating experience. In 2011, the USDA/FSIS changed the internal doneness temperature from 71.1 to 62.8°C. However, how tenderness and water-holding capacity is affected in pork chops and roasts differing in thickness and color score cooked to 62.8°C is unknown. Understanding these relationships from chops and roasts cooked to 62.8°C is crucial to the pork industry.Materials and MethodsBoneless and bone-in pork loins were purchased commercially on 3 selection trips to represent the National Pork Board subjective color scores of 2 and 4. The tenderloin was removed from the bone-in loins and randomly assigned to treatments. The sirloin and blade ends were removed, and bone-in ribeye chops were cut to either 1.3, 1.9 or 2.5 cm thick. Twelve chops were cut from each loin with a portion of the rib bone present in each chop. The blade end of the boneless loins was removed, and blade chops were cut to either 1.3, 1.9 or 2.5 cm thick. Three blade ends within color score were used to obtain 12 chops. The boneless center-cut chops were cut to either 1.3, 1.9 or 2.5 cm. Each boneless loin was cut into 12 chops. Boneless loin roasts (0.9 and 1.8 kg roasts) were cut from color score 4 boneless loins. Whole boneless center-cut loin roasts were cut into 2.7 kg roasts from the color score 2 loins. Prior to cooking, drip loss, pH and raw color were determined. Chops were then cooked to 62.8°C either by baking, grilling, pan frying, or pan-sautéing. Roasts were cooked to 62.8°C either by baking or grilling. Internal temperature was monitored by inserting an iron constantan thermocouple into the geometric center of the chop or roast. Cook yield, cook time, tenderness assessed by Warner-Bratzler shear force, and cooked internal color were determined. Each of the 24 treatments for each type of chop (2 colors × 3 thicknesses × 4 cooking methods) and the 8 roast treatments (4 weights × 2 cooking methods) were replicated 20 times.ResultsCooking method and chop thickness affected cook yield and cook time. Baked chops had the longest cooking times and sautéed chops had the highest cook yields (P &lt; 0.05). Grilled chops had the highest (P &lt; 0.05) cook loss. The color score 4 blade and boneless chops were more tender than the color score 2 chops (P &lt; 0.05). However, for bone-in chops, the inverse was reported (P &lt; 0.05). Thickness had minimal effect on tenderness for the boneless chops (P &lt; 0.05). Although bone-in and boneless, baked chops had the longest cooking times, they were the most (P &lt; 0.05) tender. Baked whole boneless roasts had higher cook yield and longer cook times from grilled whole boneless roasts (P &lt; 0.05). For boneless loin roasts (0.9 kg), baked roasts had higher cook yields, longer cook times, were tougher, and had a redder internal cook color than boneless loin roasts that were grilled (P &lt; 0.05). Heavier boneless loin roasts had lower cook yield, longer cook times, and were tougher compared to lighter weight boneless loin roasts (P &lt; 0.05). Baked tenderloins had higher cook yield, longer cook times and were redder in internal color than grilled tenderloin roasts (P &lt; 0.05).ConclusionOverall, this study revealed that color, cooking method, and thickness impacted drip loss, cook yield, cook time, cooked color, and tenderness of blade, boneless, and bone-in chops, tenderloins, and roasts.

Relationships Between Loin Color, Cut Thickness, Cooking Method, Water-Holding Capacity and Tenderness for Pork Cooked to 62.8°C

ObjectivesConsumer research has consistently shown that consumers over-cook pork creating a subpar eating experience. In 2011, the USDA/FSIS changed the internal doneness temperature from 71.1 to 62.8°C. However, how tenderness and water-holding capacity is affected in pork chops and roasts differing in thickness and color score cooked to 62.8°C is unknown. Understanding these relationships from chops and roasts cooked to 62.8°C is crucial to the pork industry.Materials and MethodsBoneless and bone-in pork loins were purchased commercially on 3 selection trips to represent the National Pork Board subjective color scores of 2 and 4. The tenderloin was removed from the bone-in loins and randomly assigned to treatments. The sirloin and blade ends were removed, and bone-in ribeye chops were cut to either 1.3, 1.9 or 2.5 cm thick. Twelve chops were cut from each loin with a portion of the rib bone present in each chop. The blade end of the boneless loins was removed, and blade chops were cut to either 1.3, 1.9 or 2.5 cm thick. Three blade ends within color score were used to obtain 12 chops. The boneless center-cut chops were cut to either 1.3, 1.9 or 2.5 cm. Each boneless loin was cut into 12 chops. Boneless loin roasts (0.9 and 1.8 kg roasts) were cut from color score 4 boneless loins. Whole boneless center-cut loin roasts were cut into 2.7 kg roasts from the color score 2 loins. Prior to cooking, drip loss, pH and raw color were determined. Chops were then cooked to 62.8°C either by baking, grilling, pan frying, or pan-sauteing. Roasts were cooked to 62.8°C either by baking or grilling. Internal temperature was monitored by inserting an iron constantan thermocouple into the geometric center of the chop or roast. Cook yield, cook time, tenderness assessed by Warner-Bratzler shear force, and cooked internal color were determined. Each of the 24 treatments for each type of chop (2 colors × 3 thicknesses × 4 cooking methods) and the 8 roast treatments (4 weights × 2 cooking methods) were replicated 20 times.ResultsCooking method and chop thickness affected cook yield and cook time. Baked chops had the longest cooking times and sauteed chops had the highest cook yields (P < 0.05). Grilled chops had the highest (P < 0.05) cook loss. The color score 4 blade and boneless chops were more tender than the color score 2 chops (P < 0.05). However, for bone-in chops, the inverse was reported (P < 0.05). Thickness had minimal effect on tenderness for the boneless chops (P < 0.05). Although bone-in and boneless, baked chops had the longest cooking times, they were the most (P < 0.05) tender. Baked whole boneless roasts had higher cook yield and longer cook times from grilled whole boneless roasts (P < 0.05). For boneless loin roasts (0.9 kg), baked roasts had higher cook yields, longer cook times, were tougher, and had a redder internal cook color than boneless loin roasts that were grilled (P < 0.05). Heavier boneless loin roasts had lower cook yield, longer cook times, and were tougher compared to lighter weight boneless loin roasts (P < 0.05). Baked tenderloins had higher cook yield, longer cook times and were redder in internal color than grilled tenderloin roasts (P < 0.05).ConclusionOverall, this study revealed that color, cooking method, and thickness impacted drip loss, cook yield, cook time, cooked color, and tenderness of blade, boneless, and bone-in chops, tenderloins, and roasts.

Effects of Pre-cooking Methods on Quality Characteristics of Reheated Marinated Pork Loin.

We evaluated the effects of pre-cooking methods on the quality of reheated marinated pork loin. Frozen marinated pork loins cooked using various methods (boiling, grilling, pan frying, infrared cooking, and superheated steam cooking) were reheated in a microwave, and their pH, color, cooking loss, re-heating loss, total loss, thiobarbituric acid reactive substance (TBARS) value, sensory properties, and shear force were determined. Although all parameters varied with different cooking methods, lightness values and TBARS values showed the tendency to decrease and increase, respectively, after reheating. Superheated steam-cooked samples showed the lowest values of cooking loss, total loss, TBARS value, and shear force (p<0.05) and the highest lightness, redness, and yellowssness values and juiciness, chewiness, and overall acceptability scores (p<0.05). These results show that pre-cooking with superheated steam maintains the quality characteristics of marinated pork loin upon reheating. Therefore, pre-cooking with superheated steam may be beneficial for the commercial distribution of frozen cooked marinated pork loin.

Influence of Cook Method and Degree of Doneness on Beef Flavor Attributes in Flap and Skirt Steaks

ObjectivesBeef flavor is very complex and the most important driver for consumer acceptance. Cooking method, Quality grade, and cooked internal temperature may affect beef flavor. In this study, 3 beef cuts (outside skirt, inside skirt, and flap), 2 Quality grades (USDA Choice and Select), 3 cooking methods (pan fry, pan grill, and outside grill), and 3 internal cook temperature endpoints (58°C, 70°C, and 80°C) were used to better understand trained descriptive beef flavor and texture attributes, and Warner-Bratzler shear force (WBSF) tenderness.Materials and MethodsMeat sources were purchased as subprimals in 6 reps for each cut and were fabricated into 10.16 cm wide steaks. The USDA upper two thirds Choice and USDA Select inside skirt, outside skirt, and flap steaks were cooked using a pan fry, pan grill, or outside grill methods. The steaks were cooked to an internal temperature of either 58.3, 70 or 80°C to represent medium rare, medium and well-done steaks. The steaks were evaluated by an expert trained meat descriptive panel for beef flavor and texture attributes. The trained panel descriptive flavor attributes, and WBSF were analyzed using Proc Means and Proc GLMMIX procedures of SAS (version 9.4, SAS Inst. Inc., Cary, NC) with a predetermined ɑ of 5%.ResultsCooking method and internal cook temperature endpoint tended to impact beef flavor to a greater extent than USDA Beef Quality grade for outside skirt, inside skirt and flap steaks. Internal cook temperature endpoint affected beef identity, brown, bloody/serumy, metallic, burnt, smokey-charcoal, and juiciness (P < 0.05). Pan frying tended to result in more off-flavor development and outside grilling was more often associated with positive flavor attributes. Choice steaks tended to have more positive beef flavor attributes such as beef identity, umami, brown and roasted. Quality grade affected fat-like, cardboardy, juiciness, muscle fiber tenderness and beef flavor (P < 0.05) for all 3 cuts. Pan grilling tended to result in intermediate flavor for steaks when compared to steaks cooked using outside grilling and pan frying cooking methods. The flavor attributes generally affected by cooking method included beef identity, brown, metallic, smokey-charcoal (P < 0.05).Treatments had an effect on flap tenderness measured by WBSF, Choice flap steaks were more tender (P < 0.05) than Select flaps and flap steaks cooked to 80°C were less tender (P < 0.05) than other internal temperatures. Pan-grilled flap steaks were more tender (P < 0.05) than steaks from the other cooking methods. For inside skirts, there was no effect (P > 0.05) for Quality grade on tenderness measured by Warner-Bratzler shear force values. However, inside skirts cooked to 58°C were more tender than other internal temperature endpoints, and pan-grilled skirts were more tender than other cooking methods (P < 0.05). Lastly, for WBSF measurements, treatments had no impact (P > 0.05) on outside skirt steaks.ConclusionIn the beef industry, beef flavor is a driver of consumer acceptability. This research was conducted to assist in the development of the Beef Flavor Myology tool that will aid in determining factors that impact beef flavors across various cuts, cooking methods, marbling levels, and cooked internal temperature.

Effect of cooking method on proximate and mineral composition of lake Malawi tilapia (Oreochromis karongae)

Fish is a nutritious food and an excellent source of animal protein in the human diet containing many vitamins and minerals that are essential for the human body. In Malawi, fish is the major source of affordable dietary protein for humans. Lake Malawi tilapia ( Oreochromis karongae ) locally known as Chambo , is the most preferred and highest value commercial food fish species obtained from Lake Malawi. Several methods are used to prepare/cook the fish viz.: boiling, deep frying in edible cooking oil, grilling, and/or roasting over fire. However, the fact that cooking alters the nutrient content in foods underscores the need to understand nutritional effects of different food cooking/processing methods. This study investigated effect(s) of cooking fresh fish (Lake Malawi tilapia) by boiling, roasting, pan frying and, using a locally made fireless cooker) on its proximate (protein, fat, ash and moisture) and mineral (calcium, magnesium, zinc, iron and phosphorus) composition. Highest and lowest values for crude protein were reported in fish processed using the fireless cooker (64.3±0.2%) and roasting (59.9±0.4%), respectively (P<0.05), against (64.4±0.3%) for the fresh fish (control). Fish that were pan fried showed significantly higher crude fat content (25.5±0.1%) (P<0.05) followed by samples prepared using the fireless cooker (15.3±0.1), and lowest values were found in fish that were boiled (12.1±0.2%). Fish from the fireless cooker had significantly high moisture content (10.6±0.1%), ash (17.1±0.3%), zinc (0.0±0.0μg/g), phosphorus (2.6±0.0μg/g) and reasonably, more calcium (54.2±7.0μg/g) and magnesium (0.5±0.0μg/g) (P<0.05). The lowest levels of minerals were recorded in fish that were roasted: calcium (44.8±0.1μg/g), magnesium (0.5±0.0μg/g), zinc (0.0±0.0μg/g) and phosphorus (2.0±0.1%) (P≥0.05). The results suggest that fish processed in the fireless cooker were of higher nutritional quality principally due to the relatively high content of the most needed nutrient - protein. Adopting and encouraging use of the fireless cooker could also be a way of saving energy thus; curbing dependency on fuel wood. The results also showed that cooking does not have significant effect on minerals in fresh fish. Keywords: Fireless cooker, boiling, roasting, pan frying, tilapia, Lake Malawi, Malawi

Effect of traditional Chinese cooking methods on fatty acid profiles of vegetable oils

The effect of four frying processes (vegetable salad, stir frying, pan frying, and deep frying) on fatty acid composition of ten vegetable oils (peanut oil, soybean oil, rapeseed oil, corn oil, sunflower seed oil, rice bran oil, olive oil, sesame oil, linseed oil, and peony seed oil) was investigated using GC–MS. The result showed that trans-fatty acid (TFA) was produced during all processes. Rapeseed oil had the highest TFA content in vegetable salad oil with 2.88% of total fatty acid. The TFA content of sunflower seed oil was 0.00% in vegetable salad oil, however, after stir frying and pan frying, it increased to 1.53% and 1.29%, respectively. Peanut oil had the lowest TFA content after deep frying for 12h with 0.74mg/g. It was concluded that a healthy cooking process could be acquired by a scientific collocation.

Neural Network Model for Thermal Inactivation of Salmonella Typhimurium to Elimination in Ground Chicken: Acquisition of Data by Whole Sample Enrichment, Miniature Most-Probable-Number Method

Predictive models are valuable tools for assessing food safety. Existing thermal inactivation models for Salmonella and ground chicken do not provide predictions above 71°C, which is below the recommended final cooked temperature of 73.9°C for chicken. They also do not predict when all Salmonella are eliminated without extrapolating beyond the data used to develop them. Thus, a study was undertaken to develop a model for thermal inactivation of Salmonella to elimination in ground chicken at temperatures above those of existing models. Ground chicken thigh portions (0.76 cm3) in microcentrifuge tubes were inoculated with 4.45 ± 0.25 log most probable number (MPN) of a single strain of Salmonella Typhimurium (chicken isolate). They were cooked at 50 to 100°C in 2 or 2.5°C increments in a heating block that simulated two-sided pan frying. A whole sample enrichment, miniature MPN (WSE-mMPN) method was used for enumeration. The lower limit of detection was one Salmonella cell per portion. MPN data were used to develop a multiple-layer feedforward neural network model. Model performance was evaluated using the acceptable prediction zone (APZ) method. The proportion of residuals in an APZ (pAPZ) from -1 log (fail-safe) to 0.5 log (fail-dangerous) was 0.911 (379 of 416) for dependent data and 0.910 (162 of 178) for independent data for interpolation. A pAPZ ≥0.7 indicated that model predictions had acceptable bias and accuracy. There were no local prediction problems because pAPZ for individual thermal inactivation curves ranged from 0.813 to 1.000. Independent data for interpolation satisfied the test data criteria of the APZ method. Thus, the model was successfully validated. Predicted times for a 1-log reduction ranged from 9.6 min at 56°C to 0.71 min at 100°C. Predicted times for elimination ranged from 8.6 min at 60°C to 1.4 min at 100°C. The model will be a valuable new tool for predicting and managing this important risk to public health.

Effects of cooking method, cooking oil, and food type on aldehyde emissions in cooking oil fumes

Cooking oil fumes (COFs) contain a mixture of chemicals. Of all chemicals, aldehydes draw a great attention since several of them are considered carcinogenic and formation of long-chain aldehydes is related to fatty acids in cooking oils. The objectives of this research were to compare aldehyde compositions and concentrations in COFs produced by different cooking oils, cooking methods, and food types and to suggest better cooking practices. This study compared aldehydes in COFs produced using four cooking oils (palm oil, rapeseed oil, sunflower oil, and soybean oil), three cooking methods (stir frying, pan frying, and deep frying), and two foods (potato and pork loin) in a typical kitchen. Results showed the highest total aldehyde emissions in cooking methods were produced by deep frying, followed by pan frying then by stir frying. Sunflower oil had the highest emissions of total aldehydes, regardless of cooking method and food type whereas rapeseed oil and palm oil had relatively lower emissions. This study suggests that using gentle cooking methods (e.g., stir frying) and using oils low in unsaturated fatty acids (e.g., palm oil or rapeseed oil) can reduce the production of aldehydes in COFs, especially long-chain aldehydes such as hexanal and t,t-2,4-DDE.

Microwave thawing and green tea extract efficiency for the formation of acrylamide throughout the production process of chicken burgers and chicken nuggets.

Initially, we measured the acrylamide (AA) levels of chicken burgers (CBs) and chicken nuggets (CNs) purchased from fast food restaurants. After the determination of AA in these products, we aimed to investigate whether the use of green tea extract in the covering material, and microwave thawing before frying, mitigated the formation of AA in CBs and CNs during the production process. According to our study, AA concentrations of CBs and CNs purchased from fast food restaurants were in the range of 13.43-118.97 and 32.92-134.90 ng g-1 coating, respectively. In our experiment, AA levels varied between 19.61 and 40.08 ng g-1 coating for CBs and 7.92-49.60 ng g-1 coating for CNs. Green tea extract reduced the AA formation in CBs and CNs at the pan frying and steam oven cooking heat treatment steps (P < 0.05). However, microwave thawing did not affect AA level of CBs and CNs. When the AA levels of commercial CBs and CNs are compared with those produced in our experiment, the use of green tea extract could be a novel, easy and practical application for fast food producers to minimise AA levels in the first two steps of the production without changes to the sensory properties of the final products. © 2016 Society of Chemical Industry.

Effect of different cooking procedures on microbiological quality of chevon meat balls

In this research, the effects of different cooking processes (pan fried and microwave cooking) on microbiological quality of the raw and cooked chevon meatballs were studied. Microbial flora of the raw meatballs was as follows: total plate count, 5.98±0.235 (log cfu/g); yeast and mould, 4.80±0.328 (log cfu/g); coliforms, 3.05±0.433 (log cfu/g). Highly significant (P<0.01) difference was noticed in microbiological quality of chevon meat balls. The cooking processes decreased the microbial flora approximately 2-3 log cycles, and pan frying was the effective cooking process for reducing microbial numbers compared to the microwave oven. The temperature of the Pan fried (150-160°C for 5-7 min) was higher than the To conclude, it was advised to use slightly higher temperatures than used in the microwave oven cooking procedures to increase microbial quality of the meat balls studied in this research.

Effect of Specific Oil Surface Area on the Thermal Stressing of Rapeseed Oil During Heating in an Electric Frying Pan.

The effect of specific oil surface (SOS) during pan frying of rapeseed oil on its thermal stability and antioxidant capacity (AC) was evaluated. Rapeseed oils with different oil layer heights (OLH = 0.5, 1.0, 1.5, 2.0, and 2.5 cm) were heated on an electric frying pan coated with Teflon at 180 ± 10 °C until a selected end point of 25 % total polar compounds (TPC) was reached. The changes of chemical parameters of oil samples such as peroxide value, p-anisidine value, Totox value, free fatty acids, TPC and AC using the 2,2-diphenyl-1-picrylhydrazyl assay were determined. Irrespective of the applied methods, the highest changes in oil with OLH = 0.5 cm were observed. Heating in low OLH also led to the fastest time of TPC formation in rapeseed oil; the 0.5-cm layer reached 25 % TPC in a relatively short time (71.5 min) compared to the highest OLH = 2.5 cm (t = 315.1 min). The SOS and the rate of change in the heated oils decreased with increasing OLH. Crucial effects of SOS on physicochemical oil changes were observed. The present study demonstrated the protective effect of increasing the OLH on the quality of the heated rapeseed oils.

The effect of pan frying on thermooxidative stability of refined rapeseed oil and professional blend.

The pan fryings of frozen pre-fried French fries in refined rapeseed oil (RO) and professional blend (PB) were of 8h duration. Initially, while fresh, and after every 1h of frying, the oils were analyzed for acid and anisidine values, colour, refractive index, fatty acid composition (by GC), polar fraction content and composition (by high pressure size exclusionchromatography). Additionally the fat content and fatty acid composition of French fries were determined. Hydrolytic and oxidative changes in the frying media varied with oil composition and increased with frying time. The pace of oxidation in RO was three times higher than in PB. The loss of polyunsaturated fatty acids (sum of C18:2 and C18:3) after 8h of frying was 7% in PB and 20% in RO. The polar fraction content was two times lower in PB, but did not exceed 25% in either of the frying media. The predominant fraction in RO was oxidized triacylglycerols, while in PB - diacylglycerols. During frying the proportions of triacylglycerol polymers and dimers increased in both oils, reaching 32% in RO and 23% in PB.