Simultaneous determination of typical toxic aldehydes formed during food frying and digestion using isotope dilution UHPLC-QqQ-MS/MS

An isotope dilution ultra-performance liquid chromatography-triple quadrupole mass spectrometry method was developed to simultaneously detect two typical kinds ofα,β-unsaturated aldehydes,namely 4-hydroxy-2-hexenal(4-HHE)and 4-hydroxy-2-nonenal(4-HNE),in foods.The proposed method exhibited a linear range of 10-1000 ng/mL with a limit of detection of 0.1-2.0 ng/g and a limit of quantification of 0.3-5.0 ng/g.The recovery rates of these typical toxic aldehydes(i.e.,4-HHE,4-HNE)and their d3-labeled analogues were 91.54%-105.12%with a low matrix effect.Furthermore,this proposed method was successfully applied to a real frying system and a simulated digestion system,wherein the contents of 4-HHE and 4-HNE were determined for both.Overall,the obtained results provide strong support for further research into the production of 4-HHE and 4-HNE resulting from foods during oil digestion and frying.

Sensory-directed flavor analysis of key odorants compounds development of French fries and oils in the break-in,optimum and degrading frying stage

The flavor is a decisive sensory characteristic that determines the popularity of French fries(FFs).During high-oleic rapeseed oil(RO)frying,the flavor development of FFs showed three noticeable stages including break-in(3.5%-7.5%of total polar compounds(TPC)),optimum(7.5%-22.18%of TPC),and degrading stages(above 22.18%of TPC).Further,in order to distinguish the key aroma compounds in each stage,the FFs prepared in RO at TPC of 3.5%(FF4),14.5%(FF15),and 26.96%(FF27)and their relevant oils(RO4,RO15,RO27)were selected for sensory-directed analysis.The results revealed that the FF4 had low contents of(E,E)-2,4-decadienal(deep-fried odor)which also caused lower sensory score in FF4 sample.The higher contents of(E,E)-2,4-decadienal in FF15 induced its higher deep-fried odor.The FF27 had higher hexanoic acid(sweaty odor),heptanoic acid,nonanoic acid,benzene acetaldehyde(stale odor),and trans-4,5-epoxy-(E)-2-decenal(metallic odor)compared with FF4 and FF15,thus leading to the undesirable flavor of FF27.Moreover,the decrease of 2,5-dimethylpyrazine and 2-ethyl-6-methyl-pyrazine in FF27 induced the lower roasty flavor,which may also lead to the decline of the sensory score.Similarly,the higher contents of(E)-2-undecenal,hexanoic acid,heptanoic acid,and nonanoic acid in RO27 lead to increase its rancid score and thus lower the sensory score.

Plant phenolic extracts for the quality protection of frying oil during deep frying:Sources,effects,and mechanisms

Protection of frying oil from deterioration by adding plant phenolic extracts to guarantee the quality of fried foods becomes the primary approach to promote the sustainable development of deep frying.Therefore,sources,antioxidant effects,and mechanisms of plant phenolic extracts recently applied in the quality protection of frying oil as well as challenges for the actual use of these extracts are comprehensively reviewed in this study.Spices,herbs,berries,tea leaves,and fruit and vegetable wastes are common sources for preparing phenolic extracts showing comparative antioxidant capacity referring to the synthetic antioxidants.The general effect of using these natural antioxidants is the improvement of thermal stability to extend the shelf life of frying oil and thus the modification of edible quality of fried foods.Specifically,the increases in common quality attributes and amount of hazardous products and the oxidative reduction of unsaturated triacylglycerols without negatively influencing the sensory quality are inhibited when suitable plant extracts are applied.The incorporation of plant phenolic extracts other than synthetic counterparts in frying oil has been demonstrated as a potential method to improve the frying performance of oils.However,challenges for the scale application of plant phenolic extracts,such as the purity,thermal stability,and antioxidant timing,are still needed to be further investigated.

Survival of <i>Listeria monocytogenes</i>during Frying of Chicken Burger Patties

This study was aimed to determine sufficient frying time to reduce the number of Listeria monocytogenes present in chicken burger patties to non-detectable level which is fit for human consumption. Commercially available chicken burger patties were artificially contaminated with L. monocytogenes at level of approximately 9 log CFU/ml. The contaminated chicken burger patties were cooked for 0, 2, 4, 5, 8, and 10 minutes to determine survival of L. monocyto-genes. Results demonstrated a linear correlation between mean log reduction of L. monocytogenes and frying time. L. monocytogenes was not detected in chicken burger patties that were cooked for 6 minutes and above. As a result from this study, it is suggested that a minimum frying time for burger patties is 6 minutes. This can be treated as a safety measure to avoid consequences of consumption of undercooked burger patties.

Determination of Mass Transfer Parameters During Deep Fat Frying of Rice Crackers

The accuracy of the knowledge of mass transfer parameters （effective moisture diffusivity, mass transfer Biot number and mass transfer coefficient） in the case of frying food, is essential and important for designing, modeling and process optimization. This study is undertaken to develop an approach for determining mass transfer parameters during frying of spherical rice cracker in sunflower oil at 150, 170 and 190 ℃. These parameters were evaluated from the plots of dimensionless concentration ratios against time of frying. Effective moisture diffusivity, mass transfer Biot number and mass transfer coefficient ranged between 1.24×10^-8 to 2.36×10^-8 m^2/s, 1.96 to 2.34 and 5.51×10^-6 to 9.70×10^-6 m/s, respectively. Effective moisture diffusivity and mass transfer coefficient were found to increase with an increasing frying temperature, whereas mass transfer Biot number decreased. An Arrhenius-type relationship was found between effective diffusivity coefficient and frying temperature.

Frying Performance of High Oleic Oil Enriched in Biophenols during Discontinuos and Prolonged Thermal Treatment

Biophenols are potent natural antioxidants that protect food quality by preventing oxidative deterioration of lipids. During heat treatment this protective rule prevents oxidation caused by many factors, as high temperature reached, presence of oxygen and water contained in food matrix. The aim of this study was to evaluate the frying performance of high oleic oil enriched in biophenols, comparing its thermal stability with those of high oleic oil (control sample) during thermo-oxidation and deep fat frying process. Positive effects when biophenols were added to oil were found: lower acidity levels, lower TPC values during the first 16 hours of heat treatment, absence of short chain fatty acids (C8:0) until 24 h of thermo-oxidation treatment and detection of lower acrylamide content in French friesrespect to those fried in the control oil.

Difference among the quality indices,chemical composition and frying performance of galangal flavored sunflower oil prepared by three methods

Flavored vegetable oils have attracted more and more attentions from consumers and researchers due to their high oxidative stability and sensory quality.In the present study,the quality indices,chemical composition and frying performance of galangal flavored sunflower oil prepared by infusion method(GFSO-I),combination pressing method(GFSO-C)and direct addition method(GFSO-A)were investigated.The results displayed that the preparation time,the levels for the acid value(AV),peroxide value(PV),p-anisidine value(AnV),total oxidation value(TOTOX),and the values for total polar compounds(TPC),thiobarbituric acid(TBA),K232 and K268 of GFSO-C were prominently low(P<0.05),compared with that of GFSO-I and GFSO-A,while the fatty acid composition of them were similar.In the frying of Chinese Maye(tradional Chinese food,fried dough stick)at 180°C for 30 h,the values for TPC,TBA,K232 and K268,polymer,viscosity and b*of GFSO-C were obviously low(P<0.05),while the value for L*was obviously high(P<0.05),compared with that of GFSO-I and GFSO-A.In the sensory evaluation,the flavor,taste,crispness and overall acceptance of Chinese Maye fried by GFSO-C were better than that of Chinese Maye fried by GFSO-I and GFSO-A.Consequently,GFSO-C is more suitable for cooking,and the combination pressing method is optimal for industrial production of GFSO.

Relationship between Oil Uptake and Moisture Loss during Deep Fat Frying of Deboned Chicken Breast Meat

The relationship between moisture loss and oil uptake at different combination of Frying Oil Temperatures (FOT) and time during deep-fat frying of chicken meat was investigated in this study. Chicken meat samples were diced and fried at different FOT (170°C, 180°C, and 190°C) in an industrial fryer for periods varying from 5 to 900 s. Fat analysis was accomplished in a soxhlet extraction apparatus with petroleum ether solvent. Prior to fat analysis samples were freeze dried and the moisture analysis was based on the standard AOAC standard method. The results show that a cook value of 415 s was found to give the most ideal sensory characteristics. The relationship between moisture loss and oil uptake during the initial phase of frying (°C and 190°C, respectively, and the rate (1.35 g/s) at FOT 170°C was significantly (P < 0.05) lower.

Effects of Soursop flowers(Annona muricata L.)extract on chemical changes of refined palm olein stored at frying temperature

In this study,the antioxidant activity of soursop flowers extract in delaying palm olein oxidation at frying temperature was assessed.The oil was supplemented with the extract at concentrations 200–1800 ppm,and stored in the oven at 180◦C for 6 days(4 h heating per day).Palm olein containing butylated hydroxytoluene(BHT)served as positive control while the same oil without antioxidant(Control)served as negative one,in order to monitor changes in oils.After each two heating days,oil samples were collected,and their chemical indexes were determined.Peroxide,para-anisidine,TOTOX,thiobarbituric acid and iodine values were the parameters evaluated.Additionally,the evolution of the fatty acid composition of each oil sample during the storage was assessed by gas-chromatography using a flame ionization detector(GC/FID).Generally,palm olein samples containing the natural extract have exhibited the lowest rate of oxidation,and were efficient in limiting the destruction of unsaturated fatty acids in oil at frying temperature.The order of effectiveness in inhibiting oil oxidation was the following:PO+AnM1800ppm>PO+AnM1400ppm>PO+AnM1000ppm>PO+An.M600ppm>PO+An.M200ppm>PO+BHT200ppm=Control.From these results,it can be concluded that soursop flowers are a potent sources of natural antioxidants for stabilization of palm olein.

Effect of Frying-Cooking on Nutritional and Bioactive Compounds of Innovative Ovo-Vegetarian Diets

Vegetarian diets are becoming increasingly popular as meat prices as well as health concerns rise. Many people are cutting down or cutting out meat in favor of a full vegetarian diet. In present study, the applicability of different vegetables for producing ready-to-use and ready-to-eat chickpea-based ovo-vegetarian diets (OVDs) was investigated. Herein, six different vegetables (cauliflower, taro, green zucchini, pea, bean and spinach) were formulated with 25% chickpea and additional edible ingredients to produce ready-to-use OVDs. Subsequently, chemical composition, minerals content, bioactive compounds and antioxidant activity of those OVDs were investigated. However, ready-to-eat OVDs were organoleptically evaluated after frying as common cooking method. Results of composite analysis indicated 67.73% to 73.17%, 23.20% to 37.12%, 1.86% to 2.63%, 7.63% to 9.53%, 9.06% to 9.82% and 39.24% to 55.28% for moisture, crude protein, lipids, ash, fiber, and carbohydrates contents in ready-to-use OVDs, respectively. After frying, lipid content was increased in fried diets which changed the chemical composition and caloric value. Significant differences (p < 0.05) were found between macro- and micro-nutrients content of ready- to-use and ready-to-eat OVDs. The ready-to-use OVDs exhibit appropriate content of ascorbic acid, chlorophylls, carotenoids, flavonoids, and flavonols which basically depends on their ingredients. Frying process dramatically affected the ascorbic acid, chlorophylls, flavonoids, flavonols, and carotenoids contents. High organoleptic acceptability of ready-to-eat OVDs was recorded to confirm theconsumer attractiveness further. In conclusion, the possibility of producing healthy ready-to-eatand ready-to-use OVDs incorporated with common consumed vegetables could provide a promising approach for improving human health and dietary pattern as well as for selecting the optimum processing conditions for innovative OVDs.

The Effects of Frying Oils Supplemented with Vitamin E on Blood Parameters and Growth Performance of Rats

This study aimed at investigating effects of frying oils supplemented with vitamin E on blood parameters and growth performance of rats. Three experimental diets containing fresh corn oil or frying oil (FO) with or without vitamin E were fed to Wistar rats over a 90-day. Blood Chemistry, blood parameters (hematocrit and erythrocyte osmotic fragility) and growth performance were determined. Neither FO alone nor vitamin E had any considerable impact on the growth performance. Hematocrit of FO group did not change significantly compared to animals fed fresh oil. Although, vitamin E increased hematocrit to 16.37%, but still it had no considerable effect on restoring hematocrit to normal values. Serum triacylglycerol (TAG) did not change significantly among FO animals, while significant increase in TAG was noted between FO and vitamin E treated animals compared with other treatments. Serum total cholesterol (TC) did not change significantly among experimental animals compared with the control. Vitamin E resulted in an insignificant increase in high-density lipoprotein (HDL-C) level compared to the control. Serum low-density lipoprotein (LDL-C) level did not display any considerable difference among the three treatments. Frying oil with or without vitamin E had no significant effects on growth performance, lipid chemistry, and blood parameters. The only significant effect of FO was shown on erythrocytes hemolysis at higher concentration. Vitamin E supplementation had no impacts on undesired effects caused by frying oil.

Effects of Mixing Canola and Palm Oils with Sunflower Oil on the Formation of Trans Fatty Acids during Frying

GLC analysis was conducted to indicate the formation of trans- C18 fatty acids of sunflower, canola and palm oils during frying. Blends of sunflower oil and palm oil or canola oil were obtained by mixing sunflower oil with palm or canola oils at the volume ratios of 60: 40, 40: 60 and 20: 80 (v/v), then heated at 180?C ± 5?C for 5, 10, 15 and 20 h in the atmospheric oxygen. GLC results demonstrate that the formation of trans C18-fatty acids was generally dependent upon the frying time and oil mixing ratios. Furthermore, mixing sunflower oil with oils rich in monounsaturated fatty acids (palm or canola oils) lowered the formation of trans-C18 fatty acids during frying.

Determination of Physico-Chemical Indices of Frying Oils Used by Attieké-Fish Sellers in Daloa (Mid-West of Côte d’Ivoire)

The purpose of this article is to compare the quality of three edible oils derived from palm oil in Daloa’s city. The methodological approach of the article includes, on the one hand, a field survey determining the most used oils and the number of frying carried out by the attieké-fish sellers. On the other hand, the physico-chemical parameters (refractive index, iodine index, saponification index, acid index and peroxide index) of these oils were determined. As a result, the most used oils are A, B and C and are heated at least 3 times by the attieké-fish sellers. After repeated heating, the values of the peroxide, saponification, refraction, iodine indices of oils A and B do not match those of the codex with the exception of the acid value. For oil C, only the acid and iodine indices correspond to the codex standards. Overall, the results of the study clearly show that the repeated heating of these oils has an influence on the different physico-chemical properties studied.

Shrinkage and Density Change of De-Boned Chicken Breast during Deep-Fat Frying

The effects of frying oil temperature (FOT) and time on densities and shrinkage in chicken breast meat during deep-fat frying were investigated. De-boned Chicken breast samples were diced and fried at different FOT (170℃, 180℃, and 190℃) in an industrial fryer for periods varying from 5 to 900 s. Bulk and apparent densities were determined with a fluid displacement pycnometer, and fat analysis was conducted using soxhlet extraction with petroleum ether solvent. The physical structure of chicken meat changed significantly with the frying time and FOT (P < 0.001). Bulk density was 1.15 g/cm3 in the raw product and decreased to 0.98, 0.95, and 0.93 g/cm3 after 900 s of deep-frying at 170℃, 180℃ and 190℃, respectively. Similarly, apparent density changed from 1.13 to 1.25, 1.24 and 1.22 g/cm3 and moisture loss was linearly correlated with both densities. Volumetric shrinkage was significantly (P < 0.05) affected by the process variables and hence a linear correlation also existed with moisture loss. The rates of shrinkage were 0.013, 0.001, and 0.008/s and occurred rapidly during the first 90s of FOT (170℃, 180℃, and 190℃), respectively and decreased as frying time increased.

Development of Optimum Operating Conditions for Quality Attributes in Deep-Fat Frying of Dodo Produced from Plantain Using Response Surface Methodology

Response surface methodology involving historical data design has been successfully developed with the aim of predicting optimum operating conditions for dodo fried from plantain. Frying temperature and time were 150, 160, 170, 180 and 190°C and 2.0, 2.5, 3.0, 3.5 and 4.0 min respectively. The parameters analyzed included moisture content, oil content, texture and change in colour. The fitted functions were optimized for moisture content, oil content, texture and change in colour in order to obtain a product with the acceptable quality attributes. Frying conditions had significant (p R2) of the generated models ranged from 0.91 to 0.99. Optimum frying condition was 177.51°C for 2.10 min. This gave 14.16% moisture content, 1.54% oil content, 2.93 N texture and 40.89 change in colour. Desirability of 0.7 was obtained for optimum conditions. Therefore, the estimated response surface model can be used to optimize the frying process of dodo fried from plantain.

Optimization of Making Process for Whole Fish Frying Using a Universal Oven

[Objectives]To study the effects of different temperature,time and humidity on the sensory quality of fish meat,and to determine the optimal process parameters for whole fish frying of Sichuan-style dry-roasted fish using a universal oven.[Methods]The effects of different heating temperature,time and humidity on the sensory quality of whole fish frying were analyzed by single factor experiment and orthogonal experiment.[Results]In the whole fish frying process of the universal oven,the optimal parameters in the first stage steaming mode was as follows:215℃for temperature,15%for humidity,and 10 min for time;the optimal parameters in the second baking mode was as follows:250℃for temperature,70%for humidity,and 5 min for time.[Conclusions]Different from the traditional whole fish frying of Sichuan-style dry roasted fish,universal oven is greatly optimized in convenience,safety and environmental protection.Besides,the use of oil is reduced,and the cost is well controlled,thus it is conducive to mass production in the later period.

Waste Frying Oils-Based Biodiesel: Process and Fuel Properties

The conversion of waste frying oil into a valuable methyl ester (biodiesel) has been successfully conducted and also the acid pre-treatment process was carried out prior to the main biodiesel production process for lowering waste frying oil free fatty acid (FFA) content below 1%. The physicochemical properties of biodiesel were analyzed to ensure the product could meet the standards of fuel properties. The methanolysis was selected as the biodiesel production technique under various mixing speeds namely 350, 400 and 450 rpm, while the other parameters are maintained at the optimum process conditions such as methanol to oil molar ratio is 6:1, percentage of catalyst loading is 1.0% wt, reaction temperature is 60℃, and reaction time is 50 min. Also, the investigation on the kinematic viscosity, density and flash point of biodiesel was performed against a number of rpm. The standards of ASTM D 6751 were applied to measure the entire prescribed properties of biodiesel. The highest yield of biodiesel obtained was 99%. The values of flash point, kinematic viscosity and density were in the range of specified limitations. Other biodiesel properties fulfilled the diesel engine application requirements.

Ultrasonic-Assisted Production of Biodiesel from Waste Frying Oil Using a Two-Step Catalyzing Process

This study proposed using waste frying oil rather than refined vegetable oil as an effective way to reduce the raw material cost of producing biodiesel. In addition, the ultrasonic-assisted two-step catalyzing Process was first adopted for the production of biodiesel from waste frying oil. The results show that the total reaction time was less than 50 min and the conversion rate of fatty acid methyl esters (FAMEs) achieved was 97.1%. Therefore, the ultrasonic-assisted two-step catalyzing process has a potential application in producing biodiesel from waste frying oil.

Combined Effect of a Catalytic Reduction Device with Waste Frying Oil-Based Biodiesel on NOx Emissions of Diesel Engines

Internal combustion engines with application in automobiles and other relevant industries constitute significant environmental pollution via the release of toxic exhaust gasses like carbon monoxide (CO), hydrocarbons (HC), particulate matter (PM), and nitrogen oxide (NOx). Engine researchers and manufacturers are challenged to develop external and internal measures to ensure environmentally friendly solutions to accommodate and conform to the growing list of emission standards. Therefore, this work presents an experimental investigation of the NOx emission profile of a diesel engine that is fuelled and fitted with waste frying oil-based biodiesel and catalytic converter. Using a single-cylinder, four-stroke air-cooled CI engine at a constant speed of 1900 rpm and different loadings of 25%, 50%, 75%, and 100%;fitted with a catalytic converter at the exhaust outlet of the engine and linked to a dynamometer and a gas analyser, an experiment was conducted at biodiesel/diesel volume blends of B0 (0/10), B5 (5/95), B20 (20/80), B30 (30/70), B70 (70/30), B100 (100/0);and 30% concentration (v/v), 0.5 litre/hr flow rate of aqueous urea from the catalytic converter. The results show an increasing NOx emission as the biodiesel component increased in the blend. The catalytic converter showed a downward NOx reduction with a significant 68% reduction in efficiency at high exhaust gas temperatures. It is concluded that the combined utilisation of waste frying oil-based biodiesel and the catalytic converter yields substantial NOx emission reduction.

Effects of coating formulation on structural changes of turkey nugget during frying:MRI evaluation

Application of nondestructive techniques combined with image processing techniques has been increasing in investigating the internal structure of food products.Magnetic resonance imaging(MRI)is one of these methods.The aim of this research is to investigate the effect of coating formulation on structural properties of turkey nugget samples(turkey nugget with typical batter,tragacanth-containing batter and tragacanth)by MRI.Results revealed that the changes caused by the batter formulation could also be examined using the tomographic images.The results also indicated that the brightness of the MRI images of the nugget core and crust decreased during frying.The core of the nugget with the tragacanth-containing batter was brighter revealing its higher moisture content.Furthermore,the nugget core was less reduced in this sample compared with the other ones.This research aimed to present a valuable knowledge about nugget frying pertaining to quality evaluation.