Deep Frying Research Articles

Quality parameters during deep frying of avocado oil and extra-virgin olive oil

Avocado oil has a good thermal stability. However, there is a lack of knowledge about the behavior when hydrolysis is involved with oxidation processes. This study demonstrated potential for deep frying process of avocado oil. The behavior of cold-pressed olive oil and avocado oil in a domestic frying process with natural potatoes was studied. Both oils were subjected to successive frying cycles and the following chemical properties were analyzed: degree of acidity, peroxide value, p-anisidine value, total oxidation (TOTOX) value, polar compounds, total phe-nolic content, Fourier-transform infrared spectra with attenuated total reflectance, and fatty acid profile. A grad-ual increase was observed in the degree of acidity, p-anisidine, TOTOX, polar compounds but a decrease in total phenolic content during deep-frying period for both oils. It was determined that avocado oil and olive oil take 10 and 13 days of frying cycles, respectively, to reach the limit value of 25% for polar compounds. It was demon-strated that both vegetable oils are suitable for domestic frying processes, enduring a high number of deep-frying cycles before reaching the limit of polar compounds established by health regulations, despite the generation of oxidation and hydrolysis processes.

Investigation of the Frying Fume Composition During Deep Frying of Tempeh Using GC-MS and PTR-MS

This study employed proton transfer reaction mass spectrometry (PTR-MS) and gas chromatography–mass spectrometry (GC-MS) to identify and monitor volatile organic compounds (VOCs) in frying fumes generated during the deep frying of tempeh. The research aimed to assess the impact of frying conditions, including frying temperature, oil type, and repeated use cycles, on the formation of thermal decomposition products. A total of 78 VOCs were identified, with 42 common to both rapeseed and palm oil. An algorithm based on cosine similarity was proposed to group variables, resulting in six distinct emission clusters. The findings highlighted the prominence of saturated and unsaturated aldehydes, underscoring the role of fatty acid oxidation in shaping the frying fume composition. This study not only corroborates previous research but also provides new insights into VOC emissions during deep frying, particularly regarding the specific emission profiles of certain compound groups and the influence of frying conditions on these profiles.

Fat Uptake Reduction During Deep-Fat Frying of Fish Fillets Coated with Soy Protein Isolate Edible Coating

ABSTRACT Rohu fish (Labeo rohita) fillets were coated with 2.5% to 25% soy protein isolate (SPI) to evaluate their ability to reduce fat uptake. The coating pickup of fish fillets increased with increasing coating concentration. Fillets coated with 15% SPI showed the highest coating pickup value of 18.29% and reduced fat uptake by 57.78%. As revealed by lowered carbonyl and sulfhydryl contents, SPI coating protected proteins from oxidation during deep-frying. Increasing coating concentration decreased the hardness, chewiness, and cutting force of coated fish fillets. Therefore, the aforesaid coatings could be recommended for making low-fat fried fish fillets with 15% SPI.

Premised research on dietary exposure to benzo[a]pyrene, acrylamide, and Nnitrosodimethylamine from common fried and grilled dishes in North Vietnam

Fried and grilled cooking methods and the widespread consumption of certain dishes may expose the population to elevated levels of potentially carcinogenic compounds, such as benzo[a]pyrene (BaP), acrylamide, and N-nitrosodimethylamine (NDMA). This study aims to quickly estimate dietary exposure to these contaminants and assess the associated carcinogenic risk for several common Vietnamese fried and grilled dishes. The concentrations of the target compounds were obtained from the study showed that BaP, NDMA, and acrylamide are the groups of substances of greatest concern. The analytical results of 235 samples of meat and meat products (grilled/fried/smoked), seafood and seafood products (grilled/fried/smoked), processed oils, and potatoes showed that 12 samples detected acrylamide in the range of 5.0 – 162.0 µg/kg found in grilled/fried dishes and 5.0 – 4605 µg/kg for fried potatoes. Additionally, 204 samples detected NDMA in all groups in the range of 0.20 – 15.0 µg/kg, and 27 samples detected BaP in the range of 5.2 – 88 µg/kg in grilled/roasted food. Combined with information on food consumption patterns to estimate dietary exposure, four age groups were divided into under 6 years old, 6 – 18 years old, 18 – 50 years old, and over 50 years old, which showed that the consumption of processed foods by age groups was very different. In particular, the age group from 6 to 50 years old was the group that consumed the most of these foods (14.1 – 140 g/day). Specifically, up to 94.4% of people interviewed ate fried meat, 88.8% ate fried seafood and 85% ate fried potatoes. Risk characterization using the margin of exposure (MOE) and Cancer Slope Factor approaches indicate that certain dishes, such as grilled/smoked meat and fish, and deep-fried foods, may pose a significant cancer risk to Vietnamese consumers.

Effect of chitosan nanoparticle filled methylcellulose coatings on the polycyclic aromatic hydrocarbon levels of deep-fried meatballs

Polycyclic aromatic hydrocarbons (PAHs) are a group of carcinogens commonly found in deep-fried food products. The potential health risks of dietary exposure to PAHs are well recognized. Recent studies have shown that PAHs can penetrate into food through oil uptake, implying potential of edible coatings to reduce oil uptake and then PAHs level. This study investigated the effect of incorporation of 0.2/0.5% chitosan nanoparticles (CSNPs, w: v) into 0.8/0.5% methylcellulose (MC, w: v) for edible coating of meatballs to reduce the PAH levels under deep-frying condition at 190 °C for 5min. The results showed that the deep-fried meatballs coated with 0.5 % MC and CSNPs had the lowest moisture loss (25.87 %), oil uptake (1.29 %), lipid oxidation (0.54 mg MDA/kg) and PAH4 levels (0.73 ng/g). The results suggested that the incorporation of CSNPs into MC edible coating could be an effective method in reducing the PAHs levels and enhancing the quality and safety of deep-fried foods. Future study would incorporate CSNP-MC coatings with antioxidants to further enhance the quality and safety of deep-fried foods and their impacts on sensory properties.

Comparing effects of tangerine-peel (Citrus reticulata Blanco) age and concentration on deep-fried rabbit meat: Impact on heterocyclic aromatic amines, amino acids, and flavor compound formation

Many nutritional experts recommend rabbit meat as a high-protein source. However, the high temperatures used to prepare deep-fried rabbit meat (DFRM) typically produce numerous heterocyclic aromatic amines (HAAs), a class of substances with carcinogenic risks. In this study, we chromatographically evaluate changes in the volatile compounds, amino acids, and HAAs in DFRM while employing tangerine peel (TP) as an additive. A total of 35 volatile organic compounds are detected in the TP, which increase the concentrations of sweet and umami amino acids in the DFRM. Remarkably, the TP substantially inhibits the IQ-type HAAs, particularly MeIQ, MeIQx, 4,8-DiMeIQx, and PhIP, which are produced during deep frying. Correlation analyses reveal that the histidine, aldehydes, and alcohols are strongly and positively correlated (P < 0.001) with the MeIQ, MeIQx, 4,8-DiMeIQx, and PhIP production. This study offers innovative and natural approaches for reducing HAA formation during the frying of rabbit meat.

The relationship between the deterioration of frying oil and the generation of hazards during frying

Deep-fat frying gives food a desirable color and flavor but inevitably leads to oil deterioration and production of hazards. In this study, the simultaneous generation of multiple hazards under different frying conditions was investigated, the deterioration of frying oil was evaluated, and finally, their correlation was analyzed. The results showed that as the temperature of frying chicken wings increased from 150 to 190 °C, the levels of acrylamide (AA), heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs) in the oil also increased proportionally. At 190 °C, the fried potato oil contained the highest AA content of 2.60 mg·kg−1, while the content of HCAs and PAHs was the highest in fried chicken wings oil, with values of 5.06 μg·kg−1 and 5.18 μg·kg−1, respectively. 5-Hydroxymethylfurfural was detected only in fried potato oil. Oil quality deteriorated gradually with increasing frying temperature and heating time, as indicated by increased acid value, carbonyl value, and levels of total polar compounds. Overall, the results indicated hazards were positively correlated with oil deterioration, suggesting that oil deterioration contributed to the generation of hazards. This work links hazards and oil deterioration, which is crucial for improving the quality and safety of fried foods, while reducing negative environmental impacts, and achieving clean production.

Multiple mechanisms of action of an extremely painful venom.

Evolutionary arms races between predator and prey can lead to extremely specific and effective defense mechanisms. Such defenses include venoms that deter predators by targeting nociceptive (pain-sensing) pathways. Through co-evolution, venom toxins can become extremely efficient modulators of their molecular targets. The venom of velvet ants (Hymenoptera: Mutillidae) is notoriously painful. The intensity of a velvet ant sting has been described as "Explosive and long lasting, you sound insane as you scream. Hot oil from the deep fryer spilling over your entire hand." [1] The effectiveness of the velvet ant sting as a deterrent against potential predators has been shown across vertebrate orders, including mammals, amphibians, reptiles, and birds [2-4]. The venom's low toxicity suggests it has a targeted effect on nociceptive sensory mechanisms [5]. This leads to the hypothesis that velvet ant venom targets a conserved nociception mechanism, which we sought to uncover using Drosophila melanogaster as a model system. Drosophila larvae have peripheral sensory neurons that sense potentially damaging (noxious) stimuli such as high temperature, harsh mechanical touch, and noxious chemicals [6-9]. These polymodal nociceptors are called class IV multidendritic dendritic arborizing (cIV da) neurons, and they share many features with vertebrate nociceptors, including conserved sensory receptor channels [10,11]. We found that velvet ant venom strongly activated Drosophila nociceptors through heteromeric Pickpocket/Balboa (Ppk/Bba) ion channels. Furthermore, we found a single venom peptide (Do6a) that activated larval nociceptors at nanomolar concentrations through Ppk/Bba. Drosophila Ppk/Bba is homologous to mammalian Acid Sensing Ion Channels (ASICs) [12]. However, the Do6a peptide did not produce behavioral signs of nociception in mice, which was instead triggered by other non-specific, less potent, peptides within the venom. This suggests that Do6a is an insect-specific venom component that potently activates insect nociceptors. Consistent with this, we showed that the velvet ant's defensive sting produced aversive behavior in a predatory praying mantis. Together, our results indicate that velvet ant venom evolved to target nociceptive systems of both vertebrates and invertebrates, but through different molecular mechanisms.

Evaluation of quality parameters of unripe mature jackfruit chips at varied temperature through deep fat frying process

Evaluation of quality parameters of unripe mature jackfruit chips at varied temperature through deep fat frying process

Liver response to the consumption of fried sunflower oil

Sunflower oil is one of the most commonly used fat sources in Argentina, and deep-fat frying is the popular food preparation process. The liver response of feeding a diet containing fried sunflower oil (SFOx) on growing rats was studied. Thirty-nine male weanling Wistar rats were randomly assigned to one of three diets for 8 wks: control (C), sunflower oil (SFO), and a diet containing SFOx, both of the sunflower diets were mixed with a commercial rat chow at weight ratio of 13% (w/w). Body weight and food consumption were recorded weekly. At t=8 wk, lipid profile and glycemia were measured. Visceral adiposity was registered. Liver was weighed and preserved for histological analysis, relative fatty acid profile, fibrosis markers and oxidative status.The three diets did not alter body weights; however, the SFOx fed rats showed increased energy intake and visceral fat; therefore, in liver saturated fat content, trans fatty acids, plus other unidentified minor components, such as hydroperoxides, hydroxides, epidioxides, hydroperoxy epidioxides, hydroxylepidioxides, and epoxides, were detected. The hepatosomatic index of SFOx rats was altered and showed hepatic steatosis. SFOx rats exhibited increased liver dichlorodihydrofluorescein-diacetate and thiobarbituric acid substance levels and oxidized-proteins content. Their livers had lower relative levels of monounsaturated, polyunsaturated fatty acids and catalase activity, but matrix metalloproteinase-9 activity was unchanged.Consumption of a diet rich in fried oil during growth could induce liver damage due to steatosis, excessive lipid toxicity and the accumulation of reactive oxygen species. Further progression could lead to hepatic fibrosis.

Associations between cooking method of food and type 2 diabetes risk: A prospective analysis focusing on cooking method transitioning

Cooking process for food significantly impacts household air and increases exposure to endocrine disruptors such as acrylamide, consequently affecting human health. In the past 30 years, the transformation of cooking methods to high-temperature thermal processing has occurred widely in China. Yet the transition of cooking methods on the onset of type 2 diabetes (T2D) remains unclear, which may hinder health-based Sustainable Development Goals. We aimed to estimate the associations between dietary intake with different cooking methods and T2D risk. We included 14,745 participants (>20 y) from the China Health and Nutrition Survey (1991–2015). Food consumption was calculated using three consecutive 24-h dietary recalls combined with both individual participant level and household food inventory. Cooking methods, including boiling, steaming, baking, griddling, stir-frying, deep-frying, and raw eating, were also recorded. The consumption of baked/griddled and deep-fried foods was positively associated with 39% and 35% higher of T2D risk by comparing the highest with the lowest category of food consumption, respectively. The use of unhealthy cooking methods for processing foods including baked/griddled and deep-fried foods was attributable for 15 million T2D cases of the total T2D burden in 2011, resulting in a medical cost of $2.7 billion and was expected to be attributable for 39 million T2D cases in 2030, producing a medical cost of $223.8 billion. Replacing one serving of deep-fried foods and baked/griddle foods with boiled/steamed foods was related to 50% and 20% lower risk of T2D, respectively. Our findings recommend healthy driven cooking methods for daily diet for nourishing sustainable T2D prevention in China.

Feeding rats with used cooking oil elevates malondialdehyde, TNF-α, and creatinine compared to tempe fried with used oil.

In vivo studies on the hazards of deep-fried foods were commonly done by feeding used-or heated-cooking oil to rats. The aim of this study was to determine the effect of feeding tempe deep-fried in palm, olive, and coconut oils and the used frying oil on the blood biochemical profile of laboratory rats. An in vivo randomized control group study with pre-test and post-test was conducted. This study included healthy male Sprague-Dawley rats aged 2-3 months and weighing 100-200 grams. After acclimatization, the rats were randomly assigned to seven groups, which were: (1) regular diet (control diet); (2) diet of tempe deep-fried in 5× used palm oil (Tempe-in-used-Po); (3) diet of tempe deep-fried in 5× used coconut oil (Tempe-in-used-Co); (4) diet of tempe deep-fried in 5× used olive oil (Tempe-in-used-Oo); (5) diet of 5× used palm oil (Used-Po); (6) diet of 5× used coconut oil (Used-Co); and (7) diet of 5× used olive oil (Used-Oo). Each rat received 15 grams of a treatment diet daily and blood samples were collected after four weeks for a complete blood count and serum biochemistry analysis. The results showed that the final body weight and the weight gain of Tempe-in-used-Po, Tempe-in-used-Co, Tempe-in-used-Oo group, and Used-Po groups increased significantly compared to the control, Used-Co, and Used-Oo groups. However, there was a significant increase in serum tumor necrosis factor-alpha (TNF-α) in the Used-Co and Used-Oo groups (p<0.05), suggesting the used oil's detrimental effect. The Used-Co and Used-Oo were the only two groups whose creatinine increased significantly (p<0.05). Subsequently, only the Used-Oo group had a significantly increased malondialdehyde (MDA) level compared to all groups (p<0.05). These results prove that the effect of feeding fried food differs from used oils. Feeding used oil did not reflect the consumption of fried foods as part of the whole diet and generally resulted in more harmful effects. This is the first study to report an in vivo rat feeding study of deep-fried tempe and the used oil as part of the diet.

Effect of Oil Type on Momentum, Heat, and Mass Transfer During Deep-Fat Frying of Potato Strips: Numerical and Experimental Study

Effect of Oil Type on Momentum, Heat, and Mass Transfer During Deep-Fat Frying of Potato Strips: Numerical and Experimental Study

Effects of deep, air and vacuum frying on oyster quality and protein-mediated mechanism analysis via TMT quantitative proteomics

AbstractFried oyster is a popular aquatic food product in East Asia, but nutrient loss during thermal processing become a significant concern. The goal of this research was to examine the impact of distinct frying techniques, including deep frying (DF), air frying (AF), and vacuum frying (VF), on the nutritional, textural and flavor characteristics of oysters. The VF method demonstrated superior retention of beneficial properties and flavor, and reduced protein and lipid oxidation compared to the DF and AF methods. Furthermore, proteomic analysis of oysters was attempted to explain the molecular mechanisms governing the influence of key differential proteins. 20 major differential proteins, including actin-2 protein, tryptophan 2,3-dioxygenase and 1-alph, involved in oyster protein oxidation were identified, annotated and analyzed to elucidate their influence mechanisms. This research provides a deeper understanding of intricate interactions between frying techniques and oyster biochemistry, which offers valuable implications for enhancing food quality in seafood industry

Maternal Vitamin D3 Supplementation in an Oxidized-Oil Diet Protects Fetus from Developmental Impairment and Ameliorates Oxidative Stress in Mouse Placenta and Fetus

BackgroundFried food has increased in popularity worldwide. However, deep frying can increase the production of peroxidative toxins in food, which might be harmful to fetal development. The antioxidative effect of vitamin D3 (VD3) has been reported previously. ObjectivesThis study aimed to explore how maternal VD3 supplementation in an oxidized-oil diet during gestation affects fetal antioxidative ability and development. MethodsPregnant mice were randomly assigned into 3 groups: Control group (diet with fresh soybean oil), OSO group [diet with oxidized soybean oil (OSO)], and OSOV group (diet with OSO and 10,000 IU/Kg VD3). Mice were fed with the corresponding diet during gestation. On day 16.5 of gestation, the placenta and fetus were harvested to analyze antioxidative status. ResultsMaternal oxidized-oil diet during gestation significantly reduced placental vessel abundance, labyrinth zone area, and fetal body weight. However, dietary VD3 supplementation prevented these negative effects of oxidized-oil diet. Maternal intake of oxidized-oil diet increased serum concentrations of malondialdehyde, total-nitric oxide synthase, and inducible nitric oxide synthase, whereas VD3 supplementation showed a protection effect on it. Additionally, maternal VD3 supplementation increased the levels of antioxidative enzymes and the nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2), thereby protecting placenta and fetus from apoptosis and oxidative stress caused by an oxidized-oil diet. The gene expression and protein levels of a fatty acid transporter solute carrier family 27 member 1 in the fetal liver were increased by maternal VD3 supplementation under oxidized-oil diet. Notably, NRF2 could be co-immunoprecipitated with the VD receptor in the placenta. ConclusionsMaternal VD3 supplementation could protect fetus from oxidized-oil diet induced developmental impairment by alleviating oxidative stress in the placenta and fetus through the VD receptor/NRF2 pathway, at least partially. Thus, ensuring adequate levels of VD3 through supplementation is often critical during pregnancy.

Gluten-free snacks based on a flour composite mixture, fortified with the Asafoetida spice (Ferula assa-foetida)

A recipe of snacks based on flour composite mixtures has been developed and scientifically substantiated with the aim of extending an assortment of flour snack products belonging to the category of specialized products. These snacks are intended for consumers adhering to the health nutrition principles and, first of all, for patients with celiac disease. Gluten-free types of flour fortified with the asafoetida spice are used in the recipe. Preliminary studies demonstrated that the formulation with a ratio of 60% rice flour, 20% pea flour and 20% chickpea flour had the highest biological value among six variants of flour mixtures. Using the mass-spectrometry method, a wide spectrum of aromatic substances belonging to different classes of organic compounds was revealed in the composition of the asafoetida spice, including aliphatic alcohols, oxo-compounds, aliphatic and aromatic carboxylic acids, esters, terpenes, phenol derivatives, heterocyclic aromatic compounds (derivatives of furan and thiophene). They have a wide spectrum of action: determine taste and aroma, show the antioxidant properties, and prevent fat rancidification. The investigations showed that addition of 0.2% of asafetida to the flour mixture not only increased the oxidative stability of snacks (induction period increased by 1.5 times), but also reduced the content of lipids. This was achieved due to a decrease in fat absorption during deep-fat frying (approximately by 1.5 times). As a result, the caloric content of the product reduced by 6.8% compared to the control, the oxidation processes were retarded and the shelf-life of snacks was extended. The results of the organoleptic assessment show that gluten-free snacks with the addition of asafetida are significantly superior to the control sample. The total score of snacks with asafetida was 24 points compared to 19 points given to the control sample. They had the most harmonious appearance, color, taste, and odor according to the profilogram of organoleptic indicators among products such as gluten-free snacks based on flour composite mixtures without additives (control), with addition of dietary fibers, with addition of the asafoetida spice and dietary fibers.

Deep Fat Frying of Fruits, Vegetables and Tuber Crops: A Review

Deep Fat Frying of Fruits, Vegetables and Tuber Crops: A Review

Physicochemical characterization of wheat starch and variation of fatty acid composition in deep-fried dough sticks with different treatments.

The present study investigated the effects of different deep-frying times and temperatures on the amylose content, crystal structure, thermodynamics, and other properties of deep-fried dough sticks. Results showed that the change of amylose content in deep-fried dough sticks during the deep-frying process was positively correlated with time and temperature. Moreover, the deep-frying process of deep-fried dough sticks was accompanied by the formation of starch-lipid complexes that led to the destruction of starch structure. The degreased sample and the oil sample had the same absorption peaks at 2854 and 1746cm-1, respectively. The melting enthalpy (ΔH) of the starch-lipid complex decreased significantly. In addition, the viscosity of starch reduced as the deep-frying time and temperature increased. Furthermore, it was found that the effect of increasing deep-frying temperature was greater than that of time. PRACTICAL APPLICATION: As a popular deep-fried food, the main component of deep-fried dough sticks is starch. Starch gelatinization, protein denaturation, and interaction among components occurred during deep-frying. At present, there are few studies focusing on the properties of starch in deep-fried dough sticks in the real deep-frying system. Therefore, this study provided a theoretical basis for subsequent research by measuring the effects of different deep-frying conditions on the properties of starch in deep-fried dough sticks.

The use of chitosan aerogels as an adsorbent for the regeneration of frying oil

One of the most commonly used food preparation methods is deep-fat frying. The improvement of the quality of used frying oil (UFO) is important because the reuse of frying oil could provide significant savings to the food industry. This study aimed to enhance the quality of used sunflower oil by using chitosan aerogels (CA), which can be considered as novel adsorbents with an increased surface area compared to chitosan powder. Aerogels are novel nanostructured materials with high porosity and large surface area. In this study, CA were produced by drying the 2% (w/v) chitosan gels using supercritical drying. In the study, 32 consecutive deep-fat frying were performed using potato slices in sunflower oil at 180 ± 5 °C. The effect of the adsorbent concentration (0.5, 1, and 2% (w/w)) and different adsorption temperatures (90, 135, and 180 °C) were studied by examining the UFO before and after the adsorption treatments. The physicochemical properties of the oil were analyzed by determining free fatty acid (FFA) content, total polar compounds (TPC), smoke point, p-anisidine value (p-AnV), and color (CIE L*, a*, b*). Moreover, the structural changes of aerogels after the adsorption process were investigated by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). CA could reduce the % FFA values from 0.44% to 0.18% due to the ionic interaction between CA and FFA. In addition, TPC value and the smoke point increased after the treatments. The p-AnV was compensated with CA, indicating that secondary oxidation products were adsorbed. Moreover, CA caused a darker color after the adsorption treatments. Additionally, compared with magnesium silicate, the same concentrations of CA were found more effective in improving all the quality parameters of oil except for the L* values.

Analysis of volatile compounds and 5-hydroxymethylfurfural in fried chicken breast produced by air and deep-fat frying.

Two samples, simple-battered chicken (SBC) and normal-battered chicken (NBC), with different batters were deep-fat fried at various conditions and volatile compounds and 5-hydroxymethylfurfural (5-HMF) was analysed. The moisture content of the air-fried samples was significantly higher than that of the deep-fat fried samples in the same batter samples. A total of 72 volatile compounds (8 aldehydes, 15 monoterpenes, 12 sesquiterpenes, 2 terpene alcohols, 4 benzenes, 13 pyrazines, 2 pyridines, 6 furans, 5 alcohols, 2 pyrroles, and 3 others) were detected in fried chicken breast, and air-fried SBC possessed the highest total amount of volatile compounds. Furthermore, 5-HMF was exclusively detected in NBC samples; in particular, 1.27 ± 0.06 and 0.41 ± 0.02μg/mL were detected in deep- and air-fried NBC, respectively. This study indicates the potential of air frying to reduce the formation of 5-HMF while maintaining quality characteristics, suggesting the need for further study on other hazardous compounds.