Heated Corn Oil Research Articles

Feeding mice a diet high in oxidized linoleic acid metabolites does not alter liver oxylipin concentrations

The oxidation of dietary linoleic acid (LA) produces oxidized LA metabolites (OXLAMs) known to regulate multiple signaling pathways in vivo. Recently, we reported that feeding OXLAMs to mice resulted in liver inflammation and apoptosis. However, it is not known whether this is due to a direct effect of OXLAMs accumulating in the liver, or to their degradation into bioactive shorter chain molecules (e.g. aldehydes) that can provoke inflammation and related cascades. To address this question, mice were fed a low or high LA diet low in OXLAMs, or a low LA diet supplemented with OXLAMs from heated corn oil (high OXLAM diet). Unesterified oxidized fatty acids (i.e. oxylipins), including OXLAMs, were measured in liver after 8 weeks of dietary intervention using ultra-high pressure liquid chromatography coupled to tandem mass-spectrometry. The high OXLAM diet did not alter liver oxylipin concentrations compared to the low LA diet low in OXLAMs. Significant increases in several omega-6 derived oxylipins and reductions in omega-3 derived oxylipins were observed in the high LA dietary group compared to the low LA group. Our findings suggest that dietary OXLAMs do not accumulate in liver, and likely exert pro-inflammatory and pro-apoptotic effects via downstream secondary metabolites.

Development of Porous Epoxy Micro-Beads Using Ammonium Bicarbonate through a Single Epoxy Droplet in Corn Oil.

This paper explored the effects of ammonium bicarbonate and different ratios of epoxy to polyamide on the formation of porous epoxy micro-beads through a single epoxy droplet. A single drop of a mixture, consisting of epoxy, polyamide, and ammonium bicarbonate, was dropped into heated corn oil at a temperature of 100 °C. An epoxy droplet was formed due to the immiscibility of the epoxy mixture and corn oil. The ammonium bicarbonate within this droplet underwent a decomposition reaction, while the epoxy and polyamide underwent a curing reaction, to form porous epoxy micro-beads. The result showed that the higher ammonium bicarbonate content in the porous, epoxy micro-beads increased the decomposition rate up to 11.52 × 10−3 cm3/s. In addition, a higher total volume of gas was generated when a higher ammonium bicarbonate content was decomposed. This led to the formation of porous epoxy micro-beads with a smaller particle size, lower specific gravity, and better thermal stability. At an epoxy to polyamide ratio of 10:6, many smaller micro-beads, with particle sizes ranging from 201 to 400 μm, were obtained at an ammonium bicarbonate content of 10 phr. Moreover, the porous epoxy micro-beads with open pores were shown to have a low specific gravity of about 0.93 and high thermal stability at a high ammonium bicarbonate content. Based on the findings, it was concluded that porous epoxy micro-beads were successfully produced using a single epoxy droplet in heated corn oil, where their shape and particle size depended on the content of ammonium bicarbonate and the ratio of epoxy to polyamide used.

Heated Corn Oil and 2,4-Decadienal Suppress Gastric Emptying and Energy Intake in Humans.

Consumption of 2,4-decadienal (2,4-DD) delays gastric emptying (GE) rate in animals. Oil heating produces 2,4-DD and other aldehydes. Here we examined whether heated oil affects GE rate and food intake in humans, and whether it is mediated by 2,4-DD. In the first experiment, 10 healthy volunteers consumed 240-g pumpkin soup with 9.2 g of heated (HO) or non-heated corn oil (CO). Subsequently, 17 participants consumed pumpkin soup containing 3.1 g of either heated corn oil (HO), 1 mg 2,4-DD + non-heated corn oil (2,4-DD), or non-heated corn oil (CO). Sixty minutes following pumpkin soup, cod roe spaghetti was provided, and then energy intake was determined. To evaluate GE rate, 13C breath test (Experiment 1) and ultrasonography (Experiments 1 and 2) were used. The results from the Experiment 1 confirmed that consumption of heated corn oil reduced GE rate. Experiment 2 showed a delayed GE rate in HO and 2,4-DD trials compared with CO trial (p < 0.05). Energy intake was approximately 600–650 kJ lower in HO and 2,4-DD trials compared with CO trial (p < 0.05). These findings suggest that 2,4-DD, either formed by oil heating or added to food, contributes to suppressing GE rate and energy intake.

The Antioxidant Activity of Barley Malt Rootlet Extracts in Heated Corn Oil at Frying Temperature

In this study the antioxidant activity of barley malt rootlet (BMR) extracts was evaluated in heat treated corn oil up to 5 hours at 185°C frying temperature. The antioxidant activity of BMR extracts was measured at 25, 50, 100 and 150 ppm concentrations. The free and bound antioxidant phenolics were extracted from BMR using three different extraction methods. Conventional solvent extraction (CSE), microwave assisted extraction (MAE) and autoclave assisted pretreated solvent extraction (APSE). In the present experiment, the total phenolic content and antioxidant activity of the various extracts were measured. Thiobarbituric acid reactive substances (TBARS) assay was used to evaluate the ability of the BMR to protect lipid peroxidation in corn oil at 185°C frying temperature. The formation of TBARS at 5 hours of heat treated corn oil has shown similar antioxidant levels in 150 ppm butylated hydroxytoluene (BHT) or MAE free phenolic extract added to corn oil. TBARS value for BHT was 1.896 ± 0.013 μg/mL of corn oil and for MAE was 1.896 ± 0.034 μg/mL of corn oil. The highest level of antioxidant activity was found for the free phenolic extracts. The order of inhibition of oxidation was found to be for free phenolics as follows: BHT (100 ppm) > APSE (50 ppm) > MAE (100 ppm) > CSE (100 ppm).

Why are cooktop fires so hazardous?

A series of experiments was conducted characterizing the flammability properties of small-scale corn oil fires. The oil was placed in a pan located on the center of an electric coil heating element associated with an electric cooktop. Ignition was accomplished with a torch with the heating element off or by auto-ignition when the heating element was on. The mass loss, heat release rate, pan bottom temperature, heat flux to the surroundings, and flame height were measured. The radiative fraction and combustion efficiency were estimated from the measurements. Heating the oil on a typical electric cooktop leads to auto-ignition of the oil. Continued heating of the oil on the cooktop enhances the vaporization of the oil and leads to rapidly growing fires with relatively large peak heat release rates. Under some conditions, heated corn oil can boil-over, a phenomenon in which the oil bulk density decreases until it flows over the pan sides. For a given pan volume, the occurrence of boil-over depends on the initial fuel volume. Compared to traditional gasoline pool fires, the corn oil undergoing auto-ignition and continued heating had larger peak values of heat release rate and peak flame height by factors of 3.1 and 1.6, respectively.

Isoflavone profiles and antioxidant properties in different parts of soybean sprout.

Sprouting is one of the processing methods to enhance bioavailability of some nutrients of agricultural products. Soybeans were germinated for 6 days and soybean (SB), soybean sprout (SBS), cotyledon of soybean sprout (CSS), and hypocotyl and root of soybean sprout (HRSS) were collected. Isoflavone profiles and in vitro antioxidant activities of 80% ethanol extracts of samples were analyzed. In addition, oxidative stability of the extract was evaluated in corn oils heated at 100 °C.Thehypocotyl and root part of soybean sprout contained significantly (P<0.05) higher content of isoflavone aglycones than the cotyledon part of soybean sprout. Diphenyl-1-picrylhydrazyl radial and 2,2'-azinobis(3-ethylbenzothiazoline-6-sul-fonic acid cation radical scavenging activities of SBS were 1.6 and 1.3 times higher than those of SB, respectively (P <0.05), whereas those of CSS were 1.1 and 1.8 times higher than those of HRSS, respectively (P<0.05). CSS had higher ORAC and FRAP values than others. High correlations between contents of total flavonoids and antioxidant activities were observed in all in vitro antioxidant assays. SBS, CSS, and HRSS had significantly higher oxidative stability than SB in 100 °C heated corn oil after 9 hr treatment (P <0.05). Generally, 80% ethanol extract of CSS had high in vitro antioxidant properties whereas HRSS had high aglycone forms of isoflavones. Isoflavone aglycones may not be major ingredients providing antioxidant activities of soybean sprout. PRACTICAL APPLICATION: Soybeans are important crops for the preparation of tofu, soymilk, and protein sources. Soybean sprout prepared by germinating soybean and growing for several days is one of important food materials used as daily diet in some countries. In this study, antioxidant activities of different parts of soybean sprouts were evaluated using in vitro methods and bulk oil model systems. In addition, isoflavone profiles of soybean sprouts were determined. Enhanced antioxidant activities of soybean sprouts may help consumers choose healthier foods and extend business areas of the soybean food industry.

Effect of Consumption Heated Oils with or without Dietary Cholesterol on the Development of Atherosclerosis.

Heating oils and fats for a considerable length of time results in chemical reactions, leading to the aggravation of a free radical processes, which ultimately contributes to atherosclerosis. Our study focused on elucidating the effect of feeding heated oils with or without dietary cholesterol on the development of atherosclerosis in rabbits. We heated palm olein and corn oil at 180 °C for 18 h and 9 h per day, respectively, for two consecutive days. Next, 20 male rabbits were divided into four groups and fed the following diet for 12 weeks: (i) heated palm olein (HPO); (ii) HPO with cholesterol (HPOC); (iii) heated corn oil (HCO); and (iv) HCO with cholesterol (HCOC). Plasma total cholesterol (TC) was significantly lower in the HCO group compared to the HCOC group. Atherosclerotic lesion scores for both fatty plaques and fatty streaks were significantly higher in the HCO and HCOC groups as compared to the HPO and HPOC groups. Additionally, fibrous plaque scores were also higher in the HCO and HCOC groups as compared to the HPO and HPOC groups. These results suggest that heated palm oil confers protection against the onset of atherosclerosis compared to heated polyunsaturated oils in a rabbit model.

Effect of Emulsion Temperature on Properties of Conductive Epoxy Porous Prepared by Single Emulsion Technique

Currently, conductive porous is used in composite to reduce the conductive filler loading and improve the conductive property. In this study, conductive epoxy porous (CEP) had been fabricated by single emulsion technique from the mixture of epoxy, polyamide hardener, carbon black filler and sodium bicarbonate. Epoxy mixture was dropped into a heated corn oil at different temperatures (140, 160 and 180 °C) under stirring of 1000 rpm. Because of the immiscibility of epoxy and corn oil, epoxy droplets were formed. Initial epoxy droplets were broken into smaller droplets due to applied stirring shear. In addition, the decomposed gas (carbonic gas and water vapour) from sodium bicarbonate also caused an internal expanding pressure to further break the epoxy droplet into many fine droplets. Curing reaction of epoxy and polyamide occur simultaneously formed CEP. It was found that all the CEPs exhibited higher conductivity compared to control epoxy and epoxy composite filled equivalent content of carbon black. Furthermore, emulsion temperature of 160 °C produced the smallest porous CEP, which performed the highest electrical property.

Emission of volatile organic compounds and production of secondary organic aerosol from stir-frying spices

Cooking is an important source of volatile organic compounds (VOCs) and a potential source of secondary organic aerosol (SOA) both indoors and outdoors. In this study, VOC emissions from heating corn oil and stir-frying spices (i.e. garlic, ginger, myrcia and zanthoxylum piperitum (Sichuan pepper)) were characterized using an on-line membrane inlet vacuum ultraviolet single-photon ionization time-of-flight mass spectrometer (VUV-SPI-TOFMS). VOC emissions from heating corn oil were dominated by aldehydes, which were enhanced by factors of one order of magnitude when stir-frying spices. Stir-frying any of the spices studied generated large amounts of methylpyrrole (m/z 81). In addition, stir-frying garlic produced abundant dihydrohydroxymaltol (m/z 144) and diallyldisulfide (DADS) (m/z 146), while stir-frying ginger, myrcia and zanthoxylum piperitum produced abundant monoterpenes (m/z 136) and terpenoids (m/z 152, 154). SOA formed from emissions of stir-frying spices through reactions with excess ozone in a flow reactor as well as primary organic aerosol (POA) emissions were characterized using a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS). Stir-frying garlic and ginger generated similar POA concentrations to those from heating corn oil while stir-frying myrcia and zanthoxylum piperitum generated double the amount of emissions. No SOA was observed from stir-frying garlic and ginger. The rates of SOA production from stir-frying myrcia and zanthoxylum piperitum were 1.8μgmin−1gspice−1 and 8.7μgmin−1gspice−1, equivalent to 13.4% and 53.1% of their own POA emission rates, respectively. Therefore, the contribution of stir-frying spices to ambient organic aerosol levels is likely dominated by POA. The rates of total terpene emission from stir-frying myrcia and zanthoxylum piperitum were estimated to be 5.1μgmin−1gspice−1 and 24.9μgmin−1gspice−1, respectively. Our results suggest that stir-frying spices could be an important source of terpenes in indoor environments in Hong Kong, at least during cooking.

Investigating the amount of TFAs, CLAs and ω6/ω3 of various brands of corn oil heated at different time-temperature treatments.

A qualitative and quantitative analysis of trans fatty acids (TFAs), conjugated linoleic acids (CLAs) and linoleic acid/α-linolenic acid (ω6/ω3) in eleven different brands of fresh and heated corn oil was investigated. Corn oil was subjected to thermal treatment at 180, 210 and 230°C for 4, 8 and 12h. The kinds of fatty acids were almost the same in all eleven brands of corn oil, but there were differences in the quantities of TFAs, CLAs and ω6/ω3 among the brands. The formation of TFAs in different brands of corn oil increased slowly at 180°C and rapidly at 230°C with the maximum increase of 28 and 374%, respectively. The formation of CLAs also increased during the heating with the amount of 0.00-0.32g/100g in fresh corn oil and 0.71-1.12g/100g in corn oil heated at 230°C for 12h. The value of ω6/ω3 was high in corn oil and increased with heating temperature and time. The largest rise of ω6/ω3 can reach upwards of 239:1. The results showed that temperature control was essential for maintaining the quality and nutritional value of corn oil.

Quantifying trace elements in the emitted particulate matter during cooking and health risk assessment.

Particulate matter (PM) measurements were conducted during heating corn oil, heating corn oil mixed with the table salt and heating low fat ground beef meat using a PTFE-coated aluminum pan on an electric stove with low ventilation. The main objectives of this study were to measure the size segregated mass concentrations, emission rates, and fluxes of 24 trace elements emitted during heating cooking oil or oil with salt and cooking meat. Health risk assessments were performed based on the resulting exposure to trace elements from such cooking activities. The most abundant elements (significantly different from zero) were Ba (24.4ugm-3) during grilling meat and Ti during heating oil with salt (24.4ugm-3). The health assessment indicates that the cooking with an electric stove with poor ventilation leading to chronic exposures may pose the risk of significant adverse health effects. Carcinogenic risk exceeded the acceptable level (target cancer risk 1×10-6, US EPA 2015) by four orders of magnitude, while non-carcinogenic risk exceeded the safe level (target HQ=1, US EPA 2015) by a factor of 5-20. Cr and Co were the primary contributors to the highest carcinogenic and non-carcinogenic risks, respectively.

Preparation of Epoxy Composite Hollow Microspheres (ECHM) Using Toluenesulfonyl Hydrazide (TSH) as Blowing Agent

SummaryThe epoxy composite hollow microspheres (ECHM) was prepared by single emulsion technique. Porofor Toluenesulfonyl hydrazide (TSH) 75 was used as blowing agent. Carbon black was used as filler for polyamide‐epoxy adduct matrix, which was reverted ratio of 1:2 epoxy to polyamide. The epoxy mixture (internal phase) was dropped and stirred into a heated corn oil (external phase) to form spherical droplets. These epoxy droplets underwent two simultaneous mechanisms of curing and foaming and became hollow microspheres. As expected, higher TSH content produced lower density of ECHM because of more expansion in ECHM. This fact was also evident from the size of hollow microspheres observed by using scanning electron microscope. In addition, high TSH content of 16 phr induced higher thermal properties of ECHM compared to those of ECHM using 8 phr and 12 phr TSH.

Effect of Sodium Bicarbonate in Fabrication of Carbon Black‐Filled Epoxy Porous for Conductive Application

SummaryCarbon black‐filled epoxy porous (CBEP) was fabricated by using single emulsion technique. Mixture of epoxy, polyamide hardener, sodium bicarbonate (as blowing agent) and carbon black (as conductive filler) was dropped into a heated corn oil at 160 °C (containing free of polyunsaturated fatty acids). The epoxy‐oil system was stirred at 1000 rpm for 1 hour. Because of the immiscibility of epoxy mixture and corn oil, droplets of epoxy mixture were formed. Initial epoxy droplets were broken into small droplets due to the applied shear (from stirring). Receiving heat from oil phase, the decomposition of sodium bicarbonate and the curing reaction of epoxy and polyamide occurred simultaneously so CBEP was formed. It was found that sodium bicarbonate exhibited a significant effect on the morphology, thermal and conductivity properties of CBEP. Increase of sodium bicarbonate's content from 4 phr to 12 phr could produce larger epoxy particle size in CBEP. However, CBEP using 20 phr of sodium bicarbonate's content had the lowest particle size. The content of 20 phr could induce an early and strong decomposition reaction in the initial epoxy droplets, which broke them into smaller size; hence the smaller particle size was obtained after curing. This fact was evident from the result of bulk density, where higher sodium bicarbonate content induced lower bulk density of CBEP. Furthermore, CBEP using higher sodium bicarbonate content also exhibited better electrical conductivity.

Size segregated PM and its chemical composition emitted from heated corn oil

Characterization of the airborne particulate matter (PM) emitted from cooking components including cooking oil, and additives like salt has not been carefully investigated. This study provides new data on the concentration, composition, and emission rates/fluxes of PM (less than 3.3µm) generated during heating corn oil and corn oil with added table salt. The concept of emission flux was employed to estimate the emission rates in this study. A statistically significant reduction of 47.6% (P<0.05) in the total PM emission rate and emission flux were observed when salt was added to the heated corn oil (5.15×101mgmin−1) compared to the pure oil (9.83×101mgmin−1). The OC emission rate decreased 61.3% (P<0.05) when salt was added to the corn oil (2.35×101mgmin−1) compared to the pure corn oil (5.83×101mgmin−1). With the salt, the total EC emission rate was 6.99×10−1mgmin−1, a 62.7% reduction in EC emission compared to pure corn oil (1.88mgmin−1). These results suggest that table salt can be added to the corn oil prior to frying to reduce exposure to cooking generated PM.

Thermal oxidative stability of corn oil in ultra-high temperature short-time processed seasoned laver

The thermal oxidative properties of oils under general frying conditions (150–200°C) have been extensively studied; however, there is no information on the thermal oxidation of ultra-high temperature short-time (UHTST) processed oils. Here, we investigated the thermal oxidative properties of corn oil in seasoned laver that was prepared using the UHTST conditions (300°C for 10 s). The oxidation induction times of corn oil (CO), heated corn oil (HCO), and heated corn oil from seasoned laver (HCO-SL) were found to be 5.3, 3.3, and 4.1 h, respectively. The acid value (0.1) and peroxide value (2.2) in CO were increased to 0.2 and 2.5, respectively, in HCO and 0.2 and 5.5, respectively, in HCO-SL. The radical scavenging activities of CO, HCO, and HCO-SL were 72.4, 63.8, and 74.8%, respectively. Although both HCO and HCO-SL were treated using the UHTST conditions, HCO-SL was found to have a better induction time and antioxidant capacity than HCO.

Focus

Focus

The Effect on Growth and Lipid Profile in Rats Fed Microwave Heated Corn Oil

The Effect on Growth and Lipid Profile in Rats Fed Microwave Heated Corn Oil

Antioxidant Activity of the Extracts Derived from Terminalia catappa

The extracts derived from Terminalia catappa leaves and fruit following antioxidant activity directed isolation, were screened for their antioxidant activity through their ability to scavenge DPPH radicals. Only fractions which exhibited &gt;50% DPPH scavenging effect at each step of isolation were selected for further purification and judge their ability to reduce peroxide formation (peroxide value) in heated corn oil. The results indicated that crude ethanolic extract, aqueous fraction of crude extract and its sub fractions (petroleum ether and ethylacetate) possessed prominent antioxidant activity. In addition, phytochemical analysis showed that the five fractions obtained finally contain simple phenols, anthocyanins, phenyl propanoids and flavanols.

QUALITY DETECTION OF HEATING CORN OIL USING VISIBLE AND INVISIBLE LIGHT

The corn oil was heated at 180 o C. for six durations (3, 6, 9, 12, 15, and 18 hrs) to measure some optical, physical and chemical properties of oil with exposure by visible and invisible lights. Three light regions, ultraviolet (200-400nm), visible light (400-700nm), and near infrared (700-900nm) were used in the present work. The obtained results are summarized as follows: (1) The highest transmission light percentages were 94.89, 88.57 and 33.17 % for using wavelengths of 900 nm (IR), 700 nm (VIS) and 400 nm (UV), respectively.; (2) The highest absorption light percentages from heated corn oil were 0.09, 0.12, and 1.26 % at using 900 nm (IR) , 700 nm (VIS), and 400 nm (UV) wavelengths.; (3) The wavelength (400 nm) of UV is the highest measure of absorption light of corn oil. Meanwhile, 900 nm of IR and 700 nm of VIS are the highest measure of transmission light can be used to measure corn oil quality.; (4) The heating times were increased from 3 to 18 hrs lead to increase oxidized fatty acid, Polemer, acid value, peroxide value, and reflective index, while, the iodine value and viscosity were decreased compare with control sample.; and (5) The corn oil will start deterioration after 15 hrs of heating time whereas oxidization fatty acid more than 1% at transmission light percentages 13.69 % and 12.20% of wavelength 900 nm (IR) and 700 (VIS) and at absorption percentage 1.06% of wavelength 400 nm (UV).

Effect of dietary fats on blood cholesterol and lipid and the development of atherosclerosis in rabbits

The objective of this study was to determine the effects of dietary fat on the development of atherosclerosis and changes in blood lipids in rabbits. Forty New Zealand White rabbits were divided into 5 groups and fed commercial rabbit chow with 0% oil (control), 2% corn oil, 2% fish oil, 2% oxidized oil, or 2% heated corn oil. Cholesterol (CHO, 1.5-g/kg diet) was added to all the experimental diets. The rabbits in the control and oxidized oil groups developed the highest scores for atherosclerotic lesions but those fed fish oil, corn oil, and the heated corn oil groups had the lowest lesion scores. Plasma triacylglycerol, total CHO, and low-density lipoprotein and high-density lipoprotein CHO levels ( P < .05) in rabbits followed the trend of higher levels consistent with scores for atherosclerotic lesions. Plasma total CHO level was one factor closely related to the development of atherogenic lesions in the rabbit. Dietary CHO and oxidation status of dietary lipids significantly impacted lipid metabolism and the development of atherosclerosis in rabbits. Oxidized dietary oil accelerated the progress of atherosclerotic lesions, but polymerization of oils by heating lowered plasma CHO level and the development of atherogenic lesions in rabbits. Heating of oil appeared to reduce the absorption of CHO in the rabbit.