Chemical Properties and Cytotoxicity of Thermally Oxidized Oil

Totani, Nagao; Burenjargal, Munkhjargal; Yawata, Miho; Ojiri, Yuko

doi:10.5650/jos.57.153

Cited by 38 publications

(32 citation statements)

References 19 publications

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“…It is common understanding in Japan [11][12][13] that edible oil should have POV <30 mEq/kg for the safety reason. It has also been reported 14) that properties such as POV, COV, PC, AV, and TG have little to do with cytotoxicity causing degeneration in the liver and kidneys, but that low molecular-weight compounds…”

Section: Discussionmentioning

confidence: 99%

“…It is not clear yet by what mechanism gluten inhibited the cytotoxicity of heated oil. We suggest that the formation of low-molecular-weight compounds causing cytotoxicity, generated through decomposition of thermally oxidized oil, was inhibited and/or decreased by gluten 14) . The difference in the effect of oils heated with amino acids and gluten on cytotoxicity was conjectured to be due to the molecular size of the melanoidin formed from them 4) .…”

Section: Diet Oilmentioning

confidence: 91%

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Effects of Oil Heated with Gluten on Weight-Loss Dieting. I.

2008

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Fresh oil was heated for 20 h at 180 with amino acids or gluten. A powdered diet (AIN93G; no fat) was mixed with 7 wt% of fresh oil (control), or supernatants of the heated oils described above, and fed to male Wistar rats for 12 weeks. No gross symptoms attributable to the heated oils were observed, but the gluten group showed a slow body weight increase; a significant difference was found in the weight after age 21 weeks in spite of diet consumption comparable to that of the control group. The serum of the heated oil groups showed a tendency toward lower values on various hematological measures, especially triacylglycerol and free fatty acid and toward higher values on aspartate aminotransferase (AST) and alanine aminotransferese (ALT), than those of the control group. All the rats except one in the gluten group had the same level of AST as those of the control rats, while the amino acid group included four rats with AST over 100 IU/L, the highest value in the control group. The number of dark red patches found on the surface of the liver and histological evaluation also showed frequent damage to the livers of the amino acid group. The difference in toxicity between the two heated oils seems to be related to the molecular sizes of amino acids and gluten. Gluten or melanoidin produced during heating probably decreased or counteracted the cytotoxicity of thermally oxidized oil. It is expected that oil heated with gluten can be used as a safe and effective oil for humans on weight-reduction diets.

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Section: Discussionmentioning

confidence: 99%

Section: Diet Oilmentioning

confidence: 91%

Effects of Oil Heated with Gluten on Weight-Loss Dieting. I.

2008

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“…Ideally, the substances should be soluble in oil and effective in very limited quantities. Soybean protein employed in the present study contained various components other than protein, but it has been confirmed 20,21) that the body weightloss promoting effects in excess of those from protein were not expected from amino acids, sucrose, and carbohydrates.Dieting oils presently marketed around the world contain Salatrim ®22) , Caprenin ®23) , Olestra ®24,25) , Econa ®26-28) and Healthy Resetta ®29-31) . Salatrim ® , Caprenin ® , and Healthy Resetta ® are triacylglycerides esterified with long and short (medium) chain fatty acids.…”

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confidence: 99%

A Novel Body Weight-loss Promoting Oil Prepared with Vegetable Protein

et al. 2010

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It has been reported that oil thermally processed with wheat gluten (gluten oil) exhibited safe weight-loss promoting effects in animal experiments. However, as the oil has a high color index, and its chemical properties and smell differ from those of fresh oil, it is uncertain if the oil will find market acceptance. In order to resolve the issue, frying oil was heated with soybean protein under reduced pressure (soybean protein oil), resulting in a product with an appearance, chemical properties and smell comparable to those of fresh oil. This improved oil was mixed (7 wt%) with powdered AIN93G no fat, defined standard diet and fed to 10-week-old Wistar rats ad libitum. The experimental rats grew normally, ingesting the same amount as that of the control rats; however, there was a negative correlation between body weight increases and fecal weight increases. After the 12-week feeding period, all the rats were sacrificed to obtain blood and organs. In the experimental group, liver weight, retroperitoneal fat tissue weight and serum triacylglycerol (TG) levels decreased significantly. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and histological analysis supported the safety of the improved oil. In conclusion, it was found that soybean protein oil inhibited body weight increases without any adverse effects in animal experiments. The oil holds promise as a novel dieting oil that steadily decreases body weight at an appropriate rate.Key words: soybean protein, weight-loss promoting, fecal weight, serum triacylglycerol level, retroperitoneal fat tissueCorrespondence to: Nagao Totani, Department of Nutritional Physiology, Faculty of Nutrition, Kobe-Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe, 651-2180 JAPAN E-mail: totani@nutr.kobegakuin.ac.jp Accepted September 19, 2009 (received for review May 30, 2009 One liter of fresh frying oil (Fuji Oil Co., Ltd., Osaka, Japan) was heated at 180 and 5 Torr for 10 h in a 2-L four-neck round-bottom flask under stirring with 1wt% soybean protein. Oil heated with protein was filtered over filter paper under reduced pressure (soybean protein oil) and employed for an animal experiment. Oil AnalysesPeroxide value (POV), carbonyl value (COV), acid value (AV), iodine value (IV) and Lovibond color were measured according to the Japan Oil Chemists' Society's Standard Methods for the Analysis of Fats, Oils, and Related Materials. The content of polar compounds (PC) was analyzed by a PC Tester, 3M, Saint-Ouen l'Aumone, France 3) . Triacyglycerol contents (TG) were determined by applying samples on Chromarods followed by development in a solvent mixture, hexane/diethyl ether/acetic acid, 50:10:1 v/v/v, and quantification with Iatroscan MK-6s, Iatron Laboratories, Inc., Tokyo, Japan. After esterification of oil with diazomethane for possible free fatty acids and then with sodium methoxide for triacylglycerol, oil was analyzed by Shimadzu GC-2010 gas chromatograph equipped with 60-m SP TM -2340 capillary column of 0.25 mm bore, Supelco, St. Lo...

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“…Keywords: antioxidant activity; frying; polymerised triacylglycerols; prooxidant activity; tocopherols In spite of the low acute toxicity of oxidised fats and oils (Esterbauer 1993), a lot of undesirable effects were observed in some long-term tests with them (Alexander 1981;Izaki et al 1984;Kubow 1990;Esterbauer 1993;Chow 2007;Totani et. al.…”

Section: Introductionmentioning

confidence: 99%

“…The prooxidant capacity of the heated oils ranged from 58 mg to 360 mg α-tocopherol/kg and decreased in the order soybean oil > rapeseed oil > olive oil ≈ sunflower oil. It did not correlate with the content of polymerised triacylglycerols (except the sunflower oil) and was generally higher than the residual content of α-tocopherol.Keywords: antioxidant activity; frying; polymerised triacylglycerols; prooxidant activity; tocopherols In spite of the low acute toxicity of oxidised fats and oils (Esterbauer 1993), a lot of undesirable effects were observed in some long-term tests with them (Alexander 1981;Izaki et al 1984;Kubow 1990;Esterbauer 1993;Chow 2007;Totani et. al.…”

mentioning

confidence: 99%

Prooxidant capacity of thermoxidised plant oils

Réblová¹,

Součková²,

Fišnar³

et al. 2015

Czech J. Food Sci.

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Réblová Z., Součková Š., Fišnar J., Koplík R. (2015): Prooxidant capacity of thermoxidised plant oils. Czech J. Food Sci., 33: 416-423.The prooxidant capacity of rapeseed, sunflower, soybean, and olive oil was determined before and after heating at a temperature of 180°C for 2, 4, and 6 hours. It was quantified as losses of α-tocopherol caused by the studied oils during 24-h incubation of their acetone-methanol solutions with addition of α-tocopherol at 30°C, whereas the decrease in α-tocopherol concentration was studied as a decrease in antioxidant capacity determined by the spectrophotometric DPPH (2,2-diphenyl-1-picrylhydrazyl) method. During heating of all the studied plant oils, the prooxidant capacity grew due to the formation of reactive lipid oxidation products, but, except the sunflower oil, it did not depend on the time of heating -after the initiatory increase, the prooxidant capacity typically remained approximately constant or decreased. The prooxidant capacity of the heated oils ranged from 58 mg to 360 mg α-tocopherol/kg and decreased in the order soybean oil > rapeseed oil > olive oil ≈ sunflower oil. It did not correlate with the content of polymerised triacylglycerols (except the sunflower oil) and was generally higher than the residual content of α-tocopherol.Keywords: antioxidant activity; frying; polymerised triacylglycerols; prooxidant activity; tocopherols In spite of the low acute toxicity of oxidised fats and oils (Esterbauer 1993), a lot of undesirable effects were observed in some long-term tests with them (Alexander 1981;Izaki et al. 1984;Kubow 1990;Esterbauer 1993;Chow 2007;Totani et. al. 2008;Omwamba et al. 2010). The symptoms can be related to a decreased digestibility and availability of oxidised lipids (Esterbauer 1993;Omwamba et al. 2010), an incorporation of modified fatty acids into membranes or tissues (Alexander 1981;Chow 2007) or an effect of modified fatty acids on the metabolism of essential fatty acids (Alexander 1981). But probably the most important cause consists in an increased oxidative stress in the gastrointestinal tract or in vivo (Omwamba et al. 2010).The lipid oxidation products formed in food are able to induce undesirable oxidation processes in vivo (Udilova et al. 2003;Chow 2007;Omwamba et al. 2010). They can oxidise proteins (oxidisable amino acids such as cysteine or tyrosine) (Gardner 1983;Chow 2007), DNA (Yang & Schaich 1996;Martinez et al. 2003), unsaturated fatty acids (Udilova et al. 2003;Gomes et al. 2008Gomes et al. , 2011 and other compounds (see below). The effects of these reactions are similar to the oxidative damage due to free radicals and other oxidants originating in some cases in vivo or entering into the body for example as a result of smoking (Willcox et al. 2004). In vivo uncontrolled oxidation (i.e. an increased oxidative stress) can participate in pathological processes and illnesses such as cardiovascular, tumour or neurodegenerative diseases (Willcox et al. 2004;Chow 2007). The oxidation of proteins, DNA or fatty acids can be...

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Chemical Properties and Cytotoxicity of Thermally Oxidized Oil

Cited by 38 publications

References 19 publications

Effects of Oil Heated with Gluten on Weight-Loss Dieting. I.

Effects of Oil Heated with Gluten on Weight-Loss Dieting. I.

A Novel Body Weight-loss Promoting Oil Prepared with Vegetable Protein

Prooxidant capacity of thermoxidised plant oils

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