Chromatographic Separation of Polar and Nonpolar Components of Frying Fats

Waltking, Arthur E; Wessels, H.

doi:10.1093/jaoac/64.6.1329

Cited by 48 publications

(42 citation statements)

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“…The unsaponifiable fraction was obtained by saponification followed by solvent extraction according to [19]. The polar fraction of rice bran oil samples was isolated by means of column chromatography and determined gravimetrically according to the standard method proposed by IUPAC [20].…”

Section: Methodsmentioning

confidence: 99%

Effect of the full refining process on rice bran oil composition and its heat stability

Mezouari

Eichner

Kochhar

et al. 2006

Euro J Lipid Sci & Tech

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Effect of the full refining process on rice bran oil composition and its heat stabilityThe effects of the chemical refining process on the minor compounds of rice bran oil and its heat stability were investigated. After 8 h of heating, about 50% and 30% of total tocopherols remained in crude and refined rice bran oil, respectively. The individual tocopherols were differently affected by the refining process. The order of heat stability of tocopherols and tocotrienols in crude oil was found to be different from that in fully refined oil. A similar tendency was observed for sterols. After 8 h of heating, 65% and 72% of total sterols, and 14% and 46% of sterol esters, of crude or fully refined rice bran oil, respectively, disappeared. The heating process led to a 4% and 10.3% increase in polymer contents in crude and refined rice bran oil, respectively. Although refined rice bran oil showed good heat stability, when compared to crude oil its heat stability was decreased to some extent.

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Section: Methodsmentioning

confidence: 99%

Effect of the full refining process on rice bran oil composition and its heat stability

Mezouari

Eichner

Kochhar

et al. 2006

Euro J Lipid Sci & Tech

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“…Total polar components (TP). Polar and nonpolar components in oil samples were separated by column chromatography (8). Column-packing material used was silica gel (70-230 mesh), and the polar components were eluted with a solvent mixture composed of 87% light petroleum and 13% diethyl ether.…”

Section: Methodsmentioning

confidence: 99%

Effect of vacuum frying on the oxidative stability of oils

Shyu

Hau

Hwang

1998

J Americ Oil Chem Soc

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The purpose of this study was to evaluate frying oil quality with different assessment methods during vacuum frying of carrot slices. In six consecutive days, palm oil, lard, and soybean oil were fried under vacuum at 105°C for 20 min each hour in an 8-h shift. Peroxide value, acid value, carbonyl value, total polar components, dielectric constant (Food Oil Sensor reading), viscosity, and fatty acid composition were used to evaluate the quality of these oils. Results showed that palm oil and lard possess greater thermal stability than soybean oil. The decrease in C 18:2 /C 16:0 ratio was greater for soybean oil than the other two oils. Of the assessment methods used, peroxide value, carbonyl value, total polar components, and dielectric constant all showed good correlation with frying time and between each other. Viscosity was suitable to assess vacuum-fried lard and soybean oil, but not palm oil. The measurement of dielectric constant, on the other hand, appeared to be unsuitable to assess vacuum-fried soybean oil. JAOCS 75, 1393-1398 (1998). KEY WORDS:Carrot chips, dielectric constant, frying oil assessment, food oil sensor, lard, oxidative stability, palm oil, peroxide value, soybean oil, total polar components, vacuum frying.Deep-fat frying of food is usually performed at high temperature (about 180°C) under atmospheric pressure. Surface darkening may occur even before the food is fully cooked. Some of the fat and oil decomposition products have also been implicated in producing adverse health effects when fried oils degraded with continued use (1,2). Pressure frying is another way of deep-fat frying; food is fried in a closed system under pressure. This increases the boiling points of frying oil and moisture in food, and thus increases the rate of heat transfer to the interior of food and shortens the frying time. Food fried under pressure will usually retain more moisture and flavor. Pressure frying is conducted at high temperature and pressure, it therefore might have adverse effects on the quality of frying oils (3).In vacuum-frying operations, food is heated under reduced pressure in a closed system that can lower the boiling points of frying oil and moisture in food. Water in the fried food can be rapidly removed when the oil temperature reaches the boiling point of water. Because food is heated at lower temperature and oxygen content during vacuum frying (4), the natural color and flavor can be preserved. Vacuum frying also has less adverse effects on oil quality (5).Vegetables and fruits are generally dehydrated by freeze drying, a process that can maintain their original flavor and color. This operation, however, is energy and time consuming. Therefore, production of dehydrated vegetables and fruits with high quality in a short time is an important issue for food processors. Vacuum frying of fruits and vegetables slices may be a good alternative to process dehydrated fruits and vegetables.The purpose of this study was to evaluate the stabilities of different frying oils while vacuum-frying carrot sli...

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“…Total polar compounds were determined in oil samples by silica column chromatography, following the method proposed by the IUPAC (Waltking and Wessels 1981), with two slight modifications (Dobarganes and Perez-Camino 1988a).…”

Section: Polar Compoundsmentioning

confidence: 99%

Short-Chain Fatty Acid Formation during Thermoxidation and Frying

Márquez‐Ruiz

Dobarganes

1996

J. Sci. Food Agric.

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Formation and evolution of the short‐chain fatty acids originated by oxidation and remaining bound to the parent triglyceride, specifically heptanoate and octanoate, were studied during thermoxidation of palm olein, conventional sunflower oil and high‐oleic sunflower oil at 180°C, as well as in real used frying oils of unknown history collected by Food Inspection Services. Fatty acids were quantified by gas–liquid chromatography following transesterification of samples and using methyl nonanoate and methyl heptadecanoate as internal standards. Alteration level was determined through analyses of polar compounds and polar fatty acids. Results showed high correlation coefficients between short‐chain fatty acids and polar compounds or polar fatty acids, thus suggesting that quantification of short‐chain fatty acids is a good indication of the total alteration level in used frying oils.

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Chromatographic Separation of Polar and Nonpolar Components of Frying Fats

Cited by 48 publications

References 0 publications

Effect of the full refining process on rice bran oil composition and its heat stability

Effect of the full refining process on rice bran oil composition and its heat stability

Effect of vacuum frying on the oxidative stability of oils

Short-Chain Fatty Acid Formation during Thermoxidation and Frying

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