Veränderungen der Fette unter Fritierbedingungen und deren analytische Erfassung Beurteilung des Gebrauchswertes und Analytik von Fritierfetten II

Pardun, H.; Blass, J.J.; Kroll, Edith

doi:10.1002/lipi.19740760403

Cited by 4 publications

(2 citation statements)

References 24 publications

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“…Hydrolysis is of minor significance, whereas oxidation seems to be much more important [1]. To assess the quality of a used fat, several test methods may be applied, such as the unpleasant and subjective sensory test, the smoke point, the contents of free and oxidized fatty acids, several commercially available tests (e.g., Oxifrit for some oxidized fatty acids [5] or Fritest for some carbonyl compounds [6]) and density, viscosity, and refractive index, etc. At present and in most cases, the determinations of polar compounds by column chromatography [7,8,9,10] or HPLC [11], and of oligomeric triglycerides by gel permeation chromatography (GPC) [12] are performed in order to complement the sensory findings.…”

Section: Introductionmentioning

confidence: 99%

Determination of higher carbonyl compounds in used frying fats by HPLC of DNPH derivatives

Schulte

2002

Anal Bioanal Chem

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In current analytical practice, simple methods are required for assessing the quality of a deep-frying fat after some time of use. Therefore, a new procedure was developed for the fast and selective determination of higher carbonyl compounds, i.e., those triglycerides resulting from the oxidation and/or oxidative cleavage of double bonds in unsaturated fatty acids. For analysis, a fat sample is dissolved in a 1-butanol/toluene mixture containing 6-undecanone as an internal standard. Aldehydes and ketones present are allowed to react with 2,4-dinitrophenylhydrazine (DNPH) in acidic solution for at least 1 h at room temperature. The mixture is injected directly onto a reversed phase HPLC column that is eluted with a very steep gradient between methanol and tert-butylmethyl ether (TBME) and is fitted with a UV detector set at 370 nm. In this way, the DNPH derivatives of all higher carbonyl compounds are eluted as one single peak. The result is calculated as milliequivalents of carbonyls per kg of fat (meq kg(-1)). The method takes a minimum of time and reagents and only requires the usual equipment.

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Section: Introductionmentioning

confidence: 99%

Determination of higher carbonyl compounds in used frying fats by HPLC of DNPH derivatives

Schulte

2002

Anal Bioanal Chem

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“…However, AV and PV are not considered as suitable markers for characterizing the quality of frying oil. AV has no direct relationship with the quality of frying oil, 2,3 while PV increases to a maximum level and then decreases because of the decomposition of peroxides to carbonyl compounds, conjugated dienes, and other compounds. Compared to AV and PV, CV measures the total carbonyl content, including aldehydes and ketones, which increase spontaneously along with heating and are not easily decomposed.…”

Section: Introductionmentioning

confidence: 96%

Application of Fourier transform near-infrared spectroscopy to the quantification and monitoring of carbonyl value in frying oils

Wang

Huang

et al. 2014

Anal. Methods

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Chemical and physical parameters as quality indicators of used frying fats

Gertz

2000

Eur. J. Lipid Sci. Technol.

158

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There are many methods available in the literature to test the physical properties and chemical changes of frying fats. Physical methods include density, viscosity, smoke point, colour, refractive index, ultraviolet (UV) absorption, infra‐red spectroscopy, and dielectric constant. Chemical tests are the determination of free fatty acids (acid value), iodine value, anisidine index, saponification value, non‐oxidised monomer fatty acids, polymerised triglycerides, fatty acids insoluble in petrol ether, and total polar compounds. Quality control in the production of fried food, whether the analyst is a quality control inspector or a member of the health food inspection service, demands a simple, easy procedure, using no chemicals. The results should correspond to official methods such as polar compounds. Among all physical and chemical methods, the determination of polar materials, polymerised triglycerides by size exclusion chromatography (HPSEC), and acid value were selected to be compared with the results of the measurements of the dielectricity constant (Food Oil Sensor) and the relative viscosity and density (Fri‐Check®,respectively. More than 150 samples, taken in commerce by the food inspection, were analysed and statistically evaluated.

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Veränderungen der Fette unter Fritierbedingungen und deren analytische Erfassung Beurteilung des Gebrauchswertes und Analytik von Fritierfetten II

Cited by 4 publications

References 24 publications

Determination of higher carbonyl compounds in used frying fats by HPLC of DNPH derivatives

Determination of higher carbonyl compounds in used frying fats by HPLC of DNPH derivatives

Application of Fourier transform near-infrared spectroscopy to the quantification and monitoring of carbonyl value in frying oils

Chemical and physical parameters as quality indicators of used frying fats

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