title: The effect of raw materials on thermo-oxidative stability and glycidyl ester content of palm oil during frying.
abstract: BACKGROUND
  The objective of this research was to determine the effects of the water content of food incorporated into frying oil on oil degradation and the content of glycidyl esters. Potato chips, French fries and snacks were fried intermittently in palm oil, which was heated at 180 °C for 8 h per day over five consecutive days. Thermo-oxidative and physical alterations, changes in fatty acid composition, total polar components, polar fraction composition, and water content were analysed. The content of glycidyl esters was measured by liquid chromatography-tandem mass spectrometry.
  
  
  RESULTS
  More polar compounds were formed in the oil used for frying chips (252 g kg(-1)) than for French fries (229 g kg(-1)) or snacks (196 g kg(-1)). Reductions in glycidyl esters were found in oils used for frying--greater for frying snacks and French fries (95% and 93%) than for potato chips (87%). The rate of decrease of glycidyl esters was correlated with frying parameters, most strongly with the concentrations of diacylglycerols (r = 0.98) and total polar components (r = -0.98).
  
  
  CONCLUSIONS
  The raw material had a greater influence on polymerization conversion and glycidyl ester content than on hydrolytic and oxidative changes in the frying oil.
authors.affiliation: Department of Food Storage and Technology, Faculty of Food Science, Wrocław University of Environmental and Life Sciences, 51-630, Wrocław, Poland.
authors.forename: Magda A
authors.initials: MA
authors.lastname: Aniołowska
authors.affiliation: Department of Food Storage and Technology, Faculty of Food Science, Wrocław University of Environmental and Life Sciences, 51-630, Wrocław, Poland.
authors.forename: Agnieszka M
authors.initials: AM
authors.lastname: Kita
mesh_terms: D003296:Cooking; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D000073878:Palm Oil; D010938:Plant Oils / Q000737:chemistry*; D011198:Solanum tuberosum; D013696:Temperature; D013997:Time Factors
chemical_list: D010938:Plant Oils; D000073878:Palm Oil
keywords: frying; glycidyl fatty acid esters; palm oil; raw material