Quality alterations of four frying fats during long-term heating (conventional analysis and nirs calibration)

András Szabó, György BázáR, László Locsmándi, Róbert Romvári

Research output: Contribution to journalArticle

10 Citations (Scopus)


Rapeseed oil, sunflower oil, pig (mangalica breed) and goose fat were heated (36 h, 4 h sampling intervals) at seven temperatures (140, 150, 160, 165, 170, 175 and 180C; n = 256) to follow quality alterations. Acid value (AV) increased permanently, while the increase of peroxide value (PV) was followed by a drop. Carbonyl number tended to increase, while p-anisidine value (pAV) showed two-peaked alterations. Total polar material (TPM) and dimeric and polymeric triacylglycerol content of oils increased up to over 60 and 25%, while by animal fats, these reached 45 and 19%, respectively. Near-infrared spectroscopy (0.1 mm layer, transflectance mode, 800-2,400 nm wavelength, second derivative, modified partial least squares regression) was used for quantitative calibrations. Estimation accuracy of sampling event, heat-sum (heating hours × temperature) exceeded R2 = 0.94, with over 0.9 cross-validation values, analyzing fats separately. Calibrations for AV, PV, pAV and TPM reached practical application levels.

Original languageEnglish
Pages (from-to)42-58
Number of pages17
JournalJournal of Food Quality
Issue number1
Publication statusPublished - Feb 1 2010


ASJC Scopus subject areas

  • Food Science
  • Safety, Risk, Reliability and Quality

Cite this