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BACKGROUND The study of almond fat stability is essential from a quality control perspective meanly because, in most of the cases, almonds are sold skinned and thermally treated. In this work an alternative method to Rancimat test based on attenuated total reflectance‐Fourier‐transform infrared (ATR‐FTIR) spectrometry was adapted for checking the induced degradation at 75 °C of seven almond oil cultivars, three of the top Californian producing varieties, and, four traditional cultivars harvested in Spain. RESULTS: The thermal oil degradation evolution was followed by measuring the changes in the absorbance of the selected FTIR spectra bands (3470, 3006, 1730, 1630, 988 and 970 cm−1). A first‐order kinetic behaviour was observed, after an induction time in all bands. CONCLUSIONS: Kinetic coefficients and induction times were easily obtained as the absorbance values (from difference spectra) fitted to pseudo‐first‐order kinetics after the induction time. Principal component analysis was applied to the kinetic parameters to visualize which variables could be useful to classify the almond cultivars based on their resistance to thermal oxidation processes. It was found that selecting only the induction times corresponding to the bands 3470, 3006, 1630 and 970 cm−1 a separate classification of the Californian cultivars from the Spanish ones was possible. Finally, a linear discriminant analysis was assayed using only the four induction times previously selected. Validated classification and correct in 100% of the cases was obtained for all the samples based on their Spanish or Californian origin. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Protected designations of origin 'Alicante' and 'Jijona' nougats are manufactured products produced using raw materials from Eastern Spain. In order to avoid adulteration practices, determination of volatile compounds from three different almond cultivars (Spanish Guara and Marcona and, from the USA, Butte) was performed to obtain a set of parameters for discrimination between Spanish and American cultivars. Factorial experimental design was applied for the development of a headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) analytical method for isolation and determination of the volatile compounds in almond oils. Main HS-SPME variables optimized were extraction temperature, extraction time, and stirring speed. Several volatile compounds including aldehydes, alkanes, alcohols and aromatic hydrocarbons were identified. Multivariate techniques were applied for classification and discrimination of the different almond cultivars studied. Specifically, cluster and stepwise linear discriminant analysis (LDA) were used, with LDA showing the best performance. The results obtained demonstrated that the proposed method combined with multivariate statistical analysis can be successfully applied for discrimination among different almond cultivars. [ABSTRACT FROM AUTHOR]