In this study, 27 market and edible cold-pressed oils from 10 different oilseeds were analysed. Oxidative stability and the chemical composition of oils were evaluated. The oils were investigated for their primary quality, fatty acid composition, total phenolic content and antioxidant activity. Rancimat and pressure differential scanning calorimetry (PDSC) were used to assess oils oxidative stability. Principal component analysis (PCA) was conducted to determinate impact of selected chemical characteristics on tested oils' oxidative stability in accelerated modes. PCA indicated that none of the chemical compounds correlated strongly with the oils' oxidative stability determined by the Rancimat method. Correlation coefficients describing the impact of different chemical compounds on induction time determined using the Rancimat method were between r = −0.54 (C18:3) to r = 0.62 (chlorophyll pigments). Oxidative stability of oils determined using the Rancimat and pressure differential scanning calorimetry (PDSC) were characterised by low correlation (r = 0.66). According to the statistical analyses, oils were divided into four groups, which depend on the method of oxidative stability evaluation did not differ.

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Four samples of olive oil were oxidized under polythermal (dynamic) conditions in the cell of a normalpressure differential scanning calorimeter (DSC) and in the Metrohm Rancimat apparatus. The DSC experiments were carried out in an oxygen flow atmosphere using different linearly programmed heating rates in the range of 4-20 7C/min. Through DSC exotherms, the extrapolated onset temperatures were determined and used for the assessment of the thermal-oxidative stabilities of the samples. Using the Ozawa-Flynn-Wall method and the Arrhenius equation, the activation energies (E a ), pre-exponential factors (Z) and reaction rate constants (k) for oil oxidation under DSC conditions were calculated. The Rancimat measurements of oxidation induction times were carried out under isothermal conditions in an air atmosphere at temperatures from 100 to 140 7C with intervals of 10 7C. Using the Arrhenius-type correlation between the inverse of the induction times and the absolute temperature of the measurements, E a , Z, and k for oil oxidation under Rancimat conditions were calculated. The primary kinetic parameters derived from both methods were qualitatively consistent and they help to evaluate the oxidative stabilities of oils at increased temperatures.

The aim of this paper was the analytical evaluation of human milk fat substitutes (HMFS) by the calorimetric and spectroscopic methods. The HMFS were obtained by enzymatic interesterification of blend of lard or milk fat with rapeseed oil and concentrate of fish oil. The enzymatic reactions were carried out at 60, 70, and 80°C for 2 h. A commercially immobilized 1,3-specific lipase, Lipozyme RM IM, was used as a biocatalyst. Oxidative stability of HMFS was determined using the calorimetric method. The oxidative induction time was obtained from the pressure differential scanning calorimetry curves. Peroxide value (PV) and anisidine value were determined using spectroscopic method. Interesterification caused a decrease in oxidative stability. Samples with lower induction times were characterized by higher PV. There was also a strong relation between total polar compound content and induction time. The induction times obtained for analyzed fats can be used as primary parameters for the assessment of the resistance of tested fats to their oxidative decomposition.

BACKGROUND Apple concentrate and honey were spray‐dried with traditional carriers (maltodextrin, Nutriose®, Kleptose®) and with skimmed milk powder as a carrier substitute offering added value for the final product. RESULTS Skimmed milk powder, although having the lowest glass transition temperature, was the best carrier in terms of the highest powder recovery (higher than 80% was achieved) and with powder physical properties comparable to those obtained with other carriers. Thus, skimmed milk powder was used to produce honey powder of reduced carrier content (to 25% solids). The physical properties of the powders obtained and lower powder recovery indicated more problematic drying of AC. Powders produced with skimmed milk were characterized by enhanced nutritional value compared with variants with traditional carriers. CONCLUSION Thus, skimmed milk is proposed as a natural carrier for spray‐drying, offering high processing yield, the possibility to reduce carrier content in honey powder, and to create products of nutritional added value. © 2020 Society of Chemical Industry