###### Abstract  
Amaranth and quinoa are classed as pseudocereals that do not belong to the grass family, meaning they are not technically a grain. Both of them are seeds with tremendous nutritional value; compared to other cereals, they contain much more fat. The aim of the study was to present the parameters characterizing thermal properties of amaranth and quinoa oils, such as: oxidation induction time, oxidation kinetic parameters, and melting profile. In isolated oils, the peroxide value, oxidative stability by the Rancimat test (in 120 \({}^{\circ}\)C) and the pressure differential scanning calorimetry (PDSC) method (at 100, 110, 120, 130, 140 \({}^{\circ}\)C), fatty acids composition, and their distribution between the triacylglycerglycerol positions were determined. The kinetic parameters of the oxidation process (activation energy, pre-exponential factor, and reaction rate constants) were calculated using the Ozawa-Flynn-Wall method and the Arrhenius equation. To measure the melting profile, the differential scanning calorimetry (DSC) method was used. Both types of seeds are a good source of unsaturated fatty acids. Induction time of oxidation suggests that amaranth oil may have better resistance to oxidation than quinoa oil. The melting characteristics of the oils show the presence of low-melting triacylglycerglycerol fractions, mainly containing unsaturated fatty acids, which means that a small amount of energy is required to melt the fats.  
amaranth oil; quinoa oil; oxidative stability; DSC; Rancimat 2022121216617 February 20221 February 20  
contain much more fat, supplementing the diet with this ingredient in the daily food ration. According to [PERSON] et al. [8], the fat content in quinoa seeds can range from 2 to 10%. [PERSON] and [PERSON] [9] classify quinoa as an alternative oilseed. Although the lipid content of amaranthus seed is typically 6-9%, some species such as _A. spinosus_ and _A. tenuifolius_ have been reported to contain as much as 19.3% [5].  
The high amount of fat in pseudocereals means that it can be susceptible to the oxidation process. Oxidation is one of the most important processes that takes place in oils during storage or heat treatment. Moreover, the oxidative stability of an oil is one of the most significant parameters from the point of view of oil safety [10].  
Among several available methods to measure the lipid oxidation, differential scanning calorimetry (DSC) or pressure differential scanning calorimetry (PDSC) can be considered as the most effective. The oxidative stability of lipids is determined as oxidative induction time; in practice, the time required to begin the oxidative decomposition process of the oil sample [11; 12]. Differential scanning calorimetry is an applicable tool to describe the thermal transitions of examined samples in micro-scale. It provides information about thermodynamic and kinetic characteristics dependent on the temperature of the material. In food products analysis, DSC helps in determination of the transitions resulting from the specific composition of foods because different groups of nutrients are specified by various transitions [13]. Apart from that, DSC has been suggested as a possible method for verifying quality, determining varieties, and detecting adulteration of oil. DSC is preferable to other methods because it is fast and the use of environmental damaging solvents is not required [14].  
According to our knowledge, in the literature, there are no studies on the kinetics of oxidation process of oil from pseudocereals using the PDSC method. Therefore, the aim of this study was to determine the oxidative stability and kinetic parameters of oxidation of oil isolated from quinoa and amaranth seeds. The melting characteristics of these oils are also presented, as well as the analysis of fatty acid composition and their stereochemical distribution in triacylglycerecrols.