Domesticated international (standard) apple cultivars, together with resistant apple cultivars are the core of the Serbian apple production. Furthermore, autochthonous cultivars are characterized by a good adaptability to the local environmental conditions and represent a valuable source of genetic variability, as well as an important source of the gene pool for further breeding programs. Additionally, they show a higher phenolic content and a stronger antioxidant activity, in comparison to commercial cultivars. Therefore, they are more likely to be used as a functional food. The subjects of this study were seventeen samples of fruits and leaves from autochthonous apple cultivars, five international standard cultivars, and six resistant apple cultivars. The phenolic profile was determined using ultra-high performance liquid chromatography (UHPLC), coupled with a diode array detector and a TSQ Quantum Access Max triple-quadrupole mass spectrometer. A total of twenty compounds were quantified in the samples. Most of the analyzed phenolics were detected in higher amounts in the peel, compared to the mesocarp. The results of the multivariate analysis of variance (MANOVA) indicate that 5-O-caffeoylquinic acid is present in the highest amount in the mesocarp, while in the peel and leaves, quercetin-glycosides were detected in the highest amount. According to the MANOVA: phloretin, phlorizin, 5-O-caffeoylquinic acid, kaempferol, and p-coumaric acid are present in significantly higher levels in the autochthonous cultivars, compared to the standard and resistant ones (in both fruits and leaves). Therefore, these compounds can be used as chemical tracers of the apple varietal origin.

Apple (Malus domestica Borkh.) is a widely cultivated fruit tree species valued for its nutritional and sensory properties. The global market is dominated by a limited number of cultivars selected for appearance, shelf life, and consumer preference. As a result, many traditional or autochthonous cultivars, which often possess richer phytochemical profiles and greater environmental adaptability, remain underutilized. Herein, a comprehensive study of the sugar and organic acid content of the apple pulp and leaves of 19 autochthonous apple cultivars, along with 5 standard and 6 resistant cultivars for comparison, was undertaken. Fructose (47.9–74.0 mg/g FW), glucose (16.4–33.7 mg/g FW), and sucrose (25.0–34.0 mg/g FW) were detected at the highest concentrations in the apple pulp, while sorbitol (49.9–71.5 mg/g DW) predominated in the apple leaves. Principal component analysis identified xylose, quinic acid, shikimic acid, arabinose, raffinose, malic acid, citric acid, and isocitric acid as the main factors responsible for the classification patterns among cultivars. A number of autochthonous cultivars, such as ‘Gružanjska letnja kolačara’, ‘Šećeruša’, ‘Demirka’, and ‘Hajdučica’, showed characteristics comparable to commercial cultivars such as ‘Red Delicious’, ‘Golden Delicious’, and ‘Gala Galaxy’. The obtained results empasize the value of some of the analyzed cultivars and contribute to the broader re-evaluation of the local apple germplasm.

Five different extraction methods were assessed to select an optimal procedure for extracting the phenolic antioxidants from potato tubers. Total phenolic content and antioxidant capacity were determined for each type of extraction. In total, 144 samples of four potato varieties from three production systems, over a period of three years, were analyzed. The results show that TPC and RSA tests can be used as parameters for differentiating potato parts and variety and to distinguish the samples depending on ripening time and the production system. Higher values of TPC and RSA were observed in samples from the organic cultivation system compared to integral and conventional cultivation in the same cultivar. Finally, by the employment of UHPLC-LTQ Orbitrap XL, fifty-nine phenolic compounds were identified. It was concluded that the phenolic profile is a powerful tool for confirming botanical origin, distinguishing between genotypes, and distinguishing various production systems of potato.