Strawberries are an important fruit in the European diet because of their unique taste and high content of essential nutrients and bioactive compounds. The anthocyanins are known to be colorful phenolics in strawberries. In 17 samples of six strawberry cultivars produced in Serbia, i.e., the common varieties Alba, Asia, and Clery as well as promising breeding materials (11.29.11, 11.34.6, and 11.39.3), the anthocyanin profile as well as antimicrobial and antioxidative activity profiles were determined. All investigated extracts showed antioxidative and antibacterial activities against Gram-negative Aliivibrio fischeri. The responses were quite similar in number and intensity. The HPTLC-DPPH• scavenging assay and HPTLC-Aliivibrio fischeri bioassay coupled with high-resolution mass spectrometry identified pelargonidin-3-O-glucoside (Pg-3-glc) as the main anthocyanin and prominent antioxidative and antimicrobial compound in strawberries. The density functional theory calculations at the M06-2X/6-31+G(d,p) level showed that Pg-3-glc quenches free radicals via sequential proton loss electron transfer mechanism in water and in pentyl ethanoate, where the 5-OH group is the most reactive site for proton and hydrogen atom transfer. The results were confirmed via spectrophotometry. The highest total phenolic content was found in Clery and 11.39.3, while statistically significant differences between the genotypes regarding the antioxidant activity were not confirmed. Although very similar in the anthocyanin, antioxidative, and antimicrobial profile patterns, the strawberry genotypes were successfully classified using principal component analysis.

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.

The high consumption of plant-based foods on a global scale has increased the number of adulterations in the food industry. Along with this, analytical approaches to fraud detection need to be further developed. A nontargeted effect-directed profiling by high-performance thin-layer chromatography hyphenated with five effect-directed assays (free radical scavenging assay, Aliivibrio fischeri bioassay, and acetylcholinesterase, butyrylcholinesterase, and tyrosinase inhibition assays) and multi-imaging provided additional information on the antioxidative, antimicrobial, and enzyme inhibition activities for 18 apple and 18 grape juices from markets in Serbia and Germany. Bioactive zones of interest were eluted using an elution head-based interface and further characterized by electrospray ionization high-resolution mass spectrometry. The different profiles were evaluated chemometrically, and several compounds, which were characteristic of samples from different markets located in Serbia and Germany, were identified in apple juice (such as chlorogenic acid, phloridzin, epicatechin, and caffeic acid) and grape juice (such as chlorogenic acid, epicatechin, and quercetin). The developed rapid and simple method for the quality assessment of fruit juices coming from different (geographic) markets showed clear quality differences. Thus, it could be used to learn more about quality differences, to detect fraud in fruit juice production, and to verify the authenticity of the origin.