Cocoa beans are part of the cocoa plant fruit (Theobroma cacao L.) used to prepare various products such as chocolate, cocoa butter, jelly, liqueurs, cosmetics, etc. Dark chocolate is consumed worldwide by different populations and is known for its good taste, making it one of the most favoured food products. This work aimed to determine the content of total polyphenols (TPC), total flavonoids (TFC), and the antioxidant potential measured through the ability to scavenge DPPH free radicals (DPPH), ferric reducing power (FRAP), and total antioxidant capacity (TAC), as well as major and trace elements contained in twelve commercially available dark chocolate samples, with cocoa content ranging from 40% to 99%. The total polyphenols content ranged between 10.55 and 39.82 mg/g GAE, while the total flavonoid content was from 10.04 to 37.85 mg/g CE. All applied antioxidant assays indicate that the sample with the highest cocoa percentage shows the greatest antioxidant activity (DPPH: 48.34% of inhibition; FRAP: 89.00 mg/g GAE; TAC: 83.86 mg/g AAE). Statistical methods were applied to establish the differences between the samples concerning TPC, TFC, DPPH, FRAP and TAC, as well as to differentiate the samples according to the mineral content. The results indicated that the differences in TPC and TFC between different samples depended on the cocoa content and the addition of dried fruit pieces. A good correlation between antioxidant potency composite index (ACI) and declared cocoa content was noticed (R2 = 0.8034), indicating that the declared percentage of cocoa is a reliable indicator for antioxidant activity of analysed dark chocolate samples. The nutritional evaluation proved that the studied chocolate samples were an excellent source of Mg, Fe, Mn and Cu.

Soybean is one of the most important industrial crops in the world. The rich nutritional content of the seed is the reason for the increased cultivation of this crop all over the world. However, a large number of phytopathogenic fungi that exist in soybean seeds can reduce the nutritional content, germination, and seed vigor. Soybean seed samples were collected from experimental fields in seven locations in Vojvodina Province, Serbia in the period 2016-2018. From each sample, 100 seeds were randomly selected. Seeds were surface-disinfested in 4% sodium hypochlorite for 5 min, washed two times in sterile water, and dried on a filter paper. All 100 seeds were placed in 20 Petri dishes with standard potato dextrose agar medium (PDA), five seeds in each, and incubated at 22 ± 2°C for seven days, under 12 h of alternating light/dark conditions. The first assessment was performed on the fourth day after isolation. The health status analysis of soybean seed showed that Peronospora manshurica, Macrophominaphaseolina, Botrytis cinerea, Cercospora kikuchii as well as the species from genera Alternaria, Diaporthe, and Fusarium had colonized soybean seed in Serbia over three years. Species from the genus Alternaria and Peronospora manshurica were dominant in all three examined years. Furthermore, it has been noticed that weather conditions, location, and cultivar significantly influenced the intensity of the infection. The results of this study have shown which pathogens pose a threat to successful soybean seed production and help in finding preventive measures to control these pathogens during vegetation.

Seeds of seven different genotypes of underutilised oil crop Carthamus tinctorius L. (Asteraceae) from alternative oil species collection of the Institute of Field and Vegetable Crops (Novi Sad, Serbia), were analysed for their protein, oil, fatty acids, tocopherols and total phenolics contents, with a view to test their diversity and potential as an alternative source of these valuable compounds. Seeds of the tested safflower genotypes had total protein (determined by Kjeldahl method) content from 11.5 to 16.0%, while total oil content (determined by Soxhlet method) ranged from 16.8 to 24.5% of dry matter, on average. Two main unsaturated fatty acids in safflower seeds, oleic and linoleic acids, represent approximately 90% of the total fatty acid content (determined by gas chromatography). Linoleic acid was the dominant fatty acid in all genotypes (61.2-80.2% of oil), while oleic acid was in a negative correlation with linolenic acid content and ranged from 9.6 to 29.5% of oil. The amount of saturated fatty acids ranged from 5.5 to 6.05% for palmitic, and 2.1 to 3.5% for stearic acid. Safflower seed is a source of a-tocopherol (determined by high performance liquid chromatography method with fluorescence detection) and its amount ranged from 358.8 to 461.8 mg/L of oil. The content of total phenolics (determined spectrophotometrically) ranged from 4.0 to 6.0 mg of gallic acid equivalents/g of dry weight. This comprehensive screening of valuable chemical compounds of safflower seeds shows the importance of this alternative oil seed crop as a good source of important nutrients and bioactive constituents.

Sorghum grain (Sorghum bicolor L. Moench) is a gluten-free cereal with excellent nutritional value and is a good source of antioxidants, including polyphenols, as well as minerals with proven health benefits. Herein, the phenolic composition, elemental profile, and antioxidant activity of sixteen food-grade sorghum grains (S1–S16) grown under agroecological conditions in Serbia were determined. Nine phenolic compounds characteristic of sorghum grains, such as luteolinidin, 5-methoxyluteolinidin, luteolidin derivative, luteolidin glucoside, apigeninidin, 7-methoxyapigeninidin, apigeninidin glucoside, and cyanidin derivative, were quantified. The antioxidant potential of the analyzed sorghum grains was evaluated by UV/Vis (DPPH, ABTS, and FRAP) and Electron Paramagnetic Resonance spectroscopy (hydroxyl and ascorbyl radical scavenging assays). The content of macro- and microelements was determined by Inductively Coupled Plasma Optical Emission spectroscopy. Theoretical daily intakes of selected major and trace elements were assessed and compared with the Recommended Daily Allowance or Adequate Intake. Sample S8 had the highest amount of phenolic compounds, while S4, S6, and S8 exhibited the strongest antioxidative potential. The sorghum studied could completely satisfy the daily needs of macro- (K, Mg, and P) and microelements (Se, Zn, Fe). Pattern recognition techniques confirmed the discrimination of samples based on phenolic profile and elemental analysis and recognized the main markers responsible for differences between the investigated samples. The reaction between hydroxyl radicals and luteolinidin/apigeninidin was investigated by Density Functional Theory and thermodynamically preferred mechanism was determined.

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