Antioxidants play a crucial role in mitigating oxidative stress and preventing cellular damage caused by free radicals. This study aimed to compare the effectiveness of three antioxidant assays—DPPH, TEAC, and FRAP—in quantifying the antioxidant capacity of 15 plant-based spices, herbs, and food materials from five distinct plant families. The relationship between these assays and total polyphenol content (TPC) as well as total flavonoid content (TFC) was also investigated. The results showed that FRAP exhibited the strongest correlation with TPC (r = 0.913), followed by TEAC (r = 0.856) and DPPH (r = 0.772). Lamiaceae species, such as rosemary and thyme, consistently demonstrated high antioxidant activities across all assays. The study highlights the complementary nature of these assays in assessing antioxidant capacity and underscores their utility in profiling polyphenol- and flavonoid-rich plants for potential nutritional and therapeutic applications.

Sorghum is a drought tolerant, gluten–free cereal, which is known for the abundance of polyphenol compounds, including flavonoids. It is proved that these compounds have important health benefits as antioxidants and anti–inflammatory agents. They are found in seed walls in a free form or in a bound, esterified form, which affects their digestion and utilization. The main purpose of this research was to evaluate the ratio of free and bound polyphenols in sorghum brans extracted with different solvents, and see how the extraction step can influence the physiology importance of a sorghum extract. Solvents had significant effects on the polyphenol and flavonoid content of free polyphenol extracts, but there was not any difference in terms of their antioxidant activities. In case of bound fractions from different extractions, there were significant differences in all parameters, except for the flavonoid content. Correlation analysis showed strong connection between parameters, and there were differences in correlation between extraction. Among the two varieties, Alföldi1 had significantly higher content of total phenol, flavonoid and higher values of antioxidant capacity as well compared to Zádor in both extractions. In this research only the effect of the extraction solvent was evaluated, but further investigation is necessary to specify more extraction factors. This research aimed to emphasize the importance of extractant selection in determination of bioactive compounds from plants. Our results highlights that selecting the proper extractant is essential for determination of total polyphenolic content, however, the analysis if antioxidant power is not sensitive for extraction agents.

Antioxidants play an essential role in human health by reducing damage caused by free radicals. Total polyphenol, flavonoid, and anthocyanin contents and the antioxidant capacity of two sour cherry cultivars (Cigánymeggy, Oblacsinszka) grown under conventional and organic production systems were evaluated over two consecutive years at different stages of ripening. Results showed that the concentrations of different antioxidant compounds varied during ripening, but more significant differences were observed between the growing seasons, whereas no significant differences were found between the investigated genotypes or cultivation methods. In 2024, total polyphenol values during the harvest period ranged from 1116.33 to 1874.39 mg GAE/100 g DM, while in 2025 they ranged from 909.81 to 1668.96 mg GAE/100 g DM. Polyphenol profile analysis showed that the main polyphenolic compounds of sour cherries, including cyanidin-3-glucosylrutinoside, cyanidin-3-O-rutinoside, cyanidin-3-glucoside, and cyanidin-3-sophoroside, were detected in both years, indicating that the major anthocyanin components were consistently present despite harvesting year effects.

Sour cherry ( Prunus cerasus L. ) is a rich source of polyphenolic compounds, which contribute to its numerous health-promoting properties. Fruit contains a variety of bioactive constituents, including anthocyanins, flavonols, and chlorogenic acids, which are associated with antioxidant, anti-inflammatory, and cardioprotective effects. Analyses of these compounds demonstrate the potential of sour cherry to support human health and reduce the risk of chronic diseases. However, the protection of these bioactive compounds is crucial, as food processing methods such as heat treatment, freezing, drying and storage can significantly affect their concentration and biological activity. Sour cherries are commonly processed into products such as juice, concentrates and jams. Jam quality is influenced by its recipe, processing methods, and storage conditions. During jam production, significant losses of polyphenols are observed, particularly anthocyanins, which can decrease by up to 90%. Storage further reduces their levels, with the extent of loss depending on time and temperature. These findings highlight the importance of processing and storage technologies for protecting the bioactive compounds in sour cherry jams. Graphical Abstract

Sour cherry (Prunus cerasus) is a valuable fruit known for its high antioxidant content. Its bioactive substances contribute to health maintenance, as they have strong anti-inflammatory and free radical scavenging properties. Jams made from sour cherries provide a concentrated form of the antioxidant content of fruit, thus can play an important role in a balanced diet. Heat treatment is an essential part of the jam-making process, as it ensures the microbiological stability and longer shelf life of the product. At the same time, heat can significantly affect the antioxidant content of the fruit. In this study, the authors compared the antioxidant content of six different sour cherry jams. Based on the obtained results, it was concluded that the fruit content of sour cherry jams alone is not sufficient to estimate their antioxidant capacity, but the extent of the effect of heat treatment on it is generally independent of the nature of the products. This result highlights that the fruit content and the applied technology play an important role in preserving the antioxidant content of fruits during product processing.