This article examines the extraction of rosehip to study the recovery of a number of compounds with antioxidant properties (polyphenols, flavonoids, and β-carotene). Two varieties of rosehip, cultivated and wild are used as raw material. A detailed study of the process kinetics at different operating conditions is carried out in order to determine appropriate processing parameters, which results in extracts with higher content of target compounds and higher antioxidant capacity. Data on the concentration of active components in the different parts of the fruit (skin, seeds, and pappi) are also obtained, which gives information about their distribution within the fruit. The comparison of wild and cultivated varieties demonstrates the better quality of the cultivated one. The results are useful for production of improved and enriched rosehip extracts with higher content of antioxidant substances that have proven beneficial effects on the human health.

The methods for producing natural resveratrol are of big interest because of the many health benefits of this substance and its increasing use in functional foods, food supplements and para-pharmaceutical preparations. Generally, resveratrol is extracted from different natural sources, most of them usually produced for consumption purposes (grapes, nuts). This paper presents a method for recovery of resveratrol from a widely available raw material - grapevine stems, a by-product of vine pruning. An efficient extraction-fractionation scheme is developed, based on shifting the phase equilibrium, by which more concentrated extracts of resveratrol are obtained. After a simple extraction, the initial extract is further separated into two fractions, containing either water or ethanol-soluble compounds. Using this approach, the resveratrol’s low water solubility helps isolate it from other water-soluble substances. The resulting product is almost ten times more concentrated in trans-resveratrol than the initial total extract. Additionally, a fraction containing water-soluble polyphenols is obtained, which could be used for water-based pharmaceutical and cosmetic preparations.

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This study was undertaken to evaluate and compare total phenolics and total flavonoides, and antioxidant capacity of propolis and Echinacea purpurea ethanol extracts. Methods: Propolis and dried Echinacea purpurea extracts were obtained by extraction methods. The extracts were tested for total phenol and total flavonoid contents and antioxidant capacity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Results: The content of total phenolics and total flavonoids of propolis were found to be higher than Echinacea. The E.purpurea extract exhibited nearly 10 times lower antioxidant content in comparison with the propolis extracts. The 70% ethanol extract of propolis presented maximum antioxidant content, and the IC50 concentration was found to be higher in the 96% ethanol extract. However, both of the propolis extracts exhibited similar antioxidant activities. Conclusions: In the present study, the extracts of Echinacea purpurea and propolis were studied as sources of natural antioxidants. The results from the antioxidant assays show that all extracts can act as radical scavengers to a certain extent. They exhibit potent antioxidant activity in different solvent concentrations. Further studies in this area are in progress.

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The paper explores and analyses networking and usage of available support opportunities and services for participation and competitive performance of enterprises on international markets. The empirical results are part of a representative survey of enterprises in Bulgaria, varying in size, type of activity, location, ownership (family and non-family), age and sex of the founder entrepreneur, and other characteristics. The paper focuses on small and medium-sized companies due to their importance for the economy, as well as due to their not fully deployed potential for more active participation and successful performance on the international markets. The aims and advantages of networking have been investigated in the paper, as well as the relationship between participation in networks and providing public services to the enterprises. Furthermore, the connection between the entrepreneurs' specific characteristics, on the one hand, and the involvement of their companies in networks and looking for institutional support for different initiatives (including internationalisation), on the other hand, has been analysed. Based on the conclusions drawn, some recommendations to the stakeholders have been made.