1. Tumbarski, Y.D., M.M. Todorova, M.G. Topuzova, P.I. Georgieva, N.T. Petkova and I.G. Ivanov, 2022. Postharvest biopreservation of fresh blueberries by propolis-containing edible coatings under refrigerated conditions. Curr. Res. Nutr. Food Sci., 10: 99-112.
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2. Popova, V., Z. Petkova, N. Mazova, T. Ivanova and N. Petkova, et al., 2022. Chemical composition assessment of structural parts (Seeds, Peel, Pulp) of Physalis alkekengi L. fruits. Molecules, Vol. 27. 10.3390/molecules27185787.
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3. Ognyanov, M., P. Denev, N. Petkova, Z. Petkova and M. Stoyanova, et al., 2022. Nutrient constituents, bioactive phytochemicals, and antioxidant properties of service tree (Sorbus domestica L.) fruits. Plants, Vol. 11. 10.3390/plants11141832.
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4. Gentscheva, G., I. Milkova-Tomova, I. Pehlivanov, V. Gugleva and K. Nikolova, et al., 2022. Chemical characterization of selected algae and cyanobacteria from Bulgaria as sources of compounds with antioxidant activity. Appl. Sci., Vol. 12. 10.3390/app12199935.
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5. Vassilev, D., N. Petkova, Y. Tumbarski, M. Koleva and P. Denev, 2020. Application of the principles of “green chemistry” for the synthesis of 10-undecylenic aliphatic esters with antimicrobial activity. J. Renewable Mater., 8: 675-686.
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6. Vassilev, D., N. Petkova, M. Koleva and P. Denev, 2020. Ultrasound-assisted method for the synthesis of tertiary fatty aliphatic esters with potential antimicrobial activity. Biointerface Res. Appl. Chem., 10: 6829-6836.
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7. Tumbarski, Y., N. Petkova, M. Todorova, I. Ivanov, I. Deseva, D. Mihaylova and S.A. Ibrahim, 2020. Effects of pectin-based edible coatings containing a bacteriocin of Bacillus methylotrophicus bm47 on the quality and storage life of fresh blackberries. Italian J. Food Sci., Vol. 32. 10.14674/IJFS-1663.
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8. Petkova, N.T., M.H. Ognyanov, R.Z. Vrancheva and P. Zhelev, 2020. Phytochemical, nutritional and antioxidant characteristics of whitebeam (Sorbus aria) fruits. Acta Sci. Pol. Technol. Aliment., 19: 219-229.
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9. Petkova, N., R. Arabadzhieva, D. Vassilev, G. Gencheva and Y. Tumbarski et al., 2020. Physicochemical characterization and antimicrobial properties of inulin acetate obtained by microwave-assisted synthesis. J. Renewable Mater., 8: 365-381.
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10. Petkova, N., M. Ognyanov, M. Kirchev and M. Stancheva, 2020. Bioactive compounds in water extracts prepared from rosehip‐containing herbal blends. J. Food Process Preserv., 10.1111/jfpp.14645.
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11. Petkova, N., M. Ognyanov, B. Inyutin, P. Zhelev and P. Denev, 2020. Phytochemical composition and antioxidant activity of Malus baccata (L.) Borkh. fruits. Food Sci. Appl. Biotechnol., Vol. 3. 10.30721/fsab2020.v3.i1.46.
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12. Petkova, N., I. Ivanov, D. Mihaylova and A. Lante, 2020. Effect of pressure liquid extraction and ultrasonic irradiation frequency on inulin, phenolic content and antioxidant activity in burdock (Arctium lappa L.) roots ACTA Scientiarum Polonorum Hortorum Cultus, 19: 125-133.
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13. Fidan, H., S. Stankov, N. Petkova, Z. Petkova and A. Iliev et al., 2020. Evaluation of chemical composition, antioxidant potential and functional properties of carob (Ceratonia siliqua L.) seeds. J. Food Sci. Technol., 57: 2404-2413.
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14. Deseva, I., M. Stoyanova, N. Petkova and D. Mihaylova, 2020. Red beetroot juice phytochemicals bioaccessibility: an in vitro approach.
    Pol. J. Food Nutr. Sci., 70: 45-53.
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15. Petkova, N.T., I.G. Ivanov, M. Raeva, M.G. Topuzova, M.M. Todorova and P.P. Denev, 2019. Fructans and antioxidants in leaves of culinary herbs from Asteraceae and Amaryllidaceae families. Food Res., 3: 407-415.
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16. Ognyanov, M., C. Remoroza, H.A. Schols, Y.N. Georgiev, N.T. Petkova and M. Krystyjan, 2019. Structural, rheological and functional properties of galactose-rich pectic polysaccharide fraction from leek. Carbohydr. Polym., Vol. 229. 10.1016/j.carbpol.2019.115549.
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17. Petkova, N., D. Vassilev, R. Grudeva, Y. Tumbarski, I. Vasileva, M. Koleva and P. Denev, 2018. “Green” synthesis of sucrose octaacetate and characterization of its physicochemical properties and antimicrobial activity. Chem. Biochem. Eng. Quart., 31: 395-402.
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18. Tzaneva, D., M. Djivoderova, N. Petkova, P. Denev, D. Hadzhikinov and A. Stoyanova, 2017. Rheological properties of the cosmetic gel including carboxymethyl chitosan. J. Pharmaceut. Sci. Res., 9: 1383-1387.
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19. Tzaneva, D., A. Simitchiev, N. Petkova, V. Nenov, A. Stoyanova and P. Denev, 2017. Synthesis of carboxymethyl chitosan and its rheological behaviour in pharmaceutical and cosmetic emulsions. J. Applied Pharmaceut. Sci., 7: 70-78.
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20. Tumbarski, Y., V. Lincheva, N. Petkova, R. Nikolova, R. Vrancheva and I. Ivanov, 2017. Antimicrobial activity of extract from aerial parts of Potentilla (Potentilla reptans L.). Ind. Technol., 4: 37-43.
21. Tsaneva, D., M. Nikolova, T. Prokopov, N. Petkova, A. Stoyanova and P. Denev, 2017. Evaluation of adsorption capacity of chitosan-cinnamaldehyde Schiff base. J. Pharmaceut. Sci. Res., 9: 1609-1614.
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22. Popova, A.T., N.T. Petkova, D.S. Mihaylova and I.N. Alexieva, 2017. Carbohydrate content and in vitro antioxidant capacity of different extracts of fresh Bulgarian Portulaca oleracea L. AgroFOOD Ind. Hi Tech, 28: 52-55.
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23. Petrova, I., N. Petkova, M. Ognyanov, A. Simitchiev, M. Todorova and P. Denev, 2017. Food emulsions with amidated pectin from celery (Apium graveolens var. rapaceum D.C.) tubers. Agric. Sci. Technol., 9: 246-250.
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24. Petkova, N., Y. Tumbarski, I. Ivanov and P. Denev, 2017. Design of inulin acetates with potential antimicrobial activity. Bulgarian J. Vet. Med., 20: 13-17.
25. Petkova, N., L. Ivanova, G. Filova, I. Ivanov and P. Denev, 2017. Antioxidants and carbohydrate content in infusions and microwave extracts from eight medicinal plants. J. Applied Pharmaceut. Sci., 7: 55-61.
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26. Petkova, N., I. Petrova, I. Ivanov, R. Mihov, R. Hadjikinova, M. Ognyanov and V. Nikolova, 2017. Nutritional and antioxidant potential of carob (Ceratonia siliqua) flour and evaluation of functional properties of its polysaccharide fraction. J. Pharmaceut. Sci. Res., 9: 2189-2195.
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27. Petkova, N., I. Ivanov, R. Vrancheva, P. Denev and A. Pavlov, 2017. Ultrasound and microwave-assisted extraction of elecampane (Inula helenium) roots. Nat. Prod. Commun., 12: 171-174.
28. Petkova, N., I. Ivanov, D. Mihaylova and A. Krastanov, 2017. Phenolic acids content and antioxidant capacity of commercially available Melissa officinalis L. teas in Bulgaria. Bulgarian Chem. Commun., 49: 69-74.
29. Petkova, N., I. Ivanov and P. Denev, 2017. Polyphenolic content and antioxidant activity of different green tea brands available in the Bulgarian market-comparative study. Ind. Technol., 4: 26-32.
30. Lincheva, V.B., N.T. Petkova and I.G. Ivanov, 2017. Optimization of biologically active substances extraction process from Potentilla reptans L. aerial parts. J. Applied Pharmaceut. Sci., 7: 174-179.
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31. Ivanov, I., N. Petkova and P. Denev, 2017. Physicochemical characterization of pectin from orange peels obtained after different extraction conditions. Ind. Technol., 4: 21-25.
32. Hadjikinova R., N. Petkova, D. Hadjikinov, P. Denev, D. Hrusavov, 2017. Development and validation of HPLC-RID method for determination of sugars and polyols. J. Pharmaceut. Sci. Res., 9: 1263-1269.
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33. Vlaseva, R., M. Ivanova, M. Hadjikinova, D. Hadjikinov and V. Dobreva et al., 2016. Comparative characterization of possibilities of using low-esterified and amidated pectin in fermented dairy products. J. Microbiol. Biotechnol. Food Sci., 6: 649-651.
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34. Vassilev, D., N. Petkova, M. Koleva and P. Denev, 2016. Ultrasound-assisted synthesis of sucrose and fructooligosaccharides esters as bio-plasticizers. J. Renew. Mater., 4: 24-30.
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35. Tumbarski, Y., N. Petkova and I. Ivanov, 2016. Polyphenolic content, antioxidant activity and antimicrobial properties of leaf extracts from dandelion (Taraxacum officinale). Ind. Technol., 3: 141-145.
36. Taneva, I., N. Petkova, I. Dimov, I. Ivanov and P. Denev, 2016. Characterization of rose hip (Rosa canina L.) fruits extracts and evaluation of their in vitro antioxidant activity. J. Pharmacogn. Phytochem., 5: 35-38.
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37. Petrova, I., N. Petkova and I. Ivanov, 2016. Five edible flowers-valuable source of antioxidants in human nutrition. Int. J. Pharmacogn. Phytochem. Res., 8: 604-610.
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38. Petkova, N., I. Ivanov and P. Denev, 2016. Evaluation of extracts from nettle (Urtica dioica) roots and artichoke flower heads (Cynara scolymus L.) obtained by ultrasound and microwave irradiation. Ind. Technol., 3: 98-101.
39. Petkova, N. and D. Mihaylova, 2016. Flower heads of Onopordum tauricum Willd. and Carduus acanthoides L-source of prebiotics and antioxidants. Emir. J. Food Agric., 28: 732-736.
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40. Murdzheva, D., N. Petkova, M. Todorova, I. Vasileva, I. Ivanov and P. Denev, 2016. Microwave-assisted synthesis of methyl esters of alginic acids as potential drug carrier. Int. J. Pharmaceut. Clin. Res., 8: 1361-1368.
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41. Murdzheva, D., I. Vasileva, N. Petkova, I. Ivanov, M. Todorova and P. Denev, 2016. Physicochemical properties of new alginic acids derivatives. Ind. Technol., 3: 59-66.
42. Temkov, M., N. Petkova, P. Denev and A. Krastanov, 2015. Characterization of inulin from Helianthus tuberosus L. obtained by different extraction methods-comparative study. Scient. Works Univ. Food Technol., 62: 461-464.
43. Petkova, N., R. Vrancheva, D. Mihaylova, I. Ivanov, A. Pavlov and P. Denev, 2015. Antioxidant activity and fructan content in root extracts from elecampane (Inula helenium L.). J. BioSci. Biotechnol., 4: 101-107.
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44. Petkova, N., M. Ognyanov, M. Todorova and P. Denev, 2015. Ultrasound-assisted extraction and characterisation of inulin-type fructan from roots of elecampane (Inula helenium L.). Acta Scient. Nat., 1: 225-235.
45. Petkova, N., I. Ivanov, S. Topchieva, P. Denev and A. Pavlov, 2015. Biologically active substances and in vitro antioxidant activity of different extracts from Dandelion (Taraxacum officinale) roots. Scient. Bull. Ser. F: Biotechnol, 19: 190-197.
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46. Petkova, N., D. Mihaylova, P. Denev and A. Krastanov, 2015. Evaluation of biological active substances in flower heads of Carduus thoermeri Weinm. Rom. Biotechnol. Lett., 20: 10592-10599.
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47. Manev, Z., N. Petkova, P. Denev, D. Ludneva and S. Zhelyazkov, 2015. Study the influence of dietary fiber on the rheology of alginate beads. Agric. Sci. Technol., 7: 137-140.
48. Grozeva, N., D. Pavlov, N. Petkova, I. Ivanov and P. Denev et al., 2015. Characterisation of extracts from Stevia rebaudiana Bertoni leaves. Int. J. Pharmacogn. Phytochem. Res., 7: 1236-1243.
49. Dimitrova, M., N.T. Petkova, P.P. Denev and I.N. Aleksieva, 2015. Carbohydrate composition and antioxidant activity of certain Morus species. Int. J. Pharmacogn. Phytochem. Res., 7: 621-627.
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50. Vlaseva, R., M. Ivanova, P. Denev, M. Todorova and N. Petkova, 2014. Studying the possibilities to obtain functional lactic acid fermented dairy products enriched with dietary fibers. Acta Scient. Nat., 1: 117-122.
51. Vlaseva, R., M. Ivanova, N. Petkova, M. Todorova and P. Denev, 2014. Analysis of fermented lactic acid dairy products enriched with inulin-type fructans. Scient. Bull. Ser. F: Biotechnol., 18: 145-149.
52. Petrova, I., N. Petkova, K. Kyobashieva, P. Denev, A. Simitchiev, M. Todorova and N. Dencheva, 2014. Isolation of pectic polysaccharides from celery (Apium graveolens var. rapaceum D.C.) and their application in food emulsions. Turk. J. Agric. Nat. Sci., Special Issue-2: 1818-1824.
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53. Petkova, N., R. Vrancheva, P. Denev, I. Ivanov and A. Pavlov, 2014. HPLC-RID method for determination of inulin and fructooligosacharides. Acta Scient. Nat., 1: 99-107.
54. Denev, P., N. Petkova, I. Ivanov, B. Sirakov, R. Vrancheva and A. Pavlov, 2014. Determination of biologically active substances in taproot of common chicory (Cichorium intybus L.). Scient. Bull. Ser. F: Biotechnol., 18: 124-129.
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55. Taneva, I., N. Petkova, K. Dobreva, I. Panchev and P. Denev, 2013. Isolation and characterization of pectic substances from Rosa canina L. Food Sci. Technol., 24: 38-40.