Browsing by Author "Damyanova S."
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Item Antimicrobial active packaging paper based on dill weed essential oil(2020-01-01) Kostova I.; Lasheva V.; Georgieva D.; Damyanova S.; Stoyanova A.; Stefanov S.; Gubenia O.Antimicrobial active packaging based on dill weed essential oil (DWEO) was investigated. Three types of packaging paper (100% bleached pulp 40 g/m2, 100% unbleached pulp 40 g/m2, and 100% recycled paper weighing 70 g/m2) were analysed. The antimicrobial activity was tested against the Gram-positive bacteria Staphylococcus aureus ATCC 6538 and Bacillus subtilis ATCC 6633; the Gram-negative bacteria Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Salmonella abony NTCC 6017; the yeast Saccharomyces cerevisiae ATCC 2601 and Candida albicans ATCC 10231; and the fungal strain Aspergillus brasiliensis ATCC 16404. The activity of the bleached paper treated with DWEO against moulds (Aspergillus brasiliensis) and yeasts (Candida albicans) during the five-day study period decreased from 100 to 47%, against Gram-positive bacreria (Staphylococcus aureus and Bacillus subtilis) decreased from 100 to 69%, and against Gram-negative bacteria (Salmonella abony and Escherichia coli) decreased from 76 to 12%. Unbleached paper, treated with DWEO, had stronger antimicrobial potential against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), compared to other test microorganisms. Recycled paper treated with DWEO showed fungicidal activity.Item APPLICATION POSSIBILITIES OF BIOMASS FROM FENNEL FRUITS(2023-01-01) Nikolova М.; Pencheva M.; Dimov M.; Bozadzhiev B.; Lazarov L.; Damyanova S.; Lasheva V.; Stoyanova A.; Yavorov N.During the processing of fennel fruits (Foeniculum vulgare Mill.) for obtaining essential and vegetable oils, biomass is released. It is mainly used as an additive for feeding or as an organic fertilizer. The aim of this research is to investigate the possibilities of using biomass obtained during the processing of fruits from harvest 2020 and 2021 as a biosorbent of Cr (VI) from aqueous solutions or as a biofuel. The two biomasses were milled and the final fractions obtained by sieve analysis (between 384 and 413 μm) were analyzed. The FTIR spectrum was recorded as 4000 - 400 с-1. Both biomasses act as biosorbent under the following conditions: pH 1.0, agitation speed 300 rpm, adsorbent dose 1.05 g L-1, initial Cr (VI) concentration 80 mg L-1, temperature 30°C. The energy indices used in the assessment of fennel fruit biomass potential as conditional biofuel were calculated: calorific value (15783.40 - 15968.16 kJ kg-1), density (464.19 - 582.91 kg m-3), and heat equivalent (250.05 - 317.68 kJ m-3)Item CHARACTERIZATION OF ACTIVE PAPER PACKAGING MATERIALS WITH CORIANDER ESSENTIAL OIL (CORIANDRUM SATIVUM L.)(2020-01-01) Kostova I.; Lasheva V.; Georgieva D.; Damyanova S.; Fidan H.; Stoyanova A.; Gubenia O.This study aims to investigate the antimicrobial activity of paper-based packaging materials including coriander (Coriandrum sativum L.) essential oil. Three types of packaging papers (bleached, unbleached, and recycled) are treated with an essential oil and then stored for 2 h, 24 h, and 5 days. The antibacterial activity of coriander oil is tested against Gram-positive bacteria (Staphylococcus aureus ATCC 6538 and Bacillus subtilis ATCC 6633); Gram-negative bacteria (Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027, and Salmonella abony NTCC 6017); an yeast (Candida albicans ATCC 10231), and a fungal strain (Aspergillus brasiliensis ATCC 16404). Ahigh fungicidal potential is observed in case of all packaging materials. The antimicrobial action of the bleached paper coated with coriander oil against Gram-positive bacteria during the five-day storage period decreases slightly from 100 % - 94 % to 79 % - 81 %.Item Effect of clary sage (Salvia sclarea L.) essential oil on paper packaging materials(2020-01-01) Kostova I.; Lasheva V.; Fidan H.; Georgieva D.; Damyanova S.; Stoyanova A.Introduction. The aim of research to determine the effect of clary sage (Salvia sclarea L.) essential oil on paper packaging materials. Materials and methods. Three packaging materials have been studied based on paper coated with clary sage essential oil. The chemical composition of the clary sage essential oil is determined chromatographically. Antimicrobial effect of essential oil was determined against Gram-positive, Gram-negative bacteria, yeasts, and fungi using the agar diffusion method. Results and discussion. The chemical composition of the clary sage essential oil showed a predominant amount of oxygenated monoterpenes (83.43%), followed by monoterpene hydrocarbons (7.86%), and sesquiterpene hydrocarbons (5.16%). The major components of the clary sage essential oil were linalyl acetate, B-linalool, α-terpineol, limonene, and geranyl acetate that determined the antimicrobial action of the oil. The essential oil exhibited a fungicidal action against the tested molds and yeasts. Its high antimicrobial properties could be probably due to the high content of linalyl acetate (40.31%) and B-linalool (22.72%). Our results showed high fungicidal efficacy for the three types of packaging materials. The suppressive action against C. albicans during the investigated shelf life period was about 100%. It was found a high efficiency of the recycled paper against A. brasiliensis (99.2%-81.9%). It was determined that the bactericidal effect of the tested packaging materials was lower than the Gram-negative bacterium S. abony. Conclusions. Clary sage essential oil could be used as an antimicrobial agent in the food industry due to its antimicrobial properties, in order to improve the quality of the products and extend their shelf life.Item Lavender Essential Oil as Antibacterial Treatment for Packaging Paper(2023-01-01) Todorova D.; Yavorov N.; Lasheva V.; Damyanova S.; Kostova I.Based on many years of experience, packaging is considered as an inactive barrier that protects materials and goods from environmental factors. The applicability of native chemical additive such as essential oils in wrapping papers can be used in the forms of films, treatments, coatings or others. Essential oils or extracts from different aromatic plants are used as bioactive substances for antimicrobial activity. In this research, lavender essential oil treatment of packaging papers is examined for its inhibition activity under nine microorganisms—two Gram-positive bacteria, three Gram-negative bacteria, two yeast and two fungal strains. The effectiveness of the treatment on the structural and strength indicators of the obtained paper samples is monitored. In detail, a five-day examination is conducted on the antibacterial effectiveness of lavender essential oil treatment. Results indicate that the lavender treatment of the obtained packaging paper is successful and the antifungal effect is more pronounced. The antimicrobial efficiency of paper treated with lavender essential oil is between 60 and 90% in the first two hours after treatment and gradually decreases to 40%–50% at the end of the 120 h period. The lavender essential oil treatment of wrapping paper has a promising perspective for preserving products from microbial spoilage and extending their shelf life.Item POSSIBILITIES FOR IMPARTING ANTIBACTERIAL PROPERTIES TO PAPERS(2023-01-01) Lasheva V.; Todorova D.; Yavorov N.; Damyanova S.; Kostova I.Paper is widely used as a packaging material because it is biodegradable and completely safe for the environment. The use of antimicrobials as a coating on paper can improve its mechanical, optical, physical and antimicrobial properties. Antimicrobial packaging suppresses the development of pathogenic microorganisms in order to ensure the safety of the product, extend the shelf life and protect the quality of the product. Giving antibacterial properties to papers and cardboards expands their use in different areas and for different purposes. Antibacterial paper prevents the entry and development of harmful microorganisms such as bacteria, fungi, mould. Antimicrobials that occur naturally in nature have a number of advantages, as they are considered to pose less risk to the consumer. One of the modern directions in research is the inclusion of different types of active substances in the packaging material, which can give it additional functions, such as elimination of oxygen, moisture, ethylene, ethanol emission, antimicrobial activity and others. The present work aims to obtain plant extracts, their characterization and their surface application on paper. Extracts of Bulgarian herbs St. John’s wort, cumin, rosemary, thyme and basil were obtained and characterized and studied. Plant extracts are applied by spraying on the surface of various papers. The antimicrobial effect of treated papers on gram-positive and gram-negative bacteria was studied. The results of the analysis of the obtained papers show the possibility of using plant extracts containing biologically active ingredients for the production of papers with barrier properties. The use of plant extracts is a promising and innovative solution.