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Laboratory-isolated essential oils are commonly used in experiments regarding their utilization as natural antioxidant and antimicrobial agents. This study analyzed commercially available essential oils (Serbian-FSR and Russian-FRU) of fennel (Foeniculum vulgare Mill.) and added to the pork patties to investigate their possible role as natural antioxidant and antimicrobial agents. Chemical analysis of the samples showed significant differences in profiles caused by geographical origin and other environmental factors. The main compound in both samples was trans -Anethole, but it had a much higher content in Serbian oils. On the contrary, Russian oil had a high portion of anisaldehyde and linalool. These diversities are the main reason for thermal behavior and biological activity differences. The thermal analysis has shown that FSR had a crystalline form in the solid state, while FRU had an amorphous form. During heating, in FSR, a single-step weight loss was detected, while in FRU, a two-step weight loss was observed, indicating that, in addition to evaporation, components in FRU interacted with each other, forming lesser volatile molecules. After adding pork patties, Russian oil showed higher potency and better protective behavior than Serbian oil. Moreover, mixtures of these oils were added to the patties samples, and results showed higher potency when compared to individual oil samples. This indicated that minor compounds from both oils interacted and synergistically acted to prolong the shelf life of the meat samples. Commercial essential oils could be successfully utilized to prolong shelf life and provide additional intake of natural compounds significant for the human diet. [Display omitted] • Fennel's essential oil from Serbia (FSR) and Russia (FRU) (EO) were analyzed. • Serbian oil had a crystalline form, while Russian had an amorphous form. • Biological activity assays showed that FRU was more potent than FSR. • Both oils successfully prolonged shelf life of pork patties, but FRU was more potent. • FRU and FSR mixtures were more potent comparing to the individual oils. [ABSTRACT FROM AUTHOR]

Helichrysum italicum (Roth) G. Don, also known as immortelle, is a medicinal plant from the Mediterranean region. It is widely used in traditional medicine as an antiinflammatory and antimicrobial agent. Owing to the rich composition and beneficial effects of its essential oil, it is not only attractive for use in traditional medicine but also in pharmacy, medicine, and cosmetology. This study examines the chemical composition and biological activity of the essential oil obtained from fresh and dried immortelle, as well as the influence of the drying technique on the oil's quality. To isolate the essential oil from immortelle, fresh, naturally dried, and freeze-dried aerial parts of the plant were subjected to the hydrodistillation. The essential oils obtained were then characterized chemically and biologically. GC-MS analysis showed that α-pinene (29.77%) was the dominant compound in the oil isolated from the fresh plant, while α-muurolene was the most abundant compound in samples obtained from dried plants (ranging from 30.03% to 20.15%). The essential oil isolated from the fresh plant exhibited the highest antioxidant activity, whereas the oil obtained from freeze-dried plants showed the lowest potential. In terms of amylase inhibition, similar activity was observed, while the situation was opposite for tyrosinase inhibition. This research provides a detailed insight into the influence of the drying technique on the chemical composition and biological activity of immortelle essential oil. The study demonstrates the potential of using immortelle essential oil as a natural agent for diabetes and hyperpigmentation control. [ABSTRACT FROM AUTHOR]

The prevention of food contamination by pathogenic microorganisms is a very important factor for food safety and security during storage time. The essential oils have the potential to be used as antimicrobial agents, but their full potential is limited due to the sensitivity and volatility of bioactive compounds. This study aimed to characterize Thymus vulgaris essential oil, free and nano-encapsulated in alginate-whey protein concentrate carriers using the freeze-drying technique. GC/MS analysis was done to identify the oil composition. The investigation of the antimicrobial effect of free and encapsulated oil was performed on Escherichia coli , Staphylococcus aureus , and Candida albicans , by microdilution method. The free thyme oil exhibited antimicrobial activity against all tested microorganisms in the range of 0.71–1.43 mg/ml. Interestingly, encapsulated oil was more effective at lower concentrations (0.625–1.25 mg/ml), as a consequence of a nano-size carrier (0.25 ± 0.5 μm) together with other properties (encapsulation efficiency of 86.04%). TGA pointed out a significant effect of encapsulation, in comparison to free oil, on the stability of thyme oil at temperatures from 25 to 500 °C. The results indicated a high potential of thyme oil powder carriers as natural antimicrobial additives in food products. [Display omitted] • TEO was successfully encapsulated using the freeze-drying technique. • TEO powders showed higher antimicrobial activity in comparison to free oil. • TGA of the powders vs. free oil pointed out enhanced stability of encapsulated oil. [ABSTRACT FROM AUTHOR]

In this study, the influence of the mowing and drying on the chemical profile, thermal behavior, antioxidant activity (DPPH, CUPRAC, FRAP, ABTS, HRSA, and TBARS), microbiological data (Candida albicans (ATCC 10231) , Staphylococcus aureus (ATCC 25923) , Escherichia coli (ATCC 25922) , Candida albicans (ATCC 10231) , Bacillus subtilis (ATCC 6633) , Proteus vulgaris (ATCC 13315) , Proteus mirabilis (ATCC 14153) and Aspergillus niger (ATCC 16404) and cytotoxic activity of peppermint samples (HeLa, LS-174, A549, and MRC-5) was investigated. Chemical profiles showed that mowing did not have a significant impact on essential oil composition compared to drying. Menthone was the principal compound in essential oil from the fresh material, while menthol was the main compound in the samples from the dried ones. These differences influenced the biological activity of the samples, where fresh had better antioxidants, while dried had better antimicrobial activity. Thermal analysis showed that samples completely evaporated to about 120–123 °C in non-isothermal conditions, while in isothermal conditions the time required for complete evaporation was 20–30 min, depending on the sample. An artificial neural network model was developed, for the anticipation of antioxidant activity. These models showed good prediction properties (the r2 value during the training cycle for output variables was 1.000). [Display omitted] • Essential oils were isolated from fresh and dried plant after two times mowing. • Principal compound in fresh plant was menthone, while menthol was principal in dried. • Samples were assessed for antioxidant, antimicrobial, and cytotoxic activities. • Obtained essential oils were studied for thermal behavior. • Artificial neural network model was developed, for the anticipation of antioxidant activity. [ABSTRACT FROM AUTHOR]

Rosemary (Rosmarinus officinalis L.) is a plant worldwide cultivated mainly for essential oils, extracts, and as a spice. Up-to-date results showed diversity in composition of the essential oils, which may influence their quality, biological activity, and thermal properties. Therefore, the aim of this study was to investigate the chemical composition, antimicrobial activity, and thermal properties of the rosemary essential oils originating from Serbia and Russia. Additionally, oils were added to the sunflower oils in order to investigate possible antioxidant activity during the frying. Investigation of the chemical profile marked α-pinene, eucalyptol, and camphor as the most abundant compounds in both oils. However, overall composition influenced in such manner that Russian oil showed significantly higher antimicrobial activity, while Serbian oil proved to be better antioxidant agent in case of frying of sunflower oil. This would significantly influence possible application of the oils, which could be used as an antioxidant agent for extension of the food shelf life, or antimicrobial agent for protection against different microbial strains. [ABSTRACT FROM AUTHOR]

• Bay laurel's essential oil from Serbia (SRBL) and Russia (RFBL) (EO) were analyzed. • The oils evaporation process took place in two steps. • SRBL evaporated slower at the higher temperatures then RFBL. • Antioxidant activity assays showed that SRBL was more potent then RFBL. • Antimicrobial activity showed different affinity oils toward tested microorganisms. Laurus nobilis (bay laurel) form Serbia (SRBL) and Russia (RFBL) were analyzed in order to establish the chemical profile, thermal properties and biological activity. The GC/MS analysis showed that α-pinene (31.97%) is principal compound in the RFBL followed by eucalyptol (27.95%) and α-terpineol (10.28%). In the case of the SRBL, eucalyptol (40.51%) is the most abundant compound followed by α-terpineol (15.46%), while α-pinene was found in much lower amount (4.45%). Thermal analysis showed that the evaporation process of both oils was complex process and took place in two phases. Moreover, results indicated that the SRBL evaporated slower at the higher temperatures than the RFBL. In order to assess biological activity, the antioxidant and antimicrobial activities were investigated. The SRBL was more potent antioxidant agent in the case of both assays (DPPH and total reduction capacity). In the case of the antimicrobial activity, the SRBL showed greater potential of antimicrobial activities toward all tested microorganisms, while RFBL was found to be effective against all the bacteria and yeast, but did not possess any inhibitory action against fungi. Results indicate that both oils may be used in the food and pharmaceutical industries as antioxidant and antimicrobial agent. [ABSTRACT FROM AUTHOR]

Sage herbal dust generated as a by-product from filter-tea factory contains various bioactive compounds which secured its economic potential towards valorization of under-utilized stream. The aim of this work was to utilize sage herbal dust as raw material for the recovery of value-added product. Comparative evaluation of hydrodistillation (HD) and microwave-assisted hydrodistillation (MWHD) processes applied for isolation of sage herbal dust essential oil (EO) were applied for this purpose and EO yield varied from 0.50 to 1.90%. Distillation experiments performed at different levels of power and kinetics of EO recovery were monitored, while four empirical kinetic equations were successfully applied for modeling of process kinetics according to appropriate values of statistical parameters (R² and AARD). GC-MS analysis was applied for chemical characterization of sage EOs, while DPPH assay was used to determine in vitro bioactivity and results suggested that power affected terpenoid profile and antioxidant activity in case of HD and MWHD. Thermal analysis of obtained EOs was utilized to establish correlation between thermal behavior and terpenoids profile. Results suggested that MWHD could provide excellent alternative for production of high-quality sage EO with high content of oxygenated terpenoids and adequate bioactivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanocarriers were developed by freeze-drying of thyme oil-in-WPC emulsion. • The addition of alginate (AL) and WPC denaturation had an effect on powder properties. • Raman spectroscopy coupled with PCA pointed out differences between carriers. • Dry formulations with AL were less thermally stable according to TGA. Innovative coating powders, based on whey protein concentrate (10–15 wt%) as native (WPC) or denatured protein (d -WPC), solely or in combination with alginate (0.75 wt%, AL), containing thyme essential oil, were produced using the freeze-drying technique. The impact of individual components (protein, alginate and oil) as well as the effect of heat-induced protein denaturation, was resolved regarding physicochemical, thermal and morphological properties of powders. High product yield (∼100%), particle size (223–257 nm), low moisture content (0.10–0.13%) and zeta potential (−19 to −25.6 mV) were determined for all samples. Strong antimicrobial activity of thyme oil nanocarriers against foodborne pathogens was demonstrated. Thermogravimetric analysis (TGA) indicated enhanced thermal stability of encapsulated oil. The most specific bands of structural compounds were identified in Raman spectra of the tested formulations, but principal component analysis (PCA) on recorded spectra was necessary to show the differences between carriers of different wall materials. [ABSTRACT FROM AUTHOR]