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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 vulgareMill.) 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.

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 vulgarisessential 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.