Antimicrobial Effects and Nutraceutical Composition of Asafoetida (Ferula assa foetida L.) Slurry: Impact of Harvest Methods (Case Study: Tangsorkh Rangeland, Boyerahmad County)

Asafoetida (Ferula assa foetida L.) is a crucial pharmaceutical-industrial species native to Iranian rangelands and is harvested by local communities. The resulting slurry is a significant export in the medicinal plants sector. However, the quality of the product declines as local beneficiaries collect slurries from different age bases, mix them, and supply them to the market. This study aims to investigate the antimicrobial properties, total phenolic content (TPC), and total flavonoid content (TFC) of asafoetida slurry obtained from different harvest methods to optimize product quality.

A factorial completely randomized design was employed in the rangeland of Tangsorkh, Boyerahmad County. Asafoetida slurry was harvested from three age groups (5-6 years old, 7-8 years old, and 9-10 years old) in June, July, August, and September. Essential oil extraction, TPC, and TFC measurements were conducted, and the antimicrobial effects (MIC and MBC) were tested against Escherichia coli, Staphylococcus aureus, Aspergillus flavus, and Aspergillus parasiticus.

The results showed that the TPC and TFC of asafetida slurry essential oil obtained from different ages and harvest times did not significantly differ. In terms of age, the highest (92 mg GA/g) and lowest (74 mg GA/g) TPC values belonged to the groups of 1 and 3, respectively. Similarly, the highest (37 mg quercetin/g) and lowest (20 mg quercetin/g) TFC values were respectively associated with the groups of 1 and 3. In terms of the harvest time, the highest TPC (93 mg GA/g) was found in the essential oil obtained in June, while the lowest TPC (56 mg GA/g) was related to the essential oil extracted in September. Similarly, the highest (37 mg quercetin/g) and lowest (19.3 mg quercetin/g) TFC values were respectively associated with the essential oils obtained from the products harvested in June and September. The results also demonstrated that the MICs of the essential oil were equal to 1250, 312.5, 625, and 625 ppm for E. coli, S. aureus, A. flavus, and A. parasiticus, respectively. Furthermore, the MBCs of the essential oil were respectively equal to 2500, 650, 1250, and 1250 for the four microorganisms.

The study highlights the influence of plant age and harvest time on the nutraceutical composition of asafoetida slurry. Younger plants harvested earlier exhibited higher TPC and TFC, accompanied by more pronounced antimicrobial effects. These findings underscore the importance of optimizing harvest methods to enhance the quality of asafoetida slurry.