Effects of Thymus daenensis and Satureja hortensis L. essential oils on quality properties of Iranian Doogh

Abstract

Antifungal activity of Thymus daenensis and Satureja hortensis essential oils (EOs) (0, 50, 100, and 150 ppm) were evaluated against Aspergillus fumigatus in vitro and in the Food model system (un‐heat and heat‐treated Doogh) during 21 days. In vitro results showed that minimum inhibitory concentration and minimum fungicidal concentration of T. daenensis and S. hortensis oils were 6.25 and 12.5%, respectively. In un‐heat treated samples, both EOs showed a significant inhibitory effects rather than the control group at 25 °C than 4 °C. Treatments containing 100 and 150 ppm of T. daenensis EO on the 21st day and treatment containing 50 ppm of S. hortensis EO on the 15th day had maximum inhibitory effect. No growth was observed in the heat‐treated samples and control group. The findings revealed that both EOs had noticeable antifungal activity and can be considered as a natural preservative in the food industry. Practical applications Doogh is a traditional Iranian dairy‐based drink which is the same as other dairy fermented products prone to fungal contamination. As a result, application of chemical and synthetic preservatives is common to control microbial growth and increase the shelf life. But, due to their harmful side effects, much research has been being conducted to find a suitable substitute like plant EOs, as natural preservatives in the food industry. This study assessed the antifungal activity of T. daenensis and S. hortensis EOs and their potential applications in food model system.

Antibacterial activity of Artemisia persica Boiss essential oil against Escherichia coli O157 : H7 and Listeria monocytogenes in probiotic Doogh

“…However, EO level at 75 ppm was scored good with an overall acceptability score of 7.23 showing better sensory characteristics of the product and also with appropriated viability of L. paracasei as rated by panelists. In accordance with the present results,Sasanian et al (2018) reported the highest acceptability in terms of flavor in treatments with 50 ppm of Thymus daenensis and Satureja hortensis EOs and stated that greater concentrations of EOs cannot be used due to strong aroma which may cause undesirable organoleptic effect. The sensorial properties of the different Ayran samples…”

“…The essential oils of A. persica Boiss from the Province of Yazd were previously investigated by Mirjalili et al (2006) They showed (Z)-ocimenone (39.6%), ascaridole (16.0%), and α-terpinene (10.0%) as major constituents. According to previous studies, different factors such as geographical location, harvesting time and season, climate, altitude, and other factors could extremely affect the yield and composition of volatile oils of the same species (Nikbakht et al, 2014).…”

“…Doogh as a fermented product is the most commonly consumed Iranian yogurt drink which is usually prepared by mixing water, salt, and yogurt, and acidified by fermentative bacteria including Streptococcus thermophilus and Lactobacillus delbrueckii ssp. Bulgaricus (Sasanian et al, 2018).Dairy products, including Doogh, are frequently associated with the presence of E. coli O157: H7 and L. monocytogenes, two of the most important food-borne bacterial pathogens, which are considered a serious threat to the safety of fermented milk (Al-Nabulsi et al, 2016). The ability of these pathogens to survive and grow under various adverse environmental conditions, including low pH and high salt concentration, makes them potential hazards after the consumption of milk and dairy products (Cataldo et al, 2007).Chemical additives are commonly used to prevent spoilage or growth of pathogenic microorganisms, but their toxigenic residuals and impact on human health are under discussion.…”

Physicochemical and microbiological properties of Chaerophyllum, Oliveria and Zataria essential oils and their effects on the sensory properties of a fermented dairy drink, ‘doogh’

“…These were then added to un-heated doogh samples which, as a result, became significantly capable of inhibiting the growth of Aspergillus fumigates. [4] Moreover, in the mentioned experiment, the maximum inhibitory effect was seen on the 21st day in samples containing 100 and 150 ppm of T. daenensis EO and also in the ones containing 50 ppm of S. hortensis EO on the 15th day. According to previous results reported by Edadi Ebrahimi and Javadi, [36] the aqueous extract of Echinophora platyloba is proved to have inhibitory effects against gas-producing fungi in doogh, and its inhibitory effect is more prominent against yeasts than molds.…”

“…Essential oils (EOs) and plant extracts, commonly used for flavoring the doogh, are especially renowned for their antimicrobial and antifungal activities. [4] Their unique properties emanate from phenolic compounds such as thymol, eugenol and carvacrol, while several other of its chemical constituents include linalool, sabinene, menthol, myrcene, and camphene. [5] Oliveria decumbents is a medicinal plant species of the Umbelliferae (or Apiaceae) family, with powerful aromatic exudates.…”