Department of Microbiology and Biochemistry, Faculty of Sciences, University Mohamed Boudiaf of M'sila, M'sila 28000, Algeria.
Laboratory of Biology: Applications in Health and Environment, University of M'sila, M'sila 28000, Algeria.
Int J Mol Sci. 2024 Jul 22;25(14):7989. doi: 10.3390/ijms25147989.
Chemical residues in food pose health risks such as cancer and liver issues. This has driven the search for safer natural alternatives to synthetic fungicides and preservatives. The aim of this study was to characterize the chemical composition of the essential oils (EO), determine the polyphenolic contents, and evaluate the in vitro antioxidant and antifungal activities of methanol extracts (ME), essential oils (EO), and powders from L. (rosemary) and (Desf) Benth. (thyme) from the M'sila region, Algeria. The chemical composition of the EOs was determined by GC-MS. EO was composed of 31 components, mainly camphor (41.22%), camphene (18.14%), and α-pinene (17.49%); EO was composed of 58 components, mainly, in percentage, α-pinene (22.18), myrcene (13.13), β-pinene (7.73), β-caryophyllene (10.21), and germacrene D (9.90). The total phenols and flavonoids were determined spectrophotometrically, and the rosemary ME was found to possess the highest polyphenolic content (127.1 ± 2.40 µg GAE/mg), while the thyme ME had the highest flavonoid content (48.01 ± 0.99 µg QE/mg). The antioxidant activity was assessed using three methods: rosemary ME was the most potent, followed by DPPH (IC = 13.43 ± 0.14 µg/mL), β-carotene/linoleic acid (IC = 39.01 ± 2.16 μg/mL), and reducing power (EC = 15.03 ± 1.43 µg/mL). Antifungal activity was assessed for 32 pathogenic and foodborne fungi. Four methods were applied to the solid medium. Incorporating the powdered plant into the culture medium (at 10%) reduced the fungal growth to greater than 50% in 21.88% and 6.25% of all fungal isolates, for and , respectively. The ME, applied by the well diffusion method (0.1 g/mL), was less effective. Different concentrations of EO were tested. Incorporating the EO into the culture medium (1500 μL/L) inhibited 50% of the molds to levels of 50 and 75% for and , respectively, with the complete inhibition of four fungi. Fumigated EO (15 μL) inhibited 65% of the molds to levels of 65 and 81.25% for and , respectively, with the complete inhibition of five fungi. There was little to no sporulation in conjunction with the inhibition. Our results revealed some of the potential of the studied plants to fight foodborne molds and presented their promising characteristics as a source of alternatives to chemical pesticides and synthetic preservatives. Further studies are needed to find adequate application techniques in the food safety area.
食物中的化学残留物对健康构成威胁，如癌症和肝脏问题。这促使人们寻找更安全的天然替代品来替代合成杀菌剂和防腐剂。本研究的目的是描述植物挥发油（EO）的化学成分，测定多酚含量，并评估来自阿尔及利亚 M'sila 地区的迷迭香（rosemary）和百里香（thyme）的甲醇提取物（ME）、挥发油（EO）和粉末的体外抗氧化和抗真菌活性。通过 GC-MS 确定 EO 的化学成分。迷迭香 EO 由 31 种成分组成，主要成分为樟脑（41.22%）、莰烯（18.14%）和α-蒎烯（17.49%）；百里香 EO 由 58 种成分组成，主要成分为α-蒎烯（22.18%）、月桂烯（13.13%）、β-蒎烯（7.73%）、β-石竹烯（10.21%）和大根香叶烯 D（9.90%）。总酚和类黄酮通过分光光度法测定，发现迷迭香 ME 的多酚含量最高（127.1 ± 2.40 µg GAE/mg），而百里香 ME 的类黄酮含量最高（48.01 ± 0.99 µg QE/mg）。抗氧化活性通过三种方法评估：迷迭香 ME 的活性最强，其次是 DPPH（IC = 13.43 ± 0.14 µg/mL）、β-胡萝卜素/亚油酸（IC = 39.01 ± 2.16 µg/mL）和还原力（EC = 15.03 ± 1.43 µg/mL）。采用 32 种致病菌和食源真菌对其进行了评估。在固体培养基上应用了四种方法。将植物粉末掺入培养基中（10%），对 21.88%和 6.25%的所有真菌分离株，迷迭香和百里香的真菌生长分别降低了大于 50%。通过扩散法（0.1 g/mL）应用 ME 则效果较差。测试了不同浓度的 EO。将 EO 掺入培养基中（1500 μL/L），对 50%的霉菌的抑制率达到 50%和 75%，对迷迭香和百里香的抑制率分别为 50%和 75%，四种真菌完全被抑制。熏蒸 EO（15 μL）对 65%的霉菌的抑制率达到 65%和 81.25%，对迷迭香和百里香的抑制率分别为 65%和 81.25%，五种真菌完全被抑制。抑制作用伴随着孢子形成的减少。我们的研究结果揭示了研究植物在防治食源霉菌方面的一些潜力，并展示了它们作为化学农药和合成防腐剂替代品的有前途的特性。需要进一步的研究来寻找在食品安全领域的合适应用技术。
