| Abstract |
Food spoilage caused by bacterial contamination remains a major global challenge, leading to significant food waste and foodborne illnesses. In response, there is growing interest in natural, plant-based preservatives as sustainable alternatives to synthetic chemicals. This study investigated the antibacterial properties of South Africa’s indigenous wild garlic species, Tulbaghia violacea (TV), and its hybrid (T. violacea × T. acutiloba, TVH), and evaluated their potential for extending the shelf life of fresh produce.
Plants were cultivated in both soil and aeroponic systems, and extracts were prepared using dichloromethane and ethanol, followed by concentration with a rotary evaporator. Thin-layer chromatography (TLC) and minimum inhibitory concentration (MIC) assays were conducted to assess antibacterial activity against Staphylococcus aureus. Additionally, extracts were applied as coatings on cucumbers, strawberries, and grapes to evaluate their preservative effects.
Both TV and TVH extracts inhibited Staphylococcus aureus, with variations depending on cultivation method and plant part. Soil-grown extracts generally exhibited stronger antibacterial activity. In coating tests, treated fruits showed reduced bacterial growth and slower spoilage compared with uncoated controls. TLC and MIC results further confirmed antibacterial activity in the leaves and roots of TVH and the leaves of TV.
Overall, soil-grown, dichloromethane-extracted samples demonstrated the highest antibacterial potency. These findings highlight the potential of indigenous wild garlic as a natural, sustainable preservative—offering a promising strategy to reduce food spoilage, minimise waste, and promote local biodiversity.
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