- The antibacterial, antifungal, antioxidant and anti-carcinogenic
properties attibuted to essential oils can be used as natural additives
in a range of foods. New research into basil and thyme essential oils reveals
their ability to curb Shigella, a harmful foodborne bacteria.
- Previous research has shown that thyme and basil have
antimicrobial potential. Building on this research, scientists at Ghent
university in Belgium opted to investigate the antimicrobial impact of
thyme and basil essential oil and their major constituents towards Shigella.
- According to the researchers who published their findings
in the February issue of Food Microbiology, thyme essential oil and its
major constituents thymol and carvacrol decontaminated Shigella inoculated
- They also found that thyme and basil essential oil, and
their major compounds thymol, estragol, carvacrol, linalool and p-cymene,
inhibited Shigella in an agar diffusion method.
- The researchers determined the antimicrobial effect of
basil and thyme essential oil and its major constituents thymol, p-cymene,
estragol, linalool, and carvacrol by using an agar well diffusion assay.
- Thyme essential oil, thymol and carvacrol showed inhibition
of Shigella sp. in the agar diffusion method. The potential of thyme essential
oil, thymol and carvacrol at 0.5 per cent and 1 per cent v/v for decontamination
of lettuce was evaluated.
- According to the findings, the researchers noted a decrease
of the shigellae after washing with 0.5 per cent while at 1 per cent Shigella
numbers dropped below the detection limit. The antimicrobial effect on
a subsequent lettuce sample in the same decontamination solution was significantly
decreased. In addition, application of thyme essential oil or thymol or
carvacrol for decontamination is hampered by sensoric properties of the
lettuce (browning, strong odour), note the researchers.
- "In this study, it was shown that essential oils
and their compounds have potential to be used for decontamination of minimally
processed vegetables," write the authors of the paper.
- More research into the use of essential oils as food
preservatives is needed, concluded the scientits.
- Used since antiquity for their antimicrobial potential,
herbs and spices have played a role in food protection for thousands of
- According to the researchers, in recent years, two consumer-driven
demands have arisen in the food industry. The first is the provision of
fresh, natural foods requiring minimal preparation and the second is the
control of food safety. But only a few studies have evaluated the potential
role of essential oils and their components as food preservatives.
- With the natural trend still on a steep, upward curve,
the recent findings from Belgium suggest that the food industry should
start to invest more time and money into discovering the full potential
essential oils could play in food preservation.
- Full findings are published in the February issue (Volume
21, Issue 1, February 2004, Pages 33-42) of Food Microbiology.
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