Plant extracts keep mosquitoes
at bay
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Radiation increases vegetable health benefits
 Dr
Xuetong Fan working at Agricultural Research Service in the
US has demonstrated that low dose gamma radiation prolongs
the life of nutrients in vegetables. Romaine and iceberg lettuce
and endive were treated, and the nutrients content fell at
a lower rate over eight days to untreated samples. Vegetables
that were treated with the low dose radiation had, on average,
40% more antioxidants after 8 days, up to a maximum of 88%
more.
Antioxidants have been shown to be biologically
active in prevention of cancer and reducing mortality due
to heart disease. This treatment could increase the antioxidants
available to the consumer, conferring increased health benefits.
| Antioxidant capacity of fresh-cut
vegetables exposed to ionising radiation, Xuetong
Fan, Journal of the Science of Food and Agriculture,
DOI: 10.1002/jsfa.2057 (Available on EarlyView) |
Natural mosquito defence
Mosquitoes are the vectors for malaria, a disease that is
estimated to have killed more people than any other in human
history. The World Health Organisation estimates that two
million people still die of this disease annually. Researchers
at the Lebanese University, Beirut, have found a natural way
to repel mosquitoes and prevent them from biting humans.
Current methods of controlling mosquitoes involve the use
of insecticides which can have a damaging effect on both people
and the environment. The research group tested several plant
extracts as an alternative to the use of synthetic chemicals.
Lemon grass and eucalyptus essential oils were most effective,
providing protection against bites for over an hour. Both
fennel and bay leaf extract provided protection for up to
50 minutes with orange and pine extracts the least effective.
| Repellency and toxicity of aromatic
plant extracts against the mosquito Culex pipiens molestus
(Diptera: Culicidae), Abdallah F Traboulsi, Samih
El-Haj, Marie Tueni, Khalil Taoubi, Natalie Abi Nader,
Abir Mrad, Pest Management Science, DOI: 10.1002/ps.1017
(Available on EarlyView) |
Cleaning diesel with bacteria
Diesel contains high levels of organosulphur compounds. When
burning diesel with these compounds it generates sulphur oxides
which contribute to global warming, acid rain and air pollution.
The sulphur is currently removed in a chemical process using
both high temperatures and pressures. As restrictions on the
levels of sulphur in diesel are tightened the process becomes
increasingly expensive because of the high cost of producing
the heat and pressure and cost of the catalyst.
Scientists at the Institute of Process Engineering in China
believe they have found a method which could substantially
reduce the cost of this desulphurisation. They have used a
strain of bacteria to reduce the level of sulphur without
having to go through further, costly chemical processes. Two
treatments with these bacteria were enough to reduce sulphur
levels by over 90% without the need of high temperatures or
expensive catalysts.
| Deep desulfurisation of hydrodesulfurised
diesel oil by Pseudomonas delafieldii R-8, Shan Guobin,
Xing Jianmin, Zhang Huaiying, Liu Huizhou, Journal
of Chemical Technology and Biotechnology, DOI: 10.1002/jctb.1197
(Available on EarlyView) |
Medicinal plant purification
Traditional medicines have been used for many thousands of
years to treat a huge variety of diseases. Medical interest
in these preparations has been increasing in recent years
and many of the plants used have been shown to have biologically
active compounds. Recent successes have included drugs like
artemisinins that are highly effective anti-malarial agents.
Researchers from China have been examining ways to effectively
purify these active compounds. Active extracts from plants
often contain compounds that are detrimental to human health.
The researchers have found a way to remove one of these, tannins,
using collagen fibres. Tannins can cause adverse reactions
in people, particularly when injected, where they can cause
jaundice and other liver problems. The tannins bind to the
collagen fibres allowing easy removal and the scientists have
shown a 100% success rate for removal of these potentially
harmful chemicals.
| Selective removal of tannins from
medicinal plant extracts using a collagen fiber adsorbent,
Xue-Pin Liao, Bi Shi, Journal of the Science of Food
and Agriculture, DOI: 10.1002/jsfa.2114 (Available
on EarlyView) |
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