Transcript Natural_mechanisms_final_presentation

NATURAL MECHANISMS:
Avoiding the Ingestion of Toxic Foods and Pathogens
Emily Blumenthal
Samantha Paustian
INTRODUCTION
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“Protecting Ourselves From Food,” an article by
P.W. Sherman and S.M. Flaxman, presents the
following ideas:
Spices hold antimicrobial properties and can be used
as a mechanism against ingesting toxins
 The use of these spices varies within different
geographical and climactic conditions
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For example, Indian cuisine contains a larger number of
spices than cuisine found in colder parts of the country,
such as Norway
Another mechanism, morning sickness during human
pregnancy, helps the mother to avoid ingesting the
most probable teratogens in order to protect the
growing embryo
INTRODUCTION
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From these findings, further research will be
done to investigate the antimicrobial mechanisms
and properties of spices such as:
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Onions
Garlic
Thyme
Cinnamon
Cloves
INTRODUCTION
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Morning sickness will also be investigated with
the following questions:
During what trimester does morning sickness occur
most often, and how does this relate to fetal
development?
 What spices and foods are particularly avoided
during pregnancy?
 Do any spices have any positive or negative effects on
embryo development? Although they may inhibit
certain bacteria from proliferating, do those spices
hold a toxic effect as well?
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RESULTS – ONIONS AND GARLIC (GENUS
ALLIUM)
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The article “Antimicrobial activity of essential oil extracts
of various onions (Allium cepa) and garlic (Allium
sativum)” by N. Benkeblia was studied:
Bacteria such as S. aureus and S. Enteriditis were inhibited
by garlic and onions, as well as certain fungi including
Aspergillus niger, Penicillium cyclopium and Fusarium
oxysporum. These bacteria and fungi are commonly found in
food spoilage.
 Organo-sulfur containing compounds play a large role in
the antimicrobial activity of onions and garlic:
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Cysteine sulfoxides are converted by the enzyme allinase to
thiosulfates when plant tissues are cut.
 Allicin is a cysteine sulfoxide found in garlic that has not only a
large amount of inhibitory activity, but also holds antibiotic
properties comparable to known antibiotics (1 mg of allicin = 15
IU of penicillin)
RESULTS – THYME (THYMUS VULGARIS)
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The articles “The antimicrobial effect of thyme essential oil, nisin, and
their combination against Listeria monocytogenes in minced beef
during refrigerated storage” by N. Solomakos, A. Govaris, P. Koidis
and N. Botsoglo was studied:
 L. monocytogenes, a food pathogen found within minced beef,
was shown to be inhibited by thyme essential oil.
 The herb thyme largely contains the phenols thymol and
carvacrol, which have been found to inhibit many gram-positive
bacteria.
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Thymol, a hydrophobic molecule, has the ability to pass through the
lipopolysaccharide of gram-negative bacterial cell membranes and
therefore disturb cell structure (P. Tippayatum, et al, 2007)
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(Note: this experiment also included using a combination of thyme
EO and nisin, a polypeptide bacteriocin produced by certain
strains of Lactococcus lactis, which adds to the inhibitory effect by
forming pores within the cytoplasmic membrane of gram-positive
bacteria.)
RESULTS – CINNAMON (CINNAMOMUM VERUM)
AND CLOVE (SYZYGIUM AROMATICUM)
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The article “Antimicrobial activity of cinnamon and clove oils under
modified atmosphere conditions” by N. Matan, H. Rimkeeree, A. J.
Mawson, P. Chompreeda, V. Haruthaithanasan, and M. Parker; was
studied:
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The following fungi, yeasts, and bacteria are major spoilage
organisms found in intermediate moisture foods (such as bread,
fish, condiments, cheeses, and meats) and were almost all
inhibited by cinnamon and clove essential oil (exception being A.
flavus, the most resistant organsim, which required a combination
of both oils and at a higher concentration):
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Fungal species: Aspergillus flavus, Penicillium roqueforti, Mucor
plumbeus and Eurotium
Yeast species, Debaryomyces hansenii, Pichia membranaefaciens,
Zygosaccharomyces rouxii and Candida lipolytica
Bacteria species, Staphylococcus aureus and Pediococcus
halophilus
RESULTS – CINNAMON (CINNAMOMUM
VERUM) AND CLOVE (SYZYGIUM
AROMATICUM), CONT’D
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The compounds cinnamaldehyde (found
exclusively in cinnamon) and eugenol (found in
cloves, as well as cinnamon) are accountable for
the antimicrobial activity exhibited in both
spices.
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Both inhibit production of an essential enzyme by
bacteria, and may also cause damage to bacteria cell
walls.
Eugenol, a hydrophobic molecule like thymol, also
has the ability to pass through the lipopolysaccharide
of gram-negative bacterial cell membranes and
therefore disturb cell structure (P. Tippayatum, et al,
2007).
RESULTS – MORNING SICKNESS
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The article “Morning Sickness: A
Mechanism for Protecting Mother
and Embryo”, by same authors
P.W. Sherman and S.M. Flaxman
was investigated:
Morning sickness, also known as
NVP (nausea and vomiting in
pregnancy) is an adaptive mechanism
to combat ingestion of potentially
harmful foods.
NVP occurs primarily during the first
half of pregnancy, peaking between
the 9th and 14th weeks.
Surprisingly, this window between
the 9th and 14th weeks is also when
embryo organogenesis and
development of the central nervous
system peaks and vulnerability to
teratogens is at its highest.
Figure 7 of “Protecting Ourselves From
Food,” by P.W. Sherman and S.M.
Flaxman
RESULTS – MORNING SICKNESS,
CONT’D
The occurance of
morning sickness is
also related to
instances of
miscarriage or
spontaneous abortion.
 The number of
miscarriages
decreases drastically
when nausea and
vomiting are present
during pregnancy
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Figure 6 of “Morning Sickness: A Mechanism
for Protecting Mother and Embryo”, by
same authors P.W. Sherman and S.M.
Flaxman
RESULTS – MORNING SICKNESS,
CONT’D
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Most women had the most aversions to meat products such
as beef, poultry, eggs, and fish, which hold more pathogens
and/or parasites than other types of foods.
Women were less susceptible to morning sickness if their
previous diet consisted of staple plants, with the main one
being corn.
Some phytochemicals found in spices, which in smaller
quantities can yield antimicrobial benefits, may be
detrimental to a growing embryo if too much is ingested.
Example: Capsaicin, found in chili peppers, can be
therapeutic in smaller doses, but has been found to be
associated with ulceration, necrosis, and carcinogenesis in
larger amounts.
DISCUSSION - SPICES
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Overall, the five spices that were researched (onion, garlic, thyme,
cinnamon, and cloves) all exhibited antimicrobial activity.
The incorporation of these spices into food dishes greatly reduces
the risk of ingesting foodborne pathogens and/or parasites.
Further usage of the findings of these studies include
incorporation of phytochemicals found in spices within food
packaging.
 Drawbacks to this include the strong aromas and tastes
exhibited by the spices, which will affect the final outcome of
the manufactured food product, whether intended or not. The
compounds within onions and garlic are also unstable, making
them unlikely candidates for use in food preservation.
 However, N. Matan, et. al., suggest that using the volatile gas
forms of essential oils may decrease the strength in odor and
taste of the spice, although a higher volume may be needed.
DISCUSSION – MORNING SICKNESS
Research revealed that morning sickness, or
NVP, is a naturally occurring mechanism to
decrease ingestion of possible teratogens.
 Its linkage to embryo organogenesis gives
evidence to this theory of adaptive protection to
the embryo.
 Foods that were particularly avoided by women
during pregnancy were those that had the
possibility of containing parasites and pathogens;
foods that were favored were mainly grains,
fruits and vegetables, which carry a smaller risk
of illness.
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SUMMARY
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Spices contain phytochemicals that can act as antimicrobial agents
in food, inhibiting many species of fungi, bacteria, and yeasts.
 The phytochemicals in spices and their essential oils interfere
and destabilize the operation of the phospholipid bilayer of the
cell wall and also impede with enzyme systems and genetic
material of bacteria.
 Before refrigeration, recipes integrated these spices to make the
food taste better and help from spoiling.
Morning sickness is not really a sickness but an adaptation to
protect the mother and her baby in the most sensitive period of
pregnancy where fetal development is at its highest.
 In the first trimester, the embryo is most at risk for miscarriage
due to illness of the mother or from exposure to toxins.
 Mothers who exhibit a higher occurrence of NVP during the
first trimester have a much lower risk of miscarriage.
SUMMARY, CONT’D
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Why is this all important to us?:
 Spice usage in foods where refrigeration is unavailable could help prevent
outbreaks of food-borne pathogens
 Food industries, like restaurants and packagers, could use this information to
help serve and deliver safer food and to have a better appreciation for spice
usage and its history.
 At some point in our lives we will know someone who is pregnant or will have
children ourselves.
 Understanding that morning sickness is a function to help the mother and
baby will reduce stress and confusion; knowing that the first trimester is
when the embryo is most susceptible to teratogens will inform the mother to
be most careful of her diet during that time.
Future research could include:
 The application of spices in food packaging and its effectiveness compared to
other methods
 Determining effective therapeutic dosages of spices in order to achieve
maximum benefit, as well as determining its level of toxicity
 The investigation of NVP as purely a human phenomenon, or if it applies to
other mammals, such as primates
References
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Benkeblia,N. 2004. Antimicrobial activity of essential oil extracts of
various onions (Allium cepa) and garlic (Allium sativum). Food
Science and Technology. Vol 37, No.2: 263-268.
Matan,N., Rimkeeree,H., Mawson, A.J., Chompreeda, P.,
Haruthaithanasan, V., and Parker, M. 2006. Antimicrobial activity
of cinnamon and clove oils under modified atmosphere conditions.
International Journal of Food Microbiology. Vol 107: 180-185.
Sherman, P.W. and Flaxman, S.M. 2008. Morning Sickness: Adaptive
Cause or Nonadaptive Consequence of Embryo Viability? The
American Naturalist. Vol 172, No.1:54-62.
Sherman, P.W. and Flaxman, S.M. 2001. Protecting Ourselves From
Food. American Scientist. Vol 89:142-151.
Solomakos,N., Govaris, A., Koidis, P., and Botsoglo, N. 2008. The
antimicrobial effect of thyme essential oil, nisin, and their
ombination against Listeria monocytogenes in minced beef during
refrigerated storage. Food Microbiology. Vol 25: 120-127.
Tippayatum, P. and Chonhenchob, V. 2007. Antibacterial Activites of
Thymol, Eugenol and Nisin Against Some Food Spoilage
Bacteria.Natural Science. Vol41: 319-323.