1. Anti-oxidative Properties of Lycopene
Blythe Beavers
FSTC 605
Oral Presentation
4/12/16

2. WHAT is lycopene? Lycopene is a member of the carotenoid family
The chemical and biological function of a carotenoid is
determined by their characteristic structure
It is a naturally occurring
compound that gives the
characteristic red color to
tomatoes, watermelon, guava,
grapefruit, and other red
produce
It is an antioxidant known
for its ability to prevent
cardiovascular disease (caused
by oxidative stress) and
possess an inverse relationship
with cancer
Antioxidants mitigate oxidative damage
More than 600 carotenoids have been found in plants and microorganisms and many of these have been found in human blood and tissue
Carotenoids prevent the initiating events in atherogensesis by inhibiting LDL (low density lipoprotein) oxidation

3. Chemical structure of lycopene
Sensitivities: will discuss why these are important to remember when we get to thermally processed tomatoes
Lycopene is a linear, acyclic isomer of β-carotene
It contains 11 conjugated double bonds along the center and 2 unconjugated double bonds at each end
Bonds are arranged linearly in the all-trans form
Possesses open β-ionone rings to an open chain

4. Lycopene Bioavailability
Lycopene is found in the photosynthetic pigment-protein complex of plants
The disruption of lycopene-protein complexes through breaking down cell wall structures, disrupting membranes, and reducing cellular integrity increases the accessibility of lycopene
Processed fruits and vegetables tend to be considered less valuable than fresh, however bioavailability of lycopene is improved after processing
Heat processing results in a conformational change in the cis-isomeric form which improved bioavailability
Sometimes the lycopene pigment is hidden in a plant because the green of the chlorophyll covers it up; after green degradation the red becomes apparent
Bioavailability of lycopene is improved after processing due to the denature of the lycopene-protein complex and subsequent release from the cell matrix (harsh treatments like mechanical disruption and steam are sometimes used)

5. Carotenoid comparison
Lycopene and β-carotene possess nearly identical structures, the main difference is the β-ionone ring
- This one seemingly small difference results in lycopene possessing significantly stronger antioxidant capabilities

6. Antioxidant properties
Antioxidant properties of lycopene evaluated in two ways:
Examining its protective effect against oxidative damage
Measuring its capability to scavenge free radicals directly
Lycopene is the most effective singlet oxygen quencher
Singlet oxygen (not technically a free radical) is a very reactive high-energy and short-lived oxygen species
Antioxidants scavenge radicals from the system either by reacting with them or by disrupting free radical chain reactions
The polyene chain is the structural feature that determines the chemical reactivity of carotenoids toward free radicals (aka anti- oxidative properties)
Carotenoid antioxidant activity highlighted also by ability to trap peroxyl radicals (ROO)
Oxidative damage can be to biological molecules like DNA, lipids, and protein in cell culture or animal experiments
Antioxidant reactions with free radicals result in stable and harmless products
Polyenes are highly unsaturated conjugate compounds. The predominant properties of polyenes are color and antioxidant activity. Polyenes occur as carotenoids. The configuration of this chain determines the reactivity

7. Singlet oxygen quenching
Lycopene’s superior ability to quench singlet oxygen as opposed to other carotenoids is due to the opening of the β-ionone ring
The increased number of
conjugated double bonds
allows lycopene
molecules to effectively
quench energy from singlet
oxygen and scavenge many
free radicals
- The efficacy of physical quenching greatly exceeds that of chemical quenching and involves the transfer of excitation energy from O2 to the carotenoid, resulting in ground-state oxygen and excited triplet-state carotenoid. The energy is dissipated through rotational and vibrational interactions between the excited carotenoid and the surrounding solvent to yield the ground state carotenoid and thermal energy. In the process of physical quenching the carotenoid remains intact and can undergo further cycles of singlet oxygen quenching, thus acting like a catalyst.

8. Stability of lycopene
Harsh treatments of tomatoes, including cooking or fine grinding, results in higher bioavailability of lycopene
Degradation via isomerization and oxidation do occur during processing
High temp short duration = beneficial effects on quality retention
During tomato processing, an initial los of 15.8% lycopene content from raw to scalding pulp
After this, no further degradation occurred
Lycopene content was stable for up to 12 months of storage under a variety of temps
These results indicate that lycopene is present in a variety of tomato products, is stable under conditions of processing and storage, is bioavailable and acts as an antioxidant providing protection against lipid, protein, and DNA damage

9. Benefits Natural colorant
Antioxidant activity improves after thermal processing
This is a perk the industry can really benefit from
A study was performed with human subjects which determined that a daily intake of 30 mg of lycopene can be achieved through a variety of processed tomato products.
The results show the benefit of long term lycopene consumption in preventing oxidative damage.
Lycopene is also highly hydrophobic and easily dissolves in oil
Fat in the diet has the potential to improve the absorption of lycopene
Mediterranean Diet
This diet can be achieved and represent a typical NA diet while keeping in the dietary guidelines.

10. References Literature Pictures
Di Mascio, Paolo, Stephan Kaiser, and Helmut Sies. "Lycopene as the most efficient biological carotenoid singlet oxygen quencher." Archives of biochemistry and biophysics (1989):
Kelkel, Mareike, et al. "Antioxidant and anti-proliferative properties of lycopene." Free radical research 45.8 (2011):
Shi, John, and Marc Le Maguer. "Lycopene in tomatoes: chemical and physical properties affected by food processing." Critical reviews in food science and nutrition 40.1 (2000): 1-42.
Shi, John, et al. "Stability and synergistic effect of antioxidative properties of lycopene and other active components." Critical reviews in food science and nutrition (2005):
Wenli, Yu, et al. "The antioxidant properties of lycopene concentrate extracted from tomato paste." Journal of the American Oil Chemists' Society 78.7 (2001):
Agarwal, Anita, et al. "Lycopene content of tomato products: its stability, bioavailability and in vivo antioxidant properties." Journal of medicinal food 4.1 (2001): 9-15.
Stahl, Wilhelm, and Helmut Sies. "Lycopene: a biologically important carotenoid for humans?." Archives of Biochemistry and biophysics (1996): 1-9.
Rao, A. Venket. "Processed tomato products as a source of dietary lycopene: bioavailability and antioxidant properties." Canadian Journal of Dietetic Practice and Research 65.4 (2004):
Pictures