Bioactive lignans from sesame (Sesamum indicum L.): evaluation of their antioxidant and antibacterial effects for food applications.

Antioxidants protect the body from various disease
conditions through their ability to neutralize the effects of free
radicals. Synthetic antioxidants are extensively used in processed
foods for prevention of oxidation and retention of sensory
quality. Consumer awareness and preference has led to a
vigorous interest in the search for natural antioxidants.
Sesamin and sesamolin, the major lignans present in sesame
oil, are known for their antioxidative properties. Roasted
sesame oil has a higher concentration of sesamol, the thermally
degraded product of sesamolin, which is considered a more
potent antioxidant compared to its parent molecule. The isolated
lignans and sesamol were tested for their antioxidant, free
radical scavenging and antibacterial properties. Sesamol is the
best antioxidant and free radical scavenger amongst the molecules
studied with IC50 value of 5.44 μg / mL (DPPH radical
scavenging activity). Antibacterial assays against food borne
pathogens revealed sesamol to be an antimicrobial agent with
minimal inhibitory concentration (MIC) of 2 mg /mL in the
culture. Its activity was synergistic with γ-tocopherol, also
present in sesame seeds. Inhibition of browning (60–65 %) in
fruit pulps (apple, banana and potato) was observed in presence
of 20 μM sesamol.