Screening Method for the Visual Discrimination of Olive Oil from Other Vegetable Oils by a Multispecies DNA Sensor

Area of Science:

• Agricultural Science
• Biotechnology
• Food Science

Background:

• Olive oil's health benefits and economic importance necessitate authenticity verification.
• Adulteration with cheaper vegetable oils is common, posing risks to consumers and producers.
• Current detection methods are often complex, expensive, and require specialized equipment.

Purpose of the Study:

• To develop a simple, inexpensive, and rapid screening method for olive oil adulteration.
• To create a multispecies DNA sensor capable of identifying common adulterant plant oils.
• To enable visual detection of adulteration without advanced instrumentation.

Main Methods:

• Development of a multiplex DNA sensor utilizing unique nucleotide variations for plant species discrimination.
• Employing a single Polymerase Chain Reaction (PCR) step followed by a 20-minute reaction.
• Utilizing functionalized gold nanoparticles as reporters for visual detection of plant species via red spots.

Main Results:

• Successfully identified unique nucleotide variations for discriminating seven plant species: olive, corn, sesame, soy, sunflower, almond, and hazelnut.
• The DNA sensor detected as low as <5-10% of adulterant with high reproducibility and specificity.
• The method allows for both the determination of adulteration and the identification of the specific adulterant oil.

Conclusions:

• The developed DNA sensor offers a novel, cost-effective, and user-friendly approach for olive oil authenticity testing.
• This technology addresses the critical need for accessible methods to combat olive oil fraud.
• The sensor provides a reliable tool for protecting consumers and maintaining the integrity of the olive oil market.