UC Davis Championship Poster

OliView: An Enzyme-Mediated Electrochemical Biosensor for
Olive Oil Quality Control
E. Aaron Cohen, James Lucas, Lucas Murray, Sarah Ritz, Yeonju Song, Simon Staley, Brian Tamsut
Dr. Marc Facciotti, Dr. Justin Siegel, Dr. Ilias Tagkopoulos, Dr. Selina Wang
University of California, Davis: UC Davis Genome Center; UC Davis Olive Center; College of Agricultural and Environmental Sciences; College of Biological Sciences; College of Engineering
Introduction
Methodology: Project Overview
Signal Processing
70% of “Extra Virgin” Olive Oil Consumed
in the United States is Rancid from
Exposure to Heat and Light
We trained a predictive model on a combinatorial library of
aldehydes based on observed enzyme steady-state velocities
Policy and
Practices
Enzyme
Engineering
Electrode
Potentiostat
Signal
Processing
Aldehyde Dehydrogenases with
Unique Substrate Specificities
Policy and Practice
California Department of Food
and Agriculture
 =  ∗  +  ∗  +  ∗ 
Average Catalytic Efficiency
Medium Saturated
Aldehydes (C5-C7)
WT E. coli ALDH
BBa_K1324000
W176Q E. coli ALDH
California Olive Oil Producers
Community Olive Oil Tasting
BBa_K1324001
WT Rat ALDH
BBa_K1324003
100%
Long Saturated
Aldehydes (C8-C10)
95%
Unsaturated
Aldehydes
8%
98%
100%
2%
100%
75%
71%
Parts Submitted
BBa_K1324000: Wild-Type Escherichia coli Aldehyde Dehydrogenase
BBa_K1324001: W176Q Escherichia coli Aldehyde Dehydrogenase
BBa_K1324002: W176V Escherichia coli Aldehyde Dehydrogenase
BBa_K1324003: Wild-Type Rattus norvegicus (Rat) Aldehyde Dehydrogenase
Indicators of Rancidity: Aldehyde
Composition in Olive Oil is Complex
Medium Saturated



Dropsens Electrode Detects
Enzyme-Generated NADH
1

= 2
3

1
2
3



1
2
3
−1
1
∗ 2
3
Our Mathematical Model Successfully Identified
Two out of Three
Rancid Olive Oils in a Blind Test
Our Open Source Software Package Contains:
• Measurement packages for anodic stripping, cyclic
voltammetry, and potentiostatic amperometry
• Signal Conditioning and Processing
• Statistics Package
• Enzyme Specificity Determination Tool
Performance Comparison Against an
Industry Standard Potentiostat
Acknowledgements
Long Saturated
Unsaturated
$2,000-$10,000
$60
Academic Sponsorship—for their generosity and enthusiasm
• Vice Chancellor of Research, Harris Lewin, Ph.D.
• College of Biological Sciences - Dean James Hildreth, Ph.D.
• College of Agriculture - Dean Helene Dillard, Ph.D.
• College of Engineering - Dean Enrique Lavernia, Ph.D.
• UC Davis Genome Center - Director Richard Michelmore Ph.D.
• Department of Biomedical Engineering - Chair Kyriacos Athanasiou, Ph.D., P.E.
Corporate Sponsors—for their technical support and generosity
• Pine Instruments
• Corto Olive Company
• Dropsens
• California Olive Ranch
• Life Technologies
• Seka Hills Olive Mill
• BASF
• Sigma Aldrich
• Transcriptic