Team:UC Davis/Project Overview

As students of an agricultural university, the purity and quality of agricultural products is a theme that strikes close to home. Our connection with the UC Davis Olive Oil center inspired us to look towards quality control and purity standards in the olive oil industry with our initial research. The more research we undertook, the more we understood that this industry is rife with fraud, and that consumers countrywide are in most cases not getting the products they’re paying for. Over seventy percent of imported oils and many US oils are already rancid by the time they reach the shelf. Additionally, there are currently no cheap, effective, and accessible methods for assessing Olive Oil quality. Applying our diverse set of engineering skill sets, we set out to provide producers, distributors, and consumers with a way of ensuring oil Quality.

Olive Oil quality turns out to be remarkably difficult to assess from a chemical standpoint. Olive oil is an incredibly complex mixture of tens of thousands of different chemical compounds. Additionally, there is no one molecule that signals that an oil is rancid. However, combinations, or profiles, of certain chemicals in an oil can be linked to rancidity. Based on our collaborations with both researchers at the UC Davis Olive Oil Center, and quality control experts at olive oil mills, we came to the understanding that a single group of chemicals, aldehydes, may serve as an excellent proxy for rancidity. Our challenge was then to develop a method to detect these compounds in oil, and develop a useful conclusion regarding the oil’s rancidity.

We developed an enzyme based electrochemical biosensor. We first obtained and engineered several NAD+ dependent Aldehyde Dehydrogenases to have specificity for Aldehydes commonly found in rancid oils. We then optimized an electrochemical system to detect these enzyme’s activity. After validating that our system could detect enzyme activity, we developed a mathematics and software suite that allowed us to connect measured aldehyde profiles to degree of rancidity in an Olive Oil.