Austin
Montgomery
PhD Candidate,
Sacks Lab (https://cals.cornell.edu/gavin-lavi-sacks)
Department of Food
Science and Technology
Cornell University
Understanding how beverage components interact with aluminum cans
Abstract
The
diversity of beverages packaged in an aluminum can has drastically increased
over the past decade. The manner in which beverage components interact with
aluminum cans (and the <10-micron polymer liner that separates beverage and
metal) has not been well documented in peer reviewed literature. The term
"corrosion" is generally used to describe the following three
phenomenon in canned beverages: 1. Off-aroma formation (SO2 containing
beverages can produce H2S) 2. Pinhole corrosion (high electrolyte
beverages eat through can bodies), and 3. Increased aluminum
dissolution/visible damage (high organic acid/ethanol beverages degrade the
liner). With each problem is a different analysis technique, as well. Dissolved
aluminum measurements are generally the gold standard metric for long term
studies. Electrochemical impedance spectroscopy (EIS) can give information
about the state of the polymer liner before visual methods can detect
corrosion. H2S can be measured directly via colorimetric gas
detection tube. Through these techniques, we have developed passive and active
solutions following results from long term storage, and accelerated, short-term
tests. Passive solutions have identified the maximum concentration of corrosive
components before problems arise so that producers can adjust formations
accordingly. Active solutions involve beverage can treatments that inhibit
corrosion and extend the shelf life without compromising beverage formulation.
This talk will discuss generally how beverage components interact with aluminum
cans and provide an overview of the active and passive solutions developed to
increase the quality and shelf life of beverages in aluminum cans.