Non-destructive detection of sun stress compromised apples
Author: David Rudell
Published: 2022
Summary: Apple peel appearance and chemical changes result from different relative sun exposure. This can lead to sun scald and other defects during the cold chain. Using sun exposure-related natural peel chemical targets reported in our earlier project, we have developed an index that can be used to establish relative cumulative sun exposure of peel using non-destructive imaging. With this index, we have developed and are refining a protocol for estimating whole-apple relative sun exposure that can be used to sort apples according to sunburn symptoms, high sun scald risk, and different relative sun exposure. Rather than determining a sorting protocol based on the capacity of a specific imaging technology, our index is rooted in biology, tying our collective findings linking natural peel chemicals with sun exposure, finding non-destructive methods to estimate levels of these chemicals, determining an index using these targets that best estimates relative sun exposure, and, finally, developing a sorting procedure based on index levels over the entire surface of fruit. Refinement of this protocol is ongoing at the time of this report.
