The determination of low oxygen threshold in garlic scapes during controlled atmosphere storage

Abstract

BACKGROUND Garlic scapes are susceptible to browning and rot during storage. In order to extend the storage time, controlled or modified atmosphere storage is usually used to maintain postharvest quality. However, low O2 or high CO2 damage easily occurs during atmosphere storage due to its respiration and unsuitable packaging. Therefore, the identification of low O2 threshold signal has been an urgent issue during atmosphere storage. This work investigated the quality changes and threshold signal during the controlled atmosphere storage of garlic scapes by the detection of ethanol and chlorophyll fluorescence. RESULTS The results showed that 7% CO2/3% O2 treatment could effectively slow down the decrease of chlorophyll and ascorbic acid, inhibit the accumulation of ethanol and maintain good sensory quality. Under dynamic atmosphere, garlic scapes had a tolerable minimum O2 threshold of 1.5% by the detection of ethanol, respiratory quotient and chlorophyll fluorescence F0. However, no obvious fluorescence Fv/Fm breakpoint was detected during dynamic atmosphere storage. CONCLUSIONS Ethanol and chlorophyll fluorescence F0 could be used as an indicator of low O2 damage during atmosphere storage of garlic scapes. The tolerable low O2 threshold was 1.5% O2 for garlic scapes storage. This work provided a new insight into the preservation of garlic scapes during atmosphere storage. © 2021 Society of Chemical Industry.