Antioxidant changes during postharvest processing and storage of leek (Allium ampeloprasum var. porrum)

The evaluation of the impact of postharvest processing and storage on the health benefits of vegetables is of great practical importance. Reports on their effect on the antioxidant capacity, polyphenol and S-alk(en)yl-l-cysteine sulfoxide (ACSO) content, i.e. isoalliin and methiin of the white shaft of leek (Allium ampeloprasum var. porrum), however, are limited. This study determined the levels of the antioxidant properties of leek from postharvest processing at the farm until refrigerated storage of 13 days at the consumer. Two cases were investigated, (1) leek sold as an entire plant and (2) leek with a large part of the green leaves removed, where the shafts are sold in a plastic package. The antioxidant capacity and the total content of phenolic compounds in the white shaft of the entire and packaged leek was stable during 13 days of refrigerated storage. A significant increase in the concentration of isoalliin was observed. Comparing the entire and processed/packaged leek, significant differences could be observed in antioxidant properties. The ACSO content in the white shaft of packaged leek was significant lower than the content in the white part of the entire leek. Therefore, the minimal processing step of cutting the green leaves and roots had an influence on the levels of antioxidant properties.