Total polyphenols, total flavonoids, allicin and antioxidant capacities in garlic scape cultivars during controlled atmosphere storage

Five commercial cultivars of garlic scapes were subjected to a controlled atmosphere (O2 = 2-5%, CO2 = 3-6%) at temperature = 0 ± 0.5 °C, RH = 85-95%, for 140-224 d to document the quality and related changes in components during storage in two consecutive years. Polyphenols, flavonoids, allicin, and 2,2-diphenyl-1-picryl-hydrazl (DPPH) as well as the ferric ion reducing antioxidant power (FRAP), metal chelating capacity (MCC), and hydroxyl radical scavenging activity (HRSC) were analyzed to study overall antioxidant properties of garlic scapes in storage. The storage life was 224, 196, 196, 168, and 140 days for G025, G107, G2011-04, G110, and G064. G025 had the highest total polyphenol concentrations at 140 and 168 days in 2014 and 2015, respectively, whereas G2011-4 had the lowest concentrations of total polyphenols. The highest total polyphenols, total flavonoids and allicin concentrations were observed in G025, whereas G2011-04 displayed the lowest concentrations of total polyphenols and allicin in both years. For all cultivars, total flavonoid concentrations decreased with time. The highest weight loss was observed in G064 both in 2014 and 2015. The antioxidant capacity of G025 and G110 was higher than that of the other cultivars. DPPH and HRSC were highest in G025, and MCC and FRAP were high in G110 and G107 in both years. These results demonstrate that cultivar influences the rate of garlic scape deterioration, chemical composition properties and antioxidant activities.