Alteration of starch hydrolyzing enzyme inhibitory properties, antioxidant activities, and phenolic profile of clove buds (Syzygium aromaticum L.) by cooking duration

This study assessed the effect of cooking duration on starch hydrolyzing enzyme (-amylase and -glucosidase) activities, antioxidant (1,1-diphenyl-2 picrylhydrazyl [DPPH*], hydroxyl [OH*] radicals scavenging abilities and reducing power) properties, and phenolic profile of clove buds. Clove buds (raw) were cooked for 10 (SC10) and 20min (SC20) and subsequently, their effects were assessed on enzyme activities, antioxidant properties, and phenolic profile. Inhibition of -amylase and -glucosidase activities and radicals scavenging abilities were altered by cooking in the trend; raw < SC10 > SC20, with IC50 values ranging from 0.25 to 0.52mg/mL and 0.10 to 1.50mg/mL respectively. HPLC phenolic profile of the clove buds revealed significant (P<0.05) changes in the amount of chlorogenic acid, quercitrin, quercetin, and kaempferol at different cooking duration. Thus, cooking duration may alter the phenolic compositions and nutraceutical potentials of clove bud by activation and/or deactivation of redox-active metabolites.