Changes in the Total Polyphenolic Content and Antioxidant Capacities of Perilla (Perilla frutescens L.) Plant Extracts during the Growth Cycle

Changes in the total polyphenolics and antioxidative capacity of the perilla (Perilla frutescens L.) plant, during the growth cycle, have been analyzed in this study. These parameters were evaluated at five morphological stages. The extracts characterized by the highest total phenolic compound content were obtained at the full flowering stage. The phenolic compound profile was characterized by the presence of three major compounds, with rosmarinic acid being the most abundant. Moreover, their contents were significantly different according to the growth stage. High Trolox equivalent antioxidant capacity values were found for the last two growth stages. The lowest ferric-reducing antioxidant power value was observed for the medium vegetative stage. The highest antiradical activity against DPPH center dot was observed for extracts obtained from the early vegetative stage. The antioxidant activity changes during the growth cycle, and this change may be useful to determine the optimal harvest time.