Mentha spicata L. infusions as sources of antioxidant phenolic compounds: emerging reserve lots with special harvest requirements

Mentha spicata L., commonly known as spearmint, is widely used in both fresh and dry forms, for infusion preparation or in European and Indian cuisines. Recently, with the evolution of the tea market, several novel products with added value are emerging, and the standard lots have evolved to reserve lots, with special harvest requirements that confer them with enhanced organoleptic and sensorial characteristics. The apical leaves of these batches are collected in specific conditions having, then, a different chemical profile. In the present study, standard and reserve lots of M. spicata were assessed in terms of the antioxidants present in infusions prepared from the different lots. The reserve lots presented the highest concentration in all the compounds identified in relation to the standard lots, with 326 and 188 μg mL^-1 of total phenolic compounds, respectively. Both types of samples presented rosmarinic acid as the most abundant phenolic compound, at concentrations of 169 and 101 μg mL^-1 for reserve and standard lots, respectively. The antioxidant activity was higher in the reserve lots which had the highest total phenolic compounds content, with EC₅₀ values ranging from 152 to 336 μg mL^-1. The obtained results provide scientific information that may allow the consumer to make a conscientious choice.