From Fresh to Dried Lavender Flower: Changes in Phytochemical Profile According to Drying Method

Abstract

Lavandula angustifolia Mill. is a part of the Lamiaceae family, which includes aromatic plants used in perfumery, manufactory, food, ornamental, and medicinal sectors. Both fresh and dried lavender flowers can be exploited in different ways; however, post-harvest treatments such as drying processes can help maintain the flowers’ properties for a longer period. This study analyzed fresh (F) and dried lavender flower ultrasound-assisted extracts, comparing two different drying methods, i.e., heat-pump drying (HP) and hot-air drying (HA), to assess potential differences in their effect on the phytochemical composition (total phenolic content, total anthocyanin content, and phenolic profile) and antioxidant activity (FRAP, DPPH, and ABTS assays) of flowers, focusing on three lavender selections from north-western Alps (i.e., Susa, Stura, and Tanaro). Results showed that HP-dried flowers are to be preferred over HA-dried flowers, as they contain +66.73% of phenolics and +62.2% of anthocyanins, and they have higher antioxidant activity (from 60.32% to 284.3% more according to the assay). HP-dried flowers, particularly those from the Tanaro selection, showed also higher values in the relative antioxidant capacity index (RACI) and the global antioxidant score (GAS), ranking together with the fresh flowers. Nine bioactive compounds out of thirteen were detected by means of HPLC, seven in F (caffeic acid, hyperoside, quercetin, ellagic acid, catechin, epicatechin, and dehydroascorbic acid), four in HA (ferulic acid, hyperoside, quercitrin, and epicatechin), and two in HP (caffeic acid and hyperoside). The higher temperatures used in HA probably promoted oxidative and biochemical reactions that led to the presence and increase in these compounds. However, many other phenolic compounds may contribute to the antioxidant power of lavender extracts. Overall, HP resulted in an effective and sustainable method for drying lavender flowers and may have interesting applications to obtain final products richer in bioactive compounds and antioxidant activity to be used in the functional food industry.

Phytochemical Composition and Antimicrobial Properties of New Lavandula angustifolia Ecotypes

“…The scientific literature contains extensive data on the antioxidant properties of various L. angustifolia extracts. Caser et al [1] showed that the antioxidant potential of fresh and dried flowers of L. angustifolia Mill. assessed in the ABTS method ranges from 17.89 to 44.81 µmol TE/g and in the DPPH method from 16.06 to 47.36 µmol TE/g.…”

“…The genus Lavandula includes about 50 species cultivated around the world as an ornamental and medicinal plant [1]. This plant comes from the Mediterranean area, the Middle East, North Africa, and the Republic of Cape Verde.…”

Effect of Different Postharvest Methods on Essential Oil Content and Composition of Three Mentha Genotypes

“…The drying method impacts the phytochemical profile (e.g., in Lavendula angustifolia Mill.) [30]. In regard to separation steps of leaves and stems, Aćimović et al noted that chamomile plant material that was not separated in flowers and stems before drying contained high contents of E-β-farnesene, whereas plant material that was separated (flowers with short stems) before drying contained the pharmacologically valuable α-bisabolol as the main compound [24].…”

Antimicrobial Properties and Assessment of the Content of Bioactive Compounds Lavandula angustifolia Mill. Cultivated in Southern Poland

“…It should also be mentioned that the quality of the essential oil depends on the method of obtaining it [7]. The supercritical CO 2 extraction method yields more oxygenated compounds, whereas the simpler and easier steam distillation method in oils yields more terpene hydrocarbons [8].…”