An Investigation into Crithmum maritimum L. Leaves as a Source of Antioxidant Polyphenols

Abstract

Crithmum maritimum, commonly known as rock samphire, is a plant species with a long history of use in traditional medicine and cuisine, especially in the Mediterranean region. Despite its potential therapeutic and commercial applications, the number of studies on this plant species are scanty and sparse. The aim of this study was to optimize the solid–liquid extraction of bioactive compounds from C. maritimum leaves through response surface methodology (RSM) and to comprehensively analyze the resulting extracts. Experimental parameters including liquid-to-solid ratio, solvent composition, extraction time, and temperature were investigated. The results of the RSM revealed a notable variation in the values of the extracted bioactive compounds (polyphenols, carotenoids, and chlorophylls), indicating the selection of optimum extraction conditions. Partial least squares analysis showed that solvent composition and extraction temperature had a significant impact on the extraction of the bioactive compounds. Consequently, these conditions required a 145-min extraction at 80 °C, using a solvent consisting of 45% v/v ethanol, and a 40:1 liquid-to-solid ratio. The optimum extract was analyzed using a range of assays to determine their polyphenol content, their content in chlorophylls and carotenoids, and their antioxidant potential via FRAP and DPPH assays. The total polyphenol content was measured at 15.11 mg gallic acid equivalents (GAE)/g. High-performance liquid chromatography–diode array detector (HPLC-DAD) analysis revealed that chlorogenic acid was the most prevalent polyphenol (9.35 mg/g) in C. maritimum leaves. Kaempferol 3-glycoside (1.81 mg/g), naringin (1.24 mg/g), and hesperidin (0.79 mg/g) were some polyphenolic compounds that had also been quantified. Total carotenoids (0.32 μg/g) and total chlorophylls (0.62 μg/g) were also measured. Multivariate correlation analysis and principal component analysis revealed that total carotenoids and chlorophylls had a strong negative correlation with total polyphenol content. The reducing power (FRAP assay) of the optimized extract had a value of 85.52 μmol ascorbic acid equivalents (AAE)/g, whereas the antiradical activity (DPPH assay) was measured at 25.57 μmol AAE/g. Given the high quantity of polyphenols, these results highlight the potential use of C. maritimum as a source of bioactive compounds in the food and pharmaceutical industries.

Optimizing Extract Preparation from Laurel (Laurus nobilis L.) Leaves Using a Pulsed Electric Field

“…Total polyphenol content (TPC) was calculated as mg gallic acid equivalents (GAE) per g of dry weight (dw) and was evaluated based on a previous study [26]. Further information is given in the Supplementary Material.…”

“…The individual polyphenolic compounds from the laurel extracts were identified and quantified using High-Performance Liquid Chromatography (HPLC), based on our prior research [26]. Information is given in the Supplementary Material.…”

Extraction of Bioactive Compounds from Cistus creticus Leaves and Their Use in the Preparation of Yogurt Desserts

“…A previous methodology [32] was followed, in which 100 µL of the sample was combined with 860 µL of aqueous ethanol (35% v/v) and 40 µL of a reagent consisting of 0.5 M sodium acetate and 5% (w/v) aluminum chloride. After letting the mixture stand for 30 min at room temperature, the absorbance measurement at 415 nm was conducted.…”

Optimization of Pulsed Electric Field-Based Extraction of Bioactive Compounds from Cannabis sativa Leaves

“…A previously established methodology [32] was applied to determine TPC. Briefly, 0.10 mL of the extract was combined with 0.10 mL of Folin-Ciocalteu reagent, and after 2 min, 0.80 mL of 5% w/v aqueous sodium carbonate solution was added.…”

“…High-performance liquid chromatography (HPLC) was used to detect and quantify individual polyphenols from the sample extracts, as established in our previous research [32]. A Shimadzu CBM-20A liquid chromatograph and a Shimadzu SPD-M20A diode array detector (DAD) (both purchased by Shimadzu Europa GmbH, Duisburg, Germany) was employed for the analysis of C. sativa extracts.…”