Extraction and Stability of Olive Pomace Polyphenols in Natural Deep Eutectic Solvents

Polifenolni spojevi, zaostali u komini koja je nusproizvod u proizvodnji maslinova ulja, antioksidansi su koji imaju pozitivan učinak na ljudsko zdravlje. Za izdvajanje polifenola sve češće se primjenjuju prirodna eutektička otapala koje karakterizira netoksičnost, biorazgradljivost, nezapaljivost te niska cijena. U ovom radu upotrijebljeno je prirodno niskotemperaturno eutektičko otapalo (NADES) pripravljeno od triju komponenti: DL-jabučne kiseline, D-fruktoze i glicerola (MaFruGly) s različitim udjelima vode koji omogućavaju uspješnu ekstrakciju polifenola. Određena je optimalna metoda ekstrakcije, a nakon provedene ekstrakcije, ekstrakti su podvrgnuti mikrobiološkoj analizi te je praćena stabilnost izdvojenih polifenola. Istraživanje je pokazalo da su najuspješnije metode za ekstrakciju polifenola mikrovalno ultrazvučna te ekstrakcija ultrazvučnom sondom, a NADES s 30 % vode optimalno otapalo za održavanje stabilnosti polifenola. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.Polyphenols, left in olive pomace, which is a by-product in the production of olive oil, are antioxidants that have a positive effect on human health. For the extraction of polyphenols, the use of natural deep eutectic solvents is increasingly encountered, characterised by non-toxicity, biodegradability, nonflammability, and low price. In this work, a natural deep eutectic solvent (NADES) was prepared from three components: malic acid, D-fructose, and glycerol (MaFruGly) with different water contents that allow successful extraction of polyphenols. The optimal extraction method was determined. Following extraction, the microbial activity was tested and stability of the isolated polyphenols monitored. Research has shown that the most successful methods for polyphenol extraction are microwave ultrasound and ultrasonic probe extraction, and NADES with 30 % water has proven to be the optimal solvent for maintaining the stability of polyphenols. This work is licensed under a Creative Commons Attribution 4.0 International License

Ružička days : International conference 16th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: open lecture (1), chemical analysis and synthesis (3), chemical and biochemical engineering (8), food technology and biotechnology (8), medical chemistry and pharmacy (3), environmental protection (11) and meeting of young chemists (2)

Optimization of Bioactive Phenolics Extraction and Cosmeceutical Activity of Eco-Friendly Polypropylene-Glycol–Lactic-Acid-Based Extracts of Olive Leaf

Olive leaf is a rich source of phenolic compounds with numerous activities related to skin health and appearance. In this study, a green extraction method was developed using eco-friendly solvents: polypropylene glycol (PPG), lactic acid (LA), and water. The optimal extraction conditions were established, including solvent, extraction time, technique (magnetic stirrer vs. ultrasound-assisted extraction), and herbal material/solvent ratio. The composition of the solvent mixture was optimized using a mixture design. The content of phenolic compounds, including oleuropein and verbascoside, was determined using high-performance liquid chromatography (HPLC) and spectrophotometric methods. Using different extraction conditions, three extracts were prepared and their phytochemical compositions and antioxidant and skin-related bioactivities were investigated. The extracts were excellent inhibitors of elastase, collagenase, tyrosinase, and lipoxygenase. The best activity was shown by the extract richest in phenolics and prepared using magnetic-stirrer-assisted extraction for 20 min, with 0.8 g of herbal material extracted in 10 mL of PPG/LA/water mixture (28.6/63.6/7.8, w/w/w), closely followed by the extract prepared using the same extraction conditions but with 0.42 g of herbal material. The investigated PPG/LA/water mixtures contributed to the overall enzyme-inhibitory activity of the extracts. The prepared extracts were appropriate for direct use in cosmetic products, thus saving the time and energy consumption necessary for the evaporation of conventional solvents