o:35999 Polyphenol Release from Wild Thyme Dust Extract in Simulated Gastrointestinal Fluids en In traditional medicine, wild thyme (Thymus serpyllum L.) is a part of various herbal medicines because of the presence of various bioactives, including luteolin, apigenin, catechin, rutin, quercetin, and chlorogenic, caffeic, salvianolic, and rosmarinic acids. Plant waste or dust possesses plenty of active compounds that can be applied in various food, functional food, and pharmaceutical products. Due to the dominant per os application of the plant and its formulations, polyphenol release from wild thyme dust extract in simulated gastrointestinal fluids was investigated. The extract was prepared using wild thyme dust and 50% ethanol with hydrochloric acid in maceration at a solid-to-solvent ratio of 1:30 g/mL, for 60 min. The particle size of the plant material was 0.3 mm, as a result of the intensive comminution of the starting herbal matrix. An in vitro release study was performed using the Franz diffusion cell with two compartments separated by the acetate-cellulose membrane. The study was conducted in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). SGF contained hydrochloric acid, sodium chloride, and pepsin (pH 1.2), whereas SIF contained potassium phosphate, sodium hydroxide, pancreatin, and bile salts (pH 6.8). The data has shown that the release of polyphenol compounds in SGF continuously rose during 240 min and reached a value of 56.64% of recovered phenolics. Nevertheless, the quantity of polyphenols in the receptor compartment did not reach a plateau after 240 min of the tested period. At the same time, the diffusion of polyphenols from the extract in SIF was slower, and only 20.95% of phenolics were released during 420 min. The steady state in SIF was achieved after 360 min. The presence of pancreatin and bile salts (in SIF) can decrease the polyphenol diffusion from extract through a hydrophilic acetate cellulose membrane of the Franz diffusion cell, thus the percentage of released polyphenolics was significantly lower. Wild thyme extract was prepared at an acidic pH value allowing the extraction of bioactive compounds soluble in this pH range. Thus, the extracted bioactive compounds showed faster and higher release in gastric conditions. The polyphenol diffusion from the extract in SIF was slower in comparison to the gastric environment. In addition, the content of released polyphenolics was lower in SIF. The data obtained encourage encapsulation of wild thyme extract polyphenols to protect them from acidic conditions and provide prolonged/controlled diffusion in the intestine. The study showed a higher polyphenol release from wild thyme dust extract in SGF compared to SIF. Since the release of phenolics in the gastric environment is not desirable, the study confirmed that the protection of sensitive bioactives and their prolonged and controlled release in intestinal conditions using various carriers is necessary. 2025-03-03T08:04:22.714Z 44 yes 46 Aleksandra A. Jovanović University of Belgrade, Institute for the Application of Nuclear Energy, Serbia doktor tehnoloških nauka 0000-0001-5394-0125 Bojana Balanč University of Belgrade, Faculty of Technology and Metallurgy, Serbia person Predrag Petrović University of Belgrade, Faculty of Technology and Metallurgy, Serbia person Andrea Pirković University of Belgrade, Institute for the Application of Nuclear Energy, Serbia doktor bioloških nauka person 0000-0002-1182-4895 Lidija Mladjenović University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia master biolog person 0009-0004-2941-188X Brankica Kartalović BioSense Institute, Member of the University of Novi Sad, Serbia person Diana Lupulović University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor veterinarskih nauka person 0000-0002-2476-4887 application/pdf 271099 https://phaidrabg.bg.ac.rs/o:35999 no yes 19 70 92000005 11A41 11A29 Polyphenol Release from Wild Thyme Dust Extract in Simulated Gastrointestinal Fluids 85-86 Abstract Proceedings 85 86 II Conference FoodWaStop Sustainable Network for agrofood loss and waste prevention, management, quantification and valorisation Rectorate of the University of Córdoba, Spain 2025-03-01