Copyright © Emir Horozić et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unre- stricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Advanced Chemistry, 8 (2) (2020) 225-229 International Journal of Advanced Chemistry Website: www.sciencepubco.com/index.php/IJAC Research paper Influence of extraction technique on nutrient content, antioxidant and antimicrobial activity of aqueous extracts of commercial apricot kernels Emir Horozić 1 *, Jasmin Suljagić 1 , Jasna Gojković 1 , Eldin Halilčević 2 , Darja Kubiček 3 , Ermina Cilović Kozarević 4 1 Faculty of Technology, University of Tuzla, Urfeta Vejzagića 8, 75 000 Tuzla, B&H 2 Faculty of Mining, Geology and Civil Engineering, University of Tuzla, Urfeta Vejzagića 2, 75 000 Tuzla, B&H 3 Faculty of Natural Sciences and Mathematics, University of Tuzla, Urfeta Vejzagića 4, 75 000 Tuzla, B&H 4 Faculty of Pharmacy, University of Tuzla, Urfeta Vejzagića 8, 75 000 Tuzla, B&H *Corresponding author E-mail: emir.horozic@untz.ba Abstract This paper presents the results of influence of extraction technique on phytochemical composition and biological activity of aqueous extracts of commercial apricot kernels. Three techniques were used for extraction: maceration, ultrasonic and Soxhlet extraction. The content of total phenols, flavonoids, bioelements, antioxidant and antimicrobial activity was analyzed in the extracts. Antioxidant activity was analyzed in vitro using DPPH and FRAP methods. Antimicrobial screening was performed by diffusion technique on reference strains from the ATCC collection. The content of total phenols and flavonoids is highest in extracts obtained by ultrasonic extraction and maceration. These techniques have proven to be the best for the extraction of macro and micronutrients. The aqueous extract obtained by maceration at 300 rpm for 3 hours showed a greater inhibitory effect against the tested microorganisms, compared to the extracts ob- tained by other techniques. The least efficient method of extracting bioactive components from apricot kernels is Soxhlet extraction, with the lowest dry extract yield of 5.5%. Keywords: Extraction; Apricot Kernels; Polyphenols; Antioxidants; Antimicrobial Activity; Nutrients. 1. Introduction Fruits and vegetables are known sources of many nutrients. They contain a large number of bioactive components necessary for the nor- mal functioning of the human body and the treatment of many diseases (Yiğit et al. 2009). The use of natural remedies for the treatment of various diseases has a long history, starting with the Ayurvedic treatment and extending to the Chinese, European and other systems of traditional medicines (Raj et al. 2012). Apricot (Prunus armeniaca L.) is classified under the Prunus species of Rosaceae family of the Rosales group. Apricot has an important role in human diet, and can be used as fresh, dried or processed fruit (Ramadan et al. 2018). Due to the presence of cyanogenic glycosides (mainly amygdalin) in the apricot kernel, it is today alternatively used to treat various forms of cancer (Yan et al. 2006). In this paper, the influence of the extraction technique with the content of nutrients and phytochemicals, as well as the antioxidant and antimicrobial activity of apricot kernel extracts will be examined. 2. Material and methods 2.1. Chemicals An apricot kernel sample was purchased at a local market and crushed using an electric grinder and as such used for extraction and other analyzes. Ultrapure water, prepared with a TKA Smart2Pure device, was used for the extraction process. The chemicals used in the ex- perimental part are: methanol, diethyl ether, glacial acetic acid, hydrochloric acid, sodium carbonate, aluminum chloride, sodium nitrite, purchased from Merck (Darmstadt, Germany). Dimethyl sulfoxide (DMSO), 2,2`-diphenyl-1-picrylhydrazyl (DPPH), gallic acid, Folin & Ciocalteu's reagens, 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ), purchased from Sigma Chemical Co. (St. Louis, Missouri, USA). Iron(II) sulphate heptahydrate and iron(III) chloride hexahydrate were purchased from Honeywell (Charlotte, North Carolina, USA). All reagents were used without further purification.