Insight into chemical composition of wild growing fruits from Serbia – application of ATR-FTIR spectroscopy

Abstract

Medlar (Mespilus germanica L.), blackthorn (Prunus spunosa L.) and hawthorn (Crategus mopnogyna Jacq. L.) are fruits belonging to the Rosaceae family. Medlar originates from the southeastern part of Europe, Turkey, Iran, and Iraq. It is well known among folks in this part of the world but, due to limited growing area, it is not recognized among the wide scientific community although it has been proven as a good source of phenolic compounds (chlorogenic acid, rutin, p-coumaric acid, quercetin, vanillin, protocatechuic acid, gallic acid, caffeic acid, etc.), sugars (glucose, sucrose, fructose) different organic acids (malic, tartaric,oxalic, citric, etc.) and vitamins, especially vitamin C [1,2]. Among fatty acids saturated ones such as hexanoic and hexadecanoic acids were predominant as well as stearic, oleic, linoleic, and behenic acids [3]. Blackthorn is one of the important wild plants with powerful healthpromoting properties. Its chemical composition is characterized by the presence of phenolic compounds which act as antioxidants, specifically flavonol heterosides (quercetin and kaempferol), phenolic acids (especially 3-O-caffeoylquinic acid), and coumarin derivatives, anthocyanins (particularly cyanidin-3-O-rutonoside and peonidin-3-O-rutonoside) which are responsible for its dark blue color [4]. Hawthorn is an endemic member of the Rosaceae family which ripens in mid-autumn, is used for different culinary purposes, such as the preparation of jellies, jams, and syrups [5]. The chemical composition of hawhorns is is characterized with the predominance of the following compounds: kaempferol and quercitrin (flavonol), apigenin (flavone) and ursolic acid (phenolic acid). Additionally, flavan-3-ol monomers, dimers, trimers, and tetramers were determined too. In addition, both unripe and ripened fruits contained significant quantities of tocopherols, β-carotene as well as vitamin C [5]. Chemical compositions of medlar, blackthorn and hawthorn fruit extracts were analyzed using Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy. The spectra were recorded in the the range 500-4000 cm-1, using Nicolet™ iS™ 10 ATR-FTIR Spectrometer (Thermo Fisher Scientific). The obtained absorption maxima indicated presence of monosaccharides, polysaccharides and polyphenols in studied medlar, blackthorn and hawthorn extracts.