Nutritional Value, Phytochemical Composition and Biological Activities of Lycium barbarum L. fruits from Serbia

Cultivation of goji berries (GB), fruits of Lycium barbarum L. (Solanaceae), is expanding worldwide, including in Europe. In this study, a comparative analysis of the nutritional value, chemical composition and in vitro biological activities of GB from different locations in Serbia was performed. Proximate compositions were evaluated according to standard methods. Minerals were assessed by inductively coupled plasma techniques, while fatty acids, sterols, and phenolic profiles were analyzed by gas- and liquid chromatography-based techniques coupled with flame-ionization, mass spectrometry, or diode array detection. The total content of phenolics, flavonoids, carotenoids, and polysaccharides was assessed using spectrophotometric methods. Methanol extracts from GB were examined for their antioxidant, enzyme inhibitory (alpha-amylase, alpha-glucosidase, acetylcholinesterase and tyrosinase) and antibacterial activities. Despite significant variations among samples from different locations, the results confirmed that GB are a valuable source of dietary fiber and protein and are characterized by favorable fatty acid profiles. Phytochemical analysis revealed that beta-sitosterol, Delta(5)-avenasterol, and 24-methyldesmosterol are the predominant sterols and caffeic acid, gallic acid, quercetin and rutin are the main phenols. All GB samples showed both antioxidant and mild antimicrobial activity. A dose-dependent anti-enzymatic activity (IC50 ranging 1.68-6.88 mg/mL) was demonstrated. The results support further promotion of GB cultivation in Serbia and further investigations on their potential applications in various industries.