Biochemical Profiling and Ecotoxicological Assessment of Prunus spinosa L. Fruits from the Cluj Region: Phytochemical Composition, Contaminant Load, and Antioxidant Potential

Abstract

Prunus spinosa L. (blackthorn) is a widely distributed wild fruit species in Romania with considerable, yet underexplored, potential as a functional food ingredient and natural source of bioactive compounds. This study aimed to characterize the phytochemical composition, mineral and contaminant profiles, and antioxidant capacity of P. spinosa fruits collected from five sites in the Cluj region with contrasting land-use conditions (forest-edge, rural, suburban, and roadside). Fruits were harvested in three sampling campaigns (October 2018, October 2019, and November 2019). Analytical determinations included total polyphenol content, antioxidant capacity, fatty acid methyl esters (FAMEs), dietary fibers, chlorophyll, water content, polycyclic aromatic hydrocarbons (PAHs, 15 congeners), and metal concentrations (ICP-OES/MS). A composite Ecotoxic Pressure Index (EPI) integrating metal and PAH data was computed per site. Total polyphenol content ranged from 124 to 1172 mg GAE·kg−1 DW, while antioxidant capacity ranged from 116 and 1184 µg AAE·mg−1. One-way ANOVA revealed significant location effects on Cu, Zn, Mn, Ca, Mg, Na and K (p < 0.05). PCA (65–70% explained variance) discriminated rural/forest-edge samples (high polyphenols, low EPI) from urban/roadside samples (elevated metals and PAHs). Multiple linear regression demonstrated that polyphenols were the dominant positive predictor of antioxidant capacity (β = +0.78, p < 0.001), while Fe and total PAHs were inversely associated with antioxidant capacity (β = −0.31 and −0.28, respectively; R2 = 0.80). The observed biochemical and contaminant profiles varied according to geographical origin and land-use context, although these associations cannot be attributed exclusively to pollution exposure. Rural and forest-edge samples showed favorable descriptive profiles for several bioactive parameters, but further controlled studies are required before site-specific superiority for functional food applications can be established.