Characterisation and quantification of phenolic, anthocyanidin and terpene species in plant foods and plant food-based complementary products with antioxidant and neuroprotective properties.

Phytochemicals, including phenolic compounds and terpenes, are of interest for the treatment and prevention of conditions with oxidative stress, inflammatory and neurodegenerative pathologies. Certain plant foods have shown beneficial effects for the brain; however, the specific phenolic and terpene species in these foods are unclear. The present study aimed to characterise and quantify the phenolic, anthocyanidin and terpene species in six plant foods (Queen Garnet plum (QGP, Prunus salicina); black pepper (BPF, Piper nigrum); clove (CF, Syzygium aromaticum); elderberry (EF, Sambucus nigra); lemon balm (LBF, Melissa officinalis); and sage (SF, Salvia officinalis)) and six plant food-based complementary products (clove (CC), elderberry (EC), lemon balm (LBC), and sage (SC), plus two blends (Astragalus membranaceus and lemon balm-rich, WC and R8)). The relationships between the concentration of phytochemical species in these samples and their antioxidant capacities (i.e. oxygen and nitrogen free radical scavenging, Cu²⁺ and Fe²⁺ chelating capacities, and the ability to prevent H₂O₂-induced oxidative stress in neuroblast-like SH-SY5Y cells, in vitro) were also examined. WC had the highest concentration of phenolics, followed by QGP, EF, CC and CF. BPF had the highest total terpene concentration followed by CC, CF and SF. Correlations between certain compounds and antioxidant capacity were demonstrated. The results provide insight into the potential functional capabilities of species of phenolics and terpenes. Understanding the phytochemical profile of plant foods and their correlations may be important in understanding their potential therapeutic benefits for brain health.