Improving Jelly Nutrient Profile with Bioactive Compounds from Pine (Pinus sylvestris L.) Extracts

This study aimed to enhance the nutritional value of jellies by fortification with polyphenol extracts derived from Pinus sylvestris L. shoots at various maturation stages. Pinus sylvestris L., a coniferous species, is widely used in traditional medicine and functional foods due to its antioxidant, anti-inflammatory, and antimicrobial properties. Its needles, bark, and shoots are commonly used to extract bioactive compounds such as phenolic acids and flavonoids. In the current study, extracts were derived from young shoots collected directly from natural forest environments and processed using a decoction method to preserve bioactive compounds. The novel jelly formulations were prepared using pine shoots harvested at three maturity stages: stage I (4 cm), stage II (8 cm), and stage III (12 cm). All determinations were conducted both on the pure decoction extracts and the jelly samples to ensure a comprehensive analysis. High-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) allowed the identification of eight phenolic acids and six flavonoids in the samples. Significant differences were observed between the pine shoot extracts and jellies at different development stages. Notably, stage II exhibited optimal polyphenol content (312.2 mg GAE/100 g), DPPH free radical scavenging activity (94.9%), dry matter content (79.5%), and acidity (0.79% citric acid/g). A similar pattern emerged in the jelly samples (jelly2 (pine decoction stage II) > jelly1 (pine decoction stage I) > jelly3 (pine decoction stage III)). All extracts demonstrated antioxidant potential in DPPH free radical quenching assays. FTIR analysis evaluated structural changes in phenolic compounds during jelly formulation, focusing on key absorption bands at 1600 cm−1 (C=C stretching) and 3336 cm−1 (-OH stretching) using a Shimadzu IR Prestige-21 spectrophotometer. Compared to extracts, jellies showed diminished band intensities, indicating thermal degradation of phenolic compounds during processing. This aligns with observed reductions in antioxidant capacity and phenolic content, suggesting partial destabilization of these bioactive compounds. However, their integration into the jelly matrix highlights the potential for functional applications. The textural attributes of jellies were also assessed, and differences were attributed to the changes in acidity and moisture content of the pine shoots during maturation. Pine shoot extracts at specific maturation stages are valuable sources of antioxidant and polyphenol compounds and were successfully employed in functional applications belonging to the food or nutraceutical industry.