Unlocking the potential of elderberry (Sambucus nigra L.) fruit leather: Optimization of production and evaluation of...

Elderberry fruit leather was produced using RSM to evaluate the effects of hot air drying (60, 65, 70 °C), sucrose concentration (12, 14, 16 %), and thickness (2, 3, 4 mm) on total phenolic content (TPC), total antioxidant capacity (TAC) via DPPH, CUPRAC, FRAP and total monomeric anthocyanin (TMA) during in-vitro gastrointestinal digestion. Samples exhibited a decrease in TPC, TAC (except-DPPH), and TMA after-digestion. Increased sucrose enhanced TAC-DPPH in post-gastric and post-intestinal phases, while higher temperature boosted TAC in undigested samples but reduced TPC. Elderberry phenolics (UPLC-ESI-MS/MS) (mg/kg) included protocatechuic acid (7.02), p-salicylic acid (3.39), rutin (2.72), and gallic acid (1.66). Main anthocyanins were cyanidin-3-glucoside (110.79), cyanidin-3-sophoroside (8.09), and pelargonidin-3-glucoside (1.31). Processing improved L* and hue°, while decreasing a*, b*, Chroma. Optimum conditions were 70 °C, 15.5 % sucrose, and 4 mm. Elderberry was transformed into a non-seasonal functional snack with enhanced nutritional properties and high market potential.