Unlocking the potential of elderberry (sambucus nigra l.) fruit leather: Optimization of production and evaluation of bioactive content and bioaccessibility using response surface methodology

Abstract

Elderberry fruit leather was produced using RSM to evaluate the effects of hot air drying (60, 65, 70 degrees 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-3glucoside (110.79), cyanidin-3-sophoroside (8.09), and pelargonidin-3-glucoside (1.31). Processing improved L* and hue degrees, while decreasing a*, b*, Chroma. Optimum conditions were 70 degrees C, 15.5 % sucrose, and 4 mm. Elderberry was transformed into a non-seasonal functional snack with enhanced nutritional properties and high market potential.