Boris Duralija, Anica Bebek Markovinović, Predrag Putnik, Ines Šoštarić, Dhika Prita Hapsari, Branimir Pavlić, Luna Maslov Bandić, Amin Mousavi Khaneghah, Danijela Bursać Kovačević
Strawberries (Fragaria × ananassa Duch.) are rich in bioactive compounds and antioxidants, making them promising for functional food development. This study examined how fruit size (<15 g, 15–30 g, >30 g) affects the bioactive composition and antioxidant activity of fresh strawberries and three-dimensional (3D)-printed strawberry-based snacks using the “Albion” cultivar. Smaller fruits (<15 g) showed the highest total phenolic (134.02 ± 1.76 mg GAE/100 g) and anthocyanin contents (17.74 ± 0.26 mg Pg-3-Glc/100 g), with anthocyanins better retained in 3D-printed products (15.96 ± 0.30 mg Pg-3-Glc/100 g). Although 3D printing reduced anthocyanins by ~26%, antioxidant activity remained stable (DPPH–fresh: 295.73 ± 0.21 µmol TE/100 g vs. 3D-printed: 299.06 ± 0.21 µmol TE/100 g). A significant inverse correlation between pH and anthocyanins (r = –0.999, p = 0.02) emphasized acidity as a key factor in pigment stability. These results highlight the importance of fruit size and processing conditions for maximizing the nutritional value of 3D-printed functional foods.