Effects of Aluminium Coated with Stainless Steel on the Nutritional Quality of Tomato Products

This study evaluated the storage stability of tomato juice, paste, and purée packaged in conventional aluminium containers (ACs) and aluminium containers coated with a food-grade stainless steel layer (ASSCs). The objective was to determine whether the stainless steel coating could reduce aluminium ion migration, preserve the physicochemical and nutritional quality of tomato products during storage, and decrease the need for antioxidant, antifungal, and acidifying additives. The stainless steel coating improved the barrier performance of the Al substrate by reducing its porosity from 6.0% to 3.8%. During storage, tomato products in ACs exhibited a marked decrease in acidity (7.65–4.07 g/100 g), whereas samples stored in ASSCs showed a smaller reduction (7.65–5.98 g/100 g), indicating enhanced chemical stability. Increasing NaCl concentrations promoted Al migration, reaching 26.4 mg/kg in AC but only 9.2 mg/kg in ASSC. The vitamin C content remained nearly unchanged (2.09–2.04 mg/100 g), while total polyphenols decreased slightly (110.13–98.81 mg/100 g). Mineral analysis (Al, Cr, Mn, Ni, Zn, Fe, and Ca) confirmed higher metal concentrations in AC-stored samples, whereas aluminium migration was effectively minimised in ASSCs. These findings demonstrate that stainless steel-coated aluminium provides superior corrosion resistance, limits metal transfer, preserves the physicochemical and antioxidant quality of the tomato products, and represents a promising packaging material for extending shelf life while reducing the need for food additives.