Nutritional Composition, Bioactive Compounds and Antioxidant Potential of Pineapple Rind Flour as Functional Food Ingredient

Abstract

The global drive toward transformative food systems has intensified focus on value addition and the development of functional foods from agricultural by-products. Pineapple processing significantly contributes to the food industry yet generates substantial waste, primarily in the form of peels. These by-products are often discarded, representing an untapped resource for potential functional food ingredients. This study aimed to comprehensively evaluate the nutritional and chemical composition of pineapple rind flour (PRF) as a novel functional ingredient. PRF was prepared by dehydrating fresh pineapple rinds at 50°C for 12 h using a 21S01 DOOSAT air fryer oven. The flour was subjected to various analyses including proximate composition, vitamin and mineral profiling, essential amino acid quantification, phytochemical characterization, physicochemical property assessment and antioxidant capacity evaluation using standard analytical procedures. The results revealed that PRF contains significant nutritional components: 5.99% protein, 3.92% crude fibre and 3.81% ash. Furthermore, mineral analysis showed high concentrations of potassium (941 mg/100 g), zinc (16.04 mg/100 g) and iron (36.22 mg/100 g). Vitamins A (6.52 mg/100 g) and C (28.82 mg/100 g) were present in appreciable quantities, with B-vitamins ranging from 2.33 mg/100 g to 4.16 mg/100 g. Also, PRF showed significant essential fatty acid including oleic (65.77 mg/100 g), linoleic (172.00 mg/100 g) and arachidonic acids (169.04 mg/100 g). Additionally, phytochemical analysis revealed substantial amounts of total phenols (131.32 mgGAE/g), flavonoids (97.08 mgQE/g) and cardiac glycosides (64.26 mg/g). The antioxidant capacity of PRF as measured by FRAP, DPPH and ABTS was 181.31 μmol FeSO4/g), 96.47% and 88.22 μmol TE/g DW, respectively. Importantly, antinutritional factors were present in low concentrations. These findings demonstrate the potential of PRF as a nutrient-dense functional food ingredient, suggesting that its incorporation into food products could contribute to improved their nutritional profiles while concurrently offering a sustainable solution to agricultural waste management.