Extraction of Natural Colorants from Banana (Musa spp.) Peel and Determination of Total Carotenoids, β-Carotene and Antioxidant Activity of the Extracts

Purpose: The banana (Musa spp.) peel, which is rich in many bioactive compounds, is not utilized effectively. This study was conducted to extract natural colorants from banana peel and to determine the total carotenoid and β-carotene concentration, and antioxidant activity of the extracts.
Research Method: Ambul, Puwalu, and Cavendish banana varieties were selected and yellow colorant was extracted by heat refluxing (50⁰C for 30 minutes) with 50 mL of 1:1 hexane-acetone mixture (S1). The concentrated extracts produced from 10g of peel material were used to calculate the total carotenoid pigment concentration using the spectrophotometric method at 460 nm. The colorant was extracted from Ambul banana peel (the variety with the highest carotenoid concentration with S1) using ethanol as the solvent (S2), following the same procedure. The β-carotene concentrations of each variety’s extract were measured using the spectrophotometric method at 440 nm. 2,2-diphenyl-1-picryhydrazylhydrate (DPPH) assay was used to determine the antioxidant activity and expressed as mg/g equivalents of Trolox.
Findings and Values: The highest total carotenoid concentration (0.03 ±0.08 mg/g) was recorded in the Ambul variety with S1. The carotenoid concentration in the Ambul variety was further improved by using S2 solvent (0.04 ±0.01mg/g). The β-carotene level in the peel of all three tested banana varieties was between 1.03×10-4 to 2.45×10^-4 mg/g, with the highest in the Ambul variety with S1 solvent. DPPH assay values were between 0.01±0.00 to 1.81±0.03 mg Trolox/g. Antioxidant activity was highest in the Puwalu variety with the S1. The study concludes that Ambul banana peel is a highly potential source for the extraction of natural yellow colorant. Findings can be used to initiate a novel industrial procedure to extract yellow colorant from banana peel for potential applications in food and non-food industries.