Development of an Optimized Green Extraction Method for the Recovery of the Biocolorant From Bixa orellana L. Seeds

Abstract

The extraction of colorant from annatto seeds (Bixa orellana) is traditionally chemical based, requiring expensive equipment, which limits its feasibility for small-scale food industries. This study is aimed at developing an optimized aqueous extraction method for red–orange biocolorant from B. orellana seeds using response surface methodology. For this purpose, extraction parameters including kanwu (traditional alkaline salt) concentration (0–0.1 g/mL), soaking time (60–720 min), and cooking time (0–20 min) were optimized. In response to these treatments, the characteristics of the extracts obtained were evaluated. The linear and/or quadratic effects of the amount of kanwu, the soaking time, and the cooking time of the seeds, as well as the interaction between these parameters, strongly influence the physicochemical characteristics of the extracts. The results of the study indicate that a concentration of kanwu of 11.24 g/200 mL, 60 min of soaking, and 18 min of cooking the seeds would allow obtaining an aqueous biocolorant with the following properties: pH = 9.14, L∗ = 69.11, a∗ = 6.6, b∗ = 6.81, chroma (C∗) = 45.22, hue angle (H∗) = 46.25^°, total polyphenol content (TPC) = 0.024 mg GAE/mL, and total antioxidant activity (TAA) = 4.71 mM Trolox/mL. This colorant could be used in the food industry.