Formulation of functional cocoa liquor (Theobroma cacao) from raw and processed beans blend: physicochemical, phytochemical, sensory characteristics and in vitro antioxidant activity

Abstract

Given the health benefits of antioxidants and the importance to satisfy sensory preferences of the consumers, this study sought to balance cocoa processing methods that enhance sensory properties while preserving bioactive compounds of cocoa beans. The main objective was to elaborate a cocoa liquor with both high antioxidant activity potentials of raw beans and chocolate sensory attributes of treated beans. To achieve this goal, cocoa beans were harvested and divided into two batches. The first batch was fermented and roasted, while the second batch did not undergo any treatment, and both were dried. Fermented and unfermented cocoa beans were blended in different proportions and ground to obtain eleven samples of cocoa liquor named CL1 (100% treated beans/0% raw beans) to CL11 (0% treated beans/100% raw beans) with a step of 10% to select the best formulation. The external and internal quality of beans was evaluated by performing graining, cut test and the measure of pH. The proximate composition, as well as the zinc, iron, copper and selenium content of the cocoa liquor were determined as these minerals are cofactors of antioxidant reactions. Total polyphenols, total flavonoids, proanthocyanins and in vitro antioxidant activity of the cocoa liquor was assessed. A sensory assessment identified the cocoa liquor with the best balance of antioxidant potential and desirable organoleptic properties. The results showed that with an average mass of 1.43 g per bean and pH ≥ 5, both fermented and unfermented cocoa bean were appropriate for chocolate industry. The physicochemical and phytochemical analyses of the liquor showed that liquor CL11 exhibited the highest macronutrients, minerals and bioactive compound content, while sample CL1 recorded the lowest values. Antioxidant activity increased with the addition of unfermented beans in the blend, with the highest values of anti-radical activity and inhibition percentage recorded for sample CL11. Sensory assessment allowed selecting liquor CL3 as the best compromise between antioxidant activity and good sensory profile, notably chocolate flavor and aromas (floral, woody and toasted aromas).