Formulation, Characterisation and Evaluation of a Pomegranate Peel (Punica granatum L.) Tisane Powder Enriched with Cardamom and Fennel and Its Corresponding Aqueous Extract

Abstract

Growing interest in sustainable functional beverages and the valorisation of fruit-processing by-products has encouraged the development of plant-based tisanes using bioactive-rich residues. This study formulated and evaluated pomegranate peel (Punica granatum L.) tisane powders enriched with cardamom and fennel, together with their corresponding aqueous extracts. Dried pomegranate peel powder (40 g) was blended with cardamom (Elettaria cardamomum Maton), fennel (Foeniculum vulgare Mill.) and 1.3 g food-grade citric acid to obtain three formulations: S1b (balanced, 5:5), S2c (cardamom-dominant, 10:5) and S3f (fennel-dominant, 5:10). Aqueous extracts (Ss1b, Ss2c and Ss3f) were prepared by hot-water infusion at 85–90 °C for 15 min followed by gentle concentration. All six products were assessed for sensory acceptability using a 9-point hedonic scale (n = 30). One-way ANOVA showed highly significant differences among formulations for all sensory attributes (p < 0.001), with S2c and Ss2c obtaining the highest overall acceptability scores (8.53 ± 0.26 and 8.66 ± 0.25, respectively). These two lead formulations were further analysed for proximate composition, qualitative and quantitative phytochemical profile, DPPH free radical scavenging activity, pH and total soluble solids (TSS). The S2c powder contained 25.16 mg GAE/g total phenolics, 70.80 mg QE/g total flavonoids and 24.60 g/100 g tannins, with 82.30% DPPH scavenging activity. The Ss2c extract showed 86.03% DPPH scavenging activity and 54.0 °Brix TSS. Both products were acidic (pH 3.850–3.896). The findings indicate that pomegranate peel can be formulated into an acceptable tisane powder and concentrated aqueous extract, with the cardamom-dominant blend performing best under the conditions studied.