Abstract
https://www.sciencedirect.com/science/article/abs/pii/S0254629923000674
Two species of dragon fruit (Hylocereus polyrhizus and Hylocereus undatus) are widely cultivated as important sources of nutrients for the people of Bangladesh. The aim of this study was to analyze the physicochemical properties and nutritional composition of the peel and pulp of these two species. The physiochemical properties and nutritional composition analysis were performed using standard methods. No significant differences in specific gravity and pH were observed in the extract from the different parts of the two species of dragon fruits, but the peel extracts from both species were more acidic and stable than others. The anthocyanin contents were remarkably higher in the H. polyrhizus species that were largely significant in the peel (p <0.001). The total soluble solids (TSS) were remarkable in the pulp of H. polyrhizus species (p <0.001), while the viscosity of the H. undatus species (peel, pulp and whole fruits) was significant (p < 0.01). In nutritional analysis, the moisture, total sugar and reducing sugar contents in the pulp of H. undatus were 86.33±0.68%, 7.97±0.22% and 4.35±0.18%, respectively, and these values were higher than those in the pulp of H. polyrhizus. Meanwhile, 10.35±0.71% carbohydrate was detected in the pulp of H. polyrhizus, which was significant (p<0.001) compared to H. undatus. The peel of H. polyrhizus contained 1.02±0.15% crude fat, 1.23±0.35% crude protein and 3.96±0.71% ash, respectively, these amounts were larger than those of H. undatus, and the values were significant (p<0.05), while moisture in the peel of H. undatus amounted to 92.24±0.37%, which was significantly higher than that of H. polyrhizus (p<0.05). In case of mineral analysis, the peel of H. undatus was enriched with Ca, Mg and Zn (p<0.001; <0.05); in contrast, Fe, P, K, and Na were rich in H. polyrhizus. Significant amounts of Cu, Ca, Zn, Na and Fe were present in the pulp of H. polyrhizus (p <0.001). In this study, high amounts of crude fiber, ash, carbohydrate, Fe, P, K, and Na were observed in H. polyrhizus, and total sugar, Ca, and Mg were observed in H. undatus (p<0.001). Thus, the peel of both species is rich in crude fiber, vitamin C and minerals. The data obtained in this study reveal that the pulp of both species was rich in nutrients but most prominently in H. polyrhizus. Finally, these nutritional composition data will help the food industry manufacture a valuable food product.