Nutritional composition and health benefits of leaf-vegetable sweet potato in South China

Elucidating the chemical composition and health benefits of specially bred leaf-vegetable sweet potato (Ipomoea batatas L.) can provide a basis for improving their utilization and commercialization and also inform effective breeding strategies. In this study, the nutritional and health-related parameters of different-colored leaf tips (green and purplish-green types) from 11 leafy cultivars of sweet potatoes were determined. The results showed that the tip tissue possessed a wide range of nutritional compounds, and the contents of all of these compounds differed significantly between cultivars (p < 0.001). The crude fibre, crude protein, soluble sugar, and glucose contents ranged between 5.18-10.38, 16.2-30.3, 14.4-22.5, and 2.94-7.91 g/100 g dry weight (dw), respectively. The leaf tips were also good sources of vitamin C (99-511 mg/100 g dw), chlorophyll (892-1797 mg/100 g dw), carotenoids (117-237 mg/100 g dw), free amino acids (479-852 mg/g dw), and minerals (Ca, P, Mg, Fe, Mn, Zn, Cu, and Se), and the K/Na ratio was particularly high, reaching 384. The leaf tips showed considerable caffeoylquinic acid (CQA) derivatives, particularly the pure green-tipped cultivar GCS-3. Given these nutritional components, GCS-3, GCS-6, and GS-17-23 could be considered as healthy leaf-vegetable cultivars with commercial prospects.