Abstract:In order to make full use of the aerial parts of sweet potato and increase their added value, in this study, the nutritional components of sweet potato’s leaves, stems and stalks were analyzed, and comprehensive evaluation via principal component analysis and membership function analysis was performed. The results showed that the aerial parts of sweet potatoes were rich in nutrients like minerals, proteins, and dietary fibers, with about 70% of the amino acids belonging to medicinal and taste-active amino acids. Among them, the amino acids used in traditional Chinese medicine accounted for 68.15% of the total amino acids for the leaves, 71.48% for the stalks, and 71.64% for the stems. The taste amino acids accounted for 67.25% of the total amino acids for the leaves, 72.17% for the stalks, and 72.64% for the stems. Sweet potato leaves contained 3.8% protein, 134 mg/kg manganese, 4 509 mg/kg magnesium, and 0.24 mg/kg molybdenum while having abundant polyphenols (33.6 mg GAE/g; including flavonoids 20.9 mg CE/g), chlorophyll (91.8 mg/100 g chlorophyll-a, 33.14 mg/100 g chlorophyll-b), and carotenoids (14.5 mg/100 g). The stem contained the highest levels of dietary fiber (10.6%), zinc (41.8 mg/kg), selenium (0.16 mg/kg), chromium (3.0 mg/kg), and iron (376.0 mg/kg). The stalk was rich in calcium (27 648 mg/kg), magnesium (4 376 mg/kg), potassium (26 152 mg/kg), and molybdenum (0.21 mg/kg). The results of the comprehensive nutritional quality evaluation showed that the nutritional quality of different aerial parts of sweet potato was in this order leaf (0.92) > stem (0.31) > stalk (0.19) (P<0.05). This study provides important theoretical data for the effective development and comprehensive utilization of the aerial parts, leaves, stalks, and stems of sweet potato, and points out the direction for future development of the aerial parts of sweet potato.
