Analysis on Total Phenolic Content and Antioxidant Activity of Stem Tips of New Cultivars (Lines) Leaf-vegetable Sweet Potatoes

Abstract

【Objective】The study was carried out to analyze the total phenolic content and antioxidant activity of leaf-vegetable sweet potato tips in order to provide data for selecting and breeding high-quality leaf-vegetable cultivars of sweet potato.【Method】The total phenolic contents of leaf tips of 11 leaf-vegetable cultivars (lines) of sweet potato from South China were determined, and the antioxidant activities were evaluated by ABTS, DPPH and FRAP.【Result】There were significant differences in the total phenolic content, ABTS, DPPH and FRAP between cultivars, and the averages of these indexes were 3.64(±0.90) mg/g(GAE), 249.94(±71.47) μmol/g(TE), 253.06(±58.76) μmol/g(TE) and 375.64±107.20 μmol/g(TE), respectively. In addition, there was significant difference in the FRAP among differently colored sweet potato tips. The total phenolic content was positively correlated with antioxidant activity measured by ABTS, DPPH, and FRAP values.【Conclusion】The total phenolic contents and antioxidant activities of 11 leaf-vegetable sweet potato cultivars were significantly different, among which GCS-3, FS-18 and GCS-17-10 had the strongest comprehensive antioxidant activities. GCS-3 and FS-18 with green leaf tip and GCS-17-10 with purple-green leaf tip were high-quality leaf-vegetable sweet potato resources and had great development and utilization potentials. These results could also provide reference values in further research on the antioxidation of different colored sweet potato tips and the cultivation of new leaf-vegetable sweet potato cultivars.

Keywords

• leaf vegetable sweet potato
• phenols
• stem tip
• antioxidant
• antioxidant potency composite index(apci)