Phenolic profiles and antioxidant activity of litchi pulp of different cultivars cultivated in Southern China

► Phenolic and flavonoid contents in litchi pulp had significant varietal difference. ► Phenolics and flavonoids existed mainly in free form in litchi pulp. ► Six phenolic compounds were detected in litchi pulp by HPLC. ► Some litchi cultivars (Feizixiao and Nuomici) showed potent antioxidant activity. The phenolic profiles and antioxidant activity of litchi pulp of 13 varieties were investigated. The free, bound and total phenolic contents were 66.17–226.03, 11.18–40.54, and 101.51–259.18mg of gallic acid equivalents/100g, respectively. The free, bound and total flavonoid contents were 16.68–110.33, 10.48–22.75, and 39.43–129.86mg of catechin equivalents/100g, respectively. Free phenolics and flavonoids contributed averagely 80.1% and 75% to their total contents, respectively. Six individual phenolics (gallic acid, chlorogenic acid, (+)-catechin, caffeic acid, (−)-epicatechin, and rutin) were detected in litchi pulp by HPLC. The contents of each compound in free and bound fractions were determined. Significant varietal discrepancy in antioxidant activity was also found by FRAP and DPPH scavenging capacity methods. Antioxidant activity was significantly correlated with phenolic and flavonoid contents. Thus, phenolics and flavonoids exist mainly in the free form in litchi pulp. There were significant varietal differences in phytochemical contents and antioxidant activity of litchi pulp.