[Differences and correlations in phenolic acid content in the pulp of various categories of fruits in Shenzhen].

Abstract

Objective: To detect phenolic acid compounds in various fruits and explore the differences in phenolic acids among different types of fruits.

Methods: The collected 75 types of fruits were classified into 6 categories: citrus、melon、drupe、berry、tropical fruit and pome fruits. The phenolic acid compounds were detected by high performance liquid chromatography-mass spectrometry. The Kruskal-Wallis H test was used to examine the differences in phenolic acids among different types of fruits. The Mann-Whitney U test was used to examine the differences in phenolic acid content in fruits from the south and north. The Spearman method was used for correlation analysis of compounds in fruits.

Results: The sum of phenolic acid content in 75 types of fruit ranges from 0.22 to 485.97 mg/kg FW. The median of phenolic acid content, from highest to lowest, is in the order of pome fruits(76.17 mg/kg FW)>citrus(37.86 mg/kg FW)>berry(28.08 mg/kg FW)>tropical fruits(22.56 mg/kg FW)>drupe(20.70 mg/kg FW)>melon(1.62 mg/kg FW). Among various types of fruits, there was no statistical significance in the content of gentisic acid and p-coumaric acid, but certain differences in other components among different types of fruits(P<0.05). There were few differences in phenolic acids in northern and southern fruits, with only three components showing statistical differences: chlorogenic acid, vanillic acid, and protocatechuic acid(P<0.05). There were more and stronger correlations among phenolic acid compounds in pome fruits, followed by citrus and melon fruits. The correlations of phenolic acid compounds in tropical fruits, drupe, and berry fruits were fewer. Among phenolic acid compounds in all fruits, only sinapic acid and ferulic acid had a strong positive correlation(r=0.736, P<0.01).

Conclusion: There are certain differences in the content of chlorogenic acid, protocatechuic acid, ferulic acid, gallic acid, vanillic acid, caffeic acid, sinapic acid, salicylic acid, p-hydroxybenzoic acid, and the sum of phenolic acids among the six categories of fruits. There were certain correlations among phenolic acid compounds in fruits.