Relationship between the absence of bitter and astringency for edible fiber coconut pericarp and the content of phenols and saccharides

【Objective】Determination of phenols and sugars contents in edible fiber coconut (EFC), explore the physiological reasons for the absence of bitter and astringency in the pericarp of EFC and provide relevant data for the studying and utilization of EFC.【Method】The contents of phenols and sugars in exocarp and mesocarp of coconut fruit at three growth stages(young, tender and mature fruit) were determined by high-performance liquid chromatography technology (HPLC) with EFC as material and Hainan local variety as control. The relationship between the content of phenols and saccharides and the lack of bitter peel was analyzed.【Result】The results showed that:in the exocarp, thecatechin and tannin content in the tender fruits and mature fruits of EFC was significantly lower than that of the control material(P<0.05, the same below), the two phenols contents at tender fruit period were about 50.0% as much as the control. And the content of chlorogenic acid of EFC was also significantly lower than that of the control material in the maturefruits. In the mesocarp, the content of catechin of EFC was significantly lower than that of the control material at three growth stages, whilethe content of chlorogenic acid was significantly lower than that of the controlonlyin the tender fruits, and there was no significant difference in the tannin content between the EFC and control(P>0.05, the same below). The contents of catechin, chlorogenic acid in the EFC young fruitswere about 14.3% and 19.7% of the control, respectively. In the exocarp, there was no significant difference in fructose, glucose and sucrose contents between EFC and control materials at three growth stages. In the mesocarp, the three sugars contents in the tender fruits were significantly higher than those of the control, they were as 1.5 times, 1.7 times and 1.9 times as that of the control, respectively. The results of correlation analysis showed that glucose and sucrose contents in the pericarp were significantly negatively correlated with catechin content, while chlorogenic acid was extremely significantly negatively correlated with the content of the three sugar components (P<0.01, the same below). There was significant negative correlation between catechin content and sucrose content in mesocarp, while there was extremely significant negative correlation between tannin content and the three sugar components.【Conclusion】The reducing of the content of phenolic substances(catechin, tannin and chlorogenic acid) and the increase of the content of saccharide(fructose, glucose and sucrose) in the mesocarp of EFCmight be one of the important reasons for the absence of bitter and astringency taste in EFC.