Analysis of morphological and biochemical features in pink-husked coconut (Cocos nucifera L.)

A comparative analysis was conducted to characterize the pink-husked type in the San Ramon Tall (SNRT) coconut population. In terms of floral traits, the pink-husked palms produced two types of male flowers, distinguished by their dark pink and yellow anther filaments, while no differences were observed in the size of male flowers compared to the non-pink-husked SNRT palms. Additionally, no significant differences were found in the quantitative and qualitative traits of tender nuts and their water between the pink-husked and non-pink-husked SNRT palms. Biochemical analysis of the leaf and husk tissues revealed that pink-husked palms contained notably higher levels of phenols, flavonoids, and anthocyanins compared to the non-pink-husked palms. Phenol content was measured at 9.24 mg GAE/g in leaves and 22.22 mg GAE/g in the mesocarp of 7-month-old fruits for pink-husked palms, compared to 7.85 mg GAE/g in leaves and 19.56 mg GAE/g in the mesocarp of non-pink-husked palms. Similarly, flavonoid levels in pink-husked palms were 19.69 mg QE/g in leaves and 37.20 mg QE/g in mesocarp tissues, compared to 18.11 mg QE/g in leaves and 34.51 mg QE/g in husk tissues of non-pink types. Anthocyanin content was also higher in pink-husked palms, measuring 8.50 mg/100g in leaves and 13.89 mg/100g in mesocarp of 7-month-old fruits, while non-pink types recorded only 6.69 mg/100g in leaves and 2.74 mg/100g in mesocarp. Notably, in 4-month-old pink-husked fruits, phenol, flavonoid, and anthocyanin levels were 26.64 mg GAE/g, 38.79 mg QE/g, and 17.59 mg/100g, respectively, which were higher than the levels recorded in 7-month-old pink-husked fruits. This study suggests that pink-husked coconuts are a valuable source of phenols, flavonoids, and anthocyanins, contributing to human health. These findings underscore their potential in breeding programs, providing a distinctive marker for creating new, visually appealing coconut varieties with higher bioactive compounds.