Morphology and Antioxidant Properties in Pseudostem, Leaf, Petiole and Inflorescences of Diploid and Triploid Banana

Abstract

The objective of this research was to compare psuedostem, leaf, petiole and inflorescence morphological characteristics of five banana varieties against their total phenolic contents and antioxidant activities. These varieties included two diploids, ‘Nam Thai’ (AA) and ‘Ta Nee’ (BB), and three triploid varieties, ‘Hom Khieo Khom’ (AAA), ‘Sam Doen’ (AAB), and ‘Kluai Hak Muk Som’ (ABB). The average pseudostem heights in this selection of bananas ranged between 2.0 to 3.7 m., except for the Dwarf Cavendish ‘Hom Khieo Khom’, which was 1.25 m. Leaf lengths ranged from 107.8–201.7 cm and leaf widths from 45.5–68.3 cm. The leaf of the diploid BB ‘Ta Nee’ was the largest at 201.7cm in length and 68.6 cm in width. Banana inflorescence weights ranged from 291.7-600.8 g. The average moisture contents of the pseudostems and inflorescences were similar, ranging between 90.2–93.7%, followed by the petiole at 82.7–86.9% and the leaf at 72.0–78.6%. The diploid bananas had total phenolic contents and antioxidant activities higher than the triploid bananas. The ‘Ta Nee’ leaf had the highest total phenolic content of 198.2 mg GAE/g, followed by ‘Nam Thai’, ‘Hom Khieo Khom’, ‘Hak Muk Som’ and ‘Sam Doen’ at 141.4,108.7,100.4 and 90.1 mgGAE/g with significant difference (p < 0.05). Inflorescences had the highest antioxidant activities, followed by leaves, petioles and pseudostems. The ‘Ta Nee’ had the highest antioxidant activities in the FRAP and DPPH assays at 36.5 and 10.5 mg TEAC/g, respectively, followed by ‘Nam Thai’ (21.8 and 5.1 mg TEAC/g), ‘Hom Khieo Khom’ (6.2 and 2.5 mg TEAC/g), ‘Hak Muk Som’ (3.6 and 1.3 mg TEAC/g) and ‘Sam Doen’ (1.9 and 1.2 mg TEAC/g) with significant difference (p < 0.05). Morphological characteristics of the different banana varieties had no effect on total phenolic compound content and antioxidant activity.