Changes in total free amino acids as quality biomarkers in cut gladiolus spikes as affected by pulsing and wet cold storage

This study aimed at evaluating and quantifying Total Free Amino acids (TFAA) as indicators of quality in cut Gladiolus grandiflorus L. cv. Fado as affected by pulsing with 600 ppm 8-hydroxyquinoline sulphate plus 5% sucrose and subsequent wet-cold storage durations of 0–5 days. Spectrophotometric and thin layer chromatography of dried petal amino acid analyses of open field grown Gladiolus at Horticulture Research and Teaching Field at egerton University, Kenya, were done. A two by six factorial experiment embedded in a completely randomized design with four replicates was adopted and data was analyzed using Proc GLM model in two way Anova. Means were separated by Tukey's test at 5% level of confidence. Values of TFAA and the vase life were significantly (P< 0.0001) affected by the pulsing and wet-cold storage treatments with consequent enhanced mean vase life (10.33 ± 0.21 days) and lowered (28.006 ± 0.006 μg/mg dw) mean TFAA compared with that of the control (4.75 ± 0.21 days; 36.496 ± 0.006, respectively). Petals predominantly displayed proline, lysine, leucine, isoleucine, glutamine, glycine and threonine, which could be alternative respiratory substrates or physiological signals. The results from this study will augment existing technologies in improvement of postharvest handling of Gladiolus.