Effect of different media for dehydration of some ornamental flowers

Elevated rate of respiration and ethylene evolution along with the highly perishable and delicate nature of fresh blooms act as stumbling blocks to uphold freshness and charm of ornamental flowers year-round, in contrast to, perfectly dried, preserved and processed flowers which include novelty, longevity, aesthetics, flexibility and year round availability.
The current investigation was undertaken employing three annual flowering species namely Chrysanthemum morifolium L., Coreopsis tinctoria Nutt. and Gaillardia pulchella Foug. ‘Red plume’ to explore the aptness of six pure drying media viz., silica gel, white sand, corn meal, saw dust, rice and wheat bran and four combination media of silica gel with corn meal and sand at 1:1 and boric acid with sand and saw dust at 1:1 using embedded drying technique under both microwave oven and ambient condition for varied duration.
Initially, the impact of diverse desiccants and periods on aforesaid samples were evaluated.
As a consequence 3, 7, 7, 7, 6, 6, 5, 6, 7, 7 days and 1, 1.30, 2, 2.30, 2, 1.30, 2, 2, 1.30, 2.30 min for chrysanthemum, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1 days and 0.45, 1.15, 1.30, 1.30, 1.30, 1.30, 1, 1, 1, 1.15 min for Coreopsis sp. and 2, 5, 5, 4, 4, 4, 2, 2, 4, 4 days and 1.15, 1.45, 2.30, 2.15, 2.15, 2.15, 2, 2.15, 1.30, 2 min for Gaillardia sp. under ambient and microwave state duo were found optimum for aforementioned embedded materials.
At maximum duration the elevated rate of moisture loss along with distorted characteristics like petal detachments, crispy petals, etc., were apparent irrespective of materials and conditions.
For chrysanthemum and Coreopsis sp., moisture loss of 71.75 and 70.89% by rice bran and corn meal and 69.37% by wheat bran and silica gel under microwave drying were perceived while 83.61 and 83.52% loss was noted in sawdust and corn meal under ambient condition in Gaillardia sp.
Retention of anthocyanin and sugar content were satisfactory in sawdust, sand:boric acid and corn meal treatment of chrysanthemum, Coreopsis sp. and Gaillardia sp., respectively, under microwave condition as compared to control.
Conclusively, pure drying media with microwave drying were found superior regarding post-drying parameters and longevity under polyethylene wrap also for all species.

International Symposium on Horticulture: Priorities and Emerging Trends

M. Malakar, P. Acharyya, S. Biswas

dehydration, ambient, microwave, moisture, desiccant, longevity

https://doi.org/10.17660/ActaHortic.2019.1255.25