EVOLVING PACKAGE OF PRACTICES FOR RETAINING PHYSICAL CHARACTERISTICS OF FREEZE DRIED FLOWERS

Flowers evoke a feeling of beauty, grace, and a delicate, alive sensuality. For many centuries flowers play a significant role in human life. On different occasions, different types of flowers were used to express emotions and feelings. Preserving flowers for year-round use was an artistic form of expression for decades. Fresh flowers were preserved the freshness of flowers for years in their natural vivid colours as they tend to fade and wilt after a short period of time. Freeze dried flowers results in an outstanding floral preservation improvement over other methods and it retains more natural size and shape of flowers and is long lasting than any other method. This study was taken up to evolve package of practices for retaining physical characteristics of freeze dried flowers. Experimental research design was adopted for conducting the study. Floral freeze dryer available in the department was used for this research. Three varieties of exotic flowers viz., Bird of Paradise, Orchid and Statice and another three varieties of seasonal flowers viz., Gerbera, Carnation and Rose were selected through purposeful sampling method. Each of these flowers had different formation in terms of colour, form, texture and appearance. Fresh and partially bloomed flowers suitable for freeze drying process were selected for the study. Treated flowers were analyzed quantitatively and qualitatively to explore the effect of these treatments on colour, form, texture and appearance of the flowers. Literature pertaining to hydration treatment was explored and among them six treatments were identified for use in the experiment. Five among them were homemade preservatives with commonly available ingredients and Silverthiosulphate (STS) was a commercial treatment. Literature pertaining to post-treatment was explored and among them six treatments were selected for the experiment. Hydration treatment was an essential step to restore freshness in flowers and was tested with identified treatments on selected flowers for ten days in controlled conditions. Keeping quality was evaluated through subjective evaluation in terms of colour, form, texture and appearance. STS was found to be the best treatment among all the treatments for rose, carnation, gerbera and statice. Treatment made with Sprite and Bleach in luke warm water retained freshness for 10 days in Orchid and Bird of Paradise. The effect of hydration treatments on keeping quality were statistically assessed through F test and T test. F test revealed that there was a significant difference between the number of days and the keeping quality, whereas T test found that there was a significant difference between the treatments and the keeping quality at 5% level of significance. Pre-treatment a crucial process for retaining physical characteristics was tested on flowers with nine different compositions. It was found that the Rose and Bird of paradise treated with T9 (the third base composition blended with polymer I and II), resulted in flowers more close to reality. Carnation treated with second base composition blended with polymer I and II resulted in flowers more close to reference flower. Statice was more realistic when treated with T5, the second base composition blended with polymer I. The treatment three was found to be a good for Orchid than other treatments. Gerbera flower treated with T5 resulted in better appearance than others, resulting in over dried and shrunk form and this may be associated with high vacuum pressure set for dehydration. Red colour flowers turned darker in freeze drying process. Flower types were found to be influenced with different Pre-treatments. ANOVA one way classification proved that there was a significant difference between the pre treatments at 5% level of significance. Post treatments was found to be an essential step to prevent flowers from environmental damage. Six post treatments identified through this research, were tested on flowers dried in freeze dryer. Rose and Statice flower treated with Acrylic clear spray resulted in most natural looking flower, while dried material preservative, an imported product was found suitable for Bird of Paradise, Orchid and Gerbera. Glazing medium was suitable for Carnation. It was observed that the physical appearances of the flower were influenced by post-treatments. ANOVA one way analysis proved the hypothesis of influence of treatments on the quality of flowers at 5% level of significance. From this study it was found that, the flowers selected for the study differed from one other in terms of colour, form, texture and appearance. Each flower responded to the preservation treatments differently. The floral preservation process started with selection, hydration, pre-treatment, freeze drying and ended with post-treatment. Selection of flower and their state of freshness was an important step in freeze dry processing. Hydration treatment was an essential step to restore the freshness in flowers. Pre-treatment with different combinations of chemicals aided preservation of colour, form, texture and appearance. Post-preservation process with post-treatment improved the quality of flowers. Package of practices to be observed in the freeze drying process were evolved for each flower selected for the study.