Freeze-dried roses

Freeze-dried roses are roses whose water content has been frozen and turned into water vapor via sublimation. The result is a perfectly dried rose that is ready to be displayed at a wedding or can be preserved for a long time. 

Freeze-dried roses are a trend in the wedding industry. The flowers are easy to order ahead of time and stock, they don t go bad, and there are many varieties to choose from. A bride can order entire bouquets of freeze-dried roses for herself and others, or just some freeze-dried petals to use as confetti. After the wedding day, the dried flowers are ready to pack away as keepsakes of the occasion. 

They are not, however, the same as fresh flowers in appearance, smell, or feel. Nor can they be rehydrated like freeze-dried foods. Once they go through the freeze-drying process, they are permanently dry. One maker of freeze-dried roses explains the appeal of their product as "the most alive-looking dried roses available."14... 

About Rose City Freeze Dry Rose City Freeze Dry Web Site. Available online. URL http //www.rosecityfireezedry. com/about.shtml. Accessed November 18,2006. 

De Luca et al. [1.48] showed, that the addition of 5 % tertiary butyl alcohol (tBA) to aqueous sucrose and lactose solutions (up to 40 %) resulted in a frozen matrix, which could be easily freeze dried. De Luca demonstrated by DSC that the melting point rose distinctly (with 60 % solution to -10 °C), but the endothermic of melting returned to 25 %, indicating that not much water had frozen. In solutions with 5 % tBA the exothermic of crystallization became more visible and the melting of tBA could be recognized. 

Aliquots of nanoparticulate suspension were frozen at -20 °C in the presence of 0,5,10,15,20,25 and 30 % trehalose. Samples were freeze-dried in a Virtis Co. (model BT 6.6 X L, Gardiner, NJ) system under the following conditions a primary drying step for 24 hours at -30 °C and secondary drying step until the temperature gradually rose to 20 °C. The particles were then resuspended in distilled water (to return to starting trehalose concentration), and their size and charge were measured. 

It was found convenient to add Dry Ice to the freezing mixture, thus decreasing the frequency of packing. The temperature never rose above — io° and was usually considerably less. 

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