[Chemical and processing study on some Rosa damascena products]

The present investigation was carried out to study the chemical, sensory, and microbial characterstics of Rosa Damascena and its products i.e. syrup ,concentrated syrup, and jam during processing and storage .The obtained results could be summarized in the following points. Rosa Damascena pasteurized syrup .Syrup was prepared using two extraction temperature ( at room temperature and 40°c) ,and addition natural Rosa extract to improve antioxidant activity and color characteristics. Syrup was evaluated during processing and storage(at 5°c) .Results showed that Syrup extraction at 40°c temperature improved antioxidant activity characteristics ,while addition the natural extract of Rose improved antioxidant activity in both samples .Sample which extracted at 40°c and fortified with rose extract was preferred at the end of storage period. Rosa Damascena concentrated syrup .Samples were concentrated by using two methods : traditional boiling (open boiling kettle) and concentration under vacuum using rotary evaporator .Samples were evaluated during processing and storage(at 5°c) .Results showed that reducing sugars and phenolics compounds were higher in traditional samples compared with others (under vacuum prepared samples) which were higher in anthocyanin content .Addition rose extract increased antioxidant activity in both samples. Sample which concentrated under vacuum and fortified with rose extract was preferred at the end of storage period.. On other hand jam samples were prepared with different mixtures of sweeteners i.e. .sucrose ,fructose, aspartame and its mixtures .They stored for 6 months at room temperature and evaluated during this period .Storage increased reducing and total sugars m while anthocyanins ,phenolics compounds and antioxidant activity decreased in all samples .Sucrose jam was preferred. Meanwhile ,microbial tests showed that all rose products were accepted during storage.