Optimizing the process of extracting sour tea extract using the response surface method and evaluating the resulting beverage formulation

Notice to optimizing the use of medicinal plants by producing soft drinks can be a suitable solution in order to encourage consumers to use food with natural source that have beneficial effects on the health. The purpose of this research is optimizing the extraction process of Hibiscus Tea and providing the best way to preserve the nutritional value of this plant during extraction and applying this extract in diet soft drinks formulation by using the natural sweetener Stevia and evaluation of physico-chemical changes during storage. Thus, extracts of Hibiscus Tea was done in three temperatures of 60, 75 and 90 ° C in the range of 10 to 20 minutes and to select the best extraction temperature and time in Hibiscus Tea samples, terms of PH, antioxidant activity, anthocyanins and phenolic compounds were studied. Then by using extraction of Hibiscus Tea, soda with four different formulations was prepared. To consider the durability of soda, in 90 days, every 30 days lasting soft drink samples in terms of antioxidant activity, anthocyanins and phenolic compounds were evaluated. Finally it was determined that temperature 41.71 ° C for 18.81 minutes is the best temperature and time for extracting Hibiscus Tea, that In this optimal conditions, the antioxidant activity 62.4062%, the amount of anthocyanins 72.394 mg/l and total phenolic compounds 65.2564 mg/100 ml was determined. Also it was detrmined that antioxidant activity, anthocyanins and phenolic compounds at the end of storage time than the first day of manufacturing soft drinks decreased.