Abstract:
Food colorants are either natural or synthetic depending on source. Natural colorants are extracted from renewable sources such as plant materials, insects, algae, etc, while the synthetic colorants are manufactured chemically and are the
most commonly used dyes in the food, pharmaceutical and cosmetic industries. The anthocyanins content of four samples (hibiscus calyces, hibiscus herbal tea, strawberry fruit, strawberry juice) were determined by pH differential method using UV-spectrophotomertric technique, expressed as cyanidin-3-glucoside. The evaluation showed that hibiscus calyces under investigation had very high content (4.3%) compared with previously reported findings (0.6 – 3%). Also a clear difference, between the anthocyanins content of crude hibiscus calyces and that of the hibiscus herbal tea (2.3%) was observed. Strawberry fruit showed low anthocyanins concentration (1.3%) than the literature value (3.6%). Strawberry juice showed lower anthocyanins concentration (46.53 mg/L) than recommended value (63.6 mg/L). Clear variations were noticed in anthocyanins concentrations between the crude products and their processed forms. These variations many be attributed to many factors (agro-climatic environment in addition to the genetic and processing factors). Therefore, it is recommend to use crude roselle and strawberry (fruit) rather than the Processed
Description:
A Dissertation, Submitted in Partial Fulfillment of the Requirements
for the Degree of Master of scienc in Chemistry, Department of Applied Chemistry and Chemical Technology, Faculty of Engineering and Technologym Unviersity of Gezira, July2012uly2012
