Journal of Food Processing & Technology

Abstract

Conversion of Processed Citrus Wastes into Nutritional Components

Gamal A. El-Sharnouby, Salah M. Aleid and Mutlag M. Al-Otaibi

Food processing wastes may impose heavy burden on factories and cause enormous environmental problems. Citrus wastes typically are about 45-50% of the weight of citrus original and the percentage of waste to 30-50% for vegetables and fruits in general. Natural color plays a significant role in determining the degree of consumer acceptance of the product. In addition, carotenoids (vitamin A precursor) have high nutritional values which are important for human nutrition. The efficiency of different organic solvents such as acetone 85%, hexane, petroleum ether, ethyl acetate and ethanol 90% in the extraction of pigments from citrus peel was studied. Ethyl acetate is the best solvent in extracting carotenoids from citrus peel, followed by ethanol 90%. HPLC was used to identify the extracted pigments and their components. The extracted natural pigments were mixed with different carriers such as starch, lactose, dextrin, Arabic gum, and it was noted that lactose is the best one, followed by starch compared with different tested carriers. We also found that Alpha-tocopherol was relatively more stable than butylated hydroxy toluene (BHT) antioxidant (an artificial compound). Natural extracted pigments were used in food product (e.g. jelly) evaluations and gave the better values for the color, flavor and taste compared to commercial samples with artificial additives.