COMPARISON OF SEVERAL EXTRACTION METHODS OF BIOMATERIALS (BY WATER) FROM SIX CITRUS SPECIES PEELS

Citrus species have interest from many researchers for a long time, due to their wide distribution and the diversity in of their chemical composition. On the other hand, it is very important to study and to consistently improve extraction methods in order to increase their efficiency. Several extraction methods based on six citrus species peels have been studied by comparing total yields and concentrations of some bio-compounds (phenols, carbohydrates, proteins and pigments), as well as the antioxidant activity. Extraction methods significantly differed in their results, due to the differences in the mechanisms of action. Extraction by Reflux assisted method gave the highest yield, but it was not the best method in total phenolic content. Maceration method was better in total phenolic content, however Ultrasound method gave the highest value of carbohydrates content. Generally, Citrus species have a high content of phenols and carbohydrates, low proteins content and good polar pigments content. Regarding TLC profile, there is an increase in metabolites (number of spots) when assisted extraction methods were used, so extraction by assisted methods increases both quantity and quality of extraction yield. It was noted that water was a suitable solvent for phenols and carbohydrates extraction. Using agricultural waste such as citrus peels has many biological, environmental, industrial and so economical benefits