In this research, extraction of colouring matter from date pits powder was conferred by conventional and ultrasonic methods. Phenolic compounds present in the resulted extract were identified by HPLC analysis. Total phenolic, total flavonoid and total metallic contents were quantified; and the highest levels were obtained in case of ultrasonic extraction process at a frequency of 25 kHz. The different resultant extracts were diluted with distilled water and unified to a polyphenolic content of 48 mg per 100 mL. Dyeing results have been discussed as a function of the bio-metallic contents present in the extract. It was found that the highest colour strengths and the better fastness properties were registered in case of dyeing experiments developed using the ultrasonic extracts. Those above results could be due to the highest metallic content present in the ultrasonic extracts, which has functioned as a bio-mordant properly extracted from date pits powder.
Keywords: Date pits; bio-metallic content; colour fastness; cotton; dyeing; polyphenolic content.