Chemical characterisation of seeds and the coagulating solution of Helianthus annuus L. seed powder.
The aim of this study was to characterise the proteins and amino acids in the seeds and in the coagulating solution of Helianthus annuus seed powder. The total protein content in the seeds was determined by the Kjeldhal method. The protein and peptide profile in the coagulating solution of the seed powder was determined by High Performance Liquid Chromatography-Steric Exclusion (HPLC-SE) in the range 10-500 KDa and 204-35000 Da. Amino acid contents in the seeds and in the aqueous extract of the seed powder were determined using ISO 13903 standard methods. The coagulant activity of the aqueous extract of Helianthus annuus seed powder was assessed by Jar-test using a Lovibond ET 740 flocculator on raw water samples with turbidity levels of 138 NTU and 43.31 NTU. The results showed a total protein content of 29.10 g/100 g in Helianthus annuus seeds. The aqueous solution of Helianthus annuus seed powder contained mostly small proteins, 78.85% of which had a molecular mass of less than 10 kDa, and peptides of various sizes. The amino acid profile showed that glutamic acid was the most abundant in the seeds (6010 mg/ 100 g) and in the aqueous seed extract (55.7 mg/ 100 g). Assessment of the coagulant activity of the aqueous extract revealed a turbidity reduction rate of over 90% for both raw water samples.