THE STRUCTURE-FUNCTION RELATIONSHIP BETWEEN ASCOPHYLLUM NODOSUM POLYSACCHARIDES AND IN VITRO PREBIOTIC ACTIVITY: AN ASSESSMENT OF THE IMPACT OF EXTRACTION TECHNOLOGIES

Abstract

The impact of four extraction processes (conventional chemical (CCE), microwave-assisted (MAE), ultrasound-assisted (UAE), and enzyme-assisted extraction (EAE)) on the structure-function relationship between polysaccharides from Ascophyllum nodosum and prebiotic functioning was investigated. Fucoidan extracts from the MAE method had significantly (P < 0.05) higher fucose content and sulphate levels, higher uronic acid content, dispersity index, and lower molecular weight, as compared to other extracts. For sodium alginate, all four extracts had similar dispersity index and M/G ratio, and molecular weight range of 65 – 182 kDa; uronic acid content was highest in the MAE extract. Fucoidan from all four methods significantly improved the growth rate of Lactobacillus delbruecki at 0.1% and 0.5% inclusion concentrations, whereas no significant difference was observed for alginate extracts, relative to the un-supplemented strain. Also, fucoidan and alginate supplemented media had no significant impact on the growth rate of Lactobacillus casei as compared to the un-supplemented media.