Fermentations using moulds hydrolysing xylan improve in vitro digestibility of Palmaria palmata, a red seaweed

摘要

Palmaria palmata (dulse) is an edible red alga which constitutes a potential protein source in the human diet. However, previous studies showed that the digestibility of dulse proteins seemed to be limited by the non-proteic fraction e.g. fibers. The water-soluble xylan, a polymer of xylose, which is present in high proportions in dulse, could be involved to explain the weak digestibility of the Palmariapalmata proteins. To limit the influence of fibers and to improve the nutritional quality of these algal proteins, we have treated Palmaria palmata by fermentation by moulds which is largely used in Far East and in alimentary industry. After a 30-min predigestion by pepsin followed by a 6-hour digestion into a cell dialysis containing porcine pancreatin, the in vitro protein digestibility of fermented samples was 45% to 65% of that of casein while digestibilities were respectively 36% and 20% for fermentation blank and crude alga.