Work

Effect of extraction processes on the physicochemical and functional properties of protein-rich extracts from the red seaweed Pyropia Seriata (Nori)

Year: 2024

Type: article

Abstract: This study examined the physicochemical and techno-functional properties of protein extracts from the red seaweed ( Pyropia seriata ). The extraction processes involved variations of some of the following steps: alkaline treatment, milling, freeze drying, neutralisation, heating, and concentration. The extracts had total amino acid contents ranging between 40 and 55 % of the powders with essential amino acids comprising 25–30 % of the powders. The extracts were particularly abundant in aspartic acid and limited in the essential sulphur amino acids . The molecular weight (MW) distribution of the proteins within the extracts ranged from <10 to 50 kDa. All the extracts were soluble, with a solubility of 65–100 % depending on the final pH of the solution. The extracts had significant foaming-producing and emulsifying potential. The foaming stability ranged between 75 and 91 % for solutions between pH 7 and 11 and less than 75 % for solutions with pH of 5 or 3. Alkaline treatment significantly improved foaming capacity (120–160 %). A similar effect was also observed for emulsifying activity (0.29–0.51) and emulsifying stability (15–40 %). Milling enhanced the emulsifying potential and decreased the mg of amino acids per g powder. Neutralisation with hydrochloric acid instead of citric acid and subsequent heating and concentration showed minimal effect on the properties of the extracts and decreased the mg amino acids per g powder. This research highlights the potential of Pyropia seriata as a source of soluble alternative protein for food applications.

Source: Future Foods

DOI: 10.1016/j.fufo.2024.100501