Effect of processing on texture and microstructure of the seaweed Durvillaea antárctica

Abstract

The algae Durvillaea antarctica (cochayuyo) is the most popular edible seaweed in Chile and shows extensive variability at themarketplace. The objective of this study was to characterize the sample of D. antarctica and modify its original structure andtexture by processing: hydrothermal (HT; 40, 60, and 80 °C, for 30, 60, and 90 min), freezing and thawing cycles (F/T; 1 to 3),ultrasound (US; 10, 50, and 100% power for 5, 10, and 15 min), and high pressures (HPP; 200, 400, and 600 MPa for 1, 2, and 3min). Seaweed mainly contained (g per 100 g) 9.7 protein, 51.5 carbohydrates, and 0.1 lipids. Main free amino acids found were(mg per 100 g) alanine (347.52), glutamic acid (182.14), and aspartic acid (120.14). A 60% softening effect on the texture ofD. antarctica occurred when the hydrothermal method was applied at 80 °C for 90 min. HPP at a pressure of 600 MPa in 1 to3 min produced a 50% reduction in texture. US and F/T cycles had minor or no effect at all. Softening correlated well withmicrostructural changes revealing damage at the cellular level. HT processing is a simple method to soften this seaweed at home,while HPP may become an interesting alternative to pre-process the algae before commercialization as a ready-to-cook product.Further studies should involve changes induced by processing on nutritional value and sensorial perception.