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

Abstract

The algaeDurvillaea antarctica(cochayuyo) is the most popular edible seaweed in Chile and shows extensive variability at the marketplace. The objective of this study was to characterize the sample ofD. antarcticaand modify its original structure and texture by processing: hydrothermal (HT; 40, 60, and 80 degrees 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 3 min). 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. antarcticaoccurred when the hydrothermal method was applied at 80 degrees C for 90 min. HPP at a pressure of 600 MPa in 1 to 3 min produced a 50% reduction in texture. US and F/T cycles had minor or no effect at all. Softening correlated well with microstructural 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.