Optimization and characterization of Nori-like product made from Ulva lactuca and Gracilaria changii using mixture design

Nori is a dried edible seaweed sheet made from Porphyra, a genus of red algae that thrivesprimarily in subtropical waters. Nori-like products have been developed from tropical seaweed species but they are still considered undesirable due to their astringent taste and lower protein content compared to the original nori. This investigation aimed to produce a nori-like product by utilizing a combination of locally sourced seaweeds, Ulva lactuca and Gracilaria changii, with the addition of anchovy flour to enhance its protein content. To obtain the optimal formulation of the product, we employed a design expert software application to analyze sensory data collected from a hedonic scale assessment involving 25 trained panelists. We evaluated sensory characteristics, including appearance, aroma, texture, taste, and overall satisfaction. Additionally, we considered parameters such as crispness and colour to determine the nori-like product quality. The best-selected product, determined through sensory evaluation, underwent further analysis of its proximate and amino acids profile, as well as mineral content. The results were compared to those of commercial nori from Porphyra. The highest-quality product was found to be the nori-like product with a formula consisting of 25.40% Ulva lactuca, 7.98% Gracilaria changii, 1.50% glycerin, 4.12% anchovy powder and the remainder water.