NOVEL CULTIVATION METHOD INCREASES CRUDE PROTEIN CONTENT AND IMPACTS SENSORY ATTRIBUTES OF RED SEAWEED PALMARIA PALMATA

Abstract

The red seaweed Palmaria palmata could be a sustainable protein source with a low environmental footprint to feed a growing global population. However, its protein content should ideally be optimised to be on par with other protein sources and its sensory attributes as a food ingredient must appeal to consumers. This study aims to enhance the crude protein content of P. palmata by using herring production process water (HPPW) in the cultivation as nutrient enrichment. Moreover, the study establishes a sensory profile of cultivated P. palmata and investigates if HPPW changes its sensory attributes. It does so through two cultivation experiments and one sensory evaluation of the cultivated biomass. In the first experiment, a suitable dilution level of HPPW was established. This knowledge was used when scaling up in the second experiment where growth, crude protein content and chlorophyll a were compared between cultivation in HPPW and seawater controls. Biomass from the second experiment was then tested by a selected and trained panel in a sensory evaluation, using quantitative descriptive analysis (QDA). The results show that cultivation in HPPW significantly increased the crude protein content, chlorophyll a and growth of P. palmata. Additionally, the findings suggests that constant supply of nutrients, e.g. by having flow-through of water, is of great importance when growing P. palmata in land-based tanks. The sensory panel established that cultivated P. palmata has a strong taste of umami, salt and fish, a prominent ocean scent and a firm, sticky and chewy texture. These attributes were shared between the two evaluated treatments. However, the HPPW changed the appearance of P. palmata as colour, structure and glossiness significantly differed from seawater control. This study showcases that HPPW can have a positive impact on the nutritional characteristics and change the sensory attributes of P. palmata, establishing this red seaweed’s role as an important sustainable protein source that contributes to circular food production.