Bioactive Compounds of Edible Purple Laver Porphyra sp. (Nori)

Abstract

Porphyra sp. (nori) is widely cultivated as an important marine crop. Dried nori contains numerous nutrients, including vitamin B, which is the only vitamin absent from plant-derived food sources. Vegetarian diets are low in iron and vitamin B; depletion of both causes severe anemia. Nori also contains large amounts of iron compared with other plant-derived foods and eicosapentaenoic acid, which is an important fatty acid found in fish oils. In nori, there are also many bioactive compounds that exhibit various pharmacological activities, such as immunomodulation, anticancer, antihyperlipidemic, and antioxidative activities, indicating that consumption of nori is beneficial to human health. However, Porphyra sp. contains toxic metals (arsenic and cadmiun) and/or amphipod allergens, the levels of which vary significantly among nori products. Further evidence from human studies of such beneficial or adverse effects of nori consumption is required.

Food safety hazards in the European seaweed chain

“…Crustaceans, such as shrimp, lobster, and crab, have frequently been involved in immunoglobulin E‐mediated allergies. Therefore, that study suggested that dried nori products could potentially cause severe allergic reactions, particularly in crustacean‐allergic persons (Bito, Teng, & Watanabe, ).…”

Health Functionality and Quality Control of Laver (Porphyra, Pyropia): Current Issues and Future Perspectives as an Edible Seaweed

“…By contrast, studies of other edible seaweeds (e.g., green or brown algae) focused mainly on their non-food roles as sources of nutraceuticals, food additives, and biomaterials. Nutritional values and bioactive components of algal species linked to major health benefits were reported, highlighting the potential for growth of the laver industry as both an edible seaweed and a source of useful compounds [4,[9][10][11][12][13][14][15][16][17][18]. However, although practical studies of the utility of laver as an edible seaweed reported the distinct characteristics of various product types (i.e., material composition, effects of manufacturing processes), there is no comprehensive analysis of the literature regarding the nutritional/functional characteristics of laver and the technological basis for its quality control.…”

“…Lavers can be a component of other food products such as seaweed chips, salads, laverbread, laver cake, onigiri (rice ball), kimbab (seasoned rice roll), and laver soup [10,13,15,16]. However, previous studies of these processed products focused on organoleptic characteristics with sensory evaluation, rather than on potential for health and/or nutritional benefits.…”

“…Since most of the reported health benefits of laver could also be gained by consumption of other edible seaweeds [11], this section focuses on studies that report unique health functionalities of laver derived from components not found in other edible seaweeds, namely, porphyran, VitB 12 and taurine [9,10]. Table 4.…”

“…Heavy metal contents of processed (roasted or seasoned) laver products indicate a reduction in the levels of lead, mercury, and cadmium during the cooking process [40]. However, the increase in bioaccessible arsenic after human digestion may be a result of the roasting process [10,112]. A correlation between the arsenic content of laver and that of seawater in the cultivation area was also reported, suggesting environmental management as one of the risk control strategies [105].…”