The review of almost 100 scientific studies, published in the Journal of Agricultural and Food Chemistry, reports that some seaweed proteins have the same effects as the bioactive peptides found in milk products and dairy products, and work to reduce blood pressure in a similar way to ACE inhibitor drugs.
“Due to the environment in which they grow, macroalgae produce unique and interesting biologically active compounds,” said Maria Hayes and colleagues from Teagasc Food Research Centre, Ireland and the University of London, UK.
“The variety of macroalga species and the environments in which they are found and their ease of cultivation make macroalgae a relatively untapped source of new bioactive compounds, and more efforts are needed to fully exploit their potential for use and delivery to consumers in food products,” they added.
Bioactives
The authors noted that the global growth of the functional foods market means that researchers have turned to sourcing natural food bioactive peptides to provide preventative effects against cardiovascular disease and metabolic syndromes.
“Bioactive peptides are defined as food-derived peptides that exert a physiological hormone-like effect in humans beyond their basic, nutritional value,” said Hayes and her team.
To date, they say that most bioactive peptides have been isolated from milk-based products. However they believe that seaweeds are a rich but neglected alternative source.
“Marine organisms including seaweeds and microalgae, as a result of their exigent, competitive, and aggressive surroundings compared to terrestrial environments, produce specific and active biomolecules and secondary metabolites,” said the reviewers.
“These secondary metabolites result as a consequence of the harsh conditions in which macroalgae exist, including extremes of salinity and temperature and UV–vis irradiation, along with nutrient deficiencies,” they added.
Seaweed nutrition
From a nutritional point of view, Hayes and her team said that “edible macroalgae are a low-calorie food, with a high concentration of minerals, vitamins, and proteins and low lipid content.”
They noted that seaweeds and other algae sources are an excellent source of vitamins A, C, D, and E, along with the B vitamins, and minerals including calcium, phosphorus, sodium, and potassium.
“The variety of macroalga species and the environments in which they are found and their ease of cultivation make macroalgae a relatively untapped source of new bioactive compounds, and more efforts are needed to fully exploit their potential for use and delivery to consumers in food products,” concluded Hayes and her colleagues.
Macroalgae and microalgae are also the nutritional source of PUFAs for many fish; “hence, macroalgae are also a viable source for these bioactive molecules,” they added.
Processing effects
The reviewers added that further research is needed “to fully ascertain the effect that food-processing methods such as heating have on the bioactivity of peptides.”
“Although it has been shown that peptides can retain bioactivity after being heated up to 100 °C, many processes such as baking reach temperatures as high as 230 °C. If these high temperatures become a barrier to the survival of the bioactivities of peptides, methods of protecting these bioactivities in these environments, such as microencapsulation methods, need to be investigated,” they said.
Source: Journal of Agricultural and Food Chemistry
Volume 59, Issue 13, Pages 6829–6836, doi: 10.1021/jf201114d
“Heart Health Peptides from Macroalgae and Their Potential Use in Functional Foods”
Authors: C. Fitzgerald, E. Gallagher, D. Tasdemir, M. Hayes