Research Addresses Bioactive Components

“Nutraceuticals” (a better term for which might be “natural health products,” as used in Canada) are commodities that originate from food and/or nonfood products and are used in the form of pills, capsules, powders, or liquids with proven or perceived health benefits. “Functional foods” are those that resemble traditional foods, but render benefits beyond their nutrition and energy value in promoting health and preventing certain chronic diseases, especially cardiovascular disease, cancer, diabetes, autoimmune disorders, arthritis, and arrhythmia.  

Research on nutraceuticals and functional foods at Memorial University of Newfoundland (MUN) encompasses both plant- and marine-derived commodities. Phytochemicals in plants, especially phenolics and polyphenolics, are important in combating oxidative stress and its deleterious effects such as cancer.  

Our work has considered isolation, concentration, identification, and application of bioactives from grains, cereals, and oilseeds—the main agricultural products in Canada—as well as teas, nuts, and herbals from different countries. The harsh environmental conditions in Canada, especially in Newfoundland and Labrador, often elicit overexpression of bioactive secondary metabolites in plants. Thus, barks, stems, leaves, flowers, fruits, seeds, and/or roots of certain plants of interest may serve as a rich source of phytochemicals. For example, Newfoundland blueberries exhibit a higher antioxidant capacity than those from many other parts of North America.  

In the area of oilseeds, work has been underway to study the potential health benefits of plant lipids containing alpha- and gamma-linolenic acids and their concentrates from a production viewpoint, as well as to unravel their role and mode of action in disease prevention. Novel means have been explored for identification and inclusion of desired phytochemicals in different products, including personal-care commodities and cosmetics. Certain compounds present in evening primrose hulls were found to be strongly anticarcinogenic. 

Another area of research interest is nutraceuticals derived from marine oils, marine proteins, and marine and aquacultured seafood processing by-products. Obviously, since the feed for many of these organisms originates from phytoplankton and seaweeds, extension of research in such areas is needed.  

Marine oils, derived from the liver of white lean fish such as cod and halibut, flesh of fatty fish such as mackerel and anchovy, and blubber of marine mammals such as seals and whales, contain long-chain omega-3 polyunsaturated fatty acids, namely eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and, to a lesser extent, docosapentaenoic acid (DPA). These fatty acids and/or their associated eicosanoids, leukotrienes, and prostuglandins are essential for health.

A very large proportion of brain and retina lipids is composed of DHA, reflecting its importance in development of the fetus and dietary needs of infants and lactating mothers. Findings in this area have led to inclusion of DHA in infant formulas. Although much of the research has been on the role of EPA and DHA, the exact mode of action and potential beneficial health effects of DPA remain elusive and hence a subject of current research.

We have also used highly unsaturated fatty acids and their source materials from marine and algal sources for the production of concentrates and structured and specialty lipids. Some of these are of much interest for geriatric and medical use, and studies on hybrid products containing a variety of essential or provisionally essential fatty acids are underway.

Stabilization of such products, using natural sources of antioxidants and the mechanism(s) of action involved, have been researched for bulk oils, emulsions, and products thereof under different conditions of processing and storage. In these, the location of the fatty acids in the terminal positions (Sn-1 and Sn-3) and mid position (Sn-2) of the triacylglycerol molecules dictates their absorption, metabolism, deposition, and stability.

Work on marine proteins, protamine, and protein hydrolysates is also being done. Many of the short-chain peptides produced during the production of hydrolysates possess antibiotic-like activities, and some have been shown to act as strong antioxidants with immune-enhancing properties. Other processing by-products, such as chitin, chitosan, carotenoids, and carotenoproteins, have also been recovered, modified, and used in a variety of applications. Thus, glucosamine, chitosan oligomers, and other components with health benefits have been produced.

Technologies developed at MUN for nutraceuticals and functional foods have contributed to the promotion of health and prevention of disease around the globe.

by FEREIDOON SHAHIDI
University Research Professor
Dept. of Biochemistry
Memorial University of Newfoundland
St. John’s, NF, Canada