Algae as an ingredient in food products has less to do with slimy plants on the beach than with varieties that generally live as single-cell organisms. Prof. Sascha Rohn from the University of Hamburg’s Institute for Food Chemistry and Dr Michael Sandmann from the Institute for Food and Environmental Research (ILU) in Nuthetal/Germany explain how these organisms can constitute an enrichment in their role as ingredients.
sweets processing: What areas of application are algae suitable for?
Prof. Rohn: In order to avoid overwhelming consumers, what generally happens is that products they already accept are enriched with algae products/preparations. Innovations consisting almost exclusively of algae biomasses are quite rare, since in the end the taste is the decisive factor.
Dr Sandmann: The algae biomass quantities in food products are therefore generally in very low percentages. Potential products include snacks, desserts or yogurt, and increasingly pasta and baked goods.
sp: How is the algae noticeable?
Sandmann: A range of different characteristic flavours appear, but also, in some cases, there is an umami taste or a savoury taste impression. These are sometimes perceived as undesired flavours/tastes. Baking capability is not negatively influenced by an algae biomass concentration of up to six percent. The cookies developed with shortcut pastry showed a characteristic blue-green colour when using Spirulina algae and a yellow-green colour with Scenedesmus algae.
Rohn: The flavour components include volatile compounds stemming from the oxidation of unsaturated fatty acids and, as a result of the altered fat oxidation, from the remaining ingredients or the algae preparations themselves. The buttery odour of traditional cookies was covered up to some extent as a result of the addition of the algae.
sp: What benefits do these algae provide?
Rohn: Algae can alter the techno-functional and nutritive properties along with the sensory impression of food products. The hay-like odour and taste of Scenedesmus algae creates a spicy, fresh impression in baked foods which could be used in a targeted fashion in savoury products in the future.
Sandmann: Algae are quite easy to cultivate and constitute a biomass that can be created on a sustainable basis. Their biochemical adaptability is an added benefit. By varying the cultivation conditions, one can intentionally influence the composition of the biomass and practically apply the use of algae in a variety of products.
sp: What are the costs for the user?
Rohn: The current costs for the algae are between three Euros and 150 Euros per kilogram. The price varies heavily according to the origin and quality of the biomasses, the majority of which are still imported from far-away countries.
Algae for food products
Algae biomass has a positive effect on human health. Its important constituents include lipids with unsaturated fatty acids, proteins and complex carbohydrates, as well as natural pigments like carotinoids, which can have an antioxidant effect. The great advantage is the very simple production of algae concentrates, requiring only a photobioreactor, water, minerals, carbon dioxide and sunlight. The only algae used are microalgae cultivated “on land” in bioreactor systems. Spirulina and Chlorella are the most important algae varieties, because at present only a few types of microalgae are permitted for use in food products. Scenedesmus algae are highly promising candidates.