Writing in the journal Innovative Food Science & Emerging Technologies , lead author Luisa Gouveia from the National Institute for Industrial Engineering and Technology in Lisbon reports that pilot scale tests with the biomass at different quantities resulted in cookies very stable, accentuated green colouring.
"Green colouring is relatively difficult to impart, expecially when using only natural products," explained Gouveia.
"Chlorella sp. has been and is used as a food supplement, and… the stable non-perishable tonalities obtained [with the cookies] were agreeable to the consumer.
It is therefore concluded that a possibility of developing similar products exists."
Chlorella vulgaris is widely produced and marketed as a food supplement in many countires, including China, Japan, Europe and the US, despite not possessing GRAS status, said the researchers.
The researcher taps into a growing trend using microalgal biomass as a source of fine chemicals for the food industry, including carotenoids, omega-3 fatty acids, vitamins, pigments, and polysaccharides.
The study used Chlorella vulgaris cultivated in-house and used the resulting biomass in the preparation of short dough cookies, baked at 125 degrees C for 35 minutes.
The biomass was added at the 0.5, 1.0, 2.0, and 3.0 per cent concentration levels.
Colour and textural analyses were carried out one day one and again after three months of storage.
With increasing biomass addition a darker and greener cookie was obtained, described by the researches as "attractive."
However, no significant differences between the concentrations above one per cent was observed, they said.
From a textural point of view, the firmness of the cookies increased significantly with increasing biomass content, with positive effects reported on the structural properties of the cookies, related to the high protein content of the algal source.
"The addition of Chlorella vulgaris biomass as a natural ingredient resulted in cookies with an attractive and innovative appearance and higher textural characteristics," wrote the authors.
"In general, colour parameters remained very stable over the three months storage time."
The authors were not contactable prior to publication, and details of the price of the biomass, formulation issues, and whether an industrial partner is involved in further research and development are not known.
The natural colour market has experienced strong growth over recent years thanks to the functional food trend and a shift away from synthetic colours as consumers begin to assume more and more that all E-numbers are unhealthy.
German flavours and colours firm Wild currently markets a brilliant green colouring extracted from stinging nettle and spinach.
The extract is obtained via a special extraction process and is said to be heat and light stable for most applications.
Source: Innovative Food Science & Emerging Technologies (Elsevier) Published on-line ahead of print, doi: 10.1016/j.ifset.2007.03.026
"Chlorella vulgaris biomass used as colouring source in traditional butter cookies" Authors: L. Gouveia, A.P. Batista, A. Miranda, J. Empis and A. Raymundo