The study, published in the Journal of Food Science, tested seasonal variations in a alpha-tocopherol both dried and fresh samples of five species of algae from the Caulerpa genus.
The team of Brazilian researchers found differences in alpha-tocopherol levels arising as from the drying process in all species – but also noted that certain stypes of algae had distinct seasonal variations in alpha-tocopherol levels.
The research findings may have implications in the production of natural, vitamin E rich ingredients from algal sources, including raising the question of whether there should be specific harvesting times and whether current processing techniques could be improved.
“The seasonal variation of alpha-tocopherol levels in the Caulerpa species analyzed in this article is so remarkable that it warrants further study to determine if these changes are caused by environmental or morphological factors,” said the authors, led by Kelma Maria dos Santos Pires-Cavalcante from the Federal University of Ceará, Brazil.
Pires-Cavalcante and colleagues said that algae “have a long, traditional culinary history in Asian countries,” whilst growing influence of Asian cuisine across the world has led to increasing consumption of algae in non-Asian populations.
The authors added that the growing consumer trend to embrace organically grown and ‘natural’ foods has seen algae increasingly seen as a “healthy food.”
“In addition, algae contain minerals such as calcium, magnesium, phosphorus, potassium, iron, and iodine and both water-soluble and fat-soluble vitamins such as pro-vitamin A carotenoids, and vitamins B, C, and E,” they added.
Besides acting as an essential micronutrient, Pires-Cavalcante and co-workers noted that vitamin E (alpha-, beta-, gamma-, and delta-tocopherols and tocotrienols) is “believed to be the most important naturally occurring antioxidative agent and to be associated with the prevention and/or reduction of several diseases.”
Some species of marine algae have shown the presence of alpha-tocopherol.
However, the research team noted that the variation in vitamin content and nutritional quality in such algae depends on many factors, including seasonality, environmental conditions such as temperature, salinity, luminosity, freshness, and the method of preservation and processing.
“Compared with vegetables normally consumed as human food, there are relatively few studies addressing the composition, distribution, and/or seasonal variation of vitamin E in algae,” they said
“Considering the importance of algae in industry and animal and human nutrition, the objective of this study was to investigate seasonal variation of alpha-tocopherol in five species of green marine algae of the Caulerpa genus, both fresh and dried, as well as the effect of the drying process on alpha-tocopherol levels,” said Pires-Cavalcante and colleagues.
The researchers reported that a pattern “was not observed” for the annual distribution of alpha-tocopherol among the five species analyzed (Caulerpa cupressoides, C. sertularioides, C. racemosa, C. mexicana, and C. prolifera).
However, despite finding no overall pattern for alpha-tocopherol distribution, Pires-Cavalcante and her team reported that C. racemosa “showed a distinct profile when compared to the other species of Caulerpa genus.”
“There was a marked monthly variation of alpha-tocopherol levels, with a maximum in June … and a minimum in January,” they noted.
They said that in fresh algae material, the maximum alpha-tocopherolvalue was detected in C. cupressoides, while in the dried material it occurred in C. sertularioides.
In addition dried algae were shown to have significantly lower levels of alpha-tocopherol, which was believed to be due to substantial losses of the vitamin during the drying process.
“Losses of alpha-tocopherol due to the drying process varied from 33 per cent to 93 per cent … In general, fresh algae with high alpha-tocopherol contents experienced a large loss during drying,” said the researchers.
Source: Journal of Food Science
Published online ahead of print, doi: 10.1111/j.1750-3841.2011.02182.x
“Seasonal Changes of α-Tocopherol in Green Marine Algae (Caulerpa genus)”
Authors: K.M.S. Pires-Cavalcante, D.B. de Alencar, M.B. de Sousa, A.H. Sampaio, S. Saker-Sampaio