The research, which its authors claimed was the first of its kind, involved defatting strawberry seeds and analysing them for minerals, dietary fibre and polyphenols and was carried out by researchers in Poland.
Speaking to NutraIngredients, study lead author Krzysztof Kołodziejczyk from Lodz University of Technology in Poland said: “The most significant learning is that strawberry seeds, which are generally considered as waste product of strawberry juice production, are a source of significantly important components.”
“Since there is still large interest in sources of dietary fibre, one can imagine the use of defatted strawberry seeds in dietary fibre preparations. Defatted strawberry seeds are good source of dietary fibre, but it is not all.
“They also contain phenolics typical for strawberries. As we know phenolics can contribute in prevention of some diseases, so the content of polyphenols in preparations made of defatted strawberry seeds in not negligible.”
He said one area that further research could focus on in this area was how best to include defatted strawberries as food supplements.
“There can be several possible ways of carry on the research. One can imagine the research on preparation of products to be used as food supplements,” he told us.
“The research on comparison of defatted strawberry seeds from various cultivars could be interesting as well."
Strawberry seeds were separated from industrial press cake of strawberry juice production in three consecutive harvest seasons. They were defatted by supercritical carbon dioxide at an experimental installation in Poland.
They were analysed for protein, fat, ash, minerals, saccharides, total dietary fibre and polyphenols.
The defatted seeds were found to be composed mainly of dietary fibres (on average 728g/kg dry matter) and proteins (167g/kg dry matter). The amount of polyphenols determined by HPLC (high-performance liquid chromatography) varied from 15.6 to 17.5g/kg of dry matter respectively over the production year.
There were two main groups of polyphenols: ellagitannins and flavanols. Total content of ellagitannins in seeds varied significantly with production year, but not flavanols.
Use in food supplements
Evaluating the composition of the defatted strawberry seeds, the researchers said: “Defatted strawberry seeds can be used as additives with high- protein, high-fibre and favourable polyphenol composition, or in diet supplements rich in minerals, as well as a supplement with high nutrition value.
“Defatted strawberry seeds may have a great potential for their use in the food and pharmaceutical industry.
“Therefore, the present study facilitates the increased utilization of defatted strawberry seeds and the improved management of fruit industry by-products, resulting in environmental sustainability and economic benefits.”
Asked about whether it was easy to get funding for projects of this ilk, Kołodziejczyk told us: “It depends on some factors It depends on what institution (university, research unit etc.) you work at, what research team you are a part of, what is your position as a researcher.
“So there is no straight answer to such kind of question. The most important thing is the idea itself, and capacity to convince those who finance the projects.”
Source: Food Science and Technology
Volume 84, October 2017, Pages 18–22, doi: 10.1016/j.lwt.2017.05.014
"Defatted strawberry seeds as a source of phenolics, dietary fiber and minerals"
Authors: Katarzyna Grzelak-Błaszczyk, et al