Microalgae a Superior Source of Folates: Quantification of Folates in Halophile Microalgae by Stable Isotope Dilution Assay.

Dirk Volker Woortman,Thomas B Brück,Tobias Fuchs,Nadine Weber,Michael Rychlik,Lisa Striegel,Monika Fuchs

doi:10.3389/fbioe.2019.00481

Abstract

A multitude of human nutritional supplements based on Chlorella vulgaris biomass has recently been introduced to the specialty food market. In this study, an analysis of total folate contents in Chlorella sp. and a series of marine microalgae was conducted to evaluate folate content in alternative algae-based food production strains. For the first time, total folate content and vitamer distribution in microalgae were analyzed by stable isotope dilution assay (SIDA) using LC-MS/MS, which has demonstrated its superiority with respect to folate quantification. Consistently, high folate contents were detected in all examined microalgae samples. High folate concentrations of 3,460 ± 134 μg/100 g dry biomass were detected in freshly cultivated Chlorella vulgaris, notably also in other well-researched microalgae strains. To that end, the highest folate content currently documented for any algae sample was measured in the marine microalgae Picochlorum sp. isolate with values of 6,470 ± 167 μg/100 g dry biomass. This calls for alternative products based on other algae biomass. Our data indicate that freshwater and marine microalgae provide extremely high concentrations of folates, which warrant further studies on the regulation of pteroylpolyglutamates in algae as well as on bioaccessibility, absorption, and retention in humans.

Highlights

With an ever-growing global population and increasing limiting availability of agricultural land, there is a growing demand for edible biomass that contains high concentrations of macro- and micronutrients (Tilman et al, 2002; Foley et al, 2011; Lipper et al, 2014)
A series of freshwater and marine microalgae were analyzed for their total folate content and vitamer distribution by stable isotope dilution assay (SIDA) based on dry biomass
As a reference to our cultivated algae species, we measured the folate content of commercial, algae food supplement products based on Chlorella biomass

Summary

Introduction

With an ever-growing global population and increasing limiting availability of agricultural land, there is a growing demand for edible biomass that contains high concentrations of macro- and micronutrients (Tilman et al, 2002; Foley et al, 2011; Lipper et al, 2014). This situation is further aggravated by climate change effects, which lead to a shift and total reduction of agricultural lands (Tilman et al, 2001). The oftencited nutritional value of algae food supplements with respect to their micronutrient content and bioavailability is still a matter of scientific debate (Brown et al, 1999; Wells et al, 2017)

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Results

Conclusion