Nutritional and Antioxidant Potential of Fiddleheads from European Ferns

Abstract

Ferns are part of the diet and traditional medicine in East Asia, North America, and Oceania, however, their importance has been forgotten in Europe. Here, the nutritional and antioxidant potential of young fern fronds (fiddleheads) of eight families were studied. Most of the tested fern species excelled in high antioxidant capacity when compared to the reference leafy vegetables spinach and rocket. On average, the total phenol content reached 220 mg·g−1 of extract dry weight for all fiddleheads, and 15 out of 24 tested species exceeded 1 g Trolox equivalent per gram of extract dry weight in Oxygen Radical Absorbance Capacity (ORAC) assay. On the other hand, fiddleheads contained a comparable amount of carotenoids and ascorbic acid with the reference vegetables. In the case of fatty acid composition, fiddleheads contained especially high amounts of essential omega-3 (n3) and omega-6 (n6) polyunsaturated fatty acids with a beneficial n6/n3 ratio. The n6/n3 ratio in all tested species was between 2 and 6.4, whereas the ratio in the reference vegetables was below 0.4. All in all, fiddleheads from European ferns are a rich source of valuable antioxidants and essential fatty acids with a desirable n-6/n-3 ratio and may thus form an alternative source of these compounds, especially for those people not consuming fish and fish products.

Effect of Plasma Activated Water on Selected Chemical Compounds of Rocket-Salad (Eruca sativa Mill.) Leaves

“…The β-carotene content was 36.31 ± 3.41 mg/100 g D.W., which is consistent with the findings of [49], who reported a β-carotene content of 36.00 ± 0.01 mg/100 g in dried rocket leaves. However, both β-carotene and lutein contents found in this study were higher than the values reported by previous studies [46][47][48]. Figure 6 shows the effect of PAW treatment on the carotenoid content of control and treated samples.…”

“…Long-chain carotenoids are significantly more susceptible to oxidation and isomerization, which can happen during processing and storage [45]. Lutein and β-carotene have been reported to be the most abundant carotenoids in rocket leaves [46][47][48][49]. A higher content of β-carotene than that of lutein in both garden and wild rocket samples has been previously reported [46], however, lutein was reported at higher concentrations in rocket leaves [47,48].…”

“…Lutein and β-carotene have been reported to be the most abundant carotenoids in rocket leaves [46][47][48][49]. A higher content of β-carotene than that of lutein in both garden and wild rocket samples has been previously reported [46], however, lutein was reported at higher concentrations in rocket leaves [47,48]. The content of lutein in control rocket samples was 37.40 mg/100 g D.W., as shown in Figure 6.…”

Metabolic and Oxidative Changes in the Fern Adiantum raddianum upon Foliar Application of Metals

“…1 µg AsA/g FW (or ~5 µg of total AsA/g FW, [ 16 ]) while common species of the genus Polypodium or Dryopteris contained ca. 300–1300 µg AsA/g FW [ 25 ], indicating that the AsA quantification in ferns requires further analytical investigation. In line with the more negative impact of Cd on the ROS balance (i.e., enhanced ROS formation), the amount of AsA decreased in the leaves ( Figure 3 ), although no visible signs of damage were observed.…”

Polypodium vulgare L. (Polypodiaceae) as a Source of Bioactive Compounds: Polyphenolic Profile, Cytotoxicity and Cytoprotective Properties in Different Cell Lines

“…In certain Eastern cultures of the European continent fronds of ferns are used as a food source ( Langhansova et al, 2021 ). The young fronds of ferns (named fiddleheads), which generally exhibit a higher total phenol content than the corresponding mature fronds, are a source of nutrients and phytochemicals with a high potential to reduce oxidative stress of diseases associated with ageing ( Dvorakova et al, 2021 ).…”