Seasonal Nutritional Profile of Gelidium corneum (Rhodophyta, Gelidiaceae) from the Center of Portugal

Abstract

Gelidium corneum is a well-known agarophyte, harvested worldwide for its high agar quality. However, the species also exhibits an interesting nutritional profile, but with seasonal variations. Therefore, to evaluate the nutritional value of G. corneum, ash, crude protein, total lipids, and carbohydrates were analyzed at different times of the year. The heavy metals mercury, arsenic, lead, cadmium, and tin, as well as iodine were also measured. Finally, the seasonal antioxidant capacity of G. corneum extracts was evaluated. Our results indicate that the biomass is rich in protein (up to 16.25 ± 0.33%) and carbohydrates (up to 39.5 ± 3.29%), and low in lipids (up to 2.75 ± 0.28%), and especially in the summer, the AI, TI indexes, n-6/n-3 and h/H ratios (0.93, 0.6, 0.88 and 1.08, respectively) are very interesting. None of the contaminants exceeded the legally established limits, and the iodine values were adequate for a healthy diet. Finally, the antioxidant capacity is fair, with the DPPH £ 10.89 ± 1.46%, and ABTS £ 13.90 ± 1.54% inhibition, FRAP £ 0.91 ± 0.22 AAE.g−1, and TPC £ 6.82 ± 0.26 GAE.g−1. The results show that G. corneum is an attractive resource, with potential use as food or as a food supplement.

The Red Seaweed Giant Gelidium (Gelidium corneum) for New Bio-Based Materials in a Circular Economy Framework

“…These erect fronds can have an autonomous life when fragmented and can reattach to the substrate, so vegetative propagation, through fragmentation, is a frequent method of colonisation [76]. The species has a wide distribution, occurring in Atlantic Europe [6,73,[77][78][79][80][81][82], Mediterranean Sea [83], Atlantic islands [84][85][86], Atlantic Africa [87][88][89][90], and Atlantic America [91]. Guiry also mentions populations in the Indic and Pacific oceans, namely in India, Indonesia, Korea, Vietnam, and Australia, but no published information on these locations could be found [72] (Figure 2).…”

“…Gelidium corneum is known to have a high content of polysaccharides, very low content of lipids, and a fairly high content of protein [180,181]. Further, a close analysis of G. corneum shows that there are significant seasonal variations in the moisture, ash, protein, lipid, and carbohydrate content of the harvested wild biomass [6]. This biomass seems to have interesting nutritional properties that should not be overlooked as food, feed supplement, or feed.…”

“…Seaweeds are known for their healthy primary and secondary metabolite content, such as a high protein content with a balanced essential amino acid content, low lipid content, and high fibre and mineral content. They also contain hydrocolloids, pigments, fatty acids, polyphenols, vitamins, minerals, and terpenoids, and other biomolecules [3][4][5][6][7]. These bioactive compounds show a beneficial effect on human health and well-being, such as antioxidant, antimicrobial, anti-cancer, anti-inflammatory, and antithrombotic effects, and immune-system improvement, among others [8][9][10][11][12][13].…”

“…Despite the importance of the agar market and the conservation concern, Gelidium sp. has been studied in the last two decades to evaluate other biomass properties such as antioxidant [48][49][50], antimicrobial [6,14,51,52], anti-inflammatory [53], antiproliferative or cytotoxic [54,55], biosorption of contaminants [56][57][58][59][60][61][62][63], and phyto-stimulant [64]. Besides, the use of agarophytic biomass has been proposed by several authors for biorefinery, including in the energy sector [65][66][67].…”

“…Yet, the stranded biomass and waste may also be suitable to in-corporate into new bio-based materials. The agar industry, e.g., produces annually many tonnes of residual Gelidium biomass, which are treated as waste [68] or are used in the fertilizer industry with a very low commercial value [6,69]. However, this waste biomass can have other uses, and, thus, a better valorisation, adding value to this biomass already used industrially, and diversifying its use.…”