The effect of drying on undervalued brown and red seaweed species: Bioactivity alterations

Abstract

The effect of drying on two brown seaweed (Treptacantha abies-marina and Cystoseira humilis) and two red seaweed species (Asparagopsis armata and Asparagopsis taxiformis) was evaluated based on the levels of biological activity, such as antioxidant and anti-inflammatory properties. Moreover, the contents of some significant compound classes, such as polyphenols and beta-glucans, were determined. Seaweeds C. humilis and T. abies-marina showed high polyphenol levels (1.76-6.78 mg gallic acid equivalents g À1 dw), which clearly exceeded those determined in the Asparagopsis genus regardless of drying process. This was partially reflected in the antioxidant activity as measured by DPPH and FRAP methods, which showed that extracts from C. humilis and T. abiesmarina in most cases had stronger antioxidant activity than those from Asparagopsis species. The influence of the drying technique upon the antioxidant activity was relatively limited, since in many instances there was no effect. Concerning antiinflammatory activity, in the case of shade-dried samples, C. humilis had a higher activity (>30% COX-2 inhibition) than A. armata. However, this activity in C. humilis was not rendered available in the upper gastrointestinal (GI) tract. Indeed, only A. taxiformis displayed anti-inflammatory activity in the fraction available in the upper GI tract, showing an upper GI tract availability in the 90-100% range. Therefore, though bioactivity levels were higher in C. humilis and T. abies-marina, Asparagopsis species also had substantial levels of bioactive compound. Sun-drying produced more negative effects than shade-drying, but these effects were not very extensive.

Metabolites Alteration and Antioxidant Activity of Gracilaria verrucosa After Fermentation Using Aureobasidium melanogenum MTGK.31

“…Besides the organic solvent, we assumed that the drying treatment on the seaweed affected this result. The drying treatment is reported to reduce seaweed's total phenolic and flavonoid contents (Gupta et al, 2011;Julião et al, 2021;Norra et al, 2017).…”

Comparative Analysis of Biological Activities and Phenolic Content between Fresh and Steamed Sargassum fusiforme in Different Extraction Solvents

“…Juliao et al [59] measured the ABTS radical scavenging activity of seaweeds (Treptacantha abies-marina, Cystoseira humilis, Asparagopsis armata, and Asparagopsis taxiformis) under different drying conditions; shade-dried extracts demonstrated 20-50% lower activity compared to sun-dried extracts. As the ABTS radical scavenging activity may vary according to the drying method, it is necessary that future studies compare the activity under drying conditions and methods other than those used in our study (65 • C for 48 h).…”

Cosmeceutical Effects of Ishige okamurae Celluclast Extract

“…In this context, seaweeds have found wide pharmaceutical and industrial applications as natural sources of compounds because of their non-toxicity, easy cultivation, low cost, and presence of an array of active compounds, such as polysaccharides, proteins, minerals, vitamins, and pigments; therefore, seaweeds are the best candidates to replace synthetic compounds [ 9 , 10 , 11 ]. The majority of the algal species contain polysaccharides, polyphenols, and peptides, and most of these compounds exhibit biological functions, such as antioxidant, antimicrobial, antitumoral, anti-inflammatory, and UVB protective effects [ 12 , 13 ].…”