Mineral components and anti-oxidant activities of tropical seaweeds

Abstract

Seaweeds are known to hold substances of high nutritional value; they are the richest resources of minerals important to the biochemical reactions in the human body. Seaweeds also hold non-nutrient compounds like dietary fiber and polyphenols. However, there is not enough information on the mineral compounds of tropical seaweeds. Also we are interested in the antioxidant activities of seaweeds, especially those in the tropical area. In this study, Indonesian green, brown and red algae were used as experimental materials with their mineral components analyzed by using an atomic absorption spectrophotometer. The catechins and flavonoids of these seaweeds were extracted with methanol and analyzed by high performance liquid chromatography (HPLC) ; the anti-oxidant activities of these seaweeds were evaluated in a fish oil emulsion system. The mineral components of tropical seaweeds are dominated by calcium, potassium and sodium, as well as small amounts of copper, iron and zinc. A green alga usually contains epigallocateehin, gallocatechin, epigallocatechin gallate and catechin. However, catechin and its isomers are not found in some green and red algae. In the presence of a ferrous ion catalyst, all the methanol extracts from the seaweeds show significantly lower peroxide values of the emulsion than the control, and that of a green alga shows the strongest anti-oxidant activity. The highest chelation on ferrous ions is also found in the extract of this alga, which is significantly different from the other methanol extracts in both 3 and 24 h incubations.

Nutritional Composition and Mineral Content of Five Macroalgae From Red Sea

“…Rizvi et al (2001) andTakeshi et al (2005) detect higher values for all minerals than the present data in related species. Prasada Rao et al(1984) studied mineral composition of algal species from India including P. tetrastromatica that contained values, for all minerals, lower than the present study.…”

“…Lead is considered as toxic metal and can cause a lot of health risks (Soetan et al, 2010). Many researches detect Pb in seaweeds in high values that may reach up to 55.9 ppm (Robledo and Pelegrin, 1997;Rizvi et al, 2001;Takeshi et al, 2005).…”

In-Vitro Antioxidant Properties of Lipophilic Antioxidant Compounds from 3 Brown Seaweed

“…Previous studies have reported many compounds in seaweed, for example zeaxanthin, fucoxanthin, violaxanthin, β-carotene, phlorotannins, anthocyanin, gallic acid, kaempferol, gallic acid 4-O-glucoside, cirsimaritin, carnosic acid, epigallocatechin gallate, epicatechin and fatty acids, which are strong antioxidant components [11,14,[39][40][41]45,[53][54][55]. In this study, the antioxidant capacity in lipophilic extract were the result of pigments and phenolic compounds.…”

Algae as nutritional and functional food sources: revisiting our understanding

“…Nutritional generalization about algal mineral contents is difficult because of sometimes large seasonal, geographic, and taxonomic variations in mineral contents of marine algae (e.g., Jensen 1993 ). For example, Indonesian green, brown, and red algae contain high levels of potassium, calcium, and sodium, but significantly lower levels of iron and zinc than reported for Japanese Pyropia (as Porphyra ) yezoensis , Ulva ( Enteromorpha ) intestinalis , and Sargassum ( Hijikia ) fusiformis (Takeshi et al 2005 ). These findings may indicate that macroalgal harvests from warm equatorial areas have lower mineral nutritional value than higher latitude regions (e.g., Cabrita et al 2016 ); however, there are remarkably few data on which to assess the validity of such generalizations.…”