Seasonal Composition of Lipids, Fatty Acids Pigments in the Brown Alga <i>Sargassum pallidum</i>: The Potential for Health

Abstract

The present study describes the content of total lipids (TL), the main components of polar and neutral lipids (NL) and photosynthetic pigments (PSP) in edible seaweed Sargassum pallidum (Ochrophyta) from the Sea of Japan, Russia, in different months of the year, taking into account life cycle. Special attention was paid to the fatty acids (FAs) of total lipids as well as the accumulation of important polyunsaturated fatty acids (PUFAs) in glyceroglycolipids (GL) and reserve lipids in the seasonal cycles of growth. The content of TL strongly varied in the course of a year. The major lipid components were GL (20.3% -36.4%) and NL (19.8% -30.6%), while phospholipids (PL) were present in negligible amounts (3.2% -6.9%). Significant seasonal variations were observed in content all classes of lipids. The PUFAs prevailed in total lipids and the content of n-6 PUFAs was higher than n-3 PUFAs on all stages of life with the exception of vegetation period. Monogalactosyldiacylglycerols (MGDG) and digalactosyldiacylglecerols (DGDG) were rich in PUFAs and n-3 PUFAs were dominated among them independently of stages of growth. Saturated fatty acids (SFA) were dominated in sulfoquinovosyldiacylglycerols (SQDG). Triacylglycerols (TAG) and diacylglycerols (DAG) contained many PUFAs, especially n-6 PUFAs. Significant concentration 20:3 n-6 was in the triacylglycerols. The concentration of chlorophylls and carotenoids was increased with the growth and maturation of S. pallidum and reached maximum in period of highest day length and water temperature. The content of pigments decreased with the onset of short days and decreasing water temperatures. Nutritional value and benefit for health of human this alga were evaluated. The n-6/n-3 PUFAs ratio, nutritional quality index (atherogenic and thrombogenic indices, and ratio between hypocholesterolemic and hypercholesterolemic fatty acids) were low, suggesting a high nutritional value of S. pallidum throughout the year.

Variation in Lipid Components from 15 Species of Tropical and Temperate Seaweeds

“…This result is consistent with other studies [14,48,49,78]. Gerasimenko and Logvinov [79] reported that FAs content and composition in seaweeds differed not only by species, but also by seawater temperature. The lower temperature of seaweed habitats results in the high accumulation of n-3 PUFAs for accelerating cell metabolism, especially during the winter [38].…”

“…Several factors predicting the nutritional quality of the seaweed TL were calculated based on the formula as below [79,96,97]:n-6/n-3 ratio = 80%true∑n-6PUFAs80%true∑n-3PUFAs…”

Lipidomic Signatures Reveal Seasonal Shifts on the Relative Abundance of High-Valued Lipids from the Brown Algae Fucus vesiculosus

“…The adaptation of the lipid metabolism in brown macroalgae to lower temperatures during winter, by modulating the biosynthesis of PUFA and increasing lipid desaturation, was already reported in studies that evaluated the fatty acid profile of F. vesiculosus [33,52,53]. A similar effect was observed in the brown macroalgae Undaria pinnafida [29], Sargassum pallidium [28], Egregia menziesii [32], and Costaria costata [54] that showed higher content of PUFA and higher n -3/ n -6 ratio in response to cold temperatures. The proportion of saturated and unsaturated acyl chains in membrane lipids is a critical factor that affects lipid packing, membrane viscosity, and water permeability.…”

“…The calculated ratio of n -6/ n -3 FA was 1.20 in winter and 1.95 in spring, with an average of 1.57, which is a lower ratio than the maximum recommended by the World Health Organization (lower than 10) [55,56]. As such, F. vesiculosus can be considered a sustainable source of PUFA [28,29,51,57], either available by the consumption as edible seaweed, or used as a raw material in food industries and biotechnological applications [4]. Due to its content in n -6 and n -3 PUFA, the consumption of this seaweed could have benefits for preventing cardiovascular disorders, depression and other mental disorders [56].…”

“…The lipid metabolism of macroalgae is modulated in response to changes in environmental factors such as temperature and light [27,28,29,30,31,32,33,34]. The variation of lipids with season was evaluated in the brown alga Fucus serratus .…”