The present study describes the variation in lipid components from 15 species of seaweeds belonging to the Chlorophyta, Ochrophyta, and Rhodophyta phyla collected in tropical (Indonesia) and temperate (Japan) areas. Analyses were performed of multiple components, including chlorophylls, carotenoids, n-3 and n-6 polyunsaturated fatty acids (PUFAs), and alpha tocopherol (α-Toc). Chlorophyll (Chl) and carotenoid contents varied among phyla, but not with the sampling location. Chl a and b were the major chlorophylls in Chlorophyta. Chl a and Chl c were the main chlorophylls in Ochrophyta, while Chl a was the dominant chlorophylls in Rhodophyta. β-Carotene and fucoxanthin were detected as major seaweed carotenoids. The former was present in all species in a variety of ranges, while the latter was mainly found in Ochrophyta and in small quantities in Rhodophyta, but not in Chlorophyta. The total lipids (TL) content and fatty acids composition were strongly affected by sampling location. The TL and n-3 PUFAs levels tended to be higher in temperate seaweeds compared with those in tropical seaweeds. The major n-3 PUFAs in different phyla, namely, eicosapentaenoic acid (EPA) and stearidonic acid (SDA) in Ochrophyta, α-linolenic acid (ALA) and SDA in Chlorophyta, and EPA in Rhodophyta, accumulated in temperate seaweeds. Chlorophylls, their derivatives, and carotenoids are known to have health benefits, such as antioxidant activities, while n-3 PUFAs are known to be essential nutrients that positively influence human nutrition and health. Therefore, seaweed lipids could be used as a source of ingredients with health benefits for functional foods and nutraceuticals.

Spirulina platensis is a blue-green algae that contains bioactive compounds as a source of antioxidants. Methanol is a polar solvent; it has similarities to the content of the bioactive compound Spirulina platensis, which is polar. This study aimed to determine the effect of different concentrations of methanol solvent (50%, 70%, 96%) using UAE on the content of bioactive antioxidant compounds from Spirulina platensis. The parameters observed were yield, antioxidant activity, phytochemical screening, and GC-MS. The results showed that the difference in the concentration of methanol solvent using UAE significantly affected the antioxidant activity of the Spirulina platensis extract. The highest antioxidant activity was found in Spirulina platensis extract with 50% methanol solvent concentration using UAE with an average inhibition value of 91.81%. The yield value from the Spirulina platensis extract with a 50% methanol concentration was 9.3%. The qualitative phytochemical screening test carried out on Spirulina platensis extract with 50% methanol solvent using UAE showed positive results for flavonoid compounds, alkaloids, tannins and phenols. GC-MS analysis on Spirulina platensis with 50% methanol as a solvent using UAE resulted in 5 types of the most dominant compounds, pentadecanoic acid, 9-Ooctadecenoic acid, hexadecanoic acid, hexadecanal, and 1- nonadecene.

Fucoxanthin (Fx) is major carotenoids in brown algae. It showed many health beneficial effects for oxidative stress. Fucoxanthin is lower stability which may cause problem in the application for functional food. The objective of this study was to evaluate the effects of various heat processing on Fx, antioxidant activity (IC₅₀), total phenolic content, and colour stability of Sargassum ilicifolium. The various heat processing methods showed were not significantly affected to fucoxanthin and antioxidant activities however all treatments lower affected to brown seaweeds colour. Moreover, this study showed a useful proved in the design of brown seaweeds processing which minimize Fx, antioxidant activity and colour changes.