Seaweed (known as marine algae) has a tradition of being part of the animal feed in the coastal areas, from ancient times. Seaweeds, are mixed with animal feed, because when consumed alone can have negative impact on animals. Thus, seaweeds are very rich in useful metabolites (pigments, carotenoids, phlorotannins, polyunsaturated fatty acids, agar, alginate and carrageenan) and minerals (iodine, zinc, sodium, calcium, manganese, iron, selenium), being considered as a natural source of additives that can substitute the antibiotic usage in various animals. In this review, we describe the nutritional values of seaweeds and the seaweed effects in the seaweed-based animal feed/supplements.

Seaweed-based cosmetics are being gradually used by consumers as a substitute of synthetic equivalent products. These seaweed-based products normally contain purified compounds or extracts with several compounds. Several seaweeds’ molecules already demonstrated a high potential as a cosmetic active ingredient (such as, mycosporine-like amino acids, fucoidan, pigments, phenolic compounds) or as a key element for the products consistency (agar, alginate, carrageenan). Moreover, seaweeds’ compounds present important qualities for cosmetic application, such as low cytotoxicity and low allergens content. However, seaweeds’ biochemical profile can be variable, and the extraction methods can cause the loss of some of the biomolecules. This review gives a general look at the seaweed cosmetics benefits and its current application in the cosmetic industry. Moreover, it focuses on the ecological and sustainable scope of seaweed exploitation to guarantee a safe source of ingredients for the cosmetic industry and consumers.

There is a need to find new possible raw food sources with interesting nutritional values. One of the most unexploited sources are seaweeds. Thus, Ulva sp. is a green edible seaweed that shows a high growth rate in nature and can support drastic abiotic changes, such as temperature and salinity. This work aims to determine the main nutritional compounds, fatty acids (FAs) and monosaccharides profiles of Ulva sp. (collected from Mondego estuary, Portugal), to identify the potential of this seaweed as a food source. The present study also highlights the potential of controlled and semi-controlled cultivation systems in Ulva sp. profiles. The results showed that the controlled cultivation systems had higher essential FA and monosaccharide content than the semi-controlled cultivation systems. However, they are in some cases identical to wild individuals of Ulva sp., supporting that cultivation of Ulva sp. can be a key for food safety. It is crucial to control the associated risks of contamination that can occur in wild specimens.

Calliblepharis jubata is an edible red seaweed and a carrageenan primary producer, considered native in Figueira da Foz (Portugal). C. jubata has the particularity of producing only one kind of carrageenan, the iota fraction. However, this seaweed is not yet valuable for the food industry or even for human consumption. In this work, we characterize important biochemical compounds of C. jubata growing up within different cultivation techniques and wild specimens. The aim of this work is to know if there are differences between the biological compounds of interest and identify the advantages for human consumption and the food industry. The results supported the nutritional value of the seaweed, where the ones from inshore cultivation (T) were more identical to the wild specimens (F), than the indoor C. jubata (A, B, C). The parameters analyzed were fatty acids, carbohydrates and carrageenan content.

With the notable scarcity of Chondrus crispus on the Portuguese coast, and interest in exploiting compounds such as carrageenan, this study focuses on investigating different aquaculture methods and recording the yield of carrageenan from specimens grown by different methods. We compare the growth of Chondrus crispus in aquaculture using Free Floating, Cages, Attempted Fixation on Rock, and Fixed Line similar to Long Line. The best method was Free Floating where Nursery 0 had a 24-day Specific Growth Rate (SGR) of 2.08 ± 0.47%/day. The worst method in terms of growth was Nursery 2 (Attempted Fixation on Rock) where the SGR at 28 days was 0.33 ± 0.69%/day, and no fixation was observed. In terms of carrageenan extraction, all culture methods gave rise to biomass that had a lower extraction yield than wild specimens, at 50.95 ± 4.10%. However, the Free-Floating method from Nursery 1 showed an acceptable carrageenan content (31.43 ± 7.00%). Therefore, we demonstrate that the concept of C. crispus cultivation may be key to promoting the sustainability and stability of this species.