Differences between Gelidium and Gracilaria algae agars

Thu, 07/01/2021 - 10:40

As we already know, agar-agar is extracted from different algae species. It is present in several sea vegetables, but its main source is red Agarophyte algae. Among these, there are two species with high agar-agar content, Gelidium and Gracilaria, which are used to produce agar with different features. 

As mentioned in another post, agar was first used in Japan from Gelidium algae (Tengusa in Japanese). At the end of the 19th century, the increase in world consumption made it necessary to find other agar sources. Thus, the Gracilaria species started being used, although the agar-agar obtained had different features that we will now see. 

The main difference is its purity, agar-agar obtained from Gelidium is considered to be of higher quality and, therefore, it works as better raw material. 

On the other hand, the process for obtaining agar-agar is different for each species. Gelidium algae agar does not need to undergo any chemical transformation during the harvesting process, while Gracilaria agar needs a strong alkaline chemical treatment in order to enhance its gelling effect.

In addition, they are also grown differently. When Gracilaria algae began to be used, it was found naturally along the coastal areas of Argentina, Chile, Indonesia and Namibia. As demand for these algae began to grow, cultivation methods were developed, both in ponds and in open waters of protected bays. On the other hand, Gelidium algae only come from natural beds, mainly from Spain, France, Indonesia, Morocco, Mexico, Portugal and the Republic of Korea. Unlike Gracilaria algae, which grows easily and has several annual harvests, Gelidium algae is a small, slow-growing plant with a single annual harvest. Although efforts have been made to cultivate them in tanks and ponds, this was only possible from a biological point of view, because the lack of rocky bottoms and open sea prevents implementing large-scale Gelidium crops in the ocean

Regarding applications, the biggest advantage of Gelidium or Gracilaria agar is its gel point (the temperature at which it turns into a gel). Gelidium agar gels at a lower temperature, which is essential for microbiology applications. Also, Gelidium is the only species that can guarantee bacteriological agar, as it grows in natural open beds and lacks growth inhibitors. These differences are not as essential in the food industry. 

Prioritizing the quality of its products, Hispanagar uses exclusively Gelidium algae for all its bacterial agars. A wide range of products from the Gelidium and Gracilaria algae are also available for food applications, adapting to consumer requirements.