I will present my project who focuses on the seaweeds used in food with their nutritional qualities especially their phycocoloïds
Elodie worked on the phycocoloïds of red alguae : the carageenans, and me I worked on the phycocoloïds of brown alguae
So I will present my part of the brown alguae
Laminaria digitata: the alginate
For worked on the alginte I choose the laminaria because it's an algua who you can find in Britany
The laminaria is an brown algua, it's an algua who can mesure 60 meters.
With water we obtain a geling agent
The proportion of manuronic acid can change the gelification properties of geling agent
This table shows the proportion of mannuronic acid alginates extracted from different parts of the laminaria
EXTRACTION :
For point out the present of alginal in the brown algue, I pic up brown algua on the beatch of Lampaul-Plouarzel for realized the extraction of algints in chemistry lab
To highlight the alginate present in brown algae, we went to pick Laminaria to extract alginate present.
Then we have covered H2 SO4 for half an hour.
And then we rinsed with distilled water.
Then we have covered 10% Na2CO3 for half an hour.
Then we filtered.
We added a second time H2SO4 to acidify our algae.
To finish we collect our alginate which is at the bottom of the beaker, we filtered a second time.
The salts of alginates is in the form of long molecules shaped slightly spaced from one another accordion.
This will cause the calcium approximation molecules, they will be stacked on each other and form the "egg box".
The molecules align and join until a network that will trap the liquid.
This network will look to the meshes of a net which will maintain the particles suspended in the structure.
USES :
Alginate is mainly used to produce alginate beads which are used in medicine to encapsulate drugs or biologicals fragile (enzymes, microorganisms, animal or human cells) but also in the molecular cuisine.
Experimental protocol of the alginate beads produced in the laboratory:
STEP1: In a beaker containing distilled water, we put a few grams of alginate powder.
STEP 2: Then we added a few drops of green food coloring.
STEP 3: Using a pipette, we collected our solution.
Then we dripped in a sieve located in a crystallizer containing calcium chloride.
The alginate is a polysaccharide extracts brown algaes.
He is used as setting agent, thickening, emulsifier and stabilizer
Alginates give a creamy texture to many foods such as ice cream.
It is also possible that alginate marble are used in medicine to encapsulate drugs.
Conclusion: With their phycocoloides, algae have a great gelling power.
We can then do a lot of things like the recipes that we have made.
Algae are an alternative to certain foods because of their nutritional properties.
May 2014
Äänestä nyt! 