FAQs

Tips and tricks for agar in food application

• · Addition of glycerol or sorbitol can prevent dehydration of the gel.
• · When replacing gelatin or pectin for gels, use 2-3 and 10 times less agar respectively
• · For "raw" preparations dissolve agar in small quantity of water. Heat remaining solution to 35-45 °C and mix with agar solution.
• · If left uncovered agar gels dry out, but if immersed in water or other liquid it swells and retains its original shape.
• · A special property of agar is the large difference between the gelling temperature and the melting temperature. This is known as hysteresis
  
  

  Name	agar (E406)
  Origin	polysaccharide obtained from red algae (several species)
  Properties, texture	thermoreversible, heat resistant, brittle gel; high hysteresis
  Clarity	clear to semi-opaque
  Dispersion	in cold or hot water
  Hydration (dissolution)	> 90 °C; heating to boil necessary for gelling.
  pH	2.5-10
  Setting	35-45 °C, rapid (minutes)
  Melting	80-90 °C%
  Promoter	sugar; sorbitol and glycerol improve elasticity.
  Inhibitor	tannic acid (counteracted by add. of glycerol); prolonged heating at pH outside the range 5.5-8
  Tolerates	salt, sugar, alcohol, acid, proteases
  Viscosity of solution	low
  Typical concentration	0.2% will set, 0.5% gives firm jelly, [0.24- 3%] *
  Synergies	locust bean gum (only with certain agar types)
  Syneresis	yes (can be prevented by replacing 0.1- 0.2% agar with locust bean gum)