Integrated Processes for Simultaneous Production of Sap and K-carrageenan from Fresh Seaweed

An integrated method is developed to utilize to a maximum extent the fresh biomass of seaweeds.

The fresh seaweed as harvested from farm is liquefied to produce a sap which is proven to be a promising low cost bio fertilizer (foliar spray) from field trials on various crops and residue processed for recovery of κ-carrageenan which is used as an emulsifier, thickener and gelling agent in a wide range of commercial products.

• The integrated process as illustrated with Kappaphycus alvarezii allows both κ-carrageenan and liquid seaweed fertilizer to be recovered from fresh seaweed which would make cultivation of the seaweed more lucrative. For a one hectare area of cultivation which conservatively yields 100 tons of fresh biomass per annum 60-80 tons of liquid biofertilizer can be produced in addition to 2.5-4.5 tons of κ-carrageenan, depending on the grade.
• The sap which has proven efficacy as biofertilizer is obtained without thermo-chemical cycling and external addition of water. It may be marketed directly requiring no further processing other than addition of preservatives.
• Simple equipment such as a grinder-cum-mixer and a press filter installed preferably near the site of harvesting may suffice for homogenizing the fresh seaweed and allowing sap to be separated.
• As compared to the ca. 850-900 kg water that needs to be removed from one ton of fresh Kappaphycus alvarezii as per the conventional
• Method of drying the whole plant, only the moisture in the wet residue amounting to 100-200 kg per ton of fresh seaweed needs to be removed as per the method of the invention thereby greatly reducing drying time and area.
• The free flowing, granular residue obtained from the fresh plant is superior to be dried whole plant as raw material for κ-carrageenan since the former is less bulky, easy to transport, easy to store, easy to handle, contains very little colour, has a higher κ-carrageenan content, and can even be used directly for gel formation in certain applications.