Improvement of yield and quality of agar from Gracilaria edulis (Gmelin) Silva.

Rao, A Chandrasekhara (2001) Improvement of yield and quality of agar from Gracilaria edulis (Gmelin) Silva. Masters thesis, Central Institute of Fisheries Education.

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    Use of optimum levels of alkali/acid and other modifications in extraction methods were determined to increase the yield and quality of agar from red seaweed Gracilaria edulis (Gmelin) Silva. Presoaking of dry weeds in water for 2 hrs increase the yield but did not improve the gel strength of colloid. Presoaking in water for 12 hrs increased considerably gel strength, melting temperature and reduced sulfate content but not the yield. Addition of 3.0 N solution of.NaOH to the 0.5 N and 1.0 N NaOH presoaked G.edulis on boiling resulted in yield of 44.91% and 49.26% respectively and also reduction of sulfate levels in agar (1.5% w/v). However addition of NaOH during boiling did not improve gel strength of agar from alkali presoaked G.edulis . Addition of different concentrations of NaOH during boiling of HCI presoaked G.edulis showed improvement neither in yield nor in the quality of agar and also resulted in hydrolysis of agar. Pretreatment of 2.0-3.0 N NaOH at 80°C for 1 hour to G.edulis presoaked for 11 hrs in water proved to be most ideal and optimized extraction to obtain higher yield (14,16%), maximum gel strength (291 g/cm^), lowest sulfate (0.732%) and highest melting point (99°C) of agar.

    Item Type: Thesis (Masters)
    Uncontrolled Keywords: Agar; Gracilaria edulis
    Subjects: Dissertations
    Divisions: CMFRI-Kochi > Mariculture Division
    Subject Area > CMFRI > CMFRI-Kochi > Mariculture Division
    CMFRI-Kochi > Mariculture Division
    Subject Area > CMFRI-Kochi > Mariculture Division
    Depositing User: Users 17220 not found.
    Date Deposited: 06 Sep 2016 05:21
    Last Modified: 07 Oct 2016 04:25

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