Characterization of Carrageenan Nitrogen Content and its Susceptibility to Enzymatic Hydrolysis

Abstract

Carrageenan extracted from Eucheuma cotionii and Chondrus crispus contained small but significant concentrations of nitrogen. Analysis of the nitrogen content by the Lowry and Coomassie Blue protein methods indicated that the nitrogen was largely proteinaceous in nature and not bound ammonia. Treatment of extracted carrageenans with proteases suggested that a portion of the nitrogen could be removed by enzymatic hydrolysis. Nitrogen losses resulted in changes in Carrageenan solution properties which were similar in pattern to those observed during commercial alkaline modification of carrageenan. These results indicated that the presence of bound protein may be an important determinant in the reactivity and properties of carrageenan.

Polysaccharides

“…Nitrogen containing components such as proteins and pigments are common impurities (0.1-1 wt %). Since the viscosity of several commercial carrageenan solution can be reduced by the addition of protein degrading enzymes, some possible linkage to the carrageenan chain is suspected [322]. Carrageenans may therefore be considered as proteoglycans [304].…”

Modified procedures for extraction and analysis of carrageenan applied to the red alga Hypnea musciformis

“…N-impurities (as well as starch) in galactans are only seldom reported in the literature (King & Lauterbach, 1987). However, as revealed by elemental analysis (tab.…”

The use of acetic acid as a source of carbon by cultured Chondrus crispus (Gigartinales, Rhodophyta) stackhouse

“…The cellulosic residue in both extractions showed the highest counts and only 7.1% (extraction 1) or 0.9% (extraction 2) of the total counts were found in the carrageenans. This indicates that the carrageenans in the cold extraction may be contaminated by other labelled compounds such as proteins (King & Lauterbach, 1987) albeit the use of proteases. Further identification of labelled compounds, such as precursors of cell wall components, would require a higher specific activity than we had.…”