Lambda carrageenans

Property High methoxyl pectin Low methoxyl pectin Kappa carrageenan Iota carrageenan Lambda carrageenan... 

X-Carrageenan (lambda-carrageenan) is a nongelling polymer containing about 35% ester sulfate by weight and no 3,6-anhydrogalactose. 

The lambda type is nongelling, and functions as a thickner. Iota-carrageenan has been recommended (45) for use in formulating low fat ground beef due to its abihty to retain moisture, especially through a freeze—thaw cycle which is typical for ground beef patties. Oat bran and oat fiber can also be used to improve moisture retention and mouth feel. Modified starches can be used as binders to maintain juiciness and tenderness in low fat meat products. Maltodextrins (dextrose equivalent less than 20) may be used as binders up to 3.5% in finished meat products. Other carbohydrates such as konjac flour, alginate, microcrystalline cellulose, methylceUulose, and carboxymethylceUulose have also been used in low fat meat products (see CELLULOSE ETHERs). 

Commercial carrageenans are composed primarily of three types of polymers kappa-, iota-, and lambda-carrageenan. 

M. D. Noseda and A. S. Cerezo, Room temperature, low-field 13C-n.m.r. spectra of degraded carrageenans Part III. Autohydrolysis of a lambda carrageenan and of its alkali-treated derivative, Int. J. Biol. Macromol., 15 (1993) 177-181. 

M. Ciancia, M. D. Noseda, M. C. Matilewicz, and A. S. Cerezo, Alkali-modification of carrageenans Mechanism and kinetics in the kappa/iota, mu/nu and lambda-series, Carbohydr. Polym., 20 (1993) 95-98. 

M. J. Evelegh, C. M. Vollmer, and E. L. McCandless, Differentiation of lambda carrageenans from Rhodophyta with immunological and spectroscopic techniques, J. Phycol., 14 (1978) 89-91. 

G. Zhou, Y. Sun, H. Xin, Z. Zhang, and Z. Xu, In vivo antitumor and immunomodulation activities of different molecular weight lambda-carrageenans from Chondrus ocellatus, Pharm. Res., 50 (2004) 47-53. 

Of these three fractions, only lambda-carrageenan cannot form gels. 

Carrageenan products, of which a large number are usually available from a single supplier for different specific applications, contain different proportions of the three main behavioral types (kappa, iota, and lambda) produced by starting with mixtures of red seaweed species. Other substances, such as potassium ions and sugar (for standardization), may be added to the obtained powder to produce the commercial product. 

During cooling of hot solutions of /c- or t-type carrageenans, gelation occurs because the linear molecules are unable to form continuous double helices due to the presence of structural irregularities. The linear helical portions then associate to form a three-dimensional network in the presence of the appropriate cation. All salts of lambda-type carrageenans are soluble and non-gelling. 

Quantification of the kappa/iota ratio and the lambda content in carrageenan blend by 13C NMR Study of xyloglucan from apple Characterization of xyloglucan polymers isolated from cyclamen seeds... 

Carrageenans are anionic polyelectrolytes prepared from red seaweed. There are three types k- (kappa), i- (iota), and 1- (lambda) carrageenan commercially available (Figure 26.3). 

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