Collagen is the most abundant protein of animal origin, comprising approximately 30% of total animal
protein. There are at least 19 variants of collagen, named type I to XIX. Types I, II, III and V are the fibrous
collagens. Type I collagen is found in all connective tissue, including bones and skins. It is a heteropolymer
of two 1 chains and one 2 chain. It consists of one-third glycine, contains no tryptophan or cysteine and
is very low in tyrosine and histidine. Guanidine hydrochloride to solubilize the part of collagen referred as GSC
and then RS-AL (crude connective tissue fractions) digested with pepsin called PSC were extracted from the
tissues of N. crepidularia. The GSC and PSC yields (on a dry weight basis) were 0.48% and 1.28% respectively.
The FT-IR spectral analysis of the collagen extract from tissues of N. crepidularia showed more or less same
number of peaks, lying within the same range of values of the commercial collagen (Human placenta collagen)
used as a standard. These results suggest that collagen could be obtained effectively from the tissues of
N. crepidularia