Different methods to extract gelatin have been described depending
on the raw material used. Depending on the degree of collagen
aggregation, the extraction process could also include the use of
proteases (Bougatef et al., 2012; Sila et al., 2015) that together with
a swelling step might lead to increases in the yield.
Squid gelatin, together with other marine gelatins, is offered as
an alternative to mammalian gelatin source due to the sociocultural
and safety considerations associated with the latter. Compared to
fish species, a special feature of squid collagen lies in its high degree
of cross-linking, due to high amount of Hydroxylysine, together
with high content of Hydroxyproline (Gomez-Guillen et al., 2002).
Squid has been used for industry transformation in Tunisia and the
skin generated, as by-products with a low market value could be a
source of many value-added products, especially gelatin. So far no
gelatin has been extracted from the skin of Loligo vulgaris and no
information on its properties is available.
Therefore, the objective of this study was to extract and characterize
the gelatin from squid (L. vulgaris) skin using an acid
protease aided process and to study its physicochemical characteristics
as well as its visco-elastic and functional properties.