Biology Reference
In-Depth Information
The amino acid composition of several protein hydrolysates prepared
using different fi sh industry wastes is presented in Table 10.6. Such
hydrolysates prepared from low quality materials like visceral waste has
the potential for application as ingredients in aquaculture feeds (Vidotti
et al., 2003; Nilsang et al., 2005) and as a source of nitrogen in microbial
growth media (Dufosse et al., 1997; Guerard et al., 2001).
Attempts to recover collagen from fi sh industry waste using enzymes
from microbial sources are very scanty. However, enzymatic hydrolysis of
other proteins present in the fi sh industry waste would leave a collagen
rich mass that can be further chemically/physically treated to obtain
collagen and gelatin ( Fig. 10.2 ) .
Shellfi sh Industry Wastes
Crustacean wastes are also important sources of chitin, with chitin
content ranging from 13 to 42% depending on the species (Johnson and
Peniston, 1982; Balogun and Akegbejo-Samsons, 1992; Bechtel, 2003; Heu
et al., 2003). Deproteinization, demineralization and decolourization are
the major steps involved in production of chitin from crustacean wastes.
Strong alkali is used in the traditional process of deproteinization at high
temperatures and prolonged periods, which results in depolymerization
and deacetylation of chitin (Synowiecki and Al-Khateeb, 2003). Further,
the disposal of spent alkali poses environmental problems. Enzymatic and
fermentation techniques are developed to overcome these problems. In
addition these bioprocessing techniques allow recovery of other valuable
products such as protein and carotenoids (Healy et al., 1994, 2003).
Stabilization of shrimp waste by lactic acid fermentation and evaluation of
resulting silage as a feed ingredient has been attempted by many workers.
The studies on fermentation of shrimp wastes included the effect of different
carbohydrate sources, starter cultures on fermentation and quality of
fermented silage (Fagbenro, 1996; Fagbenro and Bello-Olusoji, 1997; Cha
and Cadwallader, 1998; Shirai et al., 2001; Cira et al., 2002). Sachindra et al.
(1994) reported a method for fermentation of shrimp waste proteins after
removal of the chitinous shell. Fagberono (1996) fermented raw heads
from freshwater prawn with 5% Lactobacillus plantarum as starter culture
and 15% molasses as the carbohydrate source and achieved a pH of 4.5 in
7 d. Such fermented silage was found to be a good protein supplement in
the diets for cat fi sh (Fagbenro and Bello-Olusoji, 1997). Shirai et al. (2001)
demonstrated that initial glucose concentration and level of LAB are the
critical factors in shrimp waste ensilation. The conditions for fermentation
of Indian shrimp waste using Lb. plantarum have been optimized
(Sachindra et al., 2007). Further different lactic cultures were evaluated
for their effi ciency to ferment shrimp waste and Pedicoccus acidolactici was
found to be the best starter culture (Bhaskar et al., 2007).
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