Biology Reference
In-Depth Information
livestock/aquaculture feeds) readers may refer to comprehensive reviews
by other
authors (Raa and Gildberg, 1982; Gildberg, 2004; Arruda et al.,
2007; Bechtel, 2007). In the context of this review, microbial reclamation of
fi sh industry waste especially with reference to fermentation techniques
and application of proteases of microbial origin only are considered. This
chapter reviews and discusses microbial reclamation from the view points
of preservation as well as recovery of valuable components like enzymes,
carotenoids, polyunsaturated fatty acids (PUFA), etc. from fi sh industry
wastes [both fi nfi sh and shell fi sh (mainly crustacean shell fi sh)].
QUALITY AND QUANTITY OF FISH INDUSTRY WASTES
Considering the world fi sh production and fi sh production in India in
particular, it is obvious that large quantities of by-products are generated
through processing. For instance, as can be seen from the production
fi gures from both capture and culture fi sheries in India between 2003 and
2007 (
Table 10.3A
)
, India alone generates > 3 MMT of by-products annually
due to fi sh processing activities. If one considers only visceral waste and
shrimp shell waste , Indian fi sh processing industry generates >700,000
tonnes annually; while global production of fi sh viscera and shrimp shells
would amount to 11.4 MMT
(
Table 10.3B
)
.
The major by-products arising out of fi sh processing include viscera,
skin, scales, bones and bone frames (in case of
surimi
production). These
by-products are rich in protein and fat which make them more perishable.
Reports on the yield of by-products arising from processing operations
in terms of weight percentage of live fi sh/shellfi sh are very limited. A
generalized schematic representation of different by-products and their
yield is presented in Fig. 10.1. There are only a few detailed reports with
regards to yield of processing by products. For instance, frame bones
resulting from fi lleting operations account for 15% of live weight in case
of cod and salmon with more than 60% live weight of fi sh being fi llets
(Gildberg et al., 2002; Liaset et al., 2003). Similarly, shell waste including
body carapace and head in case of some Indian shrimp varieties account
for 48 to 56% of live weight (Sachindra et al., 2005a) and meat content of
some of the Indian crabs (freshwater and marine) varies from 28 to 30% of
live weight (Sachindra et al., 2005b). Some of the available data regarding
yield of by-products in different fi nfi sh and shell fi sh species is presented
in Table 10.4.
As mentioned earlier fi sh processing wastes/by-products are good
raw materials for fi shmeal and oil production (Rustad, 2003; Gbogouri
et al., 2006; Guerard, 2006). These by-products can be categorized into
material used for non-food purposes [as feed ingredients/fertilizers/
