Biology Reference
In-Depth Information
MICROBIAL RECLAMATION OF FISH INDUSTRY WASTE
Fin Fish Wastes
The major fi sh wastes which have been studied for microbial reclamation
is the visceral mass followed by the collagenous components like skin,
bone and fi ns. Fish visceral wastes contain several spoilage as well as
lactic acid bacteria (LAB) (Sudeepa et al., 2007a; Bhaskar et al., 2007b). In
addition, fi sh processing wastes including viscera have been reported to
be a good source of proteins including enzymes and fats (Gildberg, 2004;
Dauksas et al., 2005; Bhaskar et al., 2007a; Morrissey and Okada, 2007) and
also, good substrates for lactic acid fermentation (Gao et al., 2006).
Lactic Fermentation
Fermentation is the major technique that is being used for stabilizing the
nutrient rich fi sh waste, especially visceral mass, for further processing
and recovery. Conversion of fi sh processing wastes into ensilage upgrades
the biowastes and this approach is eco-friendly, safe, technologically
fl exible and economically viable (Mathew and Nair, 2006). Ensilation of
this waste can be accomplished either by direct addition of mineral or
organic acid (acid silage) or biologically by fermentation with LAB. The
usefulness of fermentation preservation is based on the fact that it is
eco-friendly in nature compared to acid/alkali preservation (Hall et al.,
1997). Lactic acid bacteria and its metabolic products during fermentation
prevent the growth of unwanted spoilage microorganisms. Researchers
working on fermentation have used varying levels of sugar cane molasses
(10 to > 35%) and different fermentation time (2 to 6 d) for ensiling of fi sh
wastes (Ahmed and Mahendrakar 1995, Lallo et al., 1997; Zahar et al.,
2002; Mathew and Nair, 2006; Ganesan et al., 2009).
The fermentation process can be effectively used for simultaneous
recovery of protein hydrolysate as well as lipids available in the waste
waste proteins by preparing fi sh sauce has been reported by Shih et al.
(2003). They found that any alterations in treatment conditions resulted
in alterations in volatile compounds as well as content of amino acids,
although not much change was observed in the over all quality of fi sh
sauces prepared from Bonito visceral waste. It was observed that the
aroma compounds found in the fermented sauces prepared from fi sh
visceral wastes mainly resulted from the lipid components of the material,
although other components like sugars and proteins also contributed to
the fl avour (Cha and Cadwallader, 1998). In another report, viscera of one
species of fi sh that is rich in endogenous enzymes and
in situ
LAB have
been used in preparation of sauce from whole sardines (Chrost, 1990; Kim
et al., 2002; Klomklao et al., 2006). Chitin recovery was also facilitated
