Biology Reference
In-Depth Information
and then remained constant at 4.2 and 4.5, and nitrogen decrease (5.3-
5.7%) was recorded; while non-protein nitrogen(N) increase (220-262%)
was reported. In addition, a net increase in the broiler weight relative to
the control diet was also noticed (Hammoumi et al., 1998).
Three different experiments were performed by Ayangbile et al. (1997)
in order to examine the effect of chemicals on preservation of crab-
processing waste and the fermentation characteristics of the waste-straw
mixture. In “Experiment 1”
1.5% propionic/formic acid (1:1) and crab-
processing waste were mixed with wheat straw, sugarcane molasses
and water (32:32:16:20, w/w) with or without 0.1% microbial inoculant
(
Streptococcus faecium
and
Lactobacillus plantarum
). In
“Experiment 2”
a
mixture of 0.2% sodium hypochlorite (NaOCl) or 0.4% hydrogen peroxide
(H
2
O
2
) were added to crab waste, and the mixture was ensiled just like
“Experiment 1 “Experiment 3” involved the addition of no chemicals, or
0.2% NaOCl, or 0.2% or 0.4% NaOCl/calcium hypochlorite [Ca (OCl)
2
]
or 1% NaNO
2
to crab waste, and the mixture was ensiled as described in
“Experiment 1”. In “Experiment 1” the addition of 1.5% propionic/formic
acid (1:1) resulted in waste degradation for up to 14 d, while 16% pH
and 48.9% water soluble carbohydrates were decreased, and an increase in
lactic acid concentration up to 252.1% were achieved with or without the
presence of microorganisms in ensiled waste. In addition, in “Experiment
2” waste deterioration was prevented for 7 d, whereas trimethylamine
(TMA) content was increased up to 246.5% and 1.87% when crab waste
was treated with NaOCl and H
2
O
2
, respectively. Finally, in “Experiment
3” the addition of 1% NaNO
2
and a combination of 0.2% NaOCl/0.2%
calcium hypochlorite [Ca(OCl)2] (1:1, w/w) or 0.2% of each alone
resulted in waste preservation for up to 10 d, while TMA concentration
was increased signifi cantly.
A mixture of fi sh waste, heads and viscera of different fi sh, but mainly
sardines (
Sardinia ilchardus
), and molasses was inoculated with 32 strains
of yeasts
Saccharomyces cerevisiae
and
Candida
sp.
and 14 strains of lactic
acid bacteria
Lactobacillus plantarum
and Pediococcus acidi-lactici
at 28°C
for 10 d and fermented at different values of pH (4.0-5.8), temperature
(20-30°C), and molasses proportions (20-30%, w/w). The results showed
that the fi nal product was free of coliforms and
Salmonella
. In addition,
a decrease in pH (17.1%), dry matter (10.5%), reducing sugars (28.4%),
protein (10.3%), total nitrogen (12.0%) and TMA (69.2%) in the fi nal
product was reported. On the other hand, a considerable increase in ash
(7%), fat (10.9%), non-protein-nitrogen (NPN) (130.8%), and total volatile
nitrogen (TVN) (49.6%) was recorded (Faid et al., 1994).
Saltwater (SW), freshwater fi sh (FW), and tilapia fi lleting residue (TR)
were separately mixed with 15% sugar cane molasses, 5%
Lactobacillus
plantarum
culture media and 0.25% sorbic acid (w/w). The addition of
