A method of preparation of smoke cured fillets of oil sardine is described. Various procedural steps like brining, smoking, packaging etc. have been described and the shelf life assessed. Sodium propionate treatment is recommended to enhance storage life; BHA to control rancidity; and thermal treatment to overcome the insect infestation. The product has good consumer appeal

Muraleedharan, V.

Valsan, A.P.

Aquatic Commons

PREPARATION OF 
fROM 
SMOKE CURED 
OIL SARDINE 
FILLETS 
V. MURALEEDHARAN AND A. P. VALSAN* 
Central fnstitute of Fisheries Technology Unit, Ca/icut-673005 
A method of preparation of smoke cured fillets 
of oil sardine is described. Various procedural steps 
like brining, smoking, packaging etc. have been described and 
the shelf life assessed. Sodium propionate treatment is recom-
mended to ehnance storage life; BHA to control rancidity; 
and thermal treatment to overcome the insect infestation. The 
product has good consumer appeal. 
INTRODUCTION 
Oil sardine constitutes about 30 % 
of the country's total marine landings. 
Because of the Jack of proper preserva-
tion facilities considerable quantity of the 
fish is either wasted or under utilized. 
Even smoke curing, a very popular method 
of preservation employed in Cey Ion, 
Malaysia and Europe, is seldom practised 
in this country. 
Various reasons are attributed to the 
neglect shown to smoke curing. In the 
first place smoke curing, as practised in 
the conventional method, yields a product 
of short storage life. Secondly smoking 
calls for more careful . and critical oper-
ations, and the carefree approach usually 
adopted in the conventional dry curing 
Very little attention has hitherto been 
paid to improve this situation. Although 
certain preliminary studies have been 
reported to standardise the procedure, 
scanty efforts appear to have been made 
to improve the keeping quality of the 
product. The present paper reports the 
results of investigations undertaken to 
prepare good quality smoked sardine fillets. 
MATERIAL AND METHODS 
Fresh oil sardine (Sardinella longiceps) 
of average length 14 em. (50 nos.jkg.) 
were obtained from the nearby fish landing 
centres. Refined salt used was of com-
mercial quality and sodium propionate, 
butylated hydroxy anisole (BHA), potas-
sium sorbate etc. were food grade. 
and wet curing will not yield a product Estimations of moisture and chloride 
of satisfactory qualities. were carried out according to A.O.A.C 
*Present address: Central Institute of Fisheries Technology Unit, 
Sassoon Dock, Colaba, Bombay-40000.5. 
146 Fish. Techno!. 
Muraleerifwran & Valsan: Preparation of smof{.e cured fillets /rom oil sardine 
(1955) methods. Total volatile nitrogen 
(T.V.N.) and trimethyl amine (T. M.A.) 
were estimated on a trichloroacetic acid 
extract (Beatty and Gibbons, 1957) by the 
microdiffusion method of Conway {1947). 
Fresh fish was headed, gutted and 
cleaned well in running water, and then 
dipped in brine (1 : 1 wjv) containing 
3% (wjv) sodium propionate and 0.1% 
(wjv) BHA. 
After brining, the fish "' was drained 
for 10 minutes, spread on a wire mesh 
tray and smoked for 6 hours at a tem-
perature of 70-80°C in a smoke kiln. 
Coconut husk, shell, and saw dust were 
used to produce smoke. Smoked fish was 
then removed from the kiln, and allowed to 
cod to room temperature. Skin, backbone 
and most of the spines were carefully 
removed. 25 g. lots were packed in clean, 
coloured cellophane paper. They were 
stored in glass containers under ambient 
conditio:1s for assessing the storage life. 
RESULTS AND DISCUSSION 
Salt solutions of varying concentrations 
were tried for dip treatment. It has been 
observed that the high fat content of oil 
sardine tended to retard the penetration 
of salt into the muscle (Valsan, 1971 
- unpublished). Therefore, a high concen-
tration of salt in the brine was found 
to be essential. Saturated brine was found 
to give the best result. Even with this, 
the duration of immersion had to be 
sufficiently I ong to effect proper penetra-
tion of salt. A period of 15 minutes dip 
was found to be optimum (Table I). 
Longer durations of dip increased the 
salt content in the meat without improv-
ing the storage life. The presence of high 
amounts of salt in fish muscle will also 
accelerate the oxidation of fat (Howgate 
and Ahmed, 1972). 
Proper draining of the brined fish 
reduces the content of surface water of 
the fish, thereby preventing the excessive 
absorption of smoke. This, in turn, 
ensures a uniformly smoked product having 
better appearance and flavour (Shewan, 
1945). Draining for 10 minutes has been 
found sufficient for brined sardine. 
By smoking the brined and drained 
fish for six hours at a temperature of 
70-80°C the fish has been found to attain 
a characteristic smoked colour and flavour. 
The moisture content under these condi-
tions comes down to 30%. Lower moisture 
level was found to diminish the recon-
stitution properties of the product besides 
accelerating the oxidation of fat, and 
also adversely affecting the appearance 
and texture. 
TABLE I 
Effect of the duration of brining on the storage life of the product 
Concentration Dip period Chloride content Storage life 
of brine (minutes) in the product % in days. 
Saturated 5 10.65 18 
Saturated 10 11.55 19 
Saturated 15 11.98 21 
Saturated 20 12.36 Rancid after 20 days 
Saturated 30 13.10 Rancid after 19 days 
VoL 13 No. 2 1976 147 
Muraleedfwran & Valsan: 'Preparation Of smo#{e cured fillets from oil sardine 
TABLE II 
Storage characteristics of smoked sardine fillets 
Days of storage TVN mg% DWB --~~----------------Physical observation 
----------------~--------Initial (immediately after curing) 50.42 
7 68.15 
14 87.04 
21 109.20 
28 129.54 
TABLE III 
Preservative treatment and its effect on the 
Stray patches of fungus and some 
mites appeared. 
Fungus on the fillets; widespread 
attack of mites; rancid odour; 
smoky flavour faded. 
storage life of the product 
*Sample Storage in 4 weeks Storage in 8 weeks Storage in 16 weeks TVNmg.% TMAmg.% TVNmg.% TMAmg.% TVN mg.% TMAmg.% 
1 115.5 6.18 138.24 7.97 ] 51.64 9.72 
2 91.5 5.46 109.30 5.99 123.43 7.67 
3 103.3 7.01 123.73 8.52 144.80 10.32 
4 97.17 6.03 117.92 7.15 136.04 8.96 
5 96.95 6.22 128.51 7.74 147.82 9.65 
6 94.52 5.61 131.24 6.98 153.21 8.74 
7 99.54 6.55 124.14 7.05 145.02 9.41 
8 97.60 6.82 129.44 8.44 150.03 10.25 
9 129.54 7.89 149.95 10.32 158.98 11.97 
*The samples have been treated as given below: 
I. Dipped m saturated brine containing 3% (v/v) of acetic acid. 
2. Dipped in saturated brine containing 3% (w/v) of sodium propionate. 
3. Dipped m saturated brine containing 3% (wjv) of sodium benzoate. 
4. Dipped m saturated brine containing 3% (wfv) of potassium sorbate. 
5. Dipped in saturated brine containing no preservative but the finished product 
was smeared with 3% (w/w of fish) of sodium propionate. 
6. Treated as in (5) above, but with 3% (w fw) of sodium benzoate. 
7. Treated as in (5) above, but with 3% (w/w) of potassium sorbate. 
8. Treated as in (5) above, but with 3% (w jw) of refined salt. 
9. Control: simply dipped in saturated brine; no preservative used. 
The smoked product prepared thus 
was found to have very short storage 
life (Table II). After three weeks the 
product became susceptible to spoilage by 
The effect of various preservatives 
for improving the keeping quality of the 
product was, therefore, studied. The results 
are give11 in Table III. 
fungus, rancidity and the attack of insects. Of all the preservatives used, sodium 
148 Fish. Techno!. 
< 0 
1:'"' 
-w 
TABLE IV ~ 
z Effect of different concentrations of 
.: 
sodium propionate on the taste -t 0 2.. 
and storage quality of the product "' 
"' .... N ;::'> 
%of Duration Taste After 7 days After 15 days After 30 days After 60 days 1:> -t 
..... p 
\0 Sam- sodium of dip of storage storage storage storage ;:1 -.....} 
0\ pie propio- (minu- TVN Fungus TVN Fungus TVN Fungus TVN Fungus Ro pro-
No. nate tes) duct mg.% mg.% mg.% mg.% ~ p (;;" 
p 
1 4.0 15 Distinct 46.50 Nil 60.05 Nil 81.17 Nil 112.16 Nil ;:1 
distaste 
'0 
2 3.5 15 Slight 47.10 Nil 63.15 Nil 89.95 Nil 115.55 Nil -t 
"' -r::t 
distaste :; p 
3 3.0 15 Natural 47.80 Nil 68.20 Nil 95.75 Nil 117.64 Nil .... .... 0 
taste ;:1 
4 2.5 15 Natural 49.50 Nil 75.40 Nil 107.42 Nil 125.87 
0 
Very ...... 
taste little "' ;a
15 Natural 51.01 Nil 79.72 Nil 109.86 Very 129.38 Fairly 
0 
5 2.0 ?!'<> 
"' taste little widespread (") ~ 
6 1.5 15 Natural 51.94 Nil 79.92 Nil 110.22 Fairly 130.42 wide- -t 
"' .... 
taste widespread spread s 7 1.0 15 Natural 53.04 Nil 83.12 Very 122.43 Fairly 140.14 wide-
"' little widespJead spread 
.... 
taste "' 
Natural 56.72 Nil 85.24 125.34 Fairly 
....... 
8 0.5 15 Very 144.23 Heavy ... 0 
taste little widtspread ~ 
9 Nil 15 Natural 68.15 Nil 87.25 Very 134.35 Wide- 166.30 Heavy 0 ;:::. 
(control) taste little spread "' p 
... 
..... 
.... 
;:1 
"' 
..... 
~ 
\0 
'M uraleedfwran & V ahan: Preparation of smoite cured fillets from oil sardine 
TABLE V 
Influence of BHA treatment on the onset of rancidity in tlie product 
Sample 
No. 
%of 
BHA 
wfv 
Taste 
and 
flavour 
Storage of the product in days 
15 30 oo 120 
1. 0.5 Distinctly aromatic 
flavour with slight 
sour taste 
Not rancid Not rancid Not rancid Not rancid 
2. 
3. 
4. 
5. 
0.25 
0.1 
0.05 
Nil 
Slight aromatic 
flavour; slight 
sour taste 
Natural flavour 
and taste 
Natural flavour 
and taste 
Natural flavour 
(control) and taste 
-do-
-do-
-do-
propionate was found to be the most 
effective in warding off the onset of fungus 
and molds. The effect of this preservative 
in dry curing of fish has already been 
reported (Valsan, 1963). This is most 
effective when incorporated in the brine 
at an optimum concentration of 3% (w/v) 
(Table IV). Higher concentrations ,of 
sodium propionateJ although slightly impr-
oved the storage life, impaired the taste 
of the product. 
The oxidation of fat and the conse-
quent development of rancidity are other 
problems encountered in smoke cured 
products. The high fat content of sardine 
and the high temperature of smoking 
favour the early onset of rancidity. In 
general the product develops rancidity 
after 3 weeks of storage and very soon 
it loses the characteristic smoked flavour 
and taste. The antioxidant property of 
smoke alone was not found to be ade-
quate to retard ra11cidity for an appreciable 
period of storage. 
150 
-do-
-do-
-do-
Rancid 
-do-
-do-
Very slightly 
rancid; but 
acceptable 
Bad 
unacceptable flavoured 
-do-
very slightly 
rancid but 
acceptable 
Bad flavoured; 
unacceptable 
Bad 
flavoured 
Earlier work has shown that B.H.A. 
is very effective to prevent rancidity in 
cured fish (Valsan, 1963) and was, there-
fore, employed in these experiments. For 
the most effective incorporation, BHA was 
dissolved in minimum volume of dilute 
alcohol (1 : 5) and then dispersed in the 
dip bath by vigorous stirring. The treated 
product was subjected to physical obser-
vation for rancidity at regular intervals. 
The optimum concentration of this anti-
oxidant was worked out to be 0.1% (w/v) 
at which level rancidity will be prevented 
for a period of 4 months (Table V). 
Another factor which shortens the 
storage life of the product is attack by 
mites and insects. Most of the degreda-
tion in the smoked product is brought 
about by mites belonging to Lardoglyphus 
konoi and Tyrophagus putrencentiae and 
beetles belonging to Necrobia rufipes and 
Dermestes spp. Different methods of 
chemical treatment to control insects have 
been suggested (Rangaswamy and Surya-
Fish. Techno!. 
< 0 
t"' 
""" 
z 
0 
N 
....... 
\0 
-....] 
0\ 
-Vl ,.... 
TABLE VI 
Combined effect of sodium propionate, BHA and heat treatment 
on the storage quality of the product 
*Sam-
ple 
No. 
1 
2 
3 
After 15 days storage 
Fun- Ranci- Inse-
gus dity cts 
Nil Not Nil 
rancid 
Nil -do- Nil 
Nil -do- Nil 
After 30 days storage After 60 days storage 
Fun- Ranci- Inse- Fungus Ranci- Inse-
gus dity cts dity cts 
Nil Not Nil Nil Not Nil 
rancid rancid 
Nil -do- A few Nil -do- Intense 
number of attack. 
insects Product 
.started 
crumbling 
Fungus Rancid A few Wide- Highly -do-
on the number of spread rancid; 
fillets insects attack bad-
flavoured 
After 120 days storage 
Fungus Ranci- Inse-
dity cts 
Nil Very slight- Nil 
ly rancid 
Nil -do- Most of the 
product 
crumbled 
into powder 
Heavy Bad- -do-
fungus flavoured 
* 1. Treated with sodium propionate (3%) and BHA (0.1%) and heated at 125°C for 15 minutes; 
2. Treated with sodium propionate (3%) and BHA (0,1 %) but not heat treated; 
3. Control - no treatment. 
~ 
;:: 
.... 
!':.. 
"' 
"' 0.. 
;:;, 
>l 
.... 
p 
;:: 
Ro 
":::: 
0 
;;;-
p 
;:! 
'i:5 
.... 
"' 
...,. 
p 
.... 
~ 
Ci' 
;:! 
0 
-
"' ~ 
0 
?;'> 
"' 
C) 
!':: 
.... 
"' 0.. 
........ 
s 
"' .... 
"' 
.,..._, 
... 
0 
;;! 
0 
:::. 
"' p 
... 
0.. 
..... 
;:! 
"' 
M uraleedfiaran & V alsan: Preparation of smo!te cured fillets from oil sardine 
narayana Rao, 1969). But such chemicals 
as pointed out by West and Hardy (1961), 
are either too expensive to adopt or are 
unadvisable for incorporation in food 
products. 
A safe and effective method was, 
therefore, employed in these studies. The 
method suggested by Valsan (1968) for 
the prevention of the attack of mites on 
Masmin was employed for the study ie. 
keeping smoked fillets at l25°C. for 15 
minutes and then allowing to cool down 
to about 65°C. After keeping for 5 mi-
nutes in the open, smoked fillets were 
packed in cellophane. The treated product 
remained free of insects for more than 
fi 'e months. 
Table VI shows the effect of the 
preservative treatment upon the keeping 
quality of the smoked product. 
ACKNOWLEDGEMENT 
The authors wish to record their 
thanks to Shri. M. R. Nair, Project Co-
ordinator, C. I. F. T. Cochin for his keen 
interest. They are also thankful to Shri. 
P. Sadanandan for his assistance in the 
execution of the work. 
REFERENCES 
AOAC. 1955. Official Methods of Ana-
lysis., 8th Edn. Association of Official 
Agricultural Chemists, Washington. 
152 
Bannerman, A. 1968. Fd. Manufacture; 
43, 5 : 48. 
Conway, E. J. 1947. Micro diffusion 
Analysis and Volumetric Errors., 1st 
Edn. Crossby Luckwood & Sons, 
London : 28. 
Cutting, C. L. 1951. Fishing News; 8, 
1 : 11. 
Cutting, C. L. and C. T. House. 1953. 
Food Investigation Advisory Note., 
No. 10, DSIR, Torry Research Station, 
London. 
Howgate, P. F. and S. F. Ahmed. 1972. 
J. Sci. Fd. Agric; 23, 2 : 615. 
Moorjani, M. N. and M. Vasantha. 1972. 
Seafood Export Journal; 4, 3 : 25. 
Nicholson. 1930. The Preservation 
and Curing of Fish; Government 
Press, Madras. : 79. 
Rangaswamy, J. R. and S. V. Suryanara-
yana Rao. 1969. Seafood Export 
Journal; I, 1 : 15. 
Shewan, J. M. 1945. Cherny. Ind; I, 
13: 98. 
Stansby M. E. and F. P. Griffiths. 1943. 
Research Report; 6. United States 
Department of the Interior, Fish and 
Wildlife Service. 
Valsan, A. P. 1968. Fish. Techno!., 5, 
1 : 37. 
Valsan, A. P. 1963. Indian J. Fish., 10, 
2B: 9. 
West, T. F. and J. E. Hardy. 1961. 
Chemical Control of Insects; 2nd 
Edn. Chapman & Hall Ltd., Lon-
don. : 75. 
Fish. Technol. 


Preparation of smoke cured fillets from oil sardine

http://aquaticcommons.org/18321/1/FT13.2_146.pdf

Preparation of smoke cured fillets from oil sardine

Abstract

Similar works

Full text

Available Versions

Aquatic Commons