Shelf Life of Brine Refiigerated Anchovies (Engraulis anchoita) for Canning
C. E. DEL VALLE, B. E. FILSINGER, M. I. YEANNES, and C. L. SOULE
ABSTRACT
The possibility of keepinganchoviesin brine at 0°C was studied. The storagelife of anchoviesunder theseconditionswasabout 85 hr. The concentrationof brine seemsto havelittle effect on the quality lossat the concentrationsusedin this study.An acceptability level for the raw material basedon sensory attributes cannot be establishedwith any degreeof accuracysincethe latter deteriorate slowly. Thiobarbituric acid number increasedslightly over the initial value throughout this study. Total volatile baseincreased abruptly after 85 hr of storage.
INTRODUCTION
OVER 11,000 TONS of anchovies (Engraulis anchoiru) were landed at the port of Mar de1Plata in 198 1. Small fish are used in the production of fish meal, while large fish are either salted and marinated or canned. This speciesis particularly suited to the canning industry because of the small size of the fish, its fat content and the abundant .catches over relatively short periods. Under the food regulations of Argentina (Codigo Alimentario Argentino, 1978) anchovies that are canned as sardines can be labelled Argentine Sardines. Traditional production procedures for sardine and sardine-like canned products have been described (Huntley, 1953; Stansby, 1967; Lopez, 1975; Burgess, 1965; Soulk et al., 1980; Yeannes et al., 1976).
Most recent technological research has been aimed at increasing production rates and exercising better quality control of the product. However, a stage of the processthat has received little attention has been the storage and conditioning of the raw material from the time it is caught until it is processed. Anchovies are caught near Mar de1 Plata from September or October to November or December and again in May or June. The length of the fishing seasonsdepends on weather conditions. The largest catches correspond to the spawning period (September-December) when the ambient temperatures are in the range IO-25’C. These temperatures cause rapid spoilage if the fish are not handled promptly.
Fishing is done mostly by coastal boats with limited holding capacity and the anchovies are landed a few hours after being caught. Even if no conditioning of the fish were done on board, spoilage resulting over such short periods would not be very sizeable. However, delays of up to 2 days may occur at the canning plants due to saturation of the processing lines. Immersing the fish in brine at O’C will effectively increase storage life at the cannery (Connell, 1975). Information on the influence of such factors as temperature, brine concentration, brine-to-fish ratio, etc., on the quality of fish is scarce. Hansen (1976) reported that mechanical circulation of the brine is not advisable for sprat and other small fishes becauseit may result in excessive salt uptake and in softening of the flesh. The brine-to-
Authors del Valle and Yeannes are affiliated with Consejo National de lnvestigaciones Ciendficas y T&micas and Authors Filsingar and So&e with lnstituto National de TeCnologia lndustiral. Centro de lnvastigaciones de Technologia Pesquera (CITEP), Marcel0 T. de Alvear 1166 - 7600, Mar del Plata, Republica Argentina.
780-JOURNAL OF FOOD SCIENCE-Volume 49 (1984)
fish ratio in static systems should be small to avoid excessive salt penetration. McLay (1970) recommended that this ratio should not exceed four parts of herring to one part of water and that the salt concentration should be below 8%.
The purpose of this study was to establish the possibility of using brine refrigeration for anchovies (Engruulis anchoiru) and to determine the storage life for different brine concentrations.
MATERIALS & METHODS
Samples
Pre-spawninagnchovieswereobtainedfrom the local fishingport (mid-September2) hr after capture.The fish did not receiveany specialtreatment during this period as is the casefor commercial handlingof anchoviesusedby the canningindustry. Upon reception at our laboratory, half an hour later, sampleswere separatedfor chemicaland sensoryanalysis.Threelots, eachof 40 kg fish, were placedin plastic containers(length 60 cm, width 40 cm and depth 30 cm) with 13.33kgbrine in each.Fish-to-brineratio wasexpressed by weightto conformwith commerciapl ractice.
Reparation of brines
The brineswere preparedbeforehandby addingsodiumchloride and ice to tap water. The concentrationsof thesebrineswere 4, 7 and 10%by weight.Thecontainerswereplacedin a chamberat 0°C wherethey remainedthroughoutthe experiment.
Sampling
Sampleswereremoved two to four times a day during the first 8 daysof storage,and then once againon the 11th day. Sufficient brine wasremovedto keepthe brine to fish ratio constant.To make up eachsample,anchovieswere taken from different locationsin the containers.
Sensory evaluation
The sensoryevaluationwas done by four trained expertswho examinedthree fish from eachcontainer at eachsampling.Scores were assignedaccordingto the table proposedby Darlan et al. (1981) for the evaluationof fresh anchovies(Engruulis onchoifu). This table takes into consideration the changes in the external appearanceof the skin, the presenceof blood clots in the head,the odor of the gills, and the characteristics of the flesh, peritoneum and viscera. Scores from 90-100 correspond to optimum quality, from 70-80 very good quality, from 50-60 good quality, from 30-40 regular quality and less than 30 poor quality. Other indexes such as color and sinking of the eyes, color of gills, adherenceof backbone to flesh, etc., were also recorded. Belly burst was evaluated as a percentageof exposedabdominal area.
Chemical analysis
.
Anchoviesremovedfor chemicalanalysiswerewashedundertap water, headed andgutted and passedtwice through a manual grinding machine. All chemical tests were done in duplicate and when the difference between the two values exceeded 10% they were discarded. Total Volatile Base (TVB-N) was determined by a modification of the direct distillation method (Giannini et al., 1979). Rancidity was measured by the thiobarbituric acid test (TBA) on trichloroacetic acid extracts (Vyncke, 1975). Determination of salt contents was performed according to the AOAC (1960) method based on titration with silver nitrate. Fat and oil concentrations were determined using a Soxhlet extraction apparatuswith a mixture of petroleum and ethyl ethers (Lees, 1969).
A
‘W-N
80-
60-
n 4 % brine A 7%brine . 10 % brine
--e 4% brine -&- 7% brine -o-- 10% brine
60-
II
11
II
II ..
500
10000
150
t [hours]
50
100
150
200 t [houri]
Fig. l-Influence
of storage time and brine concentration on the
content of total volatile base (TV&N, as mg N/lOOg muscle).
Fig. P-Influence of storage time and brine concentration assessment scores 6.A.I.
on sensory
Water content was determinedby the weight lost in 24 hr at 100 + l°C (Boeri et al., 1978) and ashesby ashingof the sample at 500 +\_10°C (Pearson,1976).
The specificgravity of the fish was calculatedfrom the weightto-volume ratio and the specific gravity of the solutions was also determined.
RESULTS & DISCUSSION
THE AVERAGE WEIGHT of the anchovies was 29.86 g/fish (a = 2.87). Water, fat and ash content were determined throughout the experiment and no changes due to the storing conditions were detected. Water content remained, for all samples, at 76.99 +-0.43% (95% confidence interval); fat, as a percentage of total weight, was 3.55 + 0.26% and ash, also as a percentage of total weight, was 3.08 + 0.23%.
The determination of total volatile base is one of the most widely used methods for evaluating the quality of fish (Pantaleon, 1969). Fig. 1 shows little or no increase in TVB-N in the first 8.5 hr of storage, indicating very little spoilage. These results were independent of the brine concentration. The rate of increase in TVB-N after 85 hr of storage was similar for the three brine concentrations.
The sensory scores (Fig. 2) show a gradual deterioration of the sensory attributes of the fish. Straight lines fitted to the data by the method of least squares indicate that the spoilage rates of fish kept at the three brine concentrations were different. Nevertheless the differences between individual slopes tested by the F test were not statistically significant at a 95% confidence level.
The sensory quality.of the fish was still very good after 85 hr of storage. Working with Maine sardines (Clupeu harengus) kept in brine, Slabyj and True (1978) reported difficulties in establishing the acceptability limit for sensory scores of the raw material that would insure acceptability of the canned product. The amount of exposed abdominal area due to belly burst (Fig. 3) became important at the same time the level of TVB-N started to increase. Enzymes and bacteria liberated from the digestive tract in belly burst might be responsible for the formation of dimethylamine and trimethylamine from trimethylamine oxide in the muscle (Yamada, 1968). Unfortunately belly burst depends heavily on the way the fish is caught and handled before it reaches the processing plant (Hansen et al., 1977).
The initial TBA value for anchovies in the present study (0.22 mg malonaldehyde/kg sample) is very similar to the value reported for sardines by Slabyj and True (1978). The
‘belly
burst %
n 4 % brine
.
1
A 7% brine
50-
l 10 % brine
A
A* .
40-
’
.
. . ..
.
30-
..
.
. A. .
.
.
20-
.
..
‘a
l
200 t [hours]
Fig. d-Influence
of storage time and brine concentration
burst (% of exposed abdominal area).
on belly
TBA values, determined during 8 days of storage, on anchovies refrigerated in 10% brine were 0.321 k 0.125 (95% confidence interval). They were 0.279 * 0.131 for fish in 7% brine and 0.251 + 0.142 for fish in 4% brine. These results show the influence of the brine concentrations. Caste11et al. (1965) and Damodaram Nambudiry (1980) reported that salt may lead to rancidity in fatty fish. A definite trend for the evolution of TBA value could not be established in this study, nevertheless the TBA values after 8 days of storage were much lower than the values reported by Slabyj and True (1978) after 3 days of storage. This difference may be due to the different species used (anchovies have lower fat contents than CZupea harengus) and the sardines being salted after catch.
The initial salt content (0.44%) of the fish was similar to values reported by Filsinger et al. (1978) for the same species. Salt uptake was highly dependent on brine concentration (Fig. 4). Considering the salt contents after 100 hr of storage to be representative of an equilibrium condition, and the dilution of the brines due to the migration of salt into the fish, an equilibrium constant can be calculated by the method proposed by Zugarramurdi and Lupih (1980). Calculated values are in the range 0.8-0.9 (moles of
Volume 49 (1984)-JOURNAL OF FOOD SCIENCE- 181
SHE,!. F LIFE OF BRINE REFRIGERATED ANCHOVIES. . .
“y 0
2.5
./ 4
if
‘\\ +/
,*-.-.-.-.-.-e
.J ,./
CL
0.5
Y
I
I
50
--A--
-.+-I 100
7% brine
10% brine
I
4
150
200
I* t[hours]
Fig. 4-Influence
of storage time and brine concentration
con tent (g NaCI/l OOg muscle).
on salt
NaCl/liters of HzO, in fish)/(moles of NaCl/liters of HzO, in brine). These authors reported an equilibrium constant
of 0.6 for whole anchovies (Engraulis anchoita) and 1.Ofor anchovies with cuts. Although whole anchovies were used
in this research, flesh fissures and ventral bursting due to deterioration could explain an equilibrium constant close to unity. Excessive salt uptake during brine storage may be undesirable for canning. Chaftel (1965) and Roman (1954) recommended that salt content in canned sardines not exceed 1.5%. This is an important fact to take into account
in the design of brine refrigerated systems. Specific gravity of the anchovies was 1.080 (U = 0.004)
for all samples. After the first 24 hr, specific gravities of the liquid phase in the three containers were 1.029 (u = 0.004), 1.038 (u = 0.003) and 1.044 (a = 0.003). These results are in agreement with the visual observation that, under the
conditions tested in this research, the fish pile up on the bottom of the containers. The nonbuoyancy of anchovies should be taken into account in the design of a device to remove them from the containers.
In conclusion, anchovies can be held in refrigerated brine at 0°C up to 85 hr. As the concentrations of the brine appeared to have only minor effects on the quality loss, the
concentration must be chosen considering other factors such as salt uptake.
REFERENCES
AOAC. 1960. “Official Methods of Analysis.” 9th ed. Association
of Official Analytical Chemists, Washington, DC.
Boeri, R.L., Davidovich, L.A., and Lupin, H.M. 1978. Comparaci6n
de mktodos para la determinaci6n
de humedad en productos
pesqueros. La Alimentacidn Latinoamericana 111: 44.
Burgess, G. 1965. “El Pescado Y las Industrias Derivadas de la
Pesca,” P. 221. Acribia. Zaragoza.
Castell, C.H.. MacLean, J., and Moore, B. 1965. Rancidity in lean
fish muscle. 4. Effect of sodium chloride and other salts. J. Fish.
Res. Bd. Canada 22: 929.
Chaftel, H. 1965, The canning of sardines in “Fish as Food,” Vol.
4. p. 250. Academic Press, New York.
C6digo Alimentario Argentino. 1978. Art. 456. Inc. c.
Connell, J.J. 1975. “Control of Fish Quality,” p. 46. Fishing News.
(Books) Limited, Surrey, England.
Damodaran Nambudiry, D. 1980. Lipid oxidation in fatty fish: the
effect of salt content in the meat. J. Food Sci. & Technol. 17(4):
176.
Darlan, L.A.. Ghys, M.I., Miccio. L.A.. and Cabezali, C.B. 1981.
Frescura Y organolepsia de 10s productos de la pesca: II. Anchoita
(Engraulis anchoita) capturada con red de cerco. Acta Bioquhnica
clinica Latinoamericana 12(4): 617.
Filsinger, B.E., Zugarramurdi, A., Sanchez, J.J., Trucco, R.E.. and
Lupin, H.M. 1978. Variaciones quimicas durante la maduracibn
de anchoita salada. La Alimentacidn
Latinoamericana
108: 26.
Giannini, D.H., Davidovich, L.A., and Lupin. H.M. 1979. Adapta-
c&n de m&odos de uso come&al para la determinacidn
de
nitr6geno b&co vola’til en merluza (Merluccius hubbsi). Revista
de Agroquimica Y Tecnologia de Alimentos 19(l): 55.
Hansen, P. 1976. Plllk handling and chilling of large catches of small
fish. Scandinavian Refrigeration 3: 78.
Hansen. P.. Feldstedt, B., Quiroga. L., and Petersen, T.E. 1977.
Container and bulk stowage abroad purse seiners. Fishing News
International. Feb.: 9.
Huntley. J.G. 1953. Herring canning. In “Report of the FAO Meet-
ing on Herring Technology,” P. 302. Bergen, Norway.
Lees R. 1969. “Manual de An&is de alimentos,” P. 183. Acribia,
ZaGagoza.
L6pez, A. 1975. “A Complete Course in Canning . ” Vol .,.2 p 560. The Canning Trade. Baltimore.
McLay, R. 1970. “Handling Fish Before Canning.” Torrv Advisory
Note N044, HMSO Press, Edinburgh.
Pantaleon. J. 1969. Controle des produits de la peche par le dosage
de l’azote basique volatile total. Presented at the Technical Con-
ference on Fish Inspection and Quality Control, Halifax, Canada,
July 15-25.
Pearson, D. 1976. “T&micas de Laboratorio para el An&is de
Alimentos,” p. 69. Acribia. Zaragoza.
Roman, M.K. 1954. Salting of pilchards for canning. F.I.R.I. Annual
Rept. 7(13).
Slabyj, B.M. and True, R.H. 1978. Effect of preprocess holding on
the auality of canned Maine sardines. J. Food Sci. 43: 1172.
Soul&‘C.L.,- Yeannes. M.I., Boeri, R.L., Moschiar, S.M., Fernandez,
V., and Lupin, H.M. 1980. Sardinas argentinas en aceite. La
Industria C&mica Latinoamericana 7(32): 6.
’
Stansby. M.E. 1967. “Tecnoloda
de la Industria Pesquera.” p.
158. Acribia. Zaragoza.
Vyncke, W. 1970. Direct determination
of the thiobarbituric
acid
value in trichloroacetic acid extracts of fish as a measure of oxida-
tive rancidity. Fette Seifen Austrichem. 72: 1084.
Yamada, K. -1968. Post-mortem breakdown of trimethylamine
oxide in fishes and marine invertebrates. Bull. Jap. Sot. Sci. Fish.
*’ 34(6): 541.
Yeannes, M.I., Elgue, A.E., and Lupin, H.M. 1976. Elaboracibn de
conaerva de sardina fuegina. La Industria Cknica. 9: 30.
Zugarramurdi, A. and Lupin, H.M. 1980. A model to explain ob-
served behavior on fish salting J. Food Sci. 45: 1305.
MS received 3/26/83; revised 8722183; accepted 916183.
EMULSIFYING CAPACITY/STABILITY
MUSCLE PROTEINS. . . From page 171
Price, J.F. and Schiveigert, B.S. 1971. “The Science of Meat and Meat Products.” W.H. Freeman and Co. San Francisco.
Sat&, R.L. 1968. Meat emulsions. Adv. in Food Res. 16: 105. Sal%, R.L. and qalbreath, J.Q. 1964. Quantitative determination of salt
soluble protem m vamous tT, es ofQmeat. Food Technol. 18: 1943. Swift, ,C.E. 1965. The emulsl ymg roperties of meat protein. In “Proc.
Meat Ind. Res. Conf.” Am. Meat ~1. Assoc. and Am. Meat Inst. Foun-
dation. Chicago, IL. Swift, C.E. and Sulzbacher, W.L. 1963. Factors affecting meat proteins as
emulsion stabilizers. Food Technol. 17: 224.
Swift, C.E., Lockett, C., and Fryar, A.J. 1961. Cornminuted meat emulsions: the capacity of meats for emulsifying fats. Food Technol. 15: 468.
MS received 4113183; revised 10/12/83; accepted 10/14/83.
Financial assistance received from the Meat and Fish Board of Turkey. The author thanks Professor Dr. T. Yazicioglu and Dr. U. Yurdagel for their advice and assistance.
182-JOURNAL OF FOOD SCIENCE-Volume 49 (1984)
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