Changes in the Physicochemical Properties, Microstructure and Sensory Characteristics of Shark Dendeng Using Different Drying Methods
Ratna Sari Dewi,
The aim of the study was to identify physico-chemical properties,
SEM (Scanning Electron Microscopy) and sensory characteristics of dendeng made
from shark flesh (Chiloscyllium sp.). Three drying methods were used
in this study and they were sun drying, oven drying and oven vacuum drying.
Before drying, the slices with dimension of 4 cmx12 cmx3 mm were soaked in a
mixture of sugar (20%), salt (1%), tamarind (4%), coriander (1.5%), galangal
root (2.5%), ginger (0.5%), garlic (1.0%) and onion (1.0%) for 12 h. The drying
was carried out until the moisture content reached 23-25%. Proximate analysis
showed there were no significant differences among these samples but had significant
influence (p<0.05) on the color. The lightness value for vacuum drying was
32.19 followed by oven drying (29.97) and sun drying (28.92). There were no
significant differences in mineral values except for sodium (Na). SEM photograph
shows that different drying methods affect the compactness of the tissue structure.
Sensory evaluation result indicated that all samples were moderately acceptable
but there were no significant difference among the samples. However, shark dendeng
using oven drying was most preferred.
Received: March 30, 2010;
Accepted: May 28, 2010;
Published: July 05, 2010
Fish provides a good source of high quality protein and also contains many
vitamins and minerals. It is an extremely perishable food. Quality losses can
occur very rapidly after catch (Zakhia, 2002). Processing
was carried out with the aim of either to supply distant markets or to produce
a range of products with different flavors and textures. Of all food preservation
methods, that of drying food had received the most widespread and enthusiastic
publicity in recent years. Actually, drying is one of the oldest methods of
food processing and preservation. Compared with other methods, drying is quite
simple. Dried products have been considered as one of the safest food groups
for humans because their manufacture involves hurdles to microbial survival
or growth (Calicioglu et al., 2002).
Sharks are a valuable resource. Sharks are commonly termed fish, even though
they are only distantly related to the classical (bony) fish (Schubring,
2007). There are numerous species of fish caught annually throughout the
world but they are not all necessarily commercially important (Yapar
et al., 2006). However, from the economic and nutritional standpoints,
it is essential to utilize the entire catch for human consumption.
The amount of catches in Malaysia is continuing to increase every year from
2500 ton in 1950 to 27948 ton in 2003 (Lack and Sant, 2006).
Fishermen in Malaysia do not specifically target sharks for capture, but normally
catch them as bycatch, with the more important targeted bony species. Once caught
however, the sharks are not discarded, but are brought back whole to the port
where the meat is sold for a low price and the fins sold at a much higher price
due to their higher demand. The smaller species of sharks are generally used
as sources of fresh, chilled, or frozen meat, while the larger sharks provide
fins and hides. But, shark product preservation including drying is still limited
(Ali et al., 1999).
Fish dendeng is a type of preserved fish product traditionally made in Indonesia
by adding sugar, salt and spices to thinly sliced fish flesh which were then
dried. It can be dried using sun drying or using dryer (mechanic). This is a
dried product like Biltong in South Africa, Beef Jerky in North America, Carne
de sol in South America, Charqui in Brazil, Lup cheong, Isusou gan, Nyoursou
gan, Sou song in China and Pemmican in North America (Leistner,
1987). Sun drying does not allow very much control over drying times and
it also exposes the dendeng to attack by insects and allows contamination by
sand and dirt. Such techniques are totally dependent upon the weather conditions
(Fellows and Hampton, 1992). Another way of drying is
by using dryer (mechanic). Oven drying is the simplest way to dry dendeng because
it needs almost no special equipment. It is also faster than sun drying or using
a food dryer. But oven drying can be used only on a small scale (Troftgruben
and Keith, 1984).
Several studies have been carried out to examine the psychochemical properties
of fish dendeng (Nasran, 1993; Arifudin,
1993; Peranginangin, 1993; Buckle
et al., 1988). The aim of this study was to evaluate the physicochemical,
microstructure and sensory characteristics of shark dendeng using different
MATERIALS AND METHODS
Preparation of shark flesh: This study was carried out over the period
end of 2007 to middle 2009. Fresh shark was purchased from the local fish market
at Bayan Baru, Pulau Pinang, Nothern Part of Malaysia. The samples were transported
to the Fish and Meat Processing Laboratory of Food Technology Programme, Universiti
Sains Malaysia in ice box. Immediately on reaching the lab, the fishes were
thoroughly washed and sliced (dimension of 4 cm widthx12 cm lengthx3 mm of thickness)
manually. Fish flesh was then washed until it was free from blood, placed in
plastic box and kept in freezer at -18°C until used (2 days).
Ingredients for spice marinate: All spice ingredients such as red sugar
(20%), salt (1%), tamarind (4%), coriander (1.5%), galangal root (2.5%), ginger
(0.5%), garlic (1.0%) and onion (1.0%) were obtained from a local supermarket.
The percentage calculated from weigh of flesh. All ingredients were in fresh
form except for coriander and salt which were in powdered form.
Preparation of dendeng: Processing of dendeng was carried out using
the method of Nasran (1993) with slight modifications.
Shark flesh was immersed in salt solution (5%) for 10 min and drained for about
15 min or until there was minimum water dripping from the flesh. The flesh was
then soaked in spice marinate for 12 h at chilling temperature (4°C). The
spice marinade was made by mixing all ingredients using blender with water added
ratio of 1:1 (w/v) from weigh of flesh.
The flesh was then pressed on both sides between wires to keep the surface
smooth and then dried by hanging them inside dryers. Dendeng was dried using
three different methods namely; sun drying, oven drying (AFOS MINI KILN, HULL,
ENGLAND) at temperature 60°C and oven vacuum drying (Model 1450D, SHEL LAB,
DENMARK) at temperature 60°C until the moisture content was about 23-25%.
Dendeng was placed in sealed polyethylene bags and kept in chiller at 4°C
before they were analyzed.
Proximate analysis: The proximate composition such as moisture content,
protein, fat and ash were determined according to AOAC (1990)
standard method. The moisture content was determined by drying the dendeng in
a hot air oven at 100-105°C for 4 h or until a constant weight was obtained.
Protein content was calculated by converting the nitrogen content (%N x 6.25)
as determined by Kjeldahls method (AOAC, 1990). Fat
was determined using Soxhlet Extraction Method utilizing petroleum ether at
40-60°C. Ash content was determined by heating the samples in the furnace
at 550°C until the white colour of samples, while carbohydrate content was
determined by difference.
Mineral analysis: Mineral content were determined by atomic absorption
spectrophotometer (Flame Perkin Elmer 3110) method. The minerals in the samples
were brought into solution by wet digestion using 6 mL HNO3 (65%)
and 1 mL H2O2 (30%). The elements, Na, Ca, Mg, Zn, K,
Fe, Cu, were measured by AAS (Flame Perkin Elmer 3110, US). Phosphorus (P) was
determined by Vanado- Molybdate colorimetric method (Pearson
et al., 1981) using a spectrophotometer UV-160A (Shimadzu UV 160
A, Japan). The results were expressed as absorbance at 450 nm. Standard curves
were used for the determination of the elements.
Colour measurement: The surface color of shark dendeng was measured
using the Minolta Spectrophotometer (Model CM-3500d; Osaka, Japan). The equipment
was calibrated using calibration box and white calibration tile. Samples were
cut into 2x2 cm rectangle and placed in the colorimeter. The color reading includes
lightness (L*), redness (a*) and yellowness (b*) using the spectramagic software
version 2.11, 1998. L* defines lightness, a* denotes the red/green value and
b* the yellow/blue value. The L* axis has the following boundaries: L* = 100
(white or total reflection) and L* = 0 (black or total absorption). Along the
a* axis, a color measurement movement in the -a direction depicts a shift toward
green; movement depicts a shift toward red. Along the b* axis, -b movement represent
a shift towards blue; shows a shift towards yellow. Twenty five measurements
were taken from each sample.
Scanning electron microscopy examination: Shark dendeng were cut into
1x1 cm rectangle and placed in Petri Dish, then cover with aluminum foil. Make
the small hole in the cover to allow the air circulation. The samples were kept
in freezer (-20°C) for 24 h then frozen samples were freeze dried (LABCONCO,
US). Samples were then attached on the SEM stub using a double-sided cellophane
tape. The surface of the samples was coated with 30 nm thickness of gold (Sputter
Coater POLARON SC515). The area was view and micrograph using Leo Supra 50 VP
Field Emission SEM apparatus Model Carl-Ziess SMT, Oberkochen (Germany) at an
accelerating voltage of 5.00 kV.
Sensory evaluation: Dendeng used for sensory analysis were fried using
electric fryer (Model FFA 3001; ANVIL, South Africa) in cooking oil (Saji palm
oil, Malaysia) at 160°C, cooled at room temperature and then cut into 2x2
cm rectangle. Sensory evaluation was determined according to Abdullah
(2000). Panels of 30 students of Food Technology Division, Universiti Sains
Malaysia participated in the study. A 7-points hedonic scale method (7: Like
very much and 1: Dislike very much) was used to evaluate the colour, odour,
taste, bite-texture and overall acceptability.
Statistical analysis: All analyses were carried out in triplicate. Statistical
analysis was carried out using Analysis of variance and significant differences
among means was determined by the Duncans Multiple Range test using SPSS
version 11.05 was used to determine significant among means. A value of p<0.05
was used to indicate significant difference.
Proximate composition: The proximate content of shark dendeng is shown
in Table 1, there was no significant differences (p<0.05)
for proximate analysis between the samples. The different drying methods did
not affect the proximate composition of shark dendeng.
Mineral content: Table 2 shows the composition of
minerals, there was no significant difference (p<0.05) noted in minerals
except for sodium. The results showed the highest sodium recorded for sun drying
followed by vacuum drying and oven drying. Other minerals did not show significant
differences since they were present in only small amounts in the spices. The
mineral (element) contents of the samples analyzed showed that shark dendeng
are rich in sodium, calcium, magnesium, phosphorus, potassium (macro-nutrients)
and had lower quantities of iron, zinc and copper (micro-nutrients).
Color properties: Instrumental color values are based on the reflectance
of light at specific wavelengths from the shark dendeng surface. Most of the
material changes occurring during fish processing are associated with color
changes. Changes in the color of dendeng are shown in Table 3,
there were significant differences (p<0.05) in colour (L*, a* and b*) of
samples. It was observed that different drying methods affected the lightness,
redness and yellowness. Statistical analysis showed that the maximum value for
color (lightness, redness and yellowness) obtained in vacuum drying followed
by oven drying while minimum value was observed in sun drying. The lightness
sample recorded for vacuum drying was 32.19 followed with oven drying 29.97
and sun drying 28.92.
|| Proximate composition of shark dendeng
|Means within a column with the same letter are not significantly
different (p<0.05); *Determinations were based on dry weight
|| Mineral contents of shark dendeng (mg/100 g)
|Means within a column with the same letter are not significantly
Scanning electron microscopy examination: SEM was used to examine the
effects of different drying methods on the structure of shark dendeng. The micrographs
of the deep tissue are shown in Fig. 1a-d. The micrographs
indicate shark dendeng using oven and vacuum drying more decrease in compactness
of the tissue structure compare with dendeng using sun drying.
Sensory evaluation: The results of the sensory evaluation of samples
are given in Table 4, there was no significant difference
(p<0.05) noted on the color, odor, taste, texture-bite and overall acceptability
of shark dendeng. The panelist failed to detect any differences in the sensory
attributes of shark dendeng. However dendeng using oven drying method gave a
higher score among the samples.
|| Color properties of shark dendeng
|Means within a column with the same letter are not significantly
||SEM micrograph (50x) of the deep tissue of fresh shark, sun
drying dendeng, oven drying dendeng, vacuum drying dendeng (a-d, respectively)
|| Mean sensory scores of shark dendeng (n = 30)
|Means values within the same column are not significantly
Proximate composition: Proximate composition of fresh shark flesh consists
of 78.96% moisture, 19.39% protein, 0.66% fat, 0.56 ash and 0.43% carbohydrate.
According to their chemical composition sharks can be seen as high in protein
and low in fat. The low fat content makes it suitable to be processed. The dendeng
in this study was higher in moisture and fat content than those reported by
Nasran (1993). Nasran (1993) reported
that the moisture and fat content of shark fish which were dried using sun drying
were 23.8 and 0.87%, respectively. The variations of the fat content of shark
dendeng are also affected by the production seasons. Buckle
et al. (1988) reported that the proximate content of fish dendeng
were 32.4-35.4% moisture, 3.0-3.8% fat, 33.4-36.9% protein, 3.0-3.8% ash. Moradi
et al. (2009) reported the fat content of pre-fried breaded fillets
was 8.80 and 8.84% at 57.70 and 57.33% moisture content for samples pre-fried
in sunflower oil and palm olein, respectively. The lipid oxidation and protein
denaturation resulted in a decrease in nutritive value. As the amount of lipid
increased the amount of water falls in almost linear proportion (Aitken
and Connell, 1979).
Mineral content: There was no significant difference (p<0.05) noted
in minerals except for sodium. The samples were probably not homogeneous due
to the uneven absorption of minerals and spices; the minerals and spices settled
at the bottom of the container; therefore samples at the bottom might absorb
more minerals and spices and since sodium was present in a relatively high amount,
the location of the samples significantly affect the sodium content. Minerals
have been reported to show significant variations among fish species (Lal,
1995). The Na content of shark dendeng ranging from 2257.72 to 2265.55 mg
100 g-1. This value is higher than emu jerky reported by Pegg
et al. (2006). According to Gokoglu et al.
(2004), the Na content of cooked rainbow trout ranged from 335.54-607 mg
kg-1. Several studies have indicated that the concentration of trace
minerals in fish is influenced by a number of factors such as seasonal and biological
differences (species, size, dark/white muscle, age, sex and sexual maturity),
food source and environment (whater chemistry, salinity, temperature and contaminants)
(Badsha and Sainsbyry, 1978; Farmer
et al., 1970; Lal, 1995).
Mineral components such as sodium, potassium, magnesium, calcium, iron, phosphorus
and iodine are important for human nutrition (Erkan and
Ozkan, 2007). The main functions of essential minerals include skeletal
structure, maintenance of colloidal system and regulation of acid-base equilibrium.
Minerals also constitute important components of hormones, enzymes and enzyme
activator (Belitz et al., 2001).
Color properties: The temperature of sun drying was around 27-29°C
at the time of drying dendeng and this makes the color of dendeng lighter than
oven drying (60°C) and vacuum drying (60°C). The color of cured meat
products is extremely critical component mainly because of its influence on
consumer preference (Moretti et al., 2009). Oven
dried foods usually are darker, more brittle and less flavorful than foods dried
by a dehydrator. The differences in the accumulated water loss and uptake of
NaCl in both split fish and fillets could probably be explained by the unrestrained
rigor contractions occurring during salting. Such contractions may have reduced
the light transparency through highly overlapped actin and myosin filaments
(Lauritzsen et al., 2004). According to Konieczny
et al. (2007), the range of L*, a* and b* value of beef jerky at
various drying time is 30.66-33.44, 7.82-13.42 and 4.10-4.76 respectively. Brennan
(2006) concluded that when the food pieces are rehydrated, their color and
texture may be significantly inferior to those of the fresh material.
It is difficult to measure the color of heterogeneous products (Louka
et al., 2004). The color attributes of dendeng were influenced by
brown sugars, tamarind, coriander and roots of galangal which were used in the
formulation. Drying also was responsible for a severe deterioration in the quality
of food and especially fish, particularly with respect to their color. Although
the maillard reaction is an obvious candidate to explain the yellow-brown color
after processing, the low amounts of reducing sugar particularly at the beginning
of processing makes this hypothesis less convincing (Louka
et al., 2004). In some places (Hong Kong) the dark color and rancid
odor of cured fish is a sign of quality (Bligh et al.,
1988). The maillard reaction, in combination with oxypolimerisation of unsaturated
fish oils, was responsible for darkening, toughening and the unpalatable, bitter
flavor associated with lengthy drying process and storage of dehydrated fish
Scanning electron microscopy examination: SEM photograph shows that
different drying methods affect the compactness of the tissue structure. The
fibers become more disrupted. Shark dendeng using sun drying had a compact,
coherent structure with hardly any spaces between the fibers. Decreased protein
solubility indicates some damage to the proteins in the dried product and this
is further echoed in the dehydration behavior of the dried fish.
Sensory evaluation: Descriptive analysis is one of the most useful tests
for sensory profiling and uses trained panels to detect and rate the intensities
of sensory attributes in a product (Chambers and Wolf, 1996;
Grosso et al., 2008). The average score of sensory
evaluation is more to the score of 5 which means that Shark dendeng is accepted
by panelist. Bligh et al. (1988) concluded the
major effect of lipid degradation is development of aesthetically unappealing
odors and flavors while the effect of oxidative rancidity on nutritive quality
of fish, especially in terms of protein availability, is debatable. Different
methods of heating can undoubtedly give rise to differences in odors and flavors;
in particular, commercial heat sterilization produces on overall character unlike
that produced by other forms of heating. This sensory evaluation constituted
subjective measuring characteristic of products (Abdullah,
Results indicate that the shark dendeng analyzed was high in protein and mineral
content. The results also demonstrated that different drying methods affect
color but not for proximate composition, mineral content and sensory analysis.
Overall, it can be concluded that oven drying is the most suitable method for
drying shark dendeng.
This research was supported under the short term research grant Universiti
Sains Malaysia 305/PTEKIND/636055 and Research University grant 1001/PTEKIWD/815032.
1: Abdullah, A., 2000. Panduan Makmal Penilaian Sensori. Universiti Kebangsaan Malaysia, Bangi, Malaysia, ISBN: 967-942-512-6.
2: Aitken, A. and J.J. Connell, 1979. Fish. In: Effects of Heating on Foodstuffs, Priestley, R.J. (Ed.). Applied Science Publisers, London, pp: 219-254.
3: Ali, A., R. Ali, M. Nasir and I. salleh, 1999. Management of Shark Fisheries in Malaysia. In: Case Studies of the Management of Elasmobranch Fisheries, Shotton, R. (Ed.). Food and Agriculture Organization of the United Nations, Rome, Italy, ISBN: 92-5-104291-8.
4: Arifudin, R., 1993. Dendeng Ikan. In: Kumpulan Hasil-hasil Penelitian Pasca Panen Perikanan, Cholik, F. (Ed.). USAID/FEDP, Jakarta, ISBN: 979-8186-31-1, pp: 114-117.
5: AOAC., 1990. Official Methods of Analysis. 15th Edn., Association of Official Analytical Chemists, Washington, DC., USA., pp: 200-210.
6: Belitz, H.D., W. Grosch and P. Schieberle, 2001. Lehrbuch der Lebensmittelchemie, Aufl. Springer Verlag, Berlin Heidelberg, New York.
7: Bligh, E.G., S.J. Shaw and A.D. Woyewoda, 1988. Effects of Drying and Smoking on Lipids of Fish. In: Fish Smoking and Drying, Drying, Burt, J.R. (Ed.). Elsevier Applied Science, London, New York, pp: 41-52.
8: Brennan, J.G., 2006. Evaporation and Dehydration. In: Food Processing Handbook, Brennan, J.G. (Ed.). Wiley-VCH Verlag, GmbH and Co., Weinheim, Germany, pp: 71-121.
9: Buckle, K.A., H. Purnomo and S. Sastrodiantoro, 1988. Stability of Dendeng. In: Food Preservation by Moisture Control, Seow, C.C. (Ed.). Elsevier Applied Science, London, New York, pp: 137-148.
10: Badsha, K.S. and M. Sainsbyry, 1978. Aspects of the biology and heavy metal accumulation of ciliata mustela. J. Fish Biol., 12: 213-220.
11: Calicioglu, M., J.N. Sofos, J. Samelis, P.A. Kendall and G.C. Smith, 2002. Destruction of acid-and non-adapted Listeria monocytogenes during drying and storage of beef jerky. Food Microbiol., 19: 545-559.
12: Chambers, E. and M.B. Wolf, 1996. Sensory Testing Methods. 2nd Edn., American Society for Testing and Materials, West Chonshohocken, PA, USA, ISBN: 978-0-8031-2068-6.
13: Cutting, C.L., 1962. The Influence of Drying, Salting and Smoking on the Nutritive Value of Fish. In: Fish in Nutrition, Heen, E. and R. Kreuzer (Eds.). Fishing News (Books), London, pp: 161-79.
14: Pearson, D., H. Egan, R.S. Kirt and R.C. Suryer, 1981. Pearson`s Chemical Analysis of Foods. 8th Edn., Churchill, Edinburgh, pp: 432-506.
15: Erkan, N. and O. Ozden, 2007. Proximate composition and mineral contents in aqua cultured sea bass (Dicentrarchus labrax), sea bream (Sparus aurata) analyzed by ICP-MS. Food Chem., 102: 721-725.
CrossRef | Direct Link |
16: Farmer, G.J., D. Ashfield and H.S. Samant, 1970. Effects of zinc on juvenile atlantic salmon (Salmon Salar): Acute toxicity, food intake, growth and bioaccumulation. Environ. Pollut., 19: 103-117.
17: Fellows, P. and A. Hampton, 1992. Fish and Fish Products. In: Small-Scale Food Processing: A Guide for Appropriate Equipment, Fellows, P. and A. Hampton (Eds.). Intermediate Technology Publications, London.
18: Gokoglu, N., P. Yerlikaya and E. Cengiz, 2004. Effects of cooking methods on the proximate composition and mineral contents of rainbow trout (Oncorhynchus mykiss). Food Chem., 84: 19-22.
CrossRef | Direct Link |
19: Grosso, N.R., A.V.A. Resurreccion, G.M. Walker and M.S. Chinnan, 2008. Sensory profiles and hexanal content of cracker-coated and roasted peanuts stored under different temperatures. J. Food Process. Preservat., 32: 1-23.
20: Konieczny, P., J. Stangierski and J. Kijowski, 2007. Physical and chemical characteristics and acceptability of home style beef jerky. Meat Sci., 76: 253-257.
21: Lack, M. and G. Sant, 2006. World shark catch, production and trade 1990-2003. Traffic Oceania. Australian Government, Department of The Environment and Heritage. http://www.environment.gov.au/coasts/publications/trends-shark.html.
22: Lal, S.P., 1995. Macro and Trace Elements in Fish and Shellfish. In: Fish and Fishery Products: Composition, Nutritive Properties and Stability, Ruiter, A. (Ed.). CAB International, Wallingford, UK., pp: 187-214.
23: Lauritzsen, K., L. Akse, A. Johansen, S. Joensen, N.K. Sørensen and R.L. Olsen, 2004. Physical and quality attributes of salted cod (Gadus morhua L.) as affected by the state of rigor and freezing prior to salting. Food Res. Int., 37: 677-688.
24: Leistner, L., 1987. Shelf Stable Products and Intermediate Moisture Foods Based on Meat. In: Water Activiti: Theory and Application to Food, Institute of Food Technologists, Rockland, L.B. and L.R. Beuchat (Eds.). Marcel Dekker Inc., New York, pp: 295-323.
25: Louka, N., F. Juhel, V. Fazilleau and P. Loonis, 2004. A novel colorimetry analysis used to compare different drying fish processes. Food Control, 15: 327-334.
CrossRef | Direct Link |
26: Moradi, Y., J. Bakar, S.H.S. Muhamad and Y.C. Man, 2009. Effects of different final cooking methods on physico-chemical properties of breaded fish fillets. Am. J. Food Technol., 4: 136-145.
CrossRef | Direct Link |
27: Moretti, V.M., F. Bellagamba, M.A. Paleari, G. Beretta, M.L. Busetto and F. Caprino, 2009. Differentiation of cured cooked hams by physico-chemical properties and chemometrics. J. Food Qual., 32: 125-140.
28: Nasran, S., 1993. Pengolahan Dendeng Cucut. In: Kumpulan Hasil-hasil Penelitian Pasca Panen Perikanan, Cholik, F. (Ed.). USAID, FEDP, Jakarta, Indonesia, ISBN: 979-8186-31-1, pp: 254-255.
29: Pegg, R.B., R. Amarowicz and W.E. Code, 2006. Nutritional characteristics of emu (Dromaius novaehollandiae) meat and its value-added products. Food Chem., 97: 193-202.
30: Peranginangin, R., 1993. Dendeng Tawes (Puntius javanicus). In: Kumpulan Hasil-hasil Penelitian Pasca Panen Perikanan, Cholik, F. (Ed.). USAID/FEDP, Jakarta, Indonesia, pp: 118-119.
31: Schubring, R., 2007. DSC measurements on sharks. Thermochim. Acta, 458: 124-131.
32: Troftgruben, J. and M. Keith, 1984. Drying food. University of Illinois at Urbana-Champaign. http://www.aces.uiuc.edu/vista/html_pubs/DRYING/dryfood.html#toc.
33: Yapar, A., S. Atay, A. Kayacier and H. Yetim, 2006. Effects of different levels of salt and phosphate on some emulsion attributes of the common carp (Cyprinus carpio L., 1758). Food Hydrocolloids, 20: 825-830.
34: Zakhia, N., 2002. Adaptation of a Quality Assurance Methodology to Traditional Fish Drying in Mali. In: Food Safety Management in Developing Countries, Hanak, E., E. Boutrif, P. Fabre and M. Pineiro (Eds.). CIRAD, FAO, Montpellier, France, ISBN: 92-5-004787-8, pp: 121-123.