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V. ANIMAL
DERIVATIVES
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17
Using Mixed Starter Cultures for
Thai Nham
Pairote Wiriyacharee
Nham is traditionally made from fresh lean pork that is trimmed;
minced; mixed thoroughly with salt, potassium nitrate, cooked rice
and seasonings; and packed in either banana leaves (1) or cylindrical
plastic bags (21. Nham production in Thailand depends on chance
contamination with wild organisms lactic acid bacteria and nitrate-
reducing bacteria. It is a long process; generally the fermentation lasts
3 to 5 days depending on the season. When nham is packed into
cylindrical plastic bags, which exclude air, and is held in the bags during
fermentation, a microenvironment is selected for microorganisms that
are not only salt tolerant but can also grow in the absence of air. In
these gram-positive fermentative types of microorganisms, lactic acid
bacteria are predominant (3,4~. The fermentable carbohydrates are
used by those organisms to produce organic acids, mainly lactic acid,
that contribute to a variety of flavors and textures. The nham finally
develops approximately 1.0 percent total acidity as lactic acid and the
pH is 4.3 (51.
MARKETING PROBLEMS
Problems in marketing traditional nham include its short shelf life
and high price and the intensive labor required for its production. It
has high energy costs if kept under refrigeration in the marketplace.
Additionally, the manufacturers have a heavy exposure to risk of losing
a large stock through a process failure. Pork meat is quite expensive,
and the raw material cost is increasing more quickly than the selling
price..In addition, large-scale production of sham has the problem of
its short storage life. A longer shelf life is required so that the nham
can be distributed to the marketplace. Therefore, the nham market
121
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122
FERMENTED FOODS
needs the product to have consistent quality, safety, and longer shelf
life. The nham should stay fresh and not turn rancid or develop an off-
flavor or change in color when it is in the marketplace.
On the other hand, nham production depends on natural fermenta-
tion; the product quality therefore varies from batch to batch. The
shelf life of nham is quite short approximately a week at Thai ambient
temperatures. Chilled conditions can extend the shelf life, but normally
the product is stored at ambient temperatures. The sanitation conditions
of the processing are also poor because of a lack of knowledge and
technology. The initial native lactic acid bacteria may be insufficient
to bring about the normal ripening process. This may allow pathogenic
bacteria to grow before lactic acid bacteria occur, resulting in the
possibility of food poisoning. Since most nham is consumed without
further cooking, proper fermentation is of paramount importance in
ensuring the products safety.
Somathiti (6) found that the initial coliform count was high in nham
approximately 107 cells per gram—and decreased to 102 cells per gram
on the fifth day. An investigation of Salmonella in nham in the Bangkok
market showed that it was present in 56 (or 12 percent) of 450 samples.
In nham produced in Chiang Mai, Chiang Rai, and Ubonratchathani,
Salmonella was found in 25 percent, 42 percent, and 11 percent,
respectively, of the total samples. However, Shigella sp. was not found
in nham bought from any of these markets.
Thus, the nham process needs to be studied to improve product
quality, to give a more uniform standard quality, and to develop the
technology for applying of the process on an industrial scale- before
launching extensively in the Thai and export markets.
NHAM DEVELOPMENT
In developing of an improved nham process, not only is there a need
for the knowledge of modern scientific discoveries and technological
developments but also the knowledge of consumers' needs and wishes.
The final product must be acceptable to consumers. A unified system
is required that combines scientific and consumer information for
systematic development of the nham product.
Effect of Starter Cultures
In our research mixed starter cultures and the carbon sources used
in nham formulation were important factors in determining product
quality (71. The starter cultures had a potential to make a good nham
quality. Cooked rice, a carbon source for lactic acid production by
starter cultures, was an important factor in nham fermentation.
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USING MIXED STARTER CULTURES
123
The addition of L. plantarum to the nham mass accelerated very
distinctly the decrease in the pH of nham. Consequently, the firmness
and color developed, influenced directly by acid production. Those
findings were in agreement with the work of many researchers (8-124.
P. cerevisiae increased the firmness later during the last period of
fermentation. The optimum growth of P. cerevisiae is at pH 5.0 (13),
the conditions during this period allow good growth and acid production
causing the increase in firmness. L. plantarum inoculation had a very
distinct effect in terms of firmness development when it was used
together with P. cerevisiae.
M. varians in the nham system significantly reduced nitrate to nitrite
during the initial fermentation and increased the tristimulus values at
the beginning of fermentation. L. plantarum then continued to intensify
the color. This finding agreed with the work of Deibel et al. (141; they
reported that nitrate-reducing activity generally occurred during the
first 2 to 16 hours, while acid production was initiated after 8 to 16
hours. It was clear that it was important to ensure the nitrate-
reducing activity of the M. varians that took place prior to its
inhibition by the growth of lactic acid bacteria. The nitrite formed was
decomposed spontaneously in acid surroundings into nitric oxide,
which subsequently reacted with myoglobin to form a pink compound-
nitrosomyoglobin. So the residual nitrate in the nham system reduced
quickly when acid was produced. The rate of nitrosomyoglobin forma-
tion increased with falling pH, and this reaction takes place best in the
pH range of 5.0 to 5.5 (15) and was therefore accelerated by L.
plantarum. The L. plantarum inoculation had a very distinct effect in
terms of color development when it was used together with M. varians.
On the other hand, L. brevis seemed to be a poor lactic acid producer
and decreased the color of the product and also produced gas, which
decreased the firmness of the nham.
Microbiological Quality
The starter cultures L. plantarum and P. cerevisiae increased during
the initial fermentation and were highest on the third day of fermentation
with 1-06 to 109 cfu/g-' (colony forming units) and then decreased slowly
during the later period of fermentation. In the nham sample, on
the other hand, the M. varians decreased during the fermentation
approximately 2 log cycles by the third day. The total bacterial count
was related to the starter cultures counts, but there was a little higher
count of approximately 1 log cycle. No yeasts or molds were detected
in the finished nham.
The pathogenic bacteria, including Enterobacteriaceae and Staphylo-
coccus aureus, decreased during fermentation. In the nham fermented
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124
FERMENTED FOODS
for 3 days the Enterobacteriaceae and S. aureus counts were 102 and
103 cfu/g-', respectively.
FERMENTATION DEVELOPMENT
In Thailand large amounts of cooked rice are added to the raw nham
mixture. It is degraded only slowly and may result in growth of
undesirable organisms during fermentation, particularly at high ripening
temperatures. Glucose is therefore added to the cooked rice. This
ensures a sufficiently rapid initial growth and nitrate reduction by M.
varians and rapid later pH drop, without inhibiting the chemical
reactions necessary for the development of firmness and desired color.
Cooked rice and glucose had no effect on pH reduction during nham
fermentation. As the fermentation time increased, the pH decreased.
The pH dropped rapidly after 18 hours of fermentation at 30°C, 43
percent relative humidity with pH 5.1. The beginning of cooked rice
reduction coincided with the increase in reducing sugars after 12 hours
of fermentation. The reducing sugars declined after another 12 hours
of fermentation, and this coincided with the decrease in pH. This
indicated that if both cooked rice and glucose were used at high levels
(10 percent and 1 percent, respectively) at the beginning of the
fermentation, the pH dropped more slowly than if lower levels were
used (8 percent cooked rice and 0.5 percent glucose). Increasing the
amount of cooked rice, on the other hand, reduced the firmness of the
nham. There was an increase in weight loss at the high level of glucose.
There were 1.0 to 1.3 percent reducing sugars and 2 to 3 percent
cooked rice in the finished nham, and this residual carbohydrate could
be used by the undesirable organisms during storage. Therefore, the
carbon source levels in nham should be reduced.
When the glucose level was maintained at 0.5 percent but the level
of cooked rice increased, a longer period was required to attain
adequate fermentation end products (16~.
It was also found that 6 percent cooked rice with 0.5 percent glucose
in the nham formulation, when fermented with starter cultures at 30°C
and 97 percent relative humidity, caused rapid pH reduction. Acid
production was good, firmness and color development were satisfac-
tory, and the product was microbiologically safe.
The rate of fermentation and the ultimate pH of nham are directly
influenced not only by the specific formulation but also by the
processing conditions. Since the safety and quality of nham depend
on the rate and extent of acid production, a thorough understanding
of these environmental parameters is essential for total control of the
product. In our research, higher temperatures increased the rate of
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USING MIXED STARTER CULTURES
125
fermentation, reduced pH, and improved firmness and color develop-
ment. The initial temperature of nham was very important in deter-
mining the final product. The achievement of lowering pH was affected
by the initial product temperature and the time at that temperature.
For experimentation with frozen meat, the temperature of nham
mixtures was 15°C; with fresh meat the temperature was 26°C. The
pH dropped more quickly in nham made with fresh meat than with
frozen meat.
Nham made using frozen meat was fermented at 30°C and 97 percent
relative humidity. It took 3 days to reduce the pH to 4.3 to 4.4, while
the nham using fresh meat fermented under the same conditions needed
only 2 days to reduce the pH to 4.1.
Nham is usually held at a high temperature during processing to
ensure rapid fermentation, but this can also accentuate the growth of
pathogens. In addition, nham is usually eaten without further cooking
by the consumer. These conditions make strict control of the product
essential. Although proper sanitation, employee hygiene, and the
control of raw materials definitely reduce contamination, ultimate
control of product safety must be inherent in the formulation and
process. The addition of starter cultures can provide sufficient
microbial numbers to ensure numerical dominance over the natural
flora, including pathogens, and in combination with the proper proc-
essing controls can guarantee the safety and quality of the final nham.
Shelf Storage
Nham is usually sold in Thai markets at ambient temperatures (20°
to 30°C). It was found that nham prepared using the improved
conditions described here when stored at these temperatures had a
shelf life of 9 to 11 days while commercial nham usually has a
shelf life of only 3 days. In supermarkets nham is stored at chilled
temperatures (5°C), and it can be exported at low temperatures (1°C).
Additionally, consumers usually store the product in a household
refrigerator (10°C). It was found that shelf life was extended to 63 to
103 days at storage temperatures of 1° to 10°C. The higher the storage
temperature, the greater the change in nham quality.
Sensory Evaluation
Nham fermented with 103 cfu/g M. varians, 103 cfu/g L. plantarum,
and 106 cfu/g P. cerevisiae with 6 percent cooked rice and 0.5 percent
glucose at 30°C, 97 percent relative humidity for 3 days, was accepted
by the trained panel, with an overall acceptability mean ideal ratio
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126
FERMENTED FOODS
score of 0.95+0.01. For quality degradation during storage, the overall
acceptability of the product depended on sourness and off-flavor
detected in the sample.
Nham using fresh meat fermented at a low temperature was given
a higher than ideal score for sourness. However, the newly developed
formulation for nham was superior to that of the commercial nham.
The consumer panel was also used to determine the effect of reducing
the fermentation time from 3 days to 2 days. The results showed that
only visual texture was significantly different from the ideal product.
In consumer testing the majority of the consumers (90 percent)
accepted the developed nham in terms of sourness, spiciness, and
saltiness.
In conclusion, the development of traditional fermented pork sau-
sage, nham, was very successful in that the product was developed by
using mixed starter cultures and had a very high quality in terms of
consistency, microbiological safety, and longer shelf life. It was also
acceptable by the target consumers. The product could be processed
in a simple plant and with equipment that was available at the fermented
meat factory with only an improvement in the technology of culture
preparation and temperature control. In addition, the developed nham
had a longer shelf life than commercial nham. The product, therefore,
could be shipped from the cottage industry producers in the north to
all provinces in Thailand, particularly to Bangkok, and also gave the
potential for overseas shipment if refrigeration is used.
REFERENCES
1. Adams, M. R. 1986. Progress in Industrial Microbiology. Vol.
23. Microorganisms in the Production of Food. New York: Elsevier
Science Publishers.
2. Pakrachpan, L. 1981. Fermented Food Industry. (In Thai).
Biotechnology Department, Faculty of Agro-Industry, Kasetsart Uni-
versity, Thailand.
3. Comenuanta, J. 1966. Thai Fermented Pork. I. Microbiology of
the Thai Fermented Pork. B.Sc. thesis, Kasetsart University, Thailand.
4. Techapinyawat, S. 1975. Microbial Study During Fermentation
of Thai Fermented Pork. M.Sc. thesis, Kasetsart University, Thailand.
5. Wiriyacharee, P. 1990. The Systematic Development of a Con-
trolled Fermentation Process Using Mixed Bacterial Starter Cultures
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USING MIXED STARTER CULTURES
127
for Nham, a Thai Semi-dry Sausage. Ph.D. thesis, Massey University,
New Zealand.
6. Somathiti, S. 1982. A Survey of Some Enteropathogenic Bacteria
in Thai Fermented Pork. M.Sc. thesis, Kasetsart University, Thailand.
7. Wiriyacharee, P., M. D. Earle, D. J. Brooks, G. Page, and L.
Rujanakraikarn. 1991. Identifying the important factors affecting the
characteristics of nham. Food 21 ~ 1 ~ :48-58.
8. Klemet, J. T., R. G. Cassens, and O. R. Fennema. 1973. The
association of protein solubility with physical properties in a fermented
sausage. Journal of Food Science 38:1128-1131.
9. Klemet, J. T., R. G. Cassens, and O. R. Fennema. 1974. The
effect of bacterial fermentation on protein solubility in a sausage model
system. Journal of Food Science 39:833-835.
10. Klettner, P. G., and W. Rodel. 1978. Testing and controlling
parameters important to dry sausage ripening. Fleischwirtschaft 58:57-
60, 63-64, 66.
11. Klettner, P. G., and P. A. Baumgartner. 1980. The technology
of raw dry sausage manufacture. Food Technology Australia 32:380-
384.
12. Palumbo, S. A., L. L. Zaika, J. C. Kissinger, and J. L. Smith.
1976. Microbiology and technology of the pepperoni process. Journal
of Food Science 41: 12-17.
13. Buchanan, R. E., and N. E. Gibson. 1974. Bergey's Manual of
Determinative Bacteriology. Baltimore, Md.: Williams and Wilkins
Co.
14. Deibel, R. H., C. F. Niven, and D. D. Wilson. 1961. Microbiology
of meat curing. III. Some microbiological and related technological
aspects in the manufacture of fermented sausages. Applied Microbiol-
ogy 9:156-165.
15. Niinivaara, F. P. 1955. The influence of pure bacterial cultures
on aging and changes of the red color of dry sausage. Thesis, University
of Helsinki, Finland, Acta Agralia Finnica No. 84.
16. Pezacki, W. 1974. Technological control of dry sausage ripening.
VIII. Effect of pre-drying on the dynamics of carbohydrate changes
taking place at the beginning of ripening. Fleischwirtschaft 58: 124- 126,
129-132, 135.
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18
Starter Cultures in Traditional
Fermented Meats
Margy Woodburn
Fermentation traditionally offers an easy and low-energy preserva-
tion method for meats that results in distinctive products that have an
important part in the diet of people making them. Such fermented
meats contribute both nutritional value and pleasure to meals. How-
ever, products are not the same from time to time. Indeed, the product
may spoil, cause illness due to pathogenic microorganisms or their
toxins, and even become lethal due to botulinum toxin production if
the normal beneficial microbial flora do not multiply as usual. To
prevent these problems, the use of starter cultures has become
commonplace in many countries, including developing countries.
One example of such fermented meat is nham, a traditional Thai
sausage. Nham is made by mixing salt (3 percent by weight) and garlic
with ground lean pork. Nitrate and nitrite salts also are added in
commercial production. The mixture is then wrapped in a banana leaf
or stuffed in cellulose tubing. Fermentation is at ambient temperature
(about 30°C in Thailand) for 3 to 4 days, after which it remains in good
condition for only 1 to 2 days without refrigeration. Since nham is
frequently eaten raw, it is important that pathogenic bacteria be killed
as well as that botulinum toxin and staphylococcal enterotoxins are
not produced. Since hogs are frequently infested with Trichinella
spiralis, these larvae should not be viable.
A study was conducted on nham made with and without the addition
of one of two levels of a commercially available dry starter culture
preparation (Griffith Laboratories, Ltd., Thailand) (11. Portions in
polyethylene film bags were inoculated, sealed, and incubated at 30°C.
The inoculum was S. aureus (a mixture of three enterotoxin-producing
strains) and E. cold (three strains). Microbial numbers, pH, and titrable
acidity were determined at intervals during the fermentation. The meat
used was from two hogs that had been experimentally infected with
128
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STARTER CULTURES IN TRADITIONAL FERMENTED MEATS 129
trichinae at weaning; viable trichinae were determined at 24-hour
intervals.
S. aureus was able to multiply (10 x ~ and remain viable only in the
control inoculated samples. E. cold was not detected at 96 hours in the
sausage made with the higher level of starter (1.5 percent by weight)
and had decreased greatly in products made with the 0.75 percent
level. The use of the higher level of starter preparation resulted in loss
of infectivity of the trichinae larvae, although further research is
necessary to confirm this effect. The addition of starter culture resulted
in more rapid acid production and slightly lower end-point pH.
It is important to keep in mind that natural fermentations are difficult
to replicate in other settings. For example, the meat mixture for nham
is traditionally wrapped in small banana leaf packets. The leaves
contribute to the surface flora of the sausage, which no doubt changes
the fermentation pattern. Flora of work surfaces and of the pork itself
may be different.
Drying often follows fermentation of similar meat products to provide
for long-term preservation. Dendeng ailing, Indonesian seasoned beef
that has only a traditional short fermentation period before drying,
was found to have a lower pH and total gram-negative bacteria,
staphylococci, and E. cold counts when prepared with a starter culture
of Lactobacillus plantarum than in the traditional manner. Those with
a starter culture dried more rapidly at 50°C and had lower water
activities (2~.
The effectiveness of lactic acid bacteria in suppressing the multiplica-
tion of undesirable microorganisms is largely attributed to the produc-
tion of organic acid. However, additional factors include the production
of bacteriocins and hydrogen peroxide. More general effects include
competition for essential nutrients.
To maximize the quality, reproducibility, and safety of the product,
strains of bacteria are selected based largely on the qualities of self-
stability and viability as used, rapid acid production, and desirable
product qualities. As in the starter culture preparation used for nham,
strains of Lactobacillus and Pedicoccus are the most common (3,44.
The compatibility of strains is important, which includes resistance to
or lack of production of bacteriocins. In addition to tolerance to the
salt and nitrite levels of the mixture, the culture must be active in the
temperature range used for the fermentation. The product must have
the expected palatability characteristics. No harmful compounds may
be produced. These same attributes can be more efficiently arrived at
through the application of the techniques of molecular biology.
The success of traditional fermentations depends on the complex
interaction of the food components, the natural flora of the ingredients,
and the surfaces in contact with the food, atmosphere, and ambient
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20
Fish-Meat Sausage
Sam Angel and Eliana Mora P.
Fermentation allows the preservation of foods of vegetable or animal
origin so that they can be stored and shipped at ambient temperatures
and used without further preparation. Lowering the pH is the ideal
way to process foods for use in less-developed regions of the world. lPro-
teins, which are needed for growth and development, especially in
children, are often in short supply in famine-ravished areas and poor
underdeveloped countries. In many areas of the world there are fre-
quently underutilized sources of muscle proteins that could provide excel-
lent starting materials for preservation by fermentation or acidulation.
In Germany a popular noncooked fermented sausage (rohwurst) has
been produced from beef and pork for many years (if. Lactic acid
produced by fermentation lowers the pH of the meat to its gel point,
which causes it to firm (2~. Further drying increases firmness and
reduces water activity. The low pH prevents the development of
pathogenic bacteria (3,4), and lower water activity prevents microbial
growth and spoilage (5~.
The pH can also be lowered by using glucono-delta-lactone, which
produces gluconic acid upon contact with water, or using citric or
lactic acids. Encapsulated acids release acid more slowly and prevent
texture breakdown. In the encapsulation process solid acid granules
are coated with hydrogenated vegetable oils or diglycerides, which
require heat to release the acid. Graves (6) patented a new water-
soluble low-temperature release coating for citric acid. The use of acids
directly saves fermentation time, and myofibrillar protein "elation can
take place within hours after mixing the meat with acids.
RESULTS AND DISCUSSION
Rohwurst beef-pork sausage served as a model for the development
of a similar product from underutilized fish, meat trim, and poultry. A
sausage-type product allows the combination of muscle from various
40
OCR for page 141
FISH-MEAT SAUSAGE
141
sources. The object was to use underutilized muscle protein sources,
especially fish, to produce a nutritious and acceptable dry sausage.
The product was to be eaten out of hand and thus help to alleviate
protein deficiency, especially in children.
Underutilized or inexpensive fish, fish tissue residue from filleting
operations, red meat trim, and spent layer hens were the raw materials
used in Israel, the United States, and Costa Rica to produce fermented
dry sausages.-
Cod or haddock frames (i.e., skeletons with residual tissue) were
mechanically deboned, and the flesh mince was mixed in equal
proportions with either beef or pork trim or mince from mechanically
deboned spent layer hens. The batters were mixed with salt, sugar,
spices, nitrite, and Lactobacillus or Pediococcus starter cultures and
stuffed into 20-mm collagen casings. They were fermented at 22°C for
up to 24 hours depending on pH development.
Control sausages consisted of beef and pork only. The pH of the
fish-meat sausages fell to 5.1 to 5.4, while the pH of the beef-pork
controls fell to 5.0 to 5.1. Drying took 1 week, at which time the fish-
meat sausages contained 17 to 30 percent moisture and the beef-pork
controls 25 to 30 percent. Fat content was 17 percent in all the batters
at the outset. After drying it was 21 to 30 percent for the fish-meat
sausages and 29 to 30 percent for the beef-pork. The fat contents
for the fish-meat sausages were significantly lower than for similar
commercial sausages in Germany.
Three panel sessions were held. Between 25 and 70 persons partici-
pated in each session. All the sausages were found acceptable, as
shown in Figure 1. A minority of the participants commented on a
fishy taste, especially for the fish-chicken sausages.
In a 3-year cooperative project (7) the flesh of pond-raised silver
carp and sea fish in Israel and Costa Rica was deboned and washed.
It was then used to prepare fermented or acidulated dry sausages with
pork or beef trim or whole-muscle turkey bottom meat. All-fish
sausages and 25 to 50 percent fish-meat sausages were prepared.
Fermentation was induced with Pediococcus plus Lactobacillus starter
cultures. Acidulation was carried out by adding encapsulated low-
temperature-release citric or higher-temperature-release lactic acids.
The pH usually fell to 4.85, except for the fish-turkey sausages where
the pH did not fall below 5.0. Starting and final pHs were similar for
the fermented and the acidulated sausages, but the pHs for the
acidulated sausages fell to their final level within a few hours as
compared to several times that for the fermented sausages. Thus, the
acidulated blend had a head start on drying. The entire process of pH
reduction, firmness development, and subsequent drying was shortened
considerably for the acidulated fish-meat sausages.
OCR for page 142
142
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FISH-MEAT SAUSAGE
143
Citric acid was found to reduce the pH at lower concentrations than
lactic acid, but in 50 percent fish-meat sausages with 0.65 percent citric
acid, which was the maximum concentration used, the pH could
not be lowered sufficiently. Lactic acid could be used at higher
concentrations to lower the pH when necessary. A pH of 4.80 to 4.85
helped the drying process, and lactic acid was of greater benefit in this
respect than citric acid.
The experimental sausages were evaluated on a kibbutz in Israel
and in 110 households in Costa Rica. The results of the evaluations in
both countries were encouraging. In Israel the scores were 5 to 5.6
out of a maximum of 9 for the 50 percent fish sausage. Over 80 percent
of the tasters in Costa Rica gave positive responses to the sausages
that contained fish (Figure 24. The highest social class was least
enthusiastic about the sausages. In Costa Rica the population is not
accustomed to eating nonheated sausages. The evaluators therefore
either cooked or fried them before eating. The organoleptic tests are
consequently being repeated with new instructions.
RECOMMENDATIONS
To minimize production costs, these sausages should contain a
minimum of 50 percent fish (from frames or other underutilized sources
such as by-catch and trash fish).
Acidulation produced sausage with a good texture, and it can be
recommended as a procedure to reduce processing time.
To improve acceptability and nutritional value as well as reduce
costs and ensure quality, more research needs to be done on:
· flavor formulation and colorants to meet local population prefer-
ences;
· reduction of fat content and introduction of new sources of fat;
· inclusion of soy or other vegetable proteins;
· chemistry and histochemistry of the acidulation and drying pro-
cesses to improve the efficiency of these steps;
· the effect of replacing nitrite on the wholesomeness of the product
Laccording to Leistner (8), spores of bacilli and clostridia do not grow
when there is a sufficiently low pH and low water activity]; and
· protein efficiency feeding for young children and adolescents.
These products should undergo taste tests for acceptability in other
Latin American countries as well as other areas with low protein
intake.
OCR for page 144
144
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FISH-MEAT SAUSAGE
REFERENCES
145
1. Klettner, P. G., and P. A. Baumgartner. 1980. The technology of
raw dry sausage manufacture. Food Technology in Australia 32:380.
2. Rodel, W., K. Krispien, and L. Leistner. 1979. Measuring water
activity of meat and meat products. Fleischwirtschaft 59:649.
3. Baird-Parker, J. and B. Freame. 1967. Combined effect of water
activity, pH and temperature on growth of Clostridium botulinum from
spore and vegetative cell inocula. Journal of Applied Bacteriology
30:420.
4. Collins-Thompson, D. L., B. Krusky, and W. R. Usborne. 1984.
The effect of nitrite on the growth of pathogens during the manufacture
of dry and semi-dry sausages. Canadian Institute of Food Science and
Technology Journal 17:102.
5. Labots, H. 1981. Aw und pH-wert konzept fur die enteilung
von fleischerzengnissen in verberbliche und lagerfahige produkte.
Fleischwirtschaft 61:1.
6. Graves, R. 1988. Sausage fermentation: New ways to control
acidulation of meat. The National Provisioner.
7. Angel, S., and E. P. Moral 1991. The development of shelf
stable fish, poultry and other meat products through energy saving
fermentative processes. Final report, Project DPE 55446536035, sub-
mitted to USAID, Washington, D.C.-U.S. Cooperative Development
Research Program Between Israel and Costa Rica. 62 pp.
8. Leistner, L. 1986. Personal communication.
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An Accelerated Process for Fish
Sauce (Paris) Procluction
R. C. Mabesa, E. V. Carpio, and It. B. Mabesa
The single, probably most important, limitation in the manufacture
of fish sauce is the length of time required for its production. It normally
takes approximately 12 months from salting to maturity. This limits
the turnover rate and overall profitability of a potentially lucrative
enterprise. Considering the capital outlay and operating expense
required to run a fish sauce business, it is imperative to develop
a simple, economical, practicable accelerated process that yields
acceptable fish sauce.
With this goal, research and development efforts were undertaken
at the food pilot plant of the Institute of Food Science and Technology,
University of the Philippines at Los Banos.
OBSERVATIONS
This investigation stemmed from the observation in commercial
tanks that freshly drawn fish sauce lacks the desirable aroma of mature
sauce; this aroma develops after overnight storage or longer. The
appropriate color is there initially but typical flavor is lacking. It was
also observed that flavor, aroma, and color development of palls in
both concrete and wooden vats is more rapid and pronounced during
the hot summer months. Constant agitation through pumping and
frequent transfer of fish sauce from one container to another also
hastened and enhanced development of flavor and aroma. It was
hypothesized, therefore, that artificial agitation and/or aeration and
heat may help with the development of desirable qualities in fish sauce.
Thus, small-scale laboratory experiments were carried out initially. It
was determined that timing is of primary importance in the application
of heat and aeration. The typical fish sauce characteristics did not
146
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AN ACCELERATED PROCESS FOR FISH SAUCE
147
develop when freshly salted fish was aerated and heated immediately
after mixing. Trials were carried out to determine the appropriate time
for aeration and heating of the fish salt mixture. It was found that
aging for about a month after salting was sufficient and that higher
temperatures resulted in more rapid and greater improvement in
quality. However, preliminary experiments indicate that the maximum
temperature should not exceed 50°C or a cooked flavor results.
A concrete tank simulating the dimensions of a commercial tank
was constructed to test the findings in the laboratory. Technical
specifications are given below (see box). It was concluded that fish
sauce comparable to traditionally manufactured sauce can be obtained
in about 2 months or less using modified reaction conditions. These
conditions are given under B and C. Sauce characteristics are given
under D.
It is likely that production time may be further reduced if strongly
halophilic, proteolytic, and thermophilic Bacillus and Pediococcus
species used in the laboratory can be used in production.
DISCUSSION
Fish sauce with the desirable qualities of traditionally produced
sauce was obtained in the pilot plant. The improved process resulted
in an acceptable product in about 2 months instead of the 10 to 12
months required for the traditional process. Clearly, savings in time
and an improved turnover rate can result if these results are applied
commercially. This means greater income-generating capacity.
Some problems, such as loss of volume and contamination with
molds and bacteria, were encountered during heating and aeration.
The former was remedied by day-to-day monitoring of fish sauce levels
and replenishment with plain tap water when necessary. The second
problem was resolved by installing cotton filters at the intake end of
the pumps and by adding sorbic acid to the sauce at 0.05 percent prior
to bottling.
CONCLUSION
With pilot-level success, there is reason to believe that the process
can be applied on a commercial scale. However, there are problems
attendant to adaptation of the process. Additional expense will be
incurred in equipment acquisition, installation, and operation. Heating
and aeration alone will increase the price of palls by about P 50 per
drum or about P 0.25 per liter. These costs must be weighed against
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148
FERMENTED FOODS
TECHNICAL SPECIFICATIONS
A. Tank
1. Type concrete, cube approximately 0.265 m x
0.265 m x 0.265m I.D.
2. Material concrete 3:2:1 mixture of sand, gravel,
and cement with Sahara water proofing added.
3. Heaters- two 1,000-watt rod-type heaters located
close to the center of the tank.
4. Air pump one aquarium-type air pump with dis-
charge capacity of 5 liters/minute; pump discharge
located 2.5 centimeters below heaters.
B. Operating Information
1. Preliminary incubation 50 days at ambient temper-
ature.
2. Air pump operated 4 hours a day for 10 days.
3. Heaters operated 4 hours a day for 10 days.
4. Temperature 45° to 60°C for 10 days.
5. Power requirement 7 amperes (pump and heater).
6. Voltage requirement—220 volts.
C. Raw Material Information
1. Total weight of fish salt mixture—320 kilograms.
2. Proportion- 1 salt:2 fish by weight (106.6 kilograms
salt:213.3 kilograms fish).
3. Fish species Decapterus macrosoma.
4. Source Navotas Fishery Port.
D. Sauce Characteristics
1. Color golden yellow-brown highly typical of fish
sauce and clear.
2. Odor slightly acidic and fishy, typical of fish sauce.
3. Flavor typical fish sauce.
4. Total solids 41 percent.
Protein 14 percent.
pH 6.0.
Salt 24 percent.
8. Specific gravity 1.21.
Yield 137.5 kilograms.
savings or advantages such as faster turnover rate, decreased overhead,
salaries, and power.
Each manufacturer or potential user of a new technology such as
this stands to gain substantially despite the additional costs. However,
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AN ACCELERATED PROCESS FOR nSH SAUCE
149
each interested user may kind his or her ~tuabon unique. A careful
study of ~11 terms, Actors, and conditions acting ~ user should be
undertaken before embarking on ~ new and innovadve process such
as this.
In light of these results and consequent problems, ends are under
may in the laboratory to reduce process costs, particularly with respect
to reducing hewing time, minimizing heat losses, increasing hewing
efficiency, and exploring akernadve sources of energy far use in the
process.
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Representative terms from entire chapter:
balao balao balao
