Fish Sauces

Fish sauce in Far East Asia

In Malaysia it is called it Budu, in Thailand it is Nam-pla, in Japan it is Shotturu, and in Philippines it is called Patis. They are a traditional fermented fish product in the form of sauces. They are not only fish sauce from different countries, but they also differ in composition and quality. For example, in the preparation of Bagoong (paste) in the Philippines, the sauce (Patis) is byproduct in the production of the paste.

Fish sauce is a high-salt fish product that contain more than 20% salt. The sauces are grouped into clear sauces such as Shotturu and Nam-pla, and the turbid sauces represented by Budu and Patis. Sauces represent the fermented fish products made from extensive proteolytic, lipolytic and nuclease activities. In sauce production, the fish (if large is eviscerated) is directly mixed with salt, packed in containers and stored for varying periods of time at room temperature.

Source & Composition

Malaysia

Budu is a fish sauce that made from small anchovies (Stolephorus spp.), Sardinella spp. or Decaterus macrosoma. Based on Malaysia Food Regulation 1985, Budu shall be the fish product obtained by salt fermentation of anchovies of Stolephorus species or mixture of anchovies with other small fish.

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The production process involves mixing of the fish with 25-33% salt and incubating the mixture in concrete containers for 6-12 months. The hydrolysed mixture is boiled for about 2 hours, cooled, filtered and bottled. The final product contains about 1.77% total nitrogen and 1.17% amino nitrogen.

Japan

There are many types of sauces produced but the main sauce is Shotturu that is produced from sand fish (Artocarpus japonicus). Sauces are also made from sardines, anchovies, mollusks and squids. Blend of fish sauce and soy sauce are also common.

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Average composition of commercial Shotturu is pH of 4.54-5.56; 26.2-30.4% NaCl; total nitrogen of 301-1598 mg/100 mL; volatile basic nitrogen of 36.2-170 mg/100 mL and trimethylamine of 16.2-44.2 mg/100 mL.

Philippines

Fish species used in the production of Patis are generally those which do not command a high market price and are available throughout the year. Some of the species used in the production are dillis, (Stolephorus commersonii), Galonggong (Decapteerus macrosoma) and Silinyasi (Sardinella fimbriata).

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Good quality Patis is expected to contain not less than 10% protein, 30% total solids, and 20% salt. The range of some constituents of Patis is: total nitrogen of 0.14-1.4 g; free ammoniacal nitrogen of 0.7-1.43 g; 17.4-26.03% salt and pH of 5.10-6.15.

Thailand

Currently, the trash fish from the large trawlers is mostly used for Nam-pla manufacture although Nam-pla can be produced from any types of fish. The increase in the quality of the trash fish available has encouraged the establishment of small industries to process it into Nam-pla.

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The composition of Nam-pla varies widely from source to source, depending on the quality of fish used (Table 1). The average chemical profile of different grades of Nam-pla is given in Table 2.

Table 1. Gross composition of Nam-pla made from different species of fishes.

Fish sps	Protein (g/l)	Salt (g/l)	Amino N (g/l)
Anchoviella sp.	22.99	260.6	14.56
Cirrhinus sp.	22.5	277.8	6.01
Trash fish	16.28	291.8	14.28

Table 2. Average composition of freshwater fish Nam-pla from Thailand

Grading	pH	% Salt	% Total N
Good	5.6	27.7	22.5
Moderate	5.2	21.4	11.5
Bad	5.92	172.1	2.1

Physical changes of the fish sauce

The process of producing the sauces primarily involves the activity of a variety of fish-gut enzymes and the muscle enzymes, some of which are active in the presence of high-salt concentration. During fermentation, the hydrolysis of protein, lipids and nucleic acids are brought about mostly by the endogenous enzymes and the microorganisms have little role to play. The extent of hydrolysis depends on the end-product desired, with the sauces being the terminal products of the hydrolytic phase. The end-products of the hydrolysis phase are peptides, amino acids, fatty acids and nucleotides which are involved in product quality and taste.

There a study about physical changes of fish during fermentation. The fish had shiny appearance and elastic texture before addition of salt and the fish loss shininess and gradually lost the scales, skin, flesh exposed, and belly disappeared. Elastic texture of fish become soft and gradually muscles become digested due to action of enzyme. As results, the extracted liquid which is fish sauce will vary in colour from straw colour, amber or reddish brown.

Flavour components

The components responsible for the flavour and aroma of fish sauce are grouped broadly into;

• An ammoniacal component consisting of ammonia and trimethylamine
• A cheesy component due to volatile and fatty acids
• A complex meaty component composed of a complex set of compounds

A study shown there are 3 fractions of flavour components of commercial Nam-pla which are basic, neutral and acidic. The basic fraction was dominated by;

• Ammonia                 
• Trimethylamine
• Dimethylamine
• 2,3-butanediol

The neutral fraction contains meaty aroma and lactones as the main component along with alcohols and heterocyclic compounds. The acidic fraction had a cheesy aroma and contained one lactone as the major component.

These studies show that the components responsible for flavour and aroma for fish sauce products are numerous and complex. Although the fish sauce can also be produced by controlled acid hydrolysis, the product does not have the same flavour and aroma as the fermented product.

Conclusion

In Far East Asia, fish has been the major source of protein in their bland rice diets. However, fish is an easily perishable commodity which Far East Asian were extending the shelf-life of fish by fermentation in the presence of salt. As results, fish sauce which made from salted fermented fish is a staple ingredient for seasoning in many Far East Asian cuisines and they have their own version of fish sauce that have different flavour and level of saltiness. The procedures of preparing the fish sauces in different countries are basically similar but are developed independently.