|Small-Scale Processing of Fish (ILO - WEP, 1982, 140 p.)|
|CHAPTER II. SALTING - DRYING - FERMENTING|
|VII. FERMENTED FISH PRODUCTS|
In this processing method, the fish or shrimp are pounded with salt so that a paste results. The paste is then subject to periods of sun drying prior to packing in sealed containers for maturation. Moisture contents range from 35 to 50% so that almost half the water is lost during processing. Fish pastes represent a considerable portion of the protein intake of many people in South-East Asia (FAO, 1971), especially by the poorest sections of the population. In many fish pastes, carbohydrate-rich materials, such as fermented flour, bran or rice are added.
VII.2.1. Ngapi (Burma)
The raw material used in this product is small anchovy (Anchoviella comersonii) or shrimp (preferably the small planktonic types which give a better natural pink colour to the product). There are a number of methods for making ngapi, depending on the type of product required. In one process, which uses one part of salt to three parts of partially dried fish, the fish or shrimps are first washed in sea water and then dried for two days in the sun. About half of the required salt is then added to the fish and mixed in a bamboo basket. This mixture is pounded for several hours until a paste is formed. The paste is then packed into wooden tubs or boxes, care being taken that all air bubbles are removed. Fermentation takes place over 7 days and the paste is then removed, further pounded for three hours during which time the remaining salt is mixed in. The mixture is then spread out to dry in the sun for 3-5 hours. The product is repacked into tubs and the fermentation continues for about a month. After a third pounding, it can be packed for sale in cellophane or brown paper. Artificial dyes are often added to improve the colour. However, their use is not recommended as some may be toxic. When stored anaerobically in the tubs or earthenware pots, the product is said to keep for about 2 years. The average composition of a shrimp or fish ngapi is 43% moisture, 20% protein, 1% ammonia, 2% fat and 22% salt.
VII.2.2. Bagoong (Philippines)
Bagoong is one of the major preserved fish products of the Philippines where, in many communities, it constitutes a staple food. The product is also exported as far as the USA to the large ethnic Filipino community. A by-product of bagoong is patis, which is the exuded liquor from the fermentation process and is similar to the Vietnamese nuoc-mam.
Bagoong has a pasty consistency, and is reddish in colour with a slightly fishy cheese-like odour. It can be prepared from fish of the genera Stolephorus, Sardinella and Decapterus, and small shrimp. In the process described by Subba Rao (1961), the fish are washed in clean water, placed in a concrete or wooden vat and mixed thoroughly with salt. The ratio of salt to fish is about one third. The mixture of fish and salt is then transferred to earthenware jars, oil drums or cement tanks and either sealed immediately or, preferably, covered with cheese cloth for five days and then sealed. The sealed containers are held in the sun for one week and the product is then transferred to five gallon cans. These cans are, in turn, sealed by soldering of the lids, and the product is allowed to ferment further for between three months and one year.
The storage life of the product is many years, and the typical composition is not less than 40% total solids, 12.5% protein and 20-25% sodium chloride.