Processing and Storage
Processing refers to mechanical or chemical operations performed on fish in order to transform or preserve them. Fish are processed in a variety of ways and in different working environments. Removing the entrails from fish (e.g. gutting or cleaning) is a simple processing technique designed to extend shelf life. Smoking, sun drying, and salting are common traditional processing methods associated with small-scale fisheries value chains and are often practiced using low cost technology and with minimal services and facilities. More sophisticated processing takes place in factory environments, which meet high international standards of hygiene and food safety. Fresh chilled, frozen and canned products are all associated with high investment factory processing and international trade.
Both low value and high value fish are processed. Low value fish are processed for both human consumption and for animal feed production. High value species from both capture fisheries and aquaculture are typically processed into fresh chilled or frozen products. By-products from processing such as frames, viscera, and skins are also processed into nutrient supplements, pharmaceutical products and fertilizer.
Artisanally processed products are important for food security and nutrition, as they provide animal protein and nutrients to low income populations. Some traditionally processed products can also be of high value and desired by wealthy consumers.
Artisanally processed dried, salted or smoked products are sold in domestic urban and rural markets, as well as sub-regional and international markets. These products are often transported long distances and marketed in areas far from where capture and processing take place. Food loss and waste (FLW) can occur if the product is damaged or stored for long periods under inadequate conditions, resulting in microbial contamination and insect infestation.
Loss Scenarios
Artisanal fish drying involves the evaporation of moisture from the surface of the fish and the migration of moisture from inside the fish to the surface. Drying is affected by the movement of air over the surface of the fish as well as the temperature and humidity of that air.
Products of artisanal fish processing (dried, salted and dried, smoked) often undergo a period of storage prior to being sold, distributed and consumed. Such storage typically takes place at the processing location and/or at a market.
Artisanal fish salting is a simple and important preservation method used in many parts of the world. It is often combined with drying.
Artisanal fish smoking is a heat drying process. The heat is typically provided by an open wood fire, over which the fish are placed. The use of fire imparts a smoke flavor and affects the color of the final products, which are usually light to dark brown.
Canned fish are an important food source. Canned fish are rich in protein and many other essential nutrients, and can be a good source of omega-3 fatty acids.
The use of "cold" handling and storage systems as an investment to prevent perishable food loss and waste (FLW) is widely used in developed countries. It can be highly cost effective compared to continually increasing production to meet increasing demands for these foods.
Freezing preserves the storage life of foods by making them more inert and slowing down the detrimental reactions that promote food spoilage and limit quality shelf life.
Fish processing plants convert fresh or frozen fish into various types of product. Processing plants can be labor intensive and or highly automated.