Utilization of seafood-processing by-products for the development of value-added food products

The fishing industry uses offal, waste, and processing by-products interchangeably, although they are different. Offal and waste mainly impart a negative connotation for those materials that cannot be used for any application and should be discarded. However, processing by-products imply that there exist some valuable components that can be used if treated properly. Some of the seafood-processing by-products are directly used for human consumption, such as roe, liver, cleaned stomach, and fried fish milt. However, some other components require further processing, including isolation and preparation. If the processing by-products are not treated properly, landfill will be the only option. Landfill is one of the most expensive options of waste disposal for the seafood industry and most countries have a limit for landfill. As a result, seafood-processing by-products are both an environmental and economic burden for this sector. However, seafood-processing by-products are a great source of protein and omega-3 polyunsaturated fatty acids that have been widely studied. Isoelectric solubilization/precipitation and protein hydrolysis are the major recovery methods for seafood-processing by-products. The utilization of seafood-processing by-products is a profitable venture in the food industry, as it not only minimizes the hazardous environmental impact of discarded seafood-processing by-products, but also provides essential nutrients for all age groups. This chapter focuses on the main value-added food products derived from seafood-processing by-products.