A New Approach to the Functional Improvement of Fish Meat Proteins

Abstract

Fish and shellfish are important protein sources and are widely used as raw material for preparation of processed seafood. Fish meat is highly nutritious, and its myofibrillar (Mf) protein has excellent functional properties, such as emulsion-and gel-forming abilities, and water-holding capabilities. Various technologies for dealing with fish meat, such as freezedrying, spray-drying, extrusion cooking, and high-hydrostatic-pressure processing, have been developed and applied to the seafood industry. However, fish Mf protein is thermally and chemically less stable than that of other vertebrates, and the food functionality is impaired easily as protein denaturation progresses. Therefore, the suppression of protein denaturation during the storage of materials and food processing is important to the manufacturing of high-quality processed seafood. Processing technologies, such as low-temperature storage to keep fish flesh close to freezing (partial freezing), mixing with edible cryoprotectants, and rapid neutralisation of meat by washing with alkaline solution, have been developed for decreasing protein denaturation during processing.Protein glycosylation is an effective method for improving the functional properties of proteins, and various techniques are available to prepare synthetic glycoproteins [3][4][5]8,18]. Recently, the focus has been placed on the neoglycoprotein-synthetic system using the Maillard reaction [14] as an effective method to improve the functional properties of food proteins. The protein glycosylation system is superior to other types of chemical modification for food proteins because it proceeds under mild and safe conditions without the use of chemicals. Food proteins, such as ovalbumin [14], ␤-lactoglobulin [9], phosvitin [26], lysozyme [36], and protamine [21], have been conjugated with various reducing sugars through the Maillard reaction to improve their functional properties such as thermal stability, emulsion-forming ability, antioxidant system to fish meat protein, and succeeded in improving its food functionality. This chapter reviews the enhancing effect of glycosylation through the Maillard reaction on food functionality of fish muscle protein and provides a discussion on the feasibility of using the protein glycosylation technology in the seafood industry. Handbook of Seafood Q uality, Safety and Health ApplicationsEdited by Cesarettin Alasalvar, Fereidoon Shahidi, Kazuo Miyashita and Udaya Wanasundara