Fish products and Byproducts Technology

Unit 13 - Diversified fish products/ value addition

13.1. Breaded and Battered Products
Coating seafood, poultry or vegetable products with a batter and/ or breading before cooking is an established domestic as well as commercial practice. Of late, the emphasis of coated products has shifted from the home front to the restaurant and fast- food outlets. Prominent among the coated products are the seafood products. Battered and breaded fish finger or fish stick has been one of the forerunner in this field and still command a sizeable share of the battered and breaded seafood trade. Such products, when frozen in ready- to- cook form, offer a convenience of high consumer value and are called ‘convenience foods’. Fish finger, fish portion and fish cake are the staple battered and breaded fish products. Breaded shrimp, scallop and oyster cater to luxury market.
The coating process:
The unit operations in development of coated products are portioning/ forming, predusting, battering, breading, fish frying, freezing, packaging and storage.
Predusting:
Predust usually a very fine, dry, raw flour material that is sprinkled on the moist surface of the frozen or fresh food substrate before any other coating is applied. It improves adhesion of the batter, because it absorbs part of the water on the surface of the food. If the batter is applied to a surface that is too moist, it can slip, leaving some areas uncovered. Also, the use of predust tends to increase pickup. The most commonly used predusts are wheat flour, gums and proteins, alone or in combination.
Batters:
Batters are of two types, adhesive and tempura. The traditional adhesive batter is a fluid, basically consisting of flour and water, into which the product is dipped before it is cooked or fried. A bond between the product and the coating is formed. The proportion of batter and water is usually in the ratio of 1:2. Higher amount of water might affect the functional need of fixing the crumbs onto the batter and also will necessitate longer time to freeze the batter. The desired viscosity and pick up decide the ratio of components in the batter mix.
The ingredients that constitute that constitute the batter include starch, salt, seasonings, gums, egg and many other items. The batter also usually incorporates a leavening agent to favour expansion of the product during frying.
Breading:
Breading is a serial- based coating, often of breadcrumbs. The main ingredients are almost same as for batters, and consist of flours, starch and seasonings. Breading is coarse in nature and applied to a moist or battered food product prior to cooking. Texture, mesh size, porosity and absorption re the major factors contributing to the texture of the breading. Mesh size may be coarse, medium or fine and is important in the formation of an attractive and economical coating system. Coarse particles are desirable to achieve textural targets; however, its excess use on a small surface area may cause its falling off during handling and transportation. Hence a balance among different mesh sizes is desirable. Cracker meal/traditional breading is widely used in fish products. Cracker-meal breaders, which are used to develop a cracker type, relatively hard texture, consist of unleavened flour. Home- style breadcrumbs are more porous than cracker meal and tend to absorb more oil and moisture. Japanese style crumbs, also called ‘Oriental style or Panko crumb’, has a characteristic flake- like elongated structure and excellent visual appeal, and provides a unique surface- texture when fried. Crumb coating are usually coloured with natural vegetable extracts to give a golden- brown appearance. These colours include paprika, annatto, turmeric or caramel.
Frying:
Fat is the frying medium. Besides being the heat transfer medium, it is also a food ingredient that will influence the eating quality. Some may have specific flavour which may be carried over the product. Usually bleached and refined vegetable oils are used for frying. At the high temperature of frying, some fat may undergo changes such as polymerization. It is therefore important to use an oil of good quality for frying. According to normal manufacturing process, prefrying in oil is carried out at 180ºC to 200ºC for about 30 sec followed by freezing the product.
Packing:
Conventional packaging materials like flexible plastic films alone are not suitable for packaging, since they provide little mechanical protection to the products. As a result, the product get damaged or broken during handling and transportation. The packaging may be a paperboard carton or a poly- lined paper bag or poly-bag, which is heat sealed. The bags are designated to give support to a larger quantity of items such as fish fingers. In recent times, thermo- formed containers are commonly used for packaging coated products. These trays produced from food-grade materials are suitable for packaging breaded items both for domestic as well as export markets. Trays are made of polyvinylidene chloride, high impact polystyrene (HIP) and high-density polyethylene (HDPE) are unaffected by subzero temperatures and provide protection to the contents against desiccation and oxidation during prolonged storage.