Costas Stathopoulos

This chapter focuses on the recovery of bioactive compounds, particularly phenolic compounds and dietary fiber, from fruit juice industry solid waste. Extraction, isolation and potential applications of phenolic compounds and dietary fiber recovered from fruit solid waste in the food industry will be discussed. With the continuity of new discoveries on extractions, isolation and characterization techniques, the use of such waste as cheap raw material to produce bioactive compounds on a commercial scale becomes tangible on a large scale. Without any extraction step prior to the fiber preparation, dietary fibers obtained directly from fruit waste contain high amounts of bioactive compounds, such as phenolic compounds, terpenes, carotenoids, depending on the fruit sources. In many reports on the use of bioactive compounds from fruit waste in food products, antioxidant activity is reported to have a synergistic effect with the addition of dietary fiber.

The effect of processing, and heat in particular, on the wheat gluten proteins can be difficult to explain due to its complex, and often unusual, rheological and biochemical properties. Heat denaturation of wheat gluten proteins and the accompanying rheological changes, together with a number of interactions, such as hydrogen bonding, SS bonding and hydrophobic interactions have an effect on the native structure of the protein. During the heat treatment of gluten, denaturation, aggregation and cross-linking all combine to give rise to a series of changes that affect rheological and biochemical properties alike. Different components of gluten might exhibit different responses to heat treatment, based on their parent wheat variety, their size, their composition, or the environment the heat treatment took place. Today's food scientists are yet to fully understand all the interactions and mechanisms involved in the effect of heat on gluten but this field of research has grown enormously over the last few decades and continuously expands offering us a better insight and understanding.

Dairy ingredients have long been used in the cereal-processing industry. They have mainly been added for their good functional properties, ease of production, and the nutritional fortification they provide to the final product. These ingredients also find applications in gluten-free products, where substitution of the structural protein complex of gluten is required in order to render the product suitable for consumption by people with celiac disease. Over the years a number of dairy ingredients have been used in the food industry. Applications have been extensive and variable, especially for dairy proteins. For caseins and caseinates these applications include baked products, cheese and imitation cheese manufacture, coffee creamers, ice creams, pasta products, cultured milk products, whipped toppings, milk-type beverages, non-milk-type beverages, confectionary products, spreads, meat products, and others. For whey protein products, applications include beverages, confectionary, desserts and dressings, meat products, dairy products, and novel dairy products. Lactose finds a number of applications in various dairy products, such as sweetened condensed milk, frozen milk products, milk and whey powders, confectionary products, baby foods, and also as flavor enhancer and an anti caking agent. Dairy ingredients are extensively used for their functionality, nutritional value, and ease of production. The most widely used dairy ingredients in gluten-free bread formulations are caseinates, skim milk powder, dry milk, whey protein concentrate, and milk protein isolate.