E : F o o d E n g i n e e r i n g & P h y s i c a l P r o p e r t i e s JFS E: Food Engineering and Physical Properties Physical Study of Minced Fish Muscle wit White-Grape By-Product Added as an Ing I. S´ ANCHEZ -A LONSO , M.T. S OLAS , ANDA.J. B ORDER ´ ı AS ABSTRACT: Functional properties of a white grape dietary fiber concentrate (WGDF) obtained from wine in residues were determined with a view to their use as potential functional ingredient in seafood products features of interest of WGDF are that it is a natural product containing high concentrations of dietary fib with a high-soluble DF (sDF)/insoluble DF (iDF) ratio and associated bioactive compounds; as such it is c potentially suitable for use as dietary fiber in the enrichment of foods. WGDF was therefore added to mi muscle (MFM) of horse mackerel (Trachurus trachurus) to take advantage of its technological properties enrich a food product that is a functional product in itself but does not contain dietary fiber. WGDF was and 4%) to MFM, which was stored for 6 mo at –20 ◦ C, and a further lot was vacuum packed. Physical and mechanic properties, sensory and color analyses, microscopy, and electrophoretic profiles were all done in sample month. The results indicate that WGDF had good functional properties, high water and oil retention capa considerable swelling properties, which would make it useful as a natural ingredient in foods. The additi to MFM augmented aggregation of myofibrillar proteins in the course of frozen storage, although electro profiles were very similar in samples with and without WGDF. The addition of WGDF to MFM made samp less springy and cohesive. SEM showed good dispersion of WGDF in MFM but the matrix was more disco in the control. Water retention was significantly enhanced when WGDF was added, and the cooking yield In sensory evaluation, samples containing 2% of WGDF scored highest in overall acceptance as compare control. Vacuum packing did not significantly affect the properties considered during frozen storage. Keywords: dietary fiber, frozen storage, functional properties, mechanical properties, microscopy, wine by- products Introduction B y-products are of particular economic interest to today’s food industry since product residues can be produced in large quan- tities and present expensive disposal problems. Dietary fiber (DF) is a major fraction in many by-products from the agricultural industry (grapes, mango, orange, lime, pea, kiwi, and others), and in some cases, for instance, grape by-products from the wine industry, the by-products have appreciable amounts of bioactive compounds (for example,polyphenolic compounds) associated with the polysac- charide matrix of the DF (Saura-Calixto and others 1991; Valiente and others 1995). The importance of DF in health and nutrition is well defined (Rodr ´ ıguez and others 2006), but DF is also of interest for its functional and technological properties (Schiever and others 2001; Border ´ ıas and others 2005). In the last few decades, an extensive market for DF-based prod- ucts, including fiber-enriched foods, has developed. High-DF ma- terials from fruits have recently begun to appear on the market for food enrichment (fiber concentrates from mango, orange, lime, and so on) because they possess better nutritional properties, more to- tal DF and sDF (soluble dietary fiber), lower caloric content, better water and oil holding capacity, swelling (SW) capacity, viscosity or gel-forming ability, stronger antioxidant capacity, and greater fer- mentability (Larrauri and others 1996; Grigelmo-Miguel and Martin- MS 20060500 Submitted 9/08/2006, Accepted 12/12/2006. Authors S ´ anchez- Alonso and Border ´ ıas are with Inst. del Fr ´ ıo (CSIC), Jos ´ e Antonio Nov ´ ais 10, 28040,Madrid, Spain. Author Solas is with Dept. de Bi- olog´ ıa Celular, Univ. Complutense, Ciudad Universitaria, 28040, Madrid, Spain. Direct inquiries to author S ´ anchez-Alonso(E-mail: isblsa@ hotmail.com). Belloso 1999a; Chau and Huang 2003). The sDF/iDF (insoluble di- etary fiber) dietary fiber ratio is important for dietary and functional properties, and it is generally accepted that such DF concentrates should have an sDF/iDF ratio close to 1:2 (Jaime and others 2002) when used as food ingredients. Grape (Vitis vinifera) by-products—grapeskins and seeds (pomace)—are increasingly being used to obtain functional ingre- dients such as grape antioxidant DF (Saura-Calixto 1998) for use in the design of healthy (functional) foods due to the DF (high sDF/iDF ratio) and associated bioactive compounds that they contain. The composition and physiological properties of grape pomace have been widely studied (Mart ´ ın-Carron and others 1997; Bravo and Saura-Calixto 1998; Go˜ ni and others 2005).However,only 2 pa- pers have been published, by the authors, in which red grape an- tioxidant DF was successfully added to restructured fish products (S´ anchez-Alonso and Border ´ ıas 2006; S ´ anchez-Alonso and others 2007c).There are no studies on addition of white grape fiber to minced fish muscle (MFM) in the literature. Seafood possesses high nutritional value and is an essential com- ponent of diet conferring beneficial effects on certain disorders; however,fish products do not contain DF. The addition of DF to fishery products is of particular interest as a means of improving the functionality of food products and as a component of new func- tional foods. From a technological point of view, the introduction of DF improves water binding and emulsion capacity, thickening, gelling,and other properties of products made with MFM, espe- cially when the raw material used is of poor functional quality. The antioxidant capacity of some fruit DF is particularly desirable in the case of products made from fatty fishes, which are highly suscepti- ble to lipid oxidation. From a physiological standpoint, the addition E94 JOURNAL OF FOOD SCIENCE—Vol. 72, Nr. 2, 2007 C 2007 Institute of Food Technologists doi: 10.1111/j.1750-3841.2007.00273.x Further reproduction without permission is prohibited