Interactions of dietary fibre and omega-3-rich oil with protein in surimi gels developed with salt substitute Alicia Debusca a , Reza Tahergorabi b , Sarah K. Beamer a , Susan Partington a , Jacek Jaczynski a,⇑ a West Virginia University, Division of Animal and Nutritional Sciences, P.O. Box 6108, Morgantown, WV 26506, USA b Oregon State University, Seafood Research and Education Center, 2001 Marine Dr., Astoria, OR 97103, USA article info Article history: Received 26 September 2012 Received in revised form 7 January 2013 Accepted 26 February 2013 Available online 7 March 2013 Keywords: Surimi Gelation Endothermic transitions Ingredient interactions Dietary fibre Salt substitute Fish oil Algal oil Flaxseed oil Omega-3 fatty acids Functional food Nutraceutical food Food product development abstract Most Western populations have insufficient intake of fibre and x-3 polyunsaturated fatty acids (PUFAs), while sodium intake greatly exceeds the recommended maximum. Surimi seafood is not currently forti- fied with these nutraceutical ingredients. Alaska pollock surimi seafood was developed with salt substi- tute and fortified with either 6 g/100 g of fibre or 10 g/100 g of x-3 oil (flax:algae:menhaden, 8:1:1) or fibre + x-3 oil (6 g/100 g of fibre + 10 g/100 g of x-3 oil). The objective was to determine effects of the dietary fortification on physicochemical properties of surimi. Fortification with either dietary fibre or x-3 oil alone or in combination enhanced (P < 0.05) rheological and textural characteristics. The com- bined fortification had a synergistic effect on rheological properties. This indicates greater gelation of sur- imi in the presence of fibre + x-3 oil, suggesting their interaction with surimi myofibrillar proteins. Fibre results in protein dehydration increasing protein concentration; while oil is immobilised by protein fill- ing void spaces in the gel matrix. Differential scanning calorimetry showed that fibre and x-3 oil did not interfere with normal denaturation of surimi proteins. Colour properties were only slightly affected (P < 0.05). Fortification of surimi with fibre and x-3 oil resulted in a quality product that could be useful in developing surimi products with nutritional benefits. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Heart disease is a number one cause of death in the United States. As of 2006, mortality from cardiovascular disease (CVD) and coronary heart disease (CHD) accounted for 1 of every 2.9 and 6.0 deaths, respectively (Lloyd-Jones et al., 2010). The Ameri- can Heart Association (AHA) recommends limiting saturated fat, cholesterol, and sodium as well as increasing fibre and unsaturated fats (Krauss et al., 2000). Dietary fibre has cardiovascular benefits (Anderson et al., 2009). The American diet is deficient in fibre with the average intake of only 15 g/day (Dietary Guidelines Advisory Committee, 2010). The Institute of Medicine recommends fibre intake to be 25– 38 g/day. Dietary fibre has been defined as remnants of plant edi- ble parts and analogous carbohydrates that are resistant to diges- tion and absorption in humans. It includes polysaccharides, oligosaccharides, lignin and associated plant substances that bene- fit human health (Bodner & Sieg, 2009; Prosky, 2000). Similar to fibre, omega-3 polyunsaturated fatty acids (x-3 PU- FAs) have cardiovascular benefits (Psota, Gebauer, & Kris-Etherton, 2006). a-linolenic acid (ALA, 18:3n3) decreases C-reactive protein (CRP), an indicator of inflammation associated with CVD (Zhao et al., 2004). Eicosapentaenoic (EPA, 20:5n3) and docosahexaenoic acids (DHA, 22:6n3) decrease triglycerides, total and LDL choles- terol, and increase HDL cholesterol (Juturu, 2008; Nair, Leitch, Fal- coner, & Garg, 1997; Narayan, Miyashita, & Hosakawa, 2006). Adequate intake of EPA and DHA may reduce CVD mortality by 30–60% (Psota et al., 2006). The cardiovascular benefits of x-3 PU- FAs have been discussed elsewhere (Anderson & Ma, 2009; Mozaff- arian & Wu, 2011; Psota et al., 2006). Plant sources such as flaxseed oil are abundant in ALA, although algal oils are rich in DHA (Arter- burn et al., 2008; Calder & Yaqoob, 2009; Gogus & Smith, 2010). Marine sources are abundant in EPA and DHA (Narayan et al., 2006). Dietary intake of ALA in Western populations is 0.5–2 g/ day and EPA + DHA is as low as <0.1 g/day. Although currently there are no official recommendations, the suggested intake of ALA is 1.1–1.6 g/day and EPA + DHA is 0.3–0.4 g/day. Some sources suggest >0.5 g of EPA + DHA per day (Calder & Yaqoob, 2009; Insti- tute of Medicine, 2005; Juturu, 2008; Kris-Etherton, Grieger, & Eth- erton, 2009). 0308-8146/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodchem.2013.02.111 ⇑ Corresponding author. Tel.: +1 (304) 293 1893; fax: +1 (304) 293 2232. E-mail address: Jacek.Jaczynski@mail.wvu.edu (J. Jaczynski). Food Chemistry 141 (2013) 201–208 Contents lists available at SciVerse ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem