We investigated the effects of 22 kinds of rice flours with different characteristics on the textural properties and whiteness of heat-induced fish meat gel without preheating. Amylose (AM), setback viscosity (SV), peaking time (PT), and crude protein (CP) positively affected the breaking force of fish meat gel. In contrast, breaking strain had a positive correlation with PT and CP, but a negative correlation with median particle size (MPS). Heat-induced gels with two added rice flours, prepared with a jet mill or a hammer mill, provided no significant differences in breaking force and breaking strain compared with gels containing rice starch. These flours were characterized by higher CP, AM, SV, and PT, as well as lower MPS, compared with the other flours. The whiteness of the gels with rice flour, except for one sample, was significantly higher than that of gels containing rice starch. Therefore, particle size, AM, PT, protein content, and SV of rice flour are important factors for producing high quality fish meat gel.Keywords: fish meat gel, heat-induced gel without preheating, rice flour, textural properties, whiteness, amylose content, particle size, milling method
IntroductionRice (Oryza sativa L.) is the most important food in Japan because it is a staple food and the only main food crop that can be domestically supplied. The Japanese self-sufficiency rate for food is low: only 39% of the calories consumed in Japan in 2010 came from non-imported food (Ministry of Agriculture, Forestry and Fisheries, 2012), so food self-sufficiency is a major problem in Japan. However, the consumption of rice has been steadily decreasing in Japan, i so the use of rice flour in baked foods, noodles, and batter has increased to promote demand for rice .Various additives have been used in fish meat products, such as kamaboko, to reduce its cost, and improve and/or enhance its texture (Ramírez et al., 2011). Starch is one of the main additives and is commonly added to these products at a level of 4% _ 12% (Hunt et al., 2009). Starch affects the textural properties of fish meat products because of its physico-chemical properties, such as water-holding capacity, and its mechanical strength during gelatinization upon heating (Yamashita and Yoneda, 1989;Yamazawa, 1991;Hunt et al., 2009). Starch is the major component of rice, accounting for approximately 80% of its total weight. Potato starch, corn starch, and wheat starch are the most popular additives used for surimi based products (Okada, 2008;Hunt et al., 2009). Japan imports most of the corn and wheat for starch production (Ministry of Agriculture, Forestry and Fisheries, 2014a). In contrast, the raw material for potato starch is supplied within Japan. However, failure of the potato crop may result in the need for other domestic additives. Wheat allergy and celiac disease S. TanimoTo et al. 1236 triggered by wheat protein such as gluten are important problems worldwide (Hiscgenhuber et al., 2006). Patients with these diseases avoid eating even fish products containing...