Marination is widely used by consumers to improve meat tenderness and flavor [163]. Artificial tenderization by acid marination, the soaking of meat in acid solution, is a commonly used culinary technique [2]. Marination affects tenderness in 3 ways, potentially: (1) pH-induced swelling of muscle fibers and/or connective tissue; (2) accelerated or additional proteolytic weakening of muscle structure and (3) increased solubilization of collagen upon
cooking [38, 100, 101]. Howat et al. [61] reported that meat tenderness was not increased by marination in weak acid (pH 2.56). However, Wenham and Locker [161] and Gault [47, 48] showed that tenderness of meats marinated with acid solutions (pH 2.58–3.17) increased, while Seuss and Martin [127] showed that meat became somewhat more tender as acid concentration increased at pH values between 1.8 and 3.0. The tenderization observed at pH values below 5.0 was believe to be caused mainly by the effects of acid pH on the water-holding capacity of muscle proteins. Oreskovich et al. [102] marinated meat with 0.1 M phosphate buffers ranging in pH from 3.25 to 10.15, 0.1 M sodium chloride, 0.4 M phosphoric acid or 0.7 M acetic acid. They reported that low muscle pH after mari- nation had positive effects on texture and resulted in increased water-binging capacity, moisture content and decreased cooking losses.