Pooled data from this study revealed that the meat portion, breed, and cooking process significantly influenced the betaine content of chicken meat, in order of significance (p < 0.05; Table 3). In addition, the interaction between the meat portion and cooking had a significant effect on the betaine content. As shown in Table 3, the betaine content of chicken meat was significantly greater (p < 0.05) in its raw state (average value of 13.6 mg/100 g) than in its cooked state (average value of 10.3 mg/100 g). However, individual comparisons revealed that the cooking effect on the betaine content was only significant in the leg meat of both breeds (p < 0.05), but not for breast meat (p > 0.05; data not shown). Therefore, it might be suggested that the effect of cooking on the abundance of betaine is dependent on the meat portion. The betaine content of raw leg meat was reduced significantly during cooking due to its high water solubility (de Zwart et al., 2003). Similar to our data, lower content of betaine in cooked broiler meat and cooked livers and hearts of turkeys compared with their raw states was previously reported (Patterson et al., 2008). Moreover, processing or cooking methods can affect the amount of betaine (de Zwart et al., 2003). For instance, boiling results in higher depletion, whereas baking, microwaving, or frying cause no significant loss.