ABSTRACT The aim of this study was to determine if sex influenced abdominal fat yield, chemical composition, pH, color, fatty acid profile, and stability (by Differential Scanning Calorimetry - DSC) of Cobb chickens. Abdominal fat yields of 1.86 and 1.49% were obtained for females and males, respectively. Abdominal fat lipid contents of 70.68 and 74.36 g/100g, moisture content of 27.87 and 24.09 g/100g, protein content of 0.91 and 0.95 g/100g, ash content of 0.038 and 0.041 g/100g were obtained in males and females, respectively. Fat pH was not different between sexes, with values of 6.71 for males and 6.63 for females (p<0.05). Color L* values of 58.67 and 55.42, a* values of 4.95 and 3.44, and b* values of 7.36 and 8.18 were obtained for males and females, respectively. Female abdominal fat contained higher proportion of oleic acid (53.87%) followed by palmitic acid (30.07%), whereas 34.69% palmitic acid, 31.92% oleic acid, and 25.30% linoleic acid were determined in males. The proportions of the evaluated fatty acids were significantly different (p>0.05) between males and females, except for palmitic acid. The DSC analysis showed no significant difference (p>0.05) between sexes for melting and crystallization points. It was concluded that sex influences abdominal chicken fat yield, chemical composition, color, and DSC parameters.

Freezing is one of the methods to preserve and guarantee the quality of meat until it reaches the consumer. Even though freezing is classified as a mild form of preservation, it causes meat changes resulting from the formation of ice crystals that subsequently affect the tenderness and functionality of meat. The aim of this study was to evaluate the physicochemical and structural characteristics of chicken half breast submitted to fast freezing (-36 °C for 2 hours) and thawed by five different methods (under refrigeration, in a microwave, in a oven with air circulation, placed in cold water, or at room temperature). After thawing, the following parameters were evaluated: moisture content, drip loss (syneresis), water activity (aw), and shear force. Samples were also histologically evaluated by light microscopy. The results indicated that, despite being submitted to fast freezing, thawing affected (p <0.05) most of the physicochemical and structural properties of the meat, except for aw. Thawing in cold water (packed in low-density polyethylene bags and placed in cold water at approximately 10 °C for 2 hours and 15 minutes) presented the best results due to lesser damage to the cell structure, as shown by the lower drip loss, higher moisture content, and greater tenderness of the samples compared to those thawed using the other methods. Histological examination showed that muscle fiber structural features and organization were maintained. Thawing at low temperatures seems to cause less damage to the meat structure and allows maintaining of its properties. It was concluded that the meat quality is not related only with the freezing method, but also with the method and conditions used in thawing.