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ABSTRACT:The aim of the present study was to investigate qualitative and quantitative properties of wings, offal (liver, heart and gizzard) and necks of chickens from organic and conventional production systems, currently available on the market for Czech consumers. Production properties (yield and weight), surface colour (lightness, redness, yellowness) and chemical indicators (dry matter, total protein, net protein, collagen, hydroxyproline, fat, ash and phosphorus) were evaluated in fresh chicken broilers. Conventionally produced chickens had higher carcass yields but higher wing yields and weights were observed in organic broilers. The skin, bones, tip (left wings) and the meat with skin (right wings) of organic broilers were heavier (P < 0.05) than those of conventional chickens. The dry matter and total protein content of deboned organic broiler wings (meat with skin) was greater (P < 0.01) than those of conventional wings. Similarly as for yields, the offal (heart, gizzard) and necks of organic chickens had significantly (P < 0.01) higher weights in comparison with conventional chickens. Colour indicators showed that the external surface of the livers, necks and gizzards (muscle) from organic chickens were darker (lightness; P < 0.01). Total protein content in livers, hearts and necks of organic chickens was greater; fat content in the livers and necks of organic broilers was also higher (P < 0.05) than those of conventional broilers. The ash and phosphorus in the necks of conventional broilers was higher (P < 0.05) than in organic chickens. This study indicates that the quantity and quality of offal and neck from organic broilers are slightly superior compared to conventional chickens.

The objective of this study was to compare the quality indicators of chicken breast meat depending on sex, to evaluate individual quality indicators and to find relationships between them. Three groups (A, B and C) of commercial meat-type hybrid broilers ROSS 308 (10 males and 10 females from each group) were used for colour measurement (CIE L*a*b*), pH, chemical analysis (amount of dry matter, fat and collagen) and texture (shear force, hardness, cohesiveness). Cooked meat indicators (texture, colour, pH and chemical indicators) were measured after heat treatment (80 °C, 30 min). In all groups we were able to prove raw meat differences between sexes only in the following indicators: carcass weight (A group P < 0.01, B and C group P < 0.001), breast weight (A group P < 0.01, B and C group P < 0.001) and pH value (A group P < 0.05, B group P < 0.001, C group P < 0.01). Differences were found (P < 0.05) between sexes in texture indicators (hardness or cohesiveness), breast meat of males was more tender. The cooked breast meat was significantly (P < 0.05) lighter, redder and more yellow than the raw meat. Raw meat pH had a significant negative correlation (r = -0.41, P < 0.001) with raw meat lightness. Cooked meat pH had a significant correlation with cooked colour indicators. The amount of collagen had significant correlations with shear force (P < 0.001), hardness (P < 0.001) and cooking loss (P < 0.01).Broiler breast meat, objective colour, texture, chemical composition

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