The aim of this study was to analyse the infl uence of linoleic acid which was added in the broiler chickens feed mixtures in relation to chemical composition of meat, content of fatty acids and composition of blood serum. There were compared the characteristics of two groups of ROSS 308 chickens in the experiment (the experimental group with 5% addition of linoleic acid and the control group). The protein content of breast was signifi cantly lower (P ≤ 0.05) in the experimental group than in the control group. There were found signifi cant diff erences (P ≤ 0.05) in the protein content between sexes. There was found statistically signifi cant (P ≤ 0.01) higher fat content in the breast of experimental group in comparison with control group. Statistically signifi cant diff erences (P ≤ 0.05) were found in fat from the thigh meat of experimental group than the control group. The analysis of the chemical composition showed higher content of fat in the breast (1.9 g.100 g −1 ) than in the thigh (11.66 g.100 g −1 ) of chickens which were fed with the addition of linoleic acid to feed mixture. This resulted in lower share of the other components. The addition of linoleic acid in the chickens feed mixture showed signifi cantly higher proportion of polyunsaturated fatty acids to saturated fatty acids (0.76). Analysis of blood serum showed higher concentration of chlorides (P ≤ 0.01) in the group with the addition of linoleic acid than the control group. Proportion of monounsaturated fatty acids was 47.06% in the experimental group and signifi cantly higher one (53.77%) was found in the control group.

Keywords: Broiler ROSS 308, linoleic acid, carcass structure

The aim of this work is an evaluation of structural properties of ketchups originating from five different producers at two different batches and consecutively their comparison in different storage conditions and a determination of their consumable quality. Using the objective instrumental method based on physical deformation of the sample we evaluated properties like, viscosity and consistency of ketchups on texturometer TA.XT plus (Stable Micro Systems, Godalming, United Kingdom). These tests were completed on the basis of regressive extrusion using a hyperbaric disc. The consistency of each ketchup from the first rate determined by regressive extrusion ranged from 2656.82 g.s-1 to 5137.37 g.s-1. The lowest value 2656.82 g.s-1 was found in the sample A after 3 days of storage at the temperature 5 °C, the highest value 5137.37 gs-1 was found in the sample C after 10 days of storage at the temperature 5 °C. The value of the consistency in each of the samples didn´t change much, not even after the ketchups were stored at a room temperature for 24 hours. The consistency of each of the ketchups from the second rate determined by the regressive extrusion ranged form 2700.14 g.s-1 to 5133.94 g.s-1. The lowest value 2700.14 g.s-1 was found in the sample A after 10 days of storage at the temperature 5 °C, the highest value 5133.94 g.s-1 was found in the sample C after buying in a market and consequential cooling to 5 °C. The value of the consistency in each of the samples didn´t change much, not even after the ketchups were stored at a room temperature for 24 hours. The results obtained from the evaluation of the texture can be used to optimize the production and thereby prolonging the duration of maintaining its characteristics during the period of minimum durability.

Keywords: Beef, shear force, chemical quality, pH value