Oxidative stability of chicken meat during storage influenced by the feeding of alfalfa meal

Abstract

The aim of our experiment was to determine the effect of the alfalfa meal component in feed mixtures of Ross broiler chickens on oxidative stability of meat. Proportion of alfalfa meal in feed mixtures was 4 and 6%. The results were compared to the control group without alfalfa meal in feed mixtures. At the end of the experiment (day 38), 6 pcs of broiler chickens from each group with an average live body weight over 1 800 g were randomly selected. The samples for chemical analysis consisted of identical proportion of breast and thigh muscle, and about 1 cm2 of skin with subcutaneous fat. Fat from the meat was obtained after the samples drying. A fat was determined by extraction by means of laboratory instrument Det N Gras Selecta P. The oxidative stability of meat on the basis of acid number of fat was determided by chemical analysis. Chicken meat was stored at -18 °C for 12 months and 18 months. The acid number of fat of stored meat for 12 months was 7.38 mg KOH per g in the control group, 7.42 mg KOH per g in the group with a proportion of 4% alfalfa meal, and 11.18 mg KOH per g in the group with proportion 6% alfalfa meal. An acid number of fat of stored meat for 18 months was 5.90 mg KOH per g in the control group, 4.65 mg KOH per g in the group with a proportion of 4% alfalfa meal, and 7.07 mg KOH per g in the group with a proportion of 6% alfalfa meal. Chicken meat is notably sensitive to lipid oxidation because of its high content of polyunsaturated fatty acids. Legislation in Title 5 of Part 3 of the Codex Alimentarius of the Slovak Republic and the Government Regulation No. 286/2003 Coll. in the Annex 4 in Part B provide the requirements for animal fats and meat products. Regulation of the European Parliament and Council (EC) No. 853/2004 lays down specific hygiene rules for food of animal origin. In particular, determination of free fatty acids content of rendered animal fat (tallow, lard, other animal fat). Legislative regulation does not contain requirements for the quality of chicken meat, the acid number of fat of fresh or frozen chicken meat, respectively. A chicken meat is preferred over other kinds of meat. It is characterized by certain dietary and nutritional properties that consumer prefers. A price of this kind of meat remains attractive. In terms of human health, oxidative stability of chicken meat is important, especially of stored meat. In general terms, the various food additives are currently used to maintain the food stability. Great attention is currently paid to additives of natural origin. Similar focus is presented in our study. We can state, on the basis of the oxidative stability results of chicken meat, that natural feed component has its justification. This issue requires further research.