The development of fast-growing strains of broiler chickens has helped achieve growing consumer demand for nutritious foods, but this has coincided with the appearance of several pectoral muscle myopathies such as wooden breast.
Meats affected by wooden breast myopathy are mainly characterized by a higher tactile hardness and white striping, depending on the severity. Additionally, those lesions can also affect the technological characteristics and chemical and nutritional composition of the meat, including the fatty acid profile.
Freezing is one of the most common and efficient forms of meat conservation, but when frozen meat is stored for long periods, changes in physiochemical characteristics can occur with negative repercussions, which can lower its quality, such as the loss of water-soluble compounds through exudates.
To date, limited research has examined the relationship between fatty acid profile and freezing in samples of chicken affected by wooden breast myopathy and whether there is an interaction between myopathy severity and long storage periods (up to 12 months).
A group of researchers with São Paulo State University and the Federal Institute of Goiano in Brazil conducted a study that characterized the variations in fatty acid profile in chicken wooden breast meat when frozen for 12 months. Their results were published in Poultry Science.
The researchers used 120 samples of pectoralis major muscle (breast fillet) from broiler chickens slaughtered at 42 days of age. The breast samples were classified according to degree of myopathy or its absence for the control group. Samples were rapidly frozen (-40°C) and stored at -18°C for 12 months. Analyses of lipid, cholesterol and fatty acid profiles were determined at the beginning of the study and after storage.
According to the study, meat affected by the severe degree of myopathy had higher lipid content and cholesterol concentrations compared to normal samples, regardless of storage time, which the researchers attributed to myodegenerative processes that lead to the replacement of damaged muscle fibers with adipose tissue. Only normal samples showed an increase in cholesterol concentration after 12 months of freezing, which may have been due to losses of water-soluble components.
The researchers found that the profiles of saturated, monounsaturated and polyunsaturated fatty acids were significantly changed in chicken breast meat affected by wooden breast myopathy after freezing for 12 months. They noted that the prolonged one-year of storage negatively affected the nutritional properties of the meat, and increased the proportion of fatty acids that cause negative effects in the consumer.
That said, the prolonged frozen storage did increase the concentrations of some fatty acids beneficial to human health, such as the long-chain saturated fatty acids lignoceric acid (C24:0) and stearic acid (C18:0) and the polyunsaturated fatty acid linolelaidic acid (C18:2n6t).
What does this mean for producers?
- Prolonged frozen storage of chicken breast meat affected by myopathy can alter the fatty acid profile and nutritional properties of the meat.
- Chicken breasts not affected by myopathy also experienced altered nutritional profiles after year-long frozen storage due to increased loss of water-soluble components.
The full paper, titled “Concentration of lipids, cholesterol, and fatty acid profile in chicken breast meat affected by wooden breast myopathy frozen for up to 12 mo,” can be found in Poultry Science and online here.
Source: Sam Shafer – Poultry Science Association
