The effect of frozen storage time on the chemical, microbiological and sensory quality or raw Turkey döner

This research was performed to determine the effects of frozen storage period and using different types of turkey meat on the chemical, microbiological and sensory charactheristics of raw turkey doner. Analysis performed on turkey doners which was prepared by using turkey breast (DK- G), thigh (DK-B) and the mixture (1:1) of breast and thigh meat (DK-BG) on the production day and 45th, 90th, 135th, 180th and 225th days of the storage period. Chemical (water, protein, ash and oil content, pH, TBA and peroxide values and loss of water during thawing), microbiological (total mesophylic aerobic bacteria count, total psicrophilic bacteria count, coliform and feacal coliform counts, and Salmonella, Exoli and S. aureus counts), and sensory analysis were performed to determine the quality changes. Results interpreted by using SAS statistical analysis programme. As results of the analysis; water, protein, oil and ash contents of the samples showed no change during the storage period. At the beginning of the storage pH values of the samples DK-G, DK-B and DK-BG were found as 6.03, 6.21 and 6.16 respectively. These values were increased to approximately 6.30, 6.37 and 6.28 at the end of the storage. Effect of storage time on the pH changes of the samples was found statistically significant (p<0,05). For all samples peroxide and TBA values were increased during the storage period. At the beginning of the storage peroxide values of the DK-G, DK-B and DK-BG samples were found as 0.62, 0.70 and 0.88 respectively. These values were increased to 2.97, 2.76 and 3.19 respectively at the end of the frozen storage. Effect of storage period on the changes of peroxide values of the samples were found statistically significant (p<0,05). However, peroxide values of the samples did not exceed the limit of 20 meg oxygen/kg. Another criteria to determine the oxidation level in meat products is TBA method. TBA values of the samples DK-G, DK-B and DK-BG were increased to 0.894, 0.981 and 0.992 from 0.370, 0.425 and 0.423 respectively. However, final TBA values of thesamples did not exceed the 1 mh malonaldehyd/kg oil which is accapted as the upper limit At the beginning of the storage, total mesphylic aerobic counts of the DK-G, DK-B and DK-BG samples were found as 3.13.106, 5.1.106, and 6.63.106. These values were decreased to 2.88.106, 4.88.106, and 5.68.106 respectively. Smilliarly, total psichrophil bacteria counts of the samples were changed from 2.72.105, 7.43.104, and 6.52.104 to 2.82.105, 6.8.104, 5.75.104 respectively. At the end of the frozen storage for 75 months, it was seen that turkey doner samples could be preserved well with no certain change in their quality. As results of the sensory analysis, it was found that samples did not loose their edible charactheristics.