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The influence of extraction and precipitation pH on the dry matter yield of broiler dark meat

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Abstract

In recent years, demand for white meat products has resulted in excess supplies and depressed prices of leg meat in the United States. One approach to increasing the utilization of dark meat is to extract the pigments and fat to make the resulting product more acceptable for the production of further-processed meat products. To date, such technologies have been inefficient (low yields) or have resulted in products of limited use. Three replicate trials were conducted to determine the effects of extraction pH and precipitation pH on the wet and dry extract yields of boneless, skinless broiler leg meat. Broiler leg meat was chopped with added water and extracted by adjusting the pH to 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, and 12.0 while mixing. After determination of extraction yields, each extraction was adjusted to pH 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, and 5.2 to determine the effect of precipitate pH on total wet and dry yields. Dry yield increased with extraction pH and precipitation pH. However, the greatest yields, over 70%, were at extraction pH values above 10.5, which have been associated with the production of potentially harmful by-products. Combinations of extraction pH values between 9 and 10.5 and precipitation pH values above 4.4 resulted in dry yields of approximately 65%. These results indicate that pH extraction and precipitation may result in economically viable yields. Further research is needed to determine the optimal conditions of yield, composition, and functionality.
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... The isolates had higher water content (∼88 %) than that of original minced broiler meat (∼75.5 %) (p < 0.05) leading to the increase in wet basis yield of the protein isolates. A significant increase in moisture content of the protein isolates was possibly due to the fact that the pellet contained a large loosely structured gel holding a large fraction of the water (Marmon and Undeland 2010;Betti and Fletchert 2005). The pH of protein isolates were found in the ranges of 4.83-5.32 ...
... Modification of acid-aided process by PW, CA, and EA could probably improve the removal of other contaminants leading to higher concentration of muscle proteins. Betti and Fletchert (2005) reported a protein recovery of 70.0-81.4 % during the protein isolation from broiler dark meat with different extraction pHs. ...
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... Furthermore, alkaline conditions at high pH (pH > 10.5) could lead to irreversible protein denaturation, possibly leading to loss of functionality (Betti & Fletcher, 2005). Its relevance depends on the specific future application of such a protein extract. ...
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... However, there is a possibility that the protein conformation will open, and that the protein will denature. Extraction of protein with a strong alkaline up to pH 11 is not recommended for food due to potential synthesis of unsafe compound for consumption during the hydrolysis reaction [28]. ...
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... Isoelectric solubilization/precipitation (ISP) was recently applied to poultry meat to improve its functional properties and was widely demonstrated to efficiently improve the gelation properties of muscle proteins derived from mechanically deboned turkey breast [8], spent hen carcass [9], and broiler dark meat [10]. The ISP-extracted poultry protein was also adopted as a food ingredient in value-added meat products [11][12][13][14], which proved its potential role in the maintenance of sustainable economic value. ...
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