Summary of a research project funded by the National Honey Board and conducted
at Clemson
University.
Investigators: P.L. Dawson, PhD and J. C. Acton, PhD
The objective of this research project was to combine honey and tumbleprocessed turkey meats and to evaluate the flavor, color, microbial growth and oxidative stability of the final product. The honey was mixed with the meat in addition to being used as a coating.
Three formulations of delistyle, luncheon turkey breast meat were developed: a control formulation with no added honey and two formulations with added honey. Liquid honey and dried honey were added to chopped turkey breast meat chunks at the 10% level (see Tables 1 and 2).
The turkey breast meat was evaluated within three days of cooking by microbial analysis, instrument shelf life tests and by sensory panels. Both trained and untrained sensory panels evaluated turkey luncheon meat with: no honey added (control); added liquid honey; and added dry honey. Color, bacterial counts, and volatile off flavor analysis were performed over extended storage times on a weekly basis and then on a monthly basis through five months. The following is a review of these results.
An untrained panel of 64 people and a trained panel of 14 tested juiciness, tenderness, sweetness, sweetness intensity and flavor. All characteristics were evaluated using an eight-point scale, except sweetness, which was evaluated using a five point scale. The untrained sensory panel ranked the three samples similarly for juiciness. The control and dry honey received similar “ moderately juicy” and “ moderately tender” rankings, and liquid honey ranked highest in sweetness and sweetness intensity (see Table 3).
The trained panel results were similar to the untrained panel results; however, the trained panel ranked dry honey first, while the untrained panel ranked the no-honey treatment first for flavor desirability. Considering widespread taste differences, the mean value did not differ significantly (see Table 4).
Meat Color Color was analyzed using a Spectroguard spectrophotometer for CIE L-, a-, and b-values, which were converted and/or reported as L-value, chroma and hue angle. Reflectance readings were measured through the package with any contribution of the package material to color being subtracted using a computer program. Three samples for each treatment were measured at eight different locations to determine color means.
The L-value indicates the degree of darkness to lightness; the
higher the
value, the lighter the color . The a-value, or hue angle, indicates
the degree of green to red; the more positive the value the more red
the sample. The
b-value
indicates the degree of hue
from blue to yellow; the more positive the value, the more
yellow the sample.
The L-value was lower in the liquid and dry honey meat samples, meaning the samples were darker in color than the no-honey control (see Figure 2). The added honey reduced the a-value or hue angle in comparison to the control meaning the color of the samples was less red. The color pigments in the honey altered the reflectance profile making the meat appear less red and more brown (see Figure 3). The added dry honey resulted in a more yellow and intense color compared to the liquid and no honey treatments (see Figure 4). Honey significantly changed the color of the turkey sample to a darker, more brown and more intense color.
Total aerobic plate counts were performed using standard microbiological methods on pour plates with serial dilutions to obtain bacteria in countable ranges. Initial total aerobic and anaerobic bacteria counts on raw batters were not significantly different (see Figure 5). A high oxygen transmission rate film was used for storage, thus anaerobic enumeration was not used. The honey-added cooked treatments resulted in lower levels of bacteria compared to the control. All samples had relatively low bacteria counts, indicating that honey may be useful for inhibiting bacterial growth in other meat products that are less stable or require longer storage time than poultry meat.
The stored meat was removed from the package, chopped to obtain a sample that would be representative of the total, then placed in a sealed vial. The sealed vial was heated in a headspace analyzer then injected into a gas chromatograph that is capable of separating volatile oxidized compounds. The compounds were identified by comparing the retention times to known standards and in some cases verified using mass spectrophotometry.
The development of off-flavor compounds from oxidation is a common problem in turkey because of its high unsaturated fat content. However, none of the honey meat samples oxidized during the storage evaluation period. This indicates that honey reduced oxidative breakdown of lipids and the development of offflavors; and therefore has a stabilizing effect on the meat flavor.
Moisture content of the cooked samples was determined using the AOAC oven procedure. Process cook yields and cook loss were determined by subtracting the pre-cook weight from the post-cook weight and dividing this result by the pre-cook weight and expressed on a percentage basis. The moisture loss was determined by subtracting the pre-cook moisture content percentage from the post-cook moisture content percentage.
The moisture content of the dry honey was lowest in the raw batter and cooked meat, followed by the liquid honey and the control. However, the meat with the added dry honey had the highest cook yield and lowest moisture loss of the three treatments (see table 6 and 7). This will be of great interest to meat processors because the dry honey reduced cook loss and increased yields but bound added water.
Honey imparts flavor, color, moisture, oxidative stability, antimicrobial effects and nutrition to processed turkey meats. Sensory analysis reveals that honey adds a sweet flavor to turkey meat, which can enhance the sometimes bland flavor of chicken and turkey breast meat. The reducing sugars in honey add a golden- to dark-brown color to the surface and interior of meat during heating via nonenzymatic (Maillard) browning. Honey also decreases moisture loss, reduces oxidative breakdown of lipids, improves cook yield and slightly lowers bacterial counts, thereby increasing shelf stability. Nutritionally, honey does not add any fat and only a few calories depending on the quantity added. These findings reveal that the addition of honey to tumble-processed turkey meats can produce more flavorful, stable, moist and healthful products.
©2007 National Honey Board
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