Summary of a research project funded by the National Honey Board and conducted
at Clemson
University. Investigators: P.L. Dawson, Ph.D. and S. Mathew
Food processors use honey in many different food products. Sweetness, functional advantages and natural appeal are some of the reasons honey is a valued food ingredient. Some of the functional characteristics that honey provides include humectancy, viscosity, flavor, color, hygroscopicity, miscibility and spreadability.
In meat products such as hams, bacon and sausage, honey enhances meat and spice flavors when mixed with the brine, can help bind ingredients and is a culture substrate in cured products.
Honey may also improve the cook yield in poultry meats. Because meat products are sold by weight, yields are very important to meat processors. A 1% loss or gain can translate into tens of thousands of dollars per week for large operations.
The sugar-amine reaction known as the Maillard browning reaction has long been known to produce compounds having antioxidant properties. While the browning reaction also produces brown pigments, some unique flavors are also associated with the reaction. The Maillard reaction occurs between a ketone and or aldehyde group from a reducing sugar and an amine when heated. In food, aldehydes and ketones are found in simple sugars including those found in honey. The amines are found in protein material including meats. Honey contains large amounts of reducing sugars, which can participate in the Maillard reaction along with the amines found in poultry meat. Honey also carries its own unique flavor attributes that may complement cooked meat flavors found in poultry.
The objectives of this research project were to determine if the addition of honey to poultry meat products prior to cooking would slow the rate of oxidation and extend the flavor quality of the final product.
To determine the effect of adding honey to poultry meat products, the honey was incorporated into the product by mixing with meat chunks prior to cooking. The meat-honey mixture was placed into a casing and cooked to form a high quality turkey breast meat product. The product was sliced to form a luncheon meat-type product. The hypothesis was that honey would both slow the development of oxidized off flavors and would add positive flavors to the final product. To further determine the antioxidative properties of a honey meat mixture, a model system was used.
Turkey breast meat rolls were processed using 0, 5 and 15% levels of dry honey and the cooked products were sliced, vacuum packaged and stored under refrigeration (4 °C). The turkey breast meat formulations included salt and phosphate at the 2% and 0.4% levels, respectively. These levels are typical of high-quality turkey breast meat products. The stored samples were evaluated over an 11-week storage period. Evaluations included cook yield and proximate composition. Flavor panel, color, microbiological and oxidative stability (using the thiobarbituric acid value and oxidative stability instrument) were also measured.
The antioxidative properties of honey and meat were evaluated using a model system consisting of turkey breast meat mixed with 0, 1, 5, 10, 15 and 20% honey. The mixture was cooked in sealed polyethylene bags to an internal temperature of 72 °C then stored at 4 °C for 48 hours. The oxidative products were evaluated using the thiobarbituric acid test, the oxidative stability instrument and gas chromatography.
The 15% honey treatment had the highest cook yield with the 0% level having the lowest with the 5% level being intermediate (Table 1). It appears that the 15% level of added honey would allow the addition of more water during the process without a loss in quality or yield. Both the 5 and 15% honey-added meats had more protein and less fat than the 0% level. This is primarily due to the dilution of these components by the addition of honey. Proximate analysis of the raw turkey, the raw turkey batter and the cooked product reflected the reduction of moisture, protein and fat content by the addition of honey (Table 2). Carbohydrate content was determined based on calculation of the addition of honey.
There was growth of bacteria in some packages of the 0 and 5% samples during the 11 weeks of storage; however, no bacterial growth was detected in the 15% honey samples for total plate count over 11 weeks of refrigeration.
Sensory trials were reported separately in two trials because there was a significant replication effect. Both trials found differences in sweetness between the samples but the added honey samples had equal or greater acceptability over the nonhoney added samples (Table 3).
The thiobarbituric acid value (TBA) is a measure of the degree of oxidation in a product. The addition of 15% honey to the meat product significantly reduced the TBA values compared to the 0 and 5% samples (Table 4). This reduction may be due to the production of antioxidative compounds during cooking via the Maillard reaction. The reduction may also occur as a result of reduced water activity in the 15% honey treatment compared to the other samples. Although the cause is still under investigation, it is clear that the 15% honey treatment slowed the rate of oxidation. The antioxidative effect was further supported by the oxidative stability instrument (OSI) results. The OSI measures the production of oxidative compounds from a controlled environment and is able to compare the relative rates of oxidation between various samples. The 15% level showed a slower rate of production of oxidative products compared to the 0 and 5% levels in the OSI. Aldehydes (C4, C4, C7, C8 and C9) were found to decrease in presence in samples as the concentration of honey was increased (1, 2, 5, 10, 15 and 20%). Aldehydes are indicators of oxidizing fats in food systems. Hexanal is a primary aldehyde produced during oxidation and this C6 compound exhibited a negative slope relationship between hexanal concentration and honey levels in raw meat (R2 = 0.86), cooked meat (R2 = 0.86) and in cooked meat held 48 hours (R2 = 0.98). Cooked meat is more susceptible to oxidation compared to raw meat.
The TBA values were not significantly different (p<0.05) between the 0 and 1% honey-containing samples, both in freshly cooked and cooked samples stored for 48 hours. Significant differences were observed between the 0% honey samples and the 5, 10, 15, and 20% honey-added samples in both freshly cooked and stored samples. The percent inhibition of oxidation between the 0, 5, 10, 15 and 20% honey cooked samples before storage was 32, 56, 58 and 64% respectively. After storage for 48 hours, the inhibition of oxidation was 14, 46, 67 and 75% for both freshly cooked and stored samples. The TBA values were not significantly different between the 15 and 20% honey-containing samples.
Continued work has begun to determe the mechanism by which honey acts as an antioxidant in meat. It is theorized that the Maillard Reaction Products are the source of the antioxidative effect; however, there may be other mechanisms in action.
It may also be possible to form antioxidative flavor compounds by combining honey with meat proteins. These flavor compounds could then be added to meat products just prior to thermal processing.
©2007 National Honey Board
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