Progress 07/01/01 to 06/30/06
Outputs
No further accomplishments since 2005 report due to reassignment of principal investigator.
Impacts
No further accomplishments since 2005 report due to reassignment of principal investigator.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
Our objective was to conduct a shelf-life study to characterize the flavor of RBO fortified WMP by sensory and instrumental analysis. An accelerated shelf-life study (forty days at 45C, aw 0.31) was conducted to accelerate flavor changes in WMP. At time 0 and after 40 days, flavor of WMP was characterized by sensory and instrumental analysis. Descriptive sensory analysis (n=11) was used to document the sensory perception of flavor of rehydrated WMP. Volatile compounds were extracted by high vacuum transfer (HVT) followed by separation into neutral/basic and acidic fractions. Aroma-active volatiles in each fraction were identified by gas chromatography olfactometry (GCO) and gas chromatography / mass spectrometry (GC-MS). The addition of RBO (0.5% w/v) had no effect on the sensory properties of WMP (p<0.05). Sensory changes in flavor occurred in both WMP (p<0.05), however a higher increase in painty/oxidized flavor was identified in the control sample after 40 days
(p<0.05). Volatile profile changes also occurred with storage time, but were not different between control and RBO-treated WMP. Our results suggest that the addition of 0.5% RBO does not drastically change the flavor profile of WMP over time but does delay the development of oxidative off-flavors. The results also suggest that extended shelf-life, high fat dried milk products can be developed as an ingredient for other dairy-based foods without significant flavor changes. Our objective was to determine consumer acceptability of RBO fortified WMP as an ingredient in yeast-raised bread. Four WMP were selected: (1) control (fresh no treatment), (2) WMP with RBO, (fresh), (3) WMP with RBO, (40 days old, accelerated shelf life), and (4) WMP, (32 months old, 22C, 50 % RH storage). WMP were rehydrated and evaluated by descriptive sensory analysis. Yeast - raised potato bread was subsequently made using a straight dough method with each of the four WMP (3.8% dry weight WMP of total recipe). A
standard dough formulation and make-procedure was used. Consumers (n=92) evaluated the four freshly baked breads for the following attributes: aroma, flavor, sweetness, texture, appearance, and overall acceptance using a 9-point hedonic scale. Trained panelists documented distinct differences in the flavor profiles of the rehydrated WMP (p<0.05). Differences were also noted for consumer acceptance of breads made with the different WMP, but these differences were more subtle than those documented by the trained panel. Breads made from WMP 3 received the highest scores for aroma liking, flavor liking, appearance liking, and overall acceptance (p<0.05). Our results suggest that the flavor of WMP (with RBO) with an extended shelf-life will not alter the flavor properties of yeast-raised potato bread. The results also suggest that extended shelf-life, high fat dried milk products can be developed as an ingredient for other baked products without significant flavor changes.
Impacts
The shelf life of whole milk powder (WMP) is approximately 6 to 9 months at 21C, considerably shorter than that of skim milk powder. Extending shelf life of WMP would be desirable. Recent research has indicated that the application of rice bran oil (RBO) could enhance shelf life of WMP. Further research is necessary to characterize flavor and flavor stability of WMP. Milk powder serves as an ingredient in many food products. The use of whole milk powder (WMP) in food production is limited due to its brief shelf life. Recent research has indicated that rice bran oil (RBO) could enhance the shelf life and delay oxidative off-flavors in WMP. Further research is necessary to determine the acceptability of RBO fortified WMP in ingredient applications such as baked goods.
Publications
- A. Coffee. 2005. The effect of high oryzanol (6
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Progress 01/01/04 to 12/31/04
Outputs
The shelf life of whole milk powder (WMP) is approximately 6 to 9 months at 21C, considerably shorter than that of skim milk powder. Extending shelf life of WMP would be desirable. Recent research has indicated that the application of rice bran oil (RBO) could enhance shelf life of WMP. Further research is necessary to characterize flavor and flavor stability of WMP. Our objective was to conduct a shelf-life study to characterize the flavor of RBO fortified WMP by sensory and instrumental analysis. An accelerated shelf-life study (forty days at 45C, aw 0.31) was conducted to accelerate flavor changes in WMP. At time 0 and after 40 days, flavor of WMP was characterized by sensory and instrumental analysis. Descriptive sensory analysis (n=11) was used to document the sensory perception of flavor of rehydrated WMP. Volatile compounds were extracted by high vacuum transfer (HVT) followed by separation into neutral/basic and acidic fractions. Aroma-active volatiles in each
fraction were identified by gas chromatography olfactometry (GCO) and gas chromatography / mass spectrometry (GC-MS). The addition of RBO (0.5% w/v) had no effect on the sensory properties of WMP (p<0.05). Sensory changes in flavor occurred in both WMP (p<0.05), however a higher increase in painty/oxidized flavor was identified in the control sample after 40 days (p<0.05). Volatile profile changes also occurred with storage time, but were not different between control and RBO-treated WMP. Our results suggest that the addition of 0.5% RBO does not drastically change the flavor profile of WMP over time but does delay the development of oxidative off-flavors. The results also suggest that extended shelf-life, high fat dried milk products can be developed as an ingredient for other dairy-based foods without significant flavor changes.
Impacts
Export potential of whole milk powder will be expanded through control of oxidation and improved functional and flavor applications.
Publications
- A. Coffee1, J. U. McGregor1, M. A. Drake2. 2005. Acceptability of potato bread produced with rice bran oil fortified whole milk powder. 1Clemson University, 2North Carolina State University. Abstract IFT annual meeting. New Orleans
- A. Coffee1, M. Carunchia Whetstine2, J.U. McGregor1, M.A. Drake2. 2004. Flavor and stability of whole milk powder with added rice bran oil. 1Clemson University, 2North Carolina State University. Abstract IFT annual meeting. Las Vegas
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Progress 01/01/03 to 12/31/03
Outputs
It is well established that Rice bran Oil (RBO) has strong antioxidant properties because of the presence of compounds such as oryzanol and tocotrienols. Recent research has established that oxidation (TBAR) in whole milk powder (WMP) can be delayed by the addition of RBO to the powder after drying. However a threshold value for the addition of RBO to WMP has not been determined. We hypothesized that a threshold panel would be able to detect the presence of RBO in reconstituted WMP at levels between 0.2% (w/v) and 1% . Our objective was to determine the flavor threshold value for RBO (5% oryzanol) added to WMP after drying. An ascending forced-choice method (ASTM procedure E679-91) of limits was used to determine the group best-estimate threshold (BET). Three trials were conducted with an untrained panel of 61 individuals from the university community. Geometric means were used to determine the BET and a nested statistical design was used to determine the amount of
variability within and between panelists. Our results showed that the panelists (41) could not determine the threshold of the RBO at these levels. The BET for the first trial was 0.2154 and 0.2200% RBO for the first and second repetitions. The BET for the first trial (panelists averages) was 0.2671% RBO. Thirty-four panelists had to be re-tested to verify high and low concentration choices. The third trial BET was 0.5652% RBO (54 panelists). Less than 50% of the panelists chose any one concentration correctly. These results suggest that the addition of RBO to WMP at levels up to 3% will not alter the flavor properties of the WMP. Our results also suggest that extended shelf-life high fat dried milk products could be developed through the used of RBO without significant flavor changes.
Impacts
Export potential of whole milk powder will be expanded.
Publications
- A.D. COFFEE, J. U. McGregor, and J. Rieck. 2004. Flavor threshold of high oryzanol (5
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Progress 01/01/02 to 12/31/02
Outputs
We have identified three potential sources of natural rice bran oil antioxidants (two oil and one powder). We have developed procedures for the use of the oil as well as the powder source. Using the Oxidative Stability Instrument we have determined that all these RBO antioxidant products are very heat stable in milk fat systems and therefore can be added at any point in the manufacturing process. The optimal point of addition will vary depending on the manufacturer's processing design and system. We have also determined that the antioxidant can be added after the drying process as an oil mist.
Impacts
Increased shelf-life of high fat containing dairy powders. Improve international competitiveness of US in export of whole milk powders.
Publications
- Osorio, L. F. 2002. Effect of drying technologies and natural rice bran oil anitoxidants on the stability of whole milk powder. PH.D. Dissertation. Clemson University
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Progress 01/01/01 to 12/31/01
Outputs
Dried acid whey was compounded (formulated) with glycerol (Fisher Scientific, Fair Lawn, NJ) and water. Mixtures of different compositions were compounded in a laboratory scale process to produce a biobased flexible film and film coating. The whey content was varied from 55% (by weight) to 70%, and the water and glycerol content from 0% to 15% and 20% to 30%, respectively. Variables that were evaluated were protein:water ratio, pH, temperature, and plasticizer level. We have not been able to create a processing system that produces an accetable film or film coating. Films that have been produced lack flexability and are very brittle. We have been able to apply coatings. However, these coatings have been very hydrophobic making them unsuitable for application to cheese products.
Impacts
Increased utilization of acid whey, a by product of the U.S. cheese industry. Increased understanding of heat induced protein reactions.
Publications
- Nanua, J. N., J. U. McGregor and J. S. Godber. 2000. The influence of high-oryzanol rice bran oil on the oxidative stability of whole milk powder. J. Dairy Science. 83:2426.
- J. N. Nanua and J. U. McGregor. 2000. The potential of high-oryzanol rice bran oil as an antioxidant in whole milk powder. 2000 annual meeting of IFT.
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