Progress 10/01/00 to 09/30/05
Outputs
Tomato pomace (unprocessed green tomatoes, liquor, trimmings, peels, cores, culls, and seeds) can be used as an ingredient in poultry diets as a source of the antioxidant, alpha-tocopherol (Vitamin E), in subsequent stored, processed meat if the fiber content of the byproduct can be reduced. White rot fungi species (Pluerotus spp) was added to pomace to convert fibrous components to digestible ingredients. Lignin biodegradation and subsequent nutritional value (crude protein, lipid, ash, acid detergent fiber, nutrient detergent fiber, in vitro digestibility, manganese, alpha-tocopherol, lycopene and beta-carotene) of treated pomace and the spent (substrate residues after harvesting of mushrooms) was assessed. Results of one experiment using an oxygen/carbon dioxide bioreactor indicated that active fungal fermentation occurred. Other results from subsequent experiments showed that the lignocellulose complex (specifically, cellulose and hemicelluloses) was degraded in
spent pomace; however, contents of alpha-tocopherol, lycopene and beta-carotene were reduced. Crude protein content increased. Added manganese did not positively improve fermentation. Successful cultivation of the oyster mushroom was achieved. More research must be conducted to determine (1) if the amount of alpha-tocopherol remaining in spent tomato pomace is useful as an antioxidant in processed meat from birds fed treated pomace and (2) if the fiber content is reduced enough to not deter growth.
Impacts
Poultry producers can use tomato pomace as a feed ingredient if the fiber content is significantly reduced enough to positively promote growth. One possible use of treated pomace is as a feed ingredient in the diets of molting laying hens.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
White rot fungi species (Pleurotus spp) are known for their ability to bioconvert fibrous components of byproducts into digestible ingredients. Particularly, the edible oyster mushroom (Pleurotus ostreatus) has the potential ability to degrade lignin selectively. Work is underway to optimize treatment procedures of tomato pomace with white-rot fungi oyster mushroom (P. ostreatus) for (a) successful bioconversion of this biomass into valuable animal feed and (b) to improve utilization of the pomace as a substrate for oyster mushroom production by amendment with varying quantities of manganese. Lignin biodegradation and subsequent nutritional values (crude protein, lipid, ash, acid detergent fiber, nutrient detergent fiber, in vitro digestibility, manganese, alpha-tocopherol, lycopene and beta-carotene) of treated tomato pomace and the spent (substrate residues after mushroom harvesting) will be assessed. Also, the activity of specific extracellular enzymes will be
determined.
Impacts
Expected outcomes of this research are development of novel methods for fungal treatments of tomato pomace and possibly rice straw, enhanced knowledge regarding the proper use of extracellular enzymes when treating agricultural byproducts with white-rot fungi and development of principles of cultivation for oyster mushroom into tomato pomace, with possible future utilization of the spent for value-added animal feed. Ultimately in future work, new foods for humans and animals could be produced while reducing a possible negative impact on the environment and human health.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
Results of research suggested that tomato pomace (unprocessed green tomatoes, liquor, trimmings, peels, cores, culls, and seeds) could be used as an ingredient in poultry diets as a source of the antioxidant, alpha-tocopherol (Vitamin E), in subsequent stored, processed meat if fiber content of pomace could be reduced. Work was conducted to determine if the edible oyster mushroom, Pleurotus Ostreatus, could biodegrade lignin in the complex lignocellulosic matrix in pomace so that cellulose could be degraded as well. Under the conditions used, oyster mushroom degraded hemicellulose but did not degrade lignin. It seemed that alpha-tocopherol content after fermentation was less affected by autoclaving during sample preparation compared to beta-carotene and lycopene. More research is planned to enhance the growth conditions for the mushroom to achieve successful lignin degradation. Grape seed extract, a source of tannins from wine making, can be added at 1.0% to
significantly retard lipid deterioration (measured as thiobarbituric acid reactive substances) in stored, processed dark turkey meat. An assay that could be used to determine the amount of tannins (flavonoids known as concentrated oligomeric catechins) added to dark turkey meat was adapted from a procedure used to determine tannins in wine. Overall percent recovery of added tannins as GSE (0.5% to 5.0%) in meat was 54.78%. When the adapted method was used to determine tannins in spiked samples, determinations for four out of five samples estimated the original value within 10%. If GSE were used as an antioxidant in dark turkey meat (possibly other types of meat as well), the method could be used as a tool in quality control for commercial products.
Impacts
Tomato pomace and grape seed extract can be important value-added products for consumers and the agricultural and health industries. Both products contain antioxidants that could be used in a variety of ways.
Publications
- King, A. and Zeidler, G. 2003. Tomato pomace as a source of alpha-tocopherol in diets of broilers. California Agriculture. IN PRESS.
- Lau, D. W.; King, A. J. 2003. Pre- and postmortem use of grape seed extract in dark poultry meat to inhibit development of thiobarbituric acid reactive substance. J. Agric. Food Chem. 51, 1602 thru 1607.
- Lau, D.W.; King, A. J.; Waterhouse, A. L. 2003. An assay to estimate tannins added to postmortem turkey meat. J. Agric. Food Chem. 51, 6640 - 6644.
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Progress 01/01/02 to 12/31/02
Outputs
Grape seed extract (GSE) contains phenolic compounds as antioxidants that reduce lipid deterioration in stored dark chicken meat by ten-fold when compared to a control. In order to determine the levels of phenolic compounds (tannins) remaining in stored dark meat after processing and storage, research was conducted to alter and refine the method used to quantify tannins in wine. It was necessary to include meat (protein) and to adjust other chemicals in the solution when developing standard curves. Ten replicates of six treatments containing approximately two grams of meat and 0, 1.0, 1.5, 2.0, 2.5 or 5.0 grams of GSE were run. Statistical analyses will be used to compare the mean regression lines produced from the experiment. Meat samples containing unknown quantities of GSE will be quantified using the refined method.
Impacts
(N/A)
Publications
- Lau, Doris. W. and King, A. 2000. Phenolic compounds as antioxidants in poultry meat. Perishables handling quarterly, Issue No. 102,University of California, Davis.
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Progress 01/01/01 to 12/31/01
Outputs
Grape seed extract (GSE) contains phenolic compounds as antioxidants that reduce lipid deterioration in stored dark chicken meat by ten-fold when compared to a control. In order to determine the levels of phenolic compounds (tannins) remaining in stored dark meat after processing and storage, research was conducted to alter and refine the method used to quantify tannins in wine. It was necessary to include meat (protein) and to adjust other chemicals in the solution when developing standard curves. Ten replicates of six treatments containing approximately two grams of meat and 0, 1.0, 1.5, 2.0, 2.5 or 5.0 grams of GSE were run. Statistical analyses will be used to compare the mean regression lines produced from the experiment. Meat samples containing unknown quantities of GSE will be quantified using the refined method.
Impacts
(N/A)
Publications
- Lau, Doris. W. and Annie King. 2000. Phenolic compounds as antioxidants in poultry meat. Perishables handling quarterly, Issue No. 102,University of California, Davis.
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