Progress 10/01/98 to 09/30/04
Outputs
This project focused on enhancing the already outstanding nutrient profile of meat by various processes designed to improve lipid profile, retard deterioration, and increase functional food value by increasing levels of important nutrients, especially starch, fiber and antioxidants. Three approaches were successfully used to enhance the functional properties of beef. Almost half of the beef processed is as a comminuted (ground) product. It is a fairly facile process to mix various ingredients into hamburger and other comminuted beef mixes. Research demonstrated that ground beef and precooked ground beef patties were enhanced from the standpoints of both quality, by inhibiting warmed-over flavor (WOF), and nutritionally, by lowering fat and adding starch and fiber. Inhibition of WOF is an important advance in technology because of the use of cooking to destroy pathogenic microorganisms prior to marketing meat to consumers. For decades, this process has not been used
because of the development of WOF. Comminuted meat, therefore, is easily altered by addition of useful ingredients. In contrast, intact muscle meats present a greater challenge and two techniques were used to address this problem. Vacuum tumbling in various types of brines that include starch, fiber and antioxidants demonstrated some improvement in resistance to WOF and modestly improved nutrient profile. A third technique studied was the rinsing and chilling technology (R&CT), a postmortem rinsing of blood from the circulatory system of beef carcasses. Reducing the residual blood and adding antioxidants was noted to enhance resistance to WOF and improve quality of meat. In addition, a significant reduction in cholesterol content was noted in several muscles, further enhancing the functional food properties of beef. A fourth approach, combining vacuum tumbling and R&CT was also studied. These studies demonstrated that using R&CT prior to vacuum tumbling greatly increased the
effectiveness of the latter technique. It was hypothesized that the R&CT altered capillaries, opening the structure of meat so that penetration by ingredients was improved during the vacuum tumbling process.
Impacts
The results of this project have developed a number of approaches designed to solve some of the most nettlesome problems in the meat industry, especially the beef industry. Precooking of meat is now a possibility and affords the processor a means of protecting consumers from diseases carried by meat. Lowering cholesterol content was thought to be virtually impossible but has been accomplished by this research.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
If evaluated on three key criteria, content, bioavailability and safety, beef ranks highest among all foods for iron and zinc, two crucial trace minerals. However, the lipid profile of beef and tallow (refined beef fat) has been criticized for decades. The presence of saturated fat and cholesterol are seen as possibly contributing to coronary heart disease by some medical authorities. Rinsing and chilling technology (RCT) is a newer processing aid that was studied as a means affecting two beneficial changes in beef muscle composition: reduction of cholesterol content and enrichment with antioxidants. Our research confirmed our previously reported finding of significant reductions of cholesterol, generally between 5 and 20%. High performance liquid chromatography and gas liquid chromatography showed good agreement and confirmed the cholesterol lowering effect of RCT. The introduction of vitamin E by RCT was shown to inhibit lipid oxidation associated with cooking and
refrigerated storage. A study was conducted to determine if adding vitamin E prior to rigor mortis, as is done by the RCT technique, is advantageous compared to adding E to meat after rigor is completed, the normal type of addition. Tocopherol and tocotrienol were compared because of reports that tocotrienols appear to be more efficiently incorporated into the sarcolemmal membrane, the focus of lipid oxidation. Tocotrienol was a more efficient antioxidant than tocopherol; prerigor introduction was more effective than postrigor. This indicates that the incorporation of antioxidants into membrane of muscle may be an active process, requiring an energy consuming transport process; these results clearly support the use of RCT as a method of antioxidant enrichment of meat. Antioxidant enrichment has two advantages, preventing loss of savory flavor compounds after cooking and enriching the meat with antioxidants known to slow the progression of atherosclerosis, the forerunner to heart
disease. In this manner, beef and other meats can be considered to have an enhanced nutraceutical value. In recent years, a controversy has developed concerning the quantity of fat and nature of the fat absorbed in deep-fat fried food. We hypothesized that frying in a saturated fat would reduce oil absorption into the fried foods and have substantiated this hypothesis in studies comparing a relatively saturated fat such as tallow to polyunsaturated vegetable oils. The amount of fat absorbed into the food is reduced. In these studies, tallow was treated to remove the cholesterol prior to use. Polyunsaturated oils were found to produce high levels of toxic chemicals when used for frying; tallow produced much lower levels of toxic chemicals, chiefly aldehydes and peroxides.
Impacts
There has been much difference of opinion regarding the cholesterol content of beef, and also among other species such as pork, poultry, and seafood. We hypothesize that differences in residual blood may explain some of these disagreements in the literature. The RCT process can be enhanced to extract even greater amounts of cholesterol from meat. The possibilities of lowering cholesterol content and enriching nutrients by the RCT technology will benefit consumers, the beef industry, and the State of Minnesota, home of the company that owns the technology.
Publications
- Yancey, E.J., Dikeman, M.E., Addis, P.B., Katsanidis, E. and Pullen, M. 2002. Effects of vascular infusion with a solution of saccharides, sodium chloride, phosphates, and vitamins E, C, and C+E on carcass traits, Warner-Bratzler shear force and palatability traits of steaks and ground beef. J. Anim. Sci. 80:1904-1910
- Yancey, E.J., Dikeman, M.E., Addis, P.B., Katsanidis, E. and Pullen, M. 2002. Effects of vascular infusion with a solution of saccharides, sodium chloride, and phosphates with or without vitamin C on carcass traits, Warner-Bratzler shear force, flavor profile, and descriptive attribute characteristics of steaks and ground beef from Charolais cattle. Meat Sci. 60:341-347
- Evans, J.C., Kodali, D.R. and Addis, P.B. 2002. Optimal tocopherol concentrations to inhibit soybean oil oxidation. J. Amer. Oil Chem. Assoc. 79:47-51.
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Progress 01/01/01 to 12/31/01
Outputs
Efforts to improve the functional food status, or nutraceutical value, of meat products have received assistance by the USDA approval of a new vascular rinsing and chilling technology applied immediately after bleeding. We have demonstrated several important alterations in muscle properties and composition if carcasses are subjected to vascular rinsing and chilling, most of them beneficial and several addressing issues of importance to consumers. Vascular rinsing and chilling achieved a significant reduction in muscle cholesterol levels, thereby accomplishing what most scientists believed to be impossible due to the integrity of the cholesterol binding to muscle components such as membranes and subcellular membranes and particles. Cholesterol, although a minor lipid component, is one of high profile. The beef triceps brachii and semitendinosus were analyzed for cholesterol by normal phase high performance liquid chromatography. A 23% reduction in cholesterol was
achieved by vascular rinsing and chilling compared to controls. In a separate study, four other muscles were analyzed by both gas liquid chromatography and high performance liquid chromatography and all four muscles displayed reduced cholesterol levels compared to controls or, in other words, cattle not subjected to vascular rinsing and chilling. In the normal exsanguination process the typical animal will lose half of the blood supply. Vascular rinsing removes a significant portion of the remaining blood. In doing so, cells such as red and white cells and platelets, and lipoprotein particles that transport cholesterol to peripheral tissues, are rinsed out of the capillary system. The loss of cholesterol rich materials from the blood likely explains much of the cholesterol lowering effect of vascular rinsing. These findings also likely explain the high degree of animal to animal variation in cholesterol content because it has long been known that animals vary greatly in terms of
efficiency of bleeding at slaughter. Vascular rinsing and chilling, as commercially practiced, affords numerous other opportunities to further the development of nutraceutical beef products. Employing normal phase high performance liquid chromatography, it was demonstrated that 3 to 8 ppm vitamin E could be deposited in beef muscle by vascular rinsing, levels that would otherwise require months of costly feeding of a vitamin E rich diet to accomplish. Infusion with a calcium rich solution greatly augments the low calcium content of beef but quality is adversely influenced and the ability of the muscle to hold water is reduced. Effects on tenderness and descriptive attribute sensory panel results were minimal in A-maturity cattle. In older animals, or lower grade beef cattle, where tenderness is a continuing problem, vascular rinsing and chilling improved tenderness significantly. In some studies, it has been demonstrated that vascular rinsing and chilling tenderizes muscles of the
chuck. It is now possible to use dry heat, short time temperature treatments to achieve acceptable chuck muscle tenderness.
Impacts
The health controversy concerning beef in the human diet will continue to adversely affect beef consumption. The hypothesized relationship of beef lipids to coronary heart disease is the focus with saturated fat and cholesterol viewed as important contributors. The possibilities of lowering meat cholesterol and adding vitamin E and other nutrients not normally found in meat at high levels are exciting and should be vigorously researched in the near future. These results will benefit consumers, the beef industry and the State of Minnesota, home of the company that owns the technology for vascular rinsing and chilling. Low cholesterol, vitamin enriched meat may be preferred by health conscious consumers and vascular rinsing may afford the possibility of influencing carcass quality in a way that is unique based on its ability to influence the crucial early postmortem time period.
Publications
- Urgul, T., Addis, P.B., Brannon, J., Endres, M. L., and Noll, S. L. 2001. High oleic corn in turkey diets: carcass composition and parts yield of market tom turkeys. Poul. Sci. 80: Supp. 1, p. 327.
- Yurttas, H. and Addis, P. B. 2001. Antioxidant activity of palm tocotrienols in meat systems. Food Technol. Nutr. Conf., 2001 PIPOC International Palm Oil Congress, Kuala Lampur, Malaysia, pp. 31-35.
- Yancey, E. J., Hunt, M. C., Dikeman, M. E., Dobbels, T. E., and Addis, P. B. 2001. Effects of vascular infusion with a solution of saccharides, sodium chloride, and phosphates with or without vitamin C on carcass traits, Warner-Bratzler shear force, flavour-profile, and descriptive attribute characteristics of steaks and ground beef from Charolais cattle. Meat Sci. 58: (in press)
- Ruan, R., Lundberg, B., Gu, L., Chen, L., Johnson, J. and Addis, P. 2000. Cellulose fiber-based compositions and their method of manufacture. U.S. Patent Pending, SLWK#600.473US1
- Ruan, R., Xu, L., Yi, L., Chen, L., Johnson, J. and Addis, P. 2000. Cellulose fiber compositions and film and the process for their manufacture. U.S. Patent No. 6,083, 582. Issue date: July 4, 2000.
- Yancey, E. J., Dikeman, M. E., Addis, P. B. , Katsanidis, E., and Pullen, M. 2001. Effects of vascular infusion with a solution of saccharides, sodium chloride, and phosphates with or without vitamin C on carcass traits, Warner-Bratzler shear force, flavour profile, and descriptive attribute characteristics of steaks and ground beef from Charolais cattle. Meat Sci. (in press)
- Yancey, E. J., Hunt, M. C., Dikeman, M. E., Addis, P. B. , and Katsanidis, E. 2001. Effect of postexsanguination vascular infusion of cattle with a solution of saccharides, sodium chloride, phosphates, and vitamins C, E, or C+E on meat display-color stability. J. Anim. Sci. 79:2619-2626.
- Yancey, E. J., Dikeman, M. E., Addis, P. B., Katsanidis, E., and Pullen, M. 2001. Effects of vascular infusion with a solution of saccharides, sodium chloride, phosphates, and vitamins C, E, or C+E on carcass traits, Warner-Bratzler shear force, and palatability traits of steaks and ground beef. J. Animal Sci. (In press)
- Addis, P., Ruan, R., Keenan, J., Oins, P., and Geleva, D. 2001. Medical and nutritional applications of highly refined soluble fiber. United States Patent Application 60/329255
- Evans, J. C., Kodali, D. R., and Addis, P. B. 2001. Optimal tocopherol concentrations to inhibit soybean oil oxidation. J. Amer. Oil Chemists' Assoc. (In press)
- Grootveld, M., Silwood, C. J. L., Addis, P. B., Claxson, A., Serra, B. B., and Viana, M. 2001. Health effects of oxidized heated oils. Foodservice Res. International 13: 39-53.
- Katsanidis, E., D. E. Meyer, R. J. Epley, P. B. Addis, and R. Ruan. 2001. Solubilized cellulose and dehydrated potato extract in cooked, low-fat comminuted beef. J. Food Sci. 66:758-761.
- Lin, G., Ruan, R. R., Chen, P., Wilcke, W., and Addis, P. 2001. Structure-function relationships of highly refined cellulose. Trans. Amer.Soc.Agricultural Engineers 44(6): (in press)
- Ruan, R., Xu, L. Yi, L., Chen, L., Johnson, J. and Addis, P. 2001. Cellulose fiber compositions and film and the process for their manufacture. International patent pending. Application No. PCT/US98/15396
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Progress 01/01/00 to 12/31/00
Outputs
Heart disease research continues to emphasize two main issues regarding consumption of fat and cholesterol. One hypothesis claims it is the nature of lipid that is responsible for arterial plaque accumulation; therefore, saturated fat and cholesterol are inherently damaging to vessels. The other hypothesis states that it is alteration of lipids, by oxidation, that renders lipid toxic to vessels. These two hypotheses are widely divergent, as saturated fat is virtually impossible to alter by oxidation; polyunsaturates are highly susceptible. Two modes of exposure of humans to lipid oxidation products can occur: (1) oxidation of lipids in the body and (2) oxidation of lipids in foods that are assimilated into tissues, including blood vessels. The latter area, neglected by researchers for many years, is now rapidly gaining attention. It is quite likely that both amount and type of fat in the diet and oxidative modification of fats in specific foods susceptible to
oxidation are involved in development of heart disease. A comparison of grass- and grain-fed cattle showed grain-fed displayed 50% less intramuscular fat (P<0.0033), 2.2% less muscle cholesterol (P<0.0231), and very slight differences in fatty acid composition, with grass-fed beef exhibiting lower saturated fatty acid contents. Studies of common food ingredients such as rice bran and oat fibers revealed significant inhibition of lipid oxidation in cooked meat. Effectiveness of antioxidant protection appeared to correlate with the lignin content of bran. This was confirmed by assaying antioxidant capacity of purified lignin. Cooked meat lipid oxidation was inhibited (P>0.05) by addition of lignin. In soybean oil, the four different tocopherol homologs displayed substantially different optimum concentrations for inhibiting oxidation. Soybean oil has tocopherol concentrations higher than optimum levels and is a large contributor to the exposure of humans to oxidatively modified lipids.
Impacts
This research has demonstrated the importance of feeding regimes for cattle for the production of beef that is low in cholesterol, fat, percentage of kilocalories from fat and total energy content. Additionally, nutriceutical additives and ingredients have been evaluated for the inhibition of lipid oxidation in foods.
Publications
- Chen, P. L.., Ruan, R. R., Addis, P. B., Yi, L. 2000. Cellulose fiber based compositions and film and the process for their manufacture. U. S. Patent 6,083,582
- Katsanidis, E. 2000. Evaluation of novel antioxidant systems and their usefulness in the production of precooked meat products. Ph. D. Thesis, University of Minnesota, St. Paul, 94p.
- Lundberg, B. M. 2000. Development of a new process to make highly refined cellulose. M. S. Thesis, University of Minnesota, St. Paul, 122p.
- Meyer, D. C. 2000. Evaluation of rice bran flour and oat fiber as antioxidants and binders in meat products. M. S. Thesis, University of Minnesota, St. Paul, 108p.
- Waibel, P. E., Brannon, J. A., and Addis, P. B. 2000. Comparison of normal and high-oil corns for turkeys. Applied Poul. Sci. 9:375-383.
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Progress 01/01/99 to 12/31/99
Outputs
Human heart disease research continues to be largely focussed on the use of antioxidants to prevent free-radical induced damage to arteries that causes plaque accumulation. Vitamin E has long been the primary focus of such research. However, vitamin E is a complex mixture of eight homologs, all variable with respect to vitamin E activity, and also variable with respect to ancillary, but important, biological properties; these include antioxidant-, antithrombotic- and hypocholesterolemic-activity. Vitamin E is composed of two types of homologs, tocopherols and tocotrienols (tocols); the tocopherols are generally higher in vitamin E activity but lower than the tocotrienols in antioxidant, antithrombotic and hypocholesterolemic activities. Efforts to sort out all of the complex effects of the eight forms of vitamin E have been slowed by the lack of methodology for isolating and quantifying vitamin E homologs and other important lipids such as cholesterol. Two isocratic
high-performance liquid chromatography (HPLC) methods for the simultaneous analysis of tocopherols, tocotrienols, and cholesterol were developed. One method involves basic saponification but was found to cause losses of some of the homologs of vitamin E. The second method omits saponification and was found not to destroy any vitamin E homologs. Ethanol is added to the sample followed by homogenization for 30 seconds. Water is added followed by homogenization for 15 seconds. Hexane is added, followed by homogenization for 15 seconds. After centrifugation the upper layer (hexane) is collected and analyzed by normal phase isocratic HPLC. Twenty microliters of the extract supernatant are injected. The HPLC column used is a silica column (Zorbax RX-SIL, 5-micrometer particle size, 4.6-millimeters inside diameter and 25 centimeters in length). The wavelength is programmed at 295 nm for vitamin E homologs and 202 nm for cholesterol. The eight tocols are eluted in only 9 minutes and
cholesterol in 11 minutes. Therefore, this method is quite simple and fast to execute and will find many applications in the analysis of foods, plasma, and tissue samples. The recovery from muscle tissue was 96% for the homologs of vitamin E and 94% for cholesterol. The method should find useful application in clinical trials designed to study the cholesterol lowering and antioxidant activity and other useful properties of the tocols, especially the tocotrienols. Some studies have suggested that tocotrienols are able to reverse atherosclerosis, reducing the amount of plaque deposited on arteries and improving blood flow. The method also has been successfully employed to evaluate new technologies currently under investigation by the meat industry to deposit antioxidants into meat tissue and lower cholesterol in meat (results reported last year). Another important finding of this study is that if saponification is used, losses of some important homologs occur. Therefore, in some studies
published in the past, if saponification was used, results may be erroneous and these studies, if repeated with improved methodology, would yield different results.
Impacts
This research provides a novel but simple method that will greatly enhance the research efforts designed to reduce the prevalence of heart disease and ultimately associated health care costs. It may be that in the future, vitamin E, especially the tocotrienols, will be used to reverse the accumulation of plaque that is so important in human heart disease.
Publications
- Waibel, P. E., Brannon, J. A. and Addis, P. B. 1999. Comparison of normal and high oil corns for turkeys. J. Appl. Poultry Res. (in press).
- Katsanidis, E. and Addis, P. B. 1999. Inhibition of rancidity and improvement of cooking yield can allow for precooking of patties as a means of controlling pathogens. Foodservice Research International 11:107-113.
- Katsanidis, E. and Addis, P. B. 1999. Novel HPLC analysis of tocopherols, tocotrienols and cholesterol in tissue. Free Radical Biol. Med. 27:11/12 p 1137-1140.
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Progress 01/01/98 to 12/31/98
Outputs
Research has clearly demonstrated that heated oils in particular and rancid foods in general are a dietary factor that induces blood vessel lesions in experimental animals. Therefore, fats and cholesterol in the diet which are altered by oxidation or heat-induced changes may become recognized as risk factors for human coronary heart disease. Improving the stability of oils and use of fiber and antioxidants to produce nutraceutical foods, foods that deliver supplemental health benefits, has been the focus of this project. Soybean oil was studied to determine the optimum level of vitamin E with respect to stabilization against rancidity. It was determined that the optimum level (340 to 660 ppm) is lower than the naturally occurring level. Therefore, vitamin E can be partly removed from soybean oil and employed in other foods or as nutritional supplements and the oil stability will be increased. Some consumer groups have long targeted meat products for criticism based on
the saturated fat and cholesterol content. An experiment was designed to address this issue by using postmortem vascular infusion of beef carcasses. It was determined that in some muscles it was possible to lower cholesterol content by as much as 22%; rinsing the capillaries reduced residual blood, including several cholesterol-containing particles such as low-density lipoprotein and red- and white-cells. The same carcass infusion technique was used to successfully impart up to 5 ppm vitamin E into muscle, thereby improving the stability of the meat during storage and after cooking.
Impacts
(N/A)
Publications
- EVANS, J. C. 1998. The influence of tocopherol isomers and their natural mixture on soybean oil oxidation kinetics. M. S. Thesis, University of Minnesota, St. Paul. 145p.
- RUAN, R., XU, L., YI, L., CHEN, L., JOHNSON, J. and ADDIS, P. 1998. Cellulose fiber compositions and film and the process for their manufacture. U. S. Patent No. 5,817,381.
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Progress 01/01/97 to 12/31/97
Outputs
Dietary saturated fat and cholesterol are overrated factors with respect to cardiovascular disease, as suggested by recent findings that saturated fat in the diet may actually protect humans from stroke. Lipid oxidation products, ubiquitous in rancid and deep-fat-fried foods, appear from our research to be far more important causes of heart disease and stroke than saturated fats. Research has continued on methodology for the determination of lipid oxidation products in foods with the ultimate goal of eliminating human exposure to these deleterious chemicals. Cholesterol oxides have long been associated with atherosclerosis, the antecedent to many cardiovascular diseases. Gas chromatographic analysis of oxysterols is influenced by injection technique and silanization conditions, factors shown to be important to relative response factors which are crucial to accurate quantification. One type of human exposure to rancid foods occurs if uncured meat is cooked, stored
refrigerated, and then consumed. Our research demonstrated that barley bran and wild rice are plant materials that are effective in preventing lipid oxidation in precooked beef patties, producing a product both safer to eat and with improved sensory characteristics. Barley bran and wild rice contain effective antioxidants that retard lipid oxidation. Wild rice, rich in starch, is an effective water binder, permitting the ground beef to be highly acceptable as a low fat product. Such a product may be considered a nutraceutical because of its low fat content, fiber content (where none usually exists) and its antioxidant content. For the consumer, health benefits include lower fat, percent calories from fat, the potential to lower cholesterol and the protection of human tissue from oxidative changes, carcinogenic changes and atherosclerosis. Our research also demonstrated the use of refined cellulose and dehydrated potato extract in the development of nutraceutical beef patties that are
able to resist water loss during cooking and resist development of lipid oxidation and associated flavor deterioration after cooking.
Impacts
(N/A)
Publications
- RUAN, R., ZOU, C. WADHAWAN, C., MARTINEZ, B. CHEN, P. and ADDIS, P. 1997. Studies of water mobility and shelf life quality of precooked wild rice using pulsed NMR. J. Food Process. Preservation 21:91-104.
- YI, LUN. 1997. Preparation and properties of a new food hydrocolloidal material, refined cellulose (RC), made from corn cobs and husks. M.S. Thesis, University of Minnesota, St. Paul.
- ADDIS, P. B. 1997. Lipid oxidation products: atherogenicity. Abstracts, 88th AOCS Annual Meeting & Expo, Seattle, May 11-14, 1997, p. 46.
- ADDIS, P. B. 1997. Applications of tocopherols and tocotrienols in food science and nutrition. National Managed Health Care Conference: Natural Antioxidants in Nutrition, Health and Food, Dallas, Texas, March 20-21, 1997.
- GIL, A. and ADDIS, P. 1997. Elementos que Diferencian a Nuestras Carnes Rojas. 1er Seminario Sobre -La importancia de la integraciun en la cadena Ccrnica,+ Plan Agropecuario 1:77-84 (Montevideo, Uruguay).
- GRAU, A., GUARDIOLA, F., CODONY, R., and ADDIS, P.B. 1997. Gas chromatographic analysis of oxysterols: influence of injection technique and silanization conditions on relative response factors. Final Program of 111th AOAC International Annual Meeting and Exposition, Sept. 7-11, San Diego, CA (Abstract G-701, pp.79-80.)
- KATSANIDIS, E., ADDIS, P.B., EPLEY, R.J., and FULCHER, R.G. 1997. Evaluation of the antioxidant properties of barley flour and wild rice in uncooked and precooked ground beef patties. J. Foodservice Systems 10:9-22.
- OELKE, E.A., PORTER, R.A., GROMBACHER, A.W. and ADDIS, P.B. 1997. Wild rice-new interest in an old crop. Cereal Foods World 42:234-247.
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Progress 01/01/96 to 12/30/96
Outputs
For more than a decade, our studies advanced the idea that dietary saturated fatand cholesterol are over-rated factors with respect to heart disease. Lipid oxidation products, ubiquitous in rancid and deep-fat-fried foods, appeared far more important. This hypothesis is now gaining persuasive support by research in other laboratories. This project has focused on methods designed to inhibit lipid oxidation and also to study factors in the diet that help to protect humans from deleterious oxidation products. Accurate determination of oxidation products is crucial to elucidation of their pathological role and accurate quantification in foods. Methodology research elucidated the kinetics of breakdown of 7-ketocholesterol during hot saponification, used by some laboratories to purify cholesterol oxidation products. Even slight warming will cause some loss of 7-ketocholesterol and the under-estimation of oxidation products present. Use of 6-ketocholestanol as an internal
standard was found to be a serious flaw in techniques used by other laboratories because of its propensity to undergo tautomerization, severely compromising the accuracy of quantification. Liquid chromatography was used to isolate and quantify tocotrienol antioxidants in barley, a grain previously shown to be a superb antioxidant in cooked ground beef patties. A method for greatly enhancing the functional value of corn coband husk cellulose was developed.
Impacts
(N/A)
Publications
- ADDIS, P.B., PARK, P. W., GUARDIOLA, F. and CODONY, R. 1996. Analysis and health effects of cholesterol oxides. Ch. 9, IFT Basic Sympos. Food Lipids and Health, Ed. McDonald, R.E. and Min, D.
- B., Marcel Dekker, Inc., pp. 199-240.
- PARK, P.W., GUARDIOLA, F., PARK, S. H., and ADDIS, P.B. 1996. Kinetic evaluation of 3(-hydroxycholest-5-en-7-one (7-ketocholesterol) stability during saponification. J. Amer. Oil Chem. Soc. 73:623-629.
- PARK, P.W., GUARDIOLA, F., PARK, S. H., and ADDIS, P.B. 1996. Kinetic evaluation of 3(-hydroxycholest-5-en-7-one (7-ketocholesterol) stability during saponification. Abstracts, AOCS Press, p. 76.
- RIVERA, J.A., ADDIS, P.B., EPLEY, R.J. ASAMARAI, A.M. and BREIDENSTEIN, B.B. 1996. Properties of wild rice/pork sausage blend. J. Muscle Foods 7:453-470.
- ASAMARAI, M., ADDIS, P. B., EPLEY, R.J. and KRICK, T.P. 1996. Wild rice hull antioxidants. J. Agric. Food Chem. 44:126-130.
- GUARDIOLA, F., CODONY, R., ADDIS, P. B., RAFECAS, M. and BOATELLA, J. 1996. Biological effects of oxysterols: current status. Food Chem. Toxicol. 34:193-211.
- JOHNSON, M. H., ADDIS, P.B. and EPLEY, R.J. 1996. Wild rice as an antioxidant forfresh-frozen and precooked beef patties. J. Food Quality 19:331-342.
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Progress 01/01/95 to 12/30/95
Outputs
Wild rice is an effective meat antioxidant because of its content of phytate, anexceptional chelator of iron. Rancidity is largely iron (ferrous) catalyzed phenomenon. Antioxidant power of wild rice & sodium phytate at levels of each ingred. selected so phytate levels were equal indicated phytate and wild rice treated pork were about equal in rancidity after storage period of 4 weeks. This suggests phytate is the key antioxidant. Phytic acid, the protonated, non-chelating form of phytate, lowered meat pH and stimulated rancidity over control values. Therefore, most of the antioxidant effect of wild rice in meat products is due to phytate chelation of iron. Wild rice hulls were found to contain several potentially valuable antioxidants. These were purified by chromatography and identified by mass spectroscopy to include 2,3,6-trimethylanisole, m-hydroxybenzaldehyde, 4-hydroxy-3-methoxy- benzaldehyde (vanillin) and 4-hydroxy-3,5-dimethoxybenzaldehyde (syring- aldehyde).
Vanillin is the flavor compound of vanilla as well as possessing excellent antioxidant characts. A survey was conducted to determine prevalence of rancid ground beef in Minneapolis-St. Paul. Fresh-frozen and precooked- frozen product from supermarkets, and cooked product from fast food chains and high schools displayed much variation and generally higher values than are optimum for consumer acceptance. Therefore, discovery of new, novel, natural antioxidants is critical to both standard meat products & nutraceutical meats.
Impacts
(N/A)
Publications
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Progress 01/01/94 to 12/30/94
Outputs
Functional foods include those that minimize human exposure to dietary intake ofaltered (oxidized) fats and cholesterol. Such foods are supplemented with effective antioxidant systems which, when consumed, impart an additional benefit to consumers by retarding deleterious peroxidative change in the body. A new potato-derived ingredient to retard rancidity (oxidation) in meat products was studied. The same ingredient was noted to have extremely high water-binding capacity, an attribute that was used to produce low-fat meat products including frankfurters, liver sausage, beef patties and pork breakfast sausage patties. Similar studies employing combinations of hydrated wild rice and full bran barley flour were extremely effective at retarding an exceptionally difficult form of rancidity in precooked uncured meat products; warmed-over flavor (WOF) is considered the most significant barrier to convenience (precooked) products. Other functional food research focused on
calcium supplementation of frankfurters, a food commonly consumed by children and one that is a poor source of calcium. Franks could be produced at 25, 50, 75, and 100% of the Recommended Dietary Allowance for calcium with only the 100% exhibiting any significant sensory or technical problems. Recent research indicates that low calcium intake during childhood and during the early adult years, instead of the post menopausal period, is a factor in osteoporosis.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
Low levels of antioxidants and excesses of chemically altered fat and cholesterol in the diet are promoters of coronary heart disease (CHD). A significant chemical alteration of fat and cholesterol is oxidation, where oxygen is incorporated into the molecule causing the molecule to become toxic. Antioxidants protect molecules from oxidation and are a focal point of modern CHD research. Barley is rich in antioxidants. Inclusion of barley bran in diet of humans decreased levels of oxidation products of cholesterol 75% in a 3-week period. Whole grain commercial cereals also outperformed "stripped" cereals (bran removed). Hyperlipidemic human subjects consumed stripped cereals, a whole grain cereal, and whole grain cereal plus 300 IU of vitamin E and 10,000 IU of beta-carotene each respectively for one week. Blood plasma samples (4) were obtained before treatment and weekly thereafter and low-density lipoprotein (LDL) particles were isolated, incubated with copper and
levels of fatty acid oxidation products were monitored. Average lag times for LDL oxidation were 45.1, 49.0, 54.4, and 64.2 minutes, respectively, for the four samples indicating increasing resistance of LDL to oxidation as increasing quantities of antioxidants were added to diet. We hypothesize that commonly made food choices may have profound effects on CHD risk. The results of these studies demonstrate the potential that exists to use functional foods to reduce the risk of CHD and perhaps other human diseases.
Impacts
(N/A)
Publications
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Progress 01/01/92 to 12/30/92
Outputs
Cholesterol and other lipids such as fats may not be as important in heart disease as was once believed. Instead, products formed when cholesterol and fat react with oxygen, cholesterol oxidation products (COPS) and other lipid oxidation products (LOPS), are believed to be significant. French-fried (deep fat fried) foods are the largest dietary source of COPS and LOPS. The COPS and LOPS content of foods also detract from both nutritional value and sensory quality. One way-to reduce COPS and LOPS content of fried foods is to use an effective filtration system for the hot oil. Three heated oil filtration systems were evaluated: (1) paper filter; (2) paper filter plus diatomaceous earth (DE); and (3) depth filtration with a filter pad under positive pressure. Results on tallow-cottonseed oil (90:10) and hydrogenated soybean shortening indicated that depth filtration was more effective at maintaining LOPS at low levels that methods 1 and 2. Mineral analysis revealed that
depth filtration was more effective at removal of pro-oxidant transition metals than were methods 1 and 2.
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Progress 01/01/91 to 12/30/91
Outputs
Cholesterol is a reactive chemical that can combine with oxygen to form a large number of cholesterol oxidation products (COPS). Many published research papers now indicate that dietary cholesterol is not an important factor in atherosclerosis but rather that COPS, either from dietary or in vivo sources, are far more deleterious to arteries. Plasma and chylomicron COPS were monitored in human subjects fed a meal rich in COPS, derived primarily from powdered (dehydrated)egg. COPS feeding resulted in postprandial elevation of COPS in total plasma and chylomicrons. Fresh eggs, almost free of COPS but rich in cholesterol, only slightly elevated plasma COPS. In most subjects, maximum plasma COPS were attained by about 3 hours postprandial. However, COPS were rapidly from the circulation starting usually at 3-31/2 hours postprandial. Males and females showed similar patterns. There are two highly significant aspects of these results. Firstly, the findings totally
refute a common assumption - namely, that COPS are not absorbed. Secondly, the results suggest, for the first time in humans, a mechanism whereby low-density lipoprotein (LDL) can be modified to the highly atherogenic modified form (mLDL) by dietary COPS. This possibility is raised by the data showing an extremely rapid clearance of COPS from the blood. Injection of mLDL into the circulation is known to evoke an extremely rapid clearance of mLDL.
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Progress 01/01/90 to 12/30/90
Outputs
An antioxidant activity was discovered in wild rice and currently underway is anexperiment designed to purify and isolate the antioxidant fraction(s) of wild rice. Antioxidant activity was discovered in an experiment designed primarily to produce a low-fat ground beef patty using wild rice as a partial replacement for fat. Low intermediate- and high-fat ground beef was mixed with three levels of hydrated, cooked wild rice (0, 15, 30%). Grade A Minnesota wild rice was cooked (hydrated) 50 min. in boiling water to yield 300% (1 lb. rice = 3 lb. cooked rice), chilled to <50(degree)F and mixed with ground beef. Patties (4 ounces) were produced, blast frozen at -33(degree)F for 10 min. and stored 48 days at 0(degree)F. Analysis revealed that as percent wild rice increased, the level of thiobarbituric acid reactive substances (TBARS) decreased, and did so to a degree greater than could be accounted for by dilution with wild rice. The lower TBARS indicates less lipid
oxidation (rancidity) indicating a natural antioxidant is present in wild rice. This finding has been confirmed in several similar experiments. Taste panel results demonstrated a preference of consumers (N = 106) for patties with 15 and 30% wild rice compared to controls, even at fat levels as low as 8% - a preference which in part is likely due to the low rancidity in ground beef with wild rice.
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Progress 01/01/89 to 12/30/89
Outputs
An earlier procedure developed in this lab for determination of cholesterol oxidation products (COPS) was modified so as to increase speed and sensitivity. The method involves high performance liquid chromatography (HPLC) on a mu-Porasil normal phase column with UV detection as before but differs in terms of the extraction method, which involved membrane filtration, and a two-stage mobile phase solvent separation which, unlike the previous method, permits quantification of 25-hydroxycholesterol. The new HPLC method permits comparisons to our standby gas-liquid chromatography (GLC) procedure and has verified data from GLC studies of COPS in foods. Therefore, by widely different techniques it is possible to cross-confirm existence of COPS in foods. The HPLC technique was employed to demonstrate that fresh and frozen pork muscle was free of COPS at the detection limit of 1-2 ppm. Refrigerated storage of pork muscle did not result in oxidation of cholesterol. The results
essentially agree with previous studies conducted on beef muscle and strongly suggest that fresh meat contains little if any COPS. GLC studies of the three plasma lipoproteins of fasted humans indicated a great deal of variation of COPS content (0-640 mu g/dl COPS), suggesting that in vivo COPS formation may occur. The relevance of these findings to atherogenesis is being studied.
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Progress 01/01/88 to 12/30/88
Outputs
The effects of normal and adverse environmental holding conditions on the formation of cholesterol oxidation products (COPS) in powdered cheese and salted and unsalted butteroil were investigated. Little or no change in COPS levels was noted in a variety of powdered dairy products stored at 4, 21, or 38C for up to 6 months. Storage for 18 mo at 4C resulted in a three-fold increase in the levels of COPS. Cheddar cheese powder continuously exposed to light (1611 lux) displayed increases in alpha-expoxide and 7-ketocholesterol through week 3, thereafter declining to a level at week 9 of about one-half of that seen at week 3. Continuous heating of butteroil (110C) caused large increase in COPS levels, with unsalted butteroil exceeding levels found in salted butteroil by 2- to 3-fold. Methods were developed for the quantification of COPS in human plasma lipoproteins and, using such methodology, it was shown that rapid absorption of COPS occurs when humans are given a
meal containing COPS. Chylomicron COPS reached maximum levels at 3.5 hr postprandial. Studies on low-density lipoproteins (LDL) which had been modified by oxidation in cultures of endothelial cells and smooth muscle cells revealed high levels of LDL-COPS, a factor which may render LDL much more atherogenic than "native" LDL. Research on Lake Superior fishes revealed very high levels of omega-3 fatty acids. Smelt, Herring, Chub, Lake Trout and Siscowet Trout displayed 3.1-, 5.7-, 8.6-, 9.3-, and 25.
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Progress 01/01/87 to 12/30/87
Outputs
Results demonstrated that beef is more resistant than turkey on the oxidation oflipids during and/or following cooking. Broiled beef steaks, and cooked-vacuumized beef roasts display a virtual absence of cholesterol oxidation products(COPS) and thiobarbituric acid reactive substances (TBARS) even, in the latter case, after storage for 8 days at 2C. TBARS and COPS increased in comminuted, cooked beef and turkey stored at 2C, although levels were low in beef (8 days, 1.7% COPS as a percentage of cholesterol) and higher in turkey (8 days 2.9% COPS). Storage of butter for 6 months failed to produce significant accumulation of COPS. Small amounts of COPs noted in Cheddar cheese at various stages in processing originated with raw materials, not with processing. Ripening did not result in further increases in COPS. Studies on fresh, processed and stored egg products demonstrated that fresh eggs are low in COPS but some powdered products accumulated high levels during
storage reaching extremely high levels after 5 years: alpha-epoxide, 66 ppm; beta-epoxide 117 ppm; cholestanetriol, 206 ppm. Storage of hard-cooked and raw eggs for 16 weeks resulted in a steady increase in COPS levels followed by an equally steady decline to original levels. Vitamin E supplemented in diets of layers failed to reduce COPS levels during storage and at the highest level (182 IU/kg feed) Vitamin E exerted a prooxidant effect increasing COPS levels.
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Progress 01/01/86 to 12/30/86
Outputs
Analysis of foods for cholesterol oxide derivatives (CODs) was continued using previously reported gas-chromatographic (gc) procedures. Results obtained on a variety of dairy products indicated wide variation: 6 of 9 cheddar cheese powders contained cholesterol oxides compared to 5/5 parmesan powders, 2/3 sour cream powders. Extensive indication of cholesterol oxidation was noted in dehydrated baby foods but little was detected in canned baby foods. Most dehydrated (freeze-dried) animal products used for camping purposes contained extensive CODs. The oxidation of cholesterol in tallow heated at various frying temperatures, 135, 150, 165, nd 180 was studied. Linearity of formation of 7-ketocholesterol with heating time was confirmed. However, no significant differences in rate of formation of 7-ketocholesterol were noted among temperatures of 135, 150, and 165. Therefore, it was not possible to construct a kinetic equation. The possible efficacy of antioxidants at
fryying temperatures was demonstrated by incorporating ascorbyl plamitate plus dl-alpha-tocopherol into tallow at 135C which delayed, but did not eliminate, CODs formation which occurred after 70 m heating time. These results confirm our earlier findings of cholesterol degradation in heated tallow and are consistent with our earlier findings of CODs in French fries obtained at fast-food restaurants.
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Progress 01/01/85 to 12/30/85
Outputs
Analysis of foods for cholesterol oxide derivatives (CODs) was continued using our previously reported liquid- and gas-chromatographic (lc and gc) procedures. Lc data indicated 70, 46 and 32 ppm 7-keto, 7 beta- and 7 alpha-hydroxy-cholesterol in powdered brain and 14 ppm 7-ketocholesterol in powdered liver. Suspected peaks for 7 alpha- and 7 beta-hydroxycholesterol in powdered liver could not be quantified in a valid manner because of interference. French fries prepared in tallow at a fast-food restaurant contained 4 ppm 7-ketocholoesterol; pancake mix containing powdered eggs had 1 ppm. No CODs could be detected in raw beef, fried chicken, cooked hamburger, beef jerky or liver sausage. CODs were isolated by cold saponification and quantified by gc. Continuous heating of tallow at 155C caused formation of 7 alpha-, 7 beta- and 7-ketocholesterol, and alpha-epoxide. 7-ketocholesterol levels reached 10% of initial cholesterol after 376 hr heating. Peaks were
confirmed by capillary gc-mass spectroscopy. Studies on pigs which suffer from the porcine stress syndrome (PSS+) demonstrated greater susceptibility to development of rancidity in muscle but elevated thiobarbituric acid values were not accompanied by cholesterol autoxidation. PSS+ (Pietrain) pigs displayed greater red blood cell osmotic fragility, greater membrane cholesterol content and decreased membrane fluidity than PSS- (Yorkshire) pigs.
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Progress 01/01/84 to 12/30/84
Outputs
Progress in analysis of oxidized cholesterol derivatives (OCDs) in foods culminated in a gas-liquid chromatograph (gc) procedure, the first enabling quantification of all major OCDs of toxicological interest. 5 alpha-cholestane internal standard was added to food which was homogenized in 2:1 chloroform/methanol. Solvent was evaporated and dried lipids saponified in 10 ml N KOH in methanol for 20 hr at 22C. Ten ml distilled water were added and nonsaponifiables extracted thrice with 10 ml portions of diethyl ether and washed with 5 ml 0.5 N KOH and 5 ml distilled water. Samples were dried, solvent-evaporated (rotary vacuum and nitrogen flash), redissolved into 100 mu 1 pyridine to which 50 mu 1 Sylon BTZ were added to trimethylsilylate the sterols. About 0.8 mu 1, held at 22C for 30 min., were directly injected into a Varian Vista 6000 gc equipped with a flame ionization detector and a fused silica capillary column (DB-1, 0.1 mu m thick). Temperature was programmed
from 180 to 250 at 3C per minute. The injector was run at 270; detector at 300. H(2) carrier gas and N(2) make up gas were used. Splt ratio was 100:1. Mass spectra were determined on all chromatographic peaks suspected as OCDs. Detailed studies on fresh and cooked beef muscle failed to detect OCDs, strongly indicating that beef muscle cholesterol is not involved in development of coronary heart disease.
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Progress 01/01/83 to 12/30/83
Outputs
Advances were made in cholesterol oxide quantification by gas-liquid (gl) and high performance (hp) liquid chromatographies. The gl method includes homogenization in 20 vol of 2:1 chloroform-methanol, filtration, and washing with 0.9% NaCl in water. Chloroform layer was dried under nitrogen and resultant extract saponified, extracted thrice with ether and combined supernatants washed with water, dried and redissolved in ether. The solution obtained was injected into gl equipped with a cross-linked, fused silica (15 m) capillary column and hydrogen flame ionization detector. Detection limit was 10-30 ng and the desired base-line-to-base-line separation of four cholesterol derivatives and cholesterol was achieved. Methodology using hp has progressed to its use for quntification of 7-oxy cholesterol derivaives in foods. A method was developed to enrich sterol oxides from large amounts of interfering triglycerides, phospholipids and cholesterol by silica gel
chromatography. Extracts are injected into a u-porosil column with a 7% isopropanol in hexane and detected with an ultraviolet detector. The detection limit for the hp method is 50 ng. Preliminary indicators are that warmed over flavor is not normally accompanied by the oxidation of cholesterol in beef and turkey.
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Progress 01/01/82 to 12/30/82
Outputs
Under revised objectives, effective July 1982, research was conducted in these following areas: effect of processing on development of postmortem muscle rancidity; and methods for isolation, identification and quantification of cholesterol and its oxidation products. Attempts to detect some evidence of In Vivo muscle membrane phospholipid oxidation in Minn. No. 1 and Pietrain pigs were largely negative. Studies did demonstrate that by using an altered processing procedure - namely, skinning and rapid chilling, it was possible to greatly reduce muscle lipid oxidation. Results also suggest that the greater susceptibility to lipid oxidation displayed by exudative muscle is due to post-mortem changes rather than In Vivo effects. Some progress has been made in separating cholesterol from its oxidation products by gas-liquid (gl.) and high performance (hp.) chromatographies. For the gl. method, the use of a capillary (glass) column improved resolution. These results are
part of a research project designed to control rancidity in meat and other foods and thereby aid in the preservation of the taste, texture, color, nutrient content and safety of foods. The PSS screening procedure developed earlier was successfully applied to neonatal screening for Duchenne muscular dystrophy in 158,000 babies. Continued use of test plus parental counseling could reduce incidence of Duchenne dystrophy by 80%.
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Progress 01/01/81 to 12/30/81
Outputs
We have improved the TBA method and developed the first method to detect free malondialdehyde in meat. We have been able to improve extraction method for TBA analysis; optimize reaction of TBA with malonaldehyde; ascertain lack of necessity of using sufanilamide to prevent interference of nitrite; and determine that Pietrain pigs exhibit a higher degree of muscle rancidity prior to and after cooking than Minn. No. 1. Direct determination of malonaldehyde will be quite useful since traditionally-used TBA method, as modified by us, can be compared to actual determination of malonaldehyde. In samples tested to date, our results indicate that TBA method, commonly used by some people as a "direct" measure of malonaldehyde, considerably overestimates amount present. Numerous other lipid oxidation products also react with TBA. Some preliminary studies and literature investigations have been conducted concerning the analytical technicals used to isolate, separate and
quantitate cholesterol oxidation derivatives. Lipid oxidation products, including malonaldehyde and cholesterol oxidation products, have all been shown to be toxic to laboratory animals. It is believed that they are toxic to humans and have properties which include carcinogenicity and atherogenicity. Attempts in this research to inhibit formation of these products or, in some cases such as cholesterol oxidation derivatives, determine exactly where they occur in the food supply, should be beneficial to both the food industry and the consumer.
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Progress 01/01/80 to 12/30/80
Outputs
Methodology was developed for the isolation and quantitation of parvalbumen and calmodulin from PxP and MxM pigs. A method for measuring calmodulin stimulation of phosphodiesterase, as a means of assaying calmodulin, was developed from earlier techniques so that sensitivity could be varied as required. Calmodulin was isolated by homogenization in urea, alcohol fractionation, dialysis and DE-52 stepwise elution with NaCl in 50 mMTris, pH 8.0. Fractions were concentrated by freeze-dehydration, dialyzed against distilled water and assayed by firefly luciferase/phosphodiesterase. To date, no differences have been detected in gross quantities or chemical characteristics of calmodulin between PxP and MxM pigs. As a preliminary to future studies in pigs, vitamin E and dietary fat source were studied in relation to rancidity in turkeys. Thiobarbituric acid values were greatly reduced by vitamin E in fresh turkeys stored at 3 degrees C for three weeks and also reduced in
birds frozen, cooked and stored 48 hours at 4 degrees C.
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Progress 01/01/79 to 12/30/79
Outputs
Data obtained on 885 P x P, 159 M x M and 108 P x M (and reciprocals) indicate that PSS is the result of a single autosomal recessive gene with a penetrance of about 94%. An improved method was developed for isolation of heart mitochondrial creatine kinase (CK) using sephacel, agarose-ATP and sephacryl S-200. Kinetics of enzyme indicates its favored direction is formation of phosphocreatine. Studies on hearts from PSS+ and PSS- pigs revealed no appreciable differences in terms of mitochondrial CK. An improved procedure for the extraction of oxidation products from muscle for determination by TBA involves homogenization in polytron in 10% TCA and 1 M H(3)PO(4) followed by filtration. PSS+ pigs displayed a greater propensity to develop muscle rancidity than PSS- pigs. Vitamin E and selenium dietary supplementation slightly (P less than .05) reduced muscle rancidity. TBA method tends to overestimate malonaldehyde.
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