Frontiers in the Nutrition Sciences Proceedings of a Symposium (1989) / Chapter Skim
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Biotechnological Developments: Potential for Improvements in Food Formulation, Nutrient Delivery, and Safety
Biotechnological Developments: Potential for Improvements in Food Formulation, Nutrient Delivery, and Safety
Pages 42-94
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From page 42... ...
. The modern food processing industry increasingly influences what consumers eat, that is, nutrient intake, although the availability of many products is largely determined by what the majority of consumers buy.
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From page 43... ...
The relationships between dietary fats and several chronic diseases have been reviewed (NRC, 1989 Visek, 1983~. _ Coronary Arterial Diseases ; Perkins and Hyperlipidemia is associated with an increased incidence of atherosclerosis, heart disease, and thrombosis and stroke, which are the major causes of morbidity and mortality in the United States (American Heart Association, 1986; Levy et al., 1979~.
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From page 44... ...
results in decreased plasma cholesterol and reduced incidence of heart disease (American Heart Association, 1986; Federation of American Societies for Experimental Biology, 1984; Keys, 1970~. Current intake of SFAs are about 13-14% of calories (National Institutes of Health, 1985~.
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From page 45... ...
In meats, dairy products, and soups, it controls microbial growth and may be a selective inhibitor of pathogenic or toxigenic microbes; in cheeses, it affects the activity of ripening enzymes and controls the microflora; and in processed meats, it functions in solubilizing myofibrillar proteins, which are required in the formation of the final product (Federation of American Societies for Experimental Biology, 1979~. Hence, sodium chloride cannot be summarily replaced or substituted.
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From page 46... ...
With the reduction in manual labor, much less dietary energy is needed; hence, less fat is required in the diet (American Heart Association, 1986~. In addition, with the elucidation of the important roles of eicosanoids in a number of chronic inflammatory and immune diseases, a reassessment of the quantitative importance of dietary _-6 PUFAs in the human diet may be warranted (Lands, 1986a,b)
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From page 47... ...
The current high'consumption of n-6 PUFAs is a relatively recent phenomenon reflecting innovative oilseed processing technology and the promotion of _-6 PUFAs in high-fat diets to reduce plasma cholesterol. Historically, mankind was accustomed to a 47
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! TABLE 2 Some Common Diseases That May Be Ameliorated by Dietary n-3 PUFAs Arthritis Atherogenesis Autoimmune diseases Burns Hyperlipidemia Ischemic heart disease Thrombosis Vasospasm (Asthma?
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From page 49... ...
Fat Consumption The current intake of fat is about 38% of calories, down from approximately 41% in 1977. Food intake data indicate that this is made up of approximately 15, 14, and 7% of calories from saturated, monoenoic, and polyunsaturated fatty acids, respectively.
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From page 50... ...
In light of the association of dietary fat with many of the major chronic diseases, there is universal agreement that dietary fat intake should be reduced to match energy output and should not exceed 30% of total calories (Federation of American Societies for Experimental Biology, 1984; National Institutes of Health, 1986b; NRC, 1989; DHHS, 1988~. In addition, the fatty acid composition of dietary fat should meet certain guidelines.
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From page 51... ...
Because animal products 'provide significant quantities of essential nutrients, appropriate modification of their fat content is a practical and prudent approach (Briggs, 1985~. APPROACHES FOR MODI FYING FATS IN FOOD PRODUCTS Reduction of the fat and cholesterol contents of foods and modification of the fatty acid composition is the goal of a number of current production and processing technologies in conventional agriculture that are being facilitated by developments in biotechnology.
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From page 52... ...
Transgenic animals Advances in the knowledge of factors affecting muscle growth and partitioning of nutrients are being explored for use in altering the composition of animal products. Adrenergic amines, especially those that bind to f-receptors (~-agonists)
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From page 53... ...
The fatty acid composition of poultry and swine reflects dietary fatty acids, and thus can be manipulated to provide a more appropriate fatty acid composition for human consumption (NRC, 1988~. Aquaculture (e.g., of catfish, trout, Atlantic salmon, tilapia, crayfish, and shrimp)
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This low-fat product (<1% fat) can be colored and flavored to simulate a range of seafood products (Lee, 1986~.
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Thus, cloning of genes coding for desirable enzyme systems (e.g., §-oxidation, cholesterol oxidation, and fatty acid desaturation) into microorganisms in starter cultures represents a possibility for the future.
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may suggest that changes in the amounts and mixtures of unsaturated fatty acids used in food formulation and processing should be reassessed. As a result of developments in oil processing and stabilization together with the increasing capacity (especially via biotechnology)
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From page 57... ...
Recombinant DNA and genetic engineering can improve production efficiencies and facilitate the rational design of components, and fermentations using genetically engineered microbes can become a significant source of functional ingredients. These developments will facilitate the production of formulated food products that more closely meet consumer criteria (i.e., nutrient balance, quality, costs, etc.)
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From page 58... ...
The success of this approach depends on the regeneration of plants from cultured cells, which is a challenging obstacle with many plant species. Genetic engineering in plants is more complex than it is in prokaryotes because plants contain nuclear, mitochondrial, and chloroplast genetic material that interacts and controls different traits; cloning and vector systems are very limited; cell replication is slower; and finally, the transformed cell must regenerate into a plant.
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From page 59... ...
These methods are mostly being used to select favorable production traits but can also be used to improve the functional and nutritional properties of the products, with transgenic modification being most appropriate in this respect (Sharp and Evans, 1986; Zaitlin et al., 1985)
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This crop could become a significant source of LNA for use in foods and as an edible oil. The various cell culture techniques in use should facilitate selection of cells with altered fatty acids.
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Thus, single-function genes for insect luciferase, soy conglycinin, and other proteins have been successfully transferred and expressed in other species of plant cells. The cloning of the gene for the insect toxin from Bacillus thuringiensis has been successfully cloned into plants and is expressed, as evidenced by insect resistance.
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Most pathways (e.g., fatty acid synthesis) require many enzymes, and hence, multigene manipulation may be required to alter a product.
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and rather sophisticated genetic engineering of such TABLE 5 Intrinsic Factors That Affect Protein Structure, Function, and Behavior in Food Systems Amino acid composition (major functional groups) Amino acid sequence (segments or polypeptides)
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These can all markedly enhance the productivity of animal products and should thereby improve the quality and safety of the food supply. The use of growth hormone (somatotropin)
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From page 65... ...
, milk with greater concentrations of transferrin or lysozyme, low-lactose milk, and f-lactoglobulin with a rich array of essential amino acids and better functional properties. Eventually, it may be possible to clone additional acyl desaturases into bovine mammary tissue and increase the degree of unsaturation of fatty acids in milk, to introduce antisense RNA into fatty acid synthetase, and to reduce milk fat.
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From page 66... ...
TABLE 6 Examples of Some fo the Major Products That Can Be Produced for the Food Industry by Biotechnological Innovations Product Uses Amino acids Glutamic acid Aspartic acid Phenylalanine Methionine Lysine Tryptophan Enzymes a-Amylase Glucoamylase Glucose isomerase Amylogalactosidase Pullulanase Proteases Rennin, Lysozyme Improved organisms Yeasts Lactic acid bacteria starters ow-calorie sweeteners Aspartame Thaumatin Monellin Stevioside Modified triglycerides and fatty acids Microbial polysaccharides Flavors, fragrances, and colorants Food testing Monoclonal antibody kits DNA Hybridization Microbial proteins Vitamins B2, B:2, C, and E Food additive Aspartame (NutraSweet) Animal feed High-fructose corn syrup Light beer Protein modification Cheeses Wine and beer Milk fermentations, cheeses Non nutritive sweeteners Cooking oil and food additives Thickeners and gelling agents Fabricated foods Salmonella, Listeria aflatoxins, clostridia Animal and human food supplements Human and animal dietary supplements 66
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From page 67... ...
Current research is focusing on extending the number of functional ingredients (colors, flavors, essences, enzymes, gums, antioxidants, fatty acids, n-3 PUFAs, and vitamins) and developing transformed microbial organisms and plant cell cultures to improve productivity (Harlander and Labuza' 1986; Knorr, 1987; Lin, 1986; Whitaker and Evans, 1987~.
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From page 68... ...
In addition, proteins that can be used in conventional food processing may be produced. Thus, in hard cheeses (e.g., provolone and emmenthal)
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From page 69... ...
Successes TABLE 7 Examples of Colon Food Enzymes That Can Be Produced by Genetic Engineering. Enzyme Substrate o-Amylase Catalase Cellulase G}ucoamylase Glucose isomerase Glucose oxidase Invertase Lactase Lipase Pectinase Protease Remeet Starch Hydrogen peroxide (cellulose Dextri ns Glucose Glucose and oxygen Sucrose lactose Lip ids Pectin Proteins Casein liquefaction to dextrins, brewing, baking Milk sterilization Juice clarif ication Hydrolysis to glucose High- fructose corn syrup Elimination of browning discoloration Production of invert sugar Hydrolys is of lactose for low- lactose milks Cheese ripening Wine or Jui ce clarification Meat tenderizer, sausage curing, dough conditioning, beer clarification Casein coagulation, cheese manufacture SOURCE: Harlander (1987)
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From page 70... ...
Cloning and site-directed mutagenesis to improve enzyme function is now feasible, but the relative costs and Food and Drug Administration approval for food uses are current obstacles (Pitcher, 1986~. In food processing, the traditional approach of trying to accommodate a process to suit the available ingredient or enzyme can now be changed so that ingredients or enzymes are redesigned to suit a particular process.
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From page 71... ...
With advances in molecular cloning, the synthesis and production of vitamins via bioengineering will increase. The possibility of eventually cloning vitamin C synthesis into microbes used in food fermentations might improve food stability, and in processed meats it could reduce the need for nitrite.
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The molecular biology and genetics of the microorganisms used in food fermentations are elucidated to improve their applications. Research to improve lactic acid starter cultures for cheese and dairy fermentations is in progress in several laboratories (Bats, 1986a,b; Chassy, 1985; McKay, 1986; Venema and Kok, 1987~.
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Hence, plant, animal, and microbial cell cultures are being exploited and enzymes are being used to transform flavors to meet the criteria of natural food products. Genetic engineering of generally recognized as safe (GRAS)
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From page 74... ...
antibodies have been used for the detection of Salmonella and Staphylococcus enterotoxins in foods DNA-DNA , hybridization probes provide a new technology for detecting various food-borne organisms. For example, Escherichia cold and Yersinia, Salmonella, and Listeria species (Fists, 1985)
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From page 75... ...
produced by algae represent a potential source of these important nutrients (Pohl, 1982~. Comment on Biotechnological'Developments The potential of genetic engineering for revolutionizing food production by conventional (animal, plant, and avian)
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From page 76... ...
, and improve the digestibility of proteins and starch and the bioavailability of nutrients (Tannenba~m, 1979~. In addition, contemporary food processing involves nutrient fortification and supplementation, product formulation on the basis of nutrient content and convenience, aseptic processing, and the production of new foods from ingredient blends.
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From page 77... ...
Irradiation is an effective method, but because of the public perception, its immediate future in food processing in the United States is uncertain. Microwave Microwaves can be used effectively for pasteurization and sterilization, microbial destruction, and enzyme inactivation in a variety of products.
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From page 78... ...
, _ Progress in microwaveable Freeze-Drying The use of improved drying techniques, especially large-scale freeze-drying, has grown rapidly and is used commercially for the preservation of such foods as diced vegetables, fruits, and spices. Separations and Fractionation Ultrafiltration, diafiltration, microfiltration, and reverse osmosis represent relatively new technologies That are changing a number of food processing operations 78
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From page 79... ...
Supercritical gas and solvent extraction technologies (Table 10) may provide additional options for selectively removing undesirable organic components from raw materials TABLE 10 Some Current Applications of Supercritical Fluid Extraction to Foods Decaffeination of coffee and tea Deodorization of oils and fats Extraction Vegetable oil and fats from seeds Food coloring from plant material Flavors, fragrances, aromas, and perfumes Hops and spices Fruit juices Drugs from plant material Oil from potato chips and snack foods and foods (Riz~i et al., 1986~.
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From page 80... ...
Thus, storage of individual vegetables and fruits for retail trade in a controlled or modified atmosphere is being used increasingly to extend the shelf life of vegetables and fruits, which should increase their year-round availability. FOOD FORMULATION In addition to ongoing consolidation and globalization, the food processing industry has undergone major changes in the past 20 years -- from mostly a commodity-handling industry to a more sophisticated industry manufacturing consumer food products.
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From page 81... ...
. In this regard, biotechnology and genetic engineering, as applied to conventional ingredient production, are timely and will enable producers of both agricultural and nonagricultural products to supply market needs.
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From page 82... ...
Nevertheless, they may have a place in food products in limited amounts. Because oils absorbed by foods during deep frying in fat are a significant source of calories in the American diet, nonabsorbable fats can be useful as a cooking or frying media.
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From page 83... ...
Thaumatin is a protein that is more than 2~000 times as sweet as sucrose and acts as a ft ~ enhancer. This protein has been cloned and can be gepertt'4 in fermented products by using transformed '~ig~o'b ~ (E4ens and Van der Waals, 1983~.
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., CONCLUSIONS .- , .. .; Improvements in the diet should ensue from the numerous developments that are occurring in molecular biology, food production technologies, fermentations, and food processing technologies.
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1986a. Use of recombinant DNA to improve lactic acid starter cultures.
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Polyunsaturated Fatty Acids and Eicosanoids. American Oil Chem.
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1986. Linolenate derived polyunsaturated fatty acids and prevention of atherosclerosis.
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1987. Monounsaturated fatty acids, plasma cholesterol and coronary heart disease.
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From page 89... ...
Nutritional and Safety Aspects of Food Processing. Marcel Dekker, New York.
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183 in P Fox and Applied Science Press, Food components with potential The n-3 polyunsaturated fatty 40:89.
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1986. Genetic engineering and process development for production of food processing enzymes and additives.
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1986b. NTH Consensus Development Conference Statement on Lowering Blood Cholesterol to Prevent Heart Disease, Vol.
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Life Sciences Research Office, Federation of American Societies for Experimental Biology, Bethesda, Md. Pitcher, W
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From page 94... ...
1979. Nutritional and safety aspects of food processing.
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