Tuesday, February 22, 2011

Biotechnology in Food

The Future of Biotechnology in Food Processing

By the year 2000 the worldwide market for biotechnology-derived food and agricultural products could be valued at tens to hundreds of billions of dollars. The results of the rapid pace of biological research since 1970 indicate that we are only scratching the surface of the potential.

We define biotechnology broadly, as the use of biological systems, including micro-organisms or components produced by micro-organisms, in industrial processes. Micro-organisms have been used in food preparation for centuries to preserve and transform raw agricultural commodities into edible products for human consumption.

Forecasts on Size of Worldwide Market for Biotechnology Agriculture and Food Processing Products

Source                                                                     Year Millions                               Dollars

Arthur D. Little                                                        1990                                           2,000–4,000

Business Communications Co.                                 1990                                             430
Policy Research Corp.                                            2000                                         50,000–100,000
Predicasts, Inc.                                                       1985                                           6,200
                                                                              1995                                        101,000
Strategic, Inc.                                                         1990                                            4,500
                                                                              2000                                            9,500
T.A. Sheets & Company                                        2000                                          21,300

Forecasts on Size of Worldwide Market for Biotechnology Agriculture and Food Processing Products

Fermentation of milk, meat and fish, fruits and vegetables, and cereal grains by micro-organisms creates products which contribute to the flavor, texture and keeping quality of food, suppress the growth of disease and spoilage organisms, and enhance the nutritional quality of the final product. Fermentation is the use of enzymes produced by micro-organisms to change an organic compound into other substances such as carbon dioxide and alcohol. Fermentation technology also has been used for the microbial production of enzymes, amino acids, vitamins, and a host of other components used as food ingredients, nutritive supplements, and food processing aids.

In essence, the food processing industry was practicing biotechnology long before it was recognized as a distinct and revolutionary scientific discipline.

One facet of biotechnology of particular application in the food industry is genetic engineering. This technique is used in the laboratory to alter the genetic material of living cells so that they can produce more or different chemicals or perform new functions. It will have a profound impact on agriculture and traditional food processing because of the tremendous potential for genetic improvement of plants, animals and micro-organisms.

The interface between biotechnology and food processing was explored in October 1985 at an International Symposium, Biotechnology in the Food Processing Industry, cosponsored by the Department of Food Science and Nutrition and the Agricultural Experiment Station at the University of Minnesota, and the Cooperative State Research Service of the U.S. Department of Agriculture (USDA).

Now let us focus on the manipulation of micro-organisms in the production of food additives and processing aids, and their role in the development of value-added technology, improved processing methods, and more efficient use of food processing wastes. Many examples are from the symposium proceedings.

Food Additives and Processing Aids

Some of the products, including enzymes, amino acids, vitamins, organic acids, and certain complex carbohydrates and flavoring agents used in food formulation are currently produced by microbial fermentation. In the future, biotechnology will be used to design micro-organisms capable of producing these high-value additives more efficiently arid cost effectively. In addition, advances in large-scale fermentation systems and bioprocess design will optimize recovery arid downstream processing of microbial products. All of these will have a profound impact on the food industry.

Biotechnology Products for the Food Industry

Product Use Enzymes amylase High fructose corn syrup isomerase rennet Cheesemaking

proteases Meat tenderizer pullulanase "Lite" beer Organic acids citric acid Acidulant benzoic, probionic acid Food preservative Amino acids methionine, lysine,trypthopan Nutritional supplement aspartic acid, phenylalanine Aspartame production Vitamins Nutritional supplement Low calorie products aspartame, thaumatin, monellin Non-nutritive sweeteners modified fatty acids and triglycerides Food additives and cooking oil Microbial polysaccharides Stabilizers, thickeners, gelling agents Flavors and pigments Flavoring and coloring agents

Single cell protein Animal and human food supplement

Some food ingredients are extracted from plant material or synthesized chemically (i.e., gums, flavors, pigments). In the future it will be possible to transfer the genetic ability of the plant to synthesize certain flavors, pigments or complex carbohydrates into food-grade micro-organisms. This transfer will allow commercial production of these high-value food additives via fermentation processes.

Enzymes. The food processing industry is currently the largest consumer of industrial enzymes, making up about 40 percent of a $400 million market. An enzyme is a complex protein produced by living cells that helps a chemical reaction along without itself being changed. Enzymes are added during food processing to control texture or appearance, enhance nutritive value, and generate desirable flavors and aromas.

Future application of biotechnology will involve enzyme engineering—changing the primary structure of an enzyme. Such changes may alter target specificity, acidic condition, or thermostability. Enzyme engineering can be used to "tailor-make" enzymes to function best in commercial food processing systems.

Immobilized enzyme technologies have been developed for the production of high fructose corn syrup, and will have broad application in processing other foods. Immobilization of an enzyme increases its stability, allows easy separation of the product from the enzyme, and so facilitates its recycling.

In the future, immobilized enzymes will replace batch fermentations for producing amino acids, aspartic acid and tryptophan, and the non-nutritive sweetener, aspartame. Immobilization of rennet, the enzyme that coagulates milk during cheesemaking, or lactase, the enzyme which cleaves lactose to glucose and galactose, could speed the development of innovative continuous processing methods in the dairy fermentation industry.

Low Calorie Foods. The current trend toward a more health- and nutrition-conscious lifestyle has encouraged the development of low calorie foods. The non-nutritive sweetener market has been predicted to reach $500 million by the year 2000.

A new class of compounds called taste-active proteins functions as sweeteners and flavor modifiers and includes compounds such as aspartame, thaumatin, and monellin. The gene which codes for the protein thaumatin has been isolated and characterized. Transfer of this gene into bacteria would allow the production of thaumatin via fermentation. If engineered into plants, new and unique foods could be developed.

Another application of biotechnology in low calorie food production is the development of low calorie fats and oils. Genetically inducing the production of shorter chain fatty acids in soybean or rapeseed would speed the development of a low calorie vegetable oil. The market for this oil could reach $2 billion a year by the end of the next decade.

Natural Food Products. Another consumer trend is the demand for natural food products. Natural flavors and colors elicit a higher price than their synthetic counterparts, as the supply of these natural additives is highly dependent upon favorable environmental conditions for growing the plant and efficient and safe extraction procedures. Numerous strains of bacteria, yeast, and mold can produce flavors and colors of interest to the food processing industry. An understanding of the metabolic pathways and the specific proteins and enzymes responsible for the synthesis of these compounds will allow the future development of more consistent and cost-effective production methods.

Value-added Technology and Waste Management

A major concern in the food processing industry is the development of methods to convert inedible plant materials and waste materials into new value-added products. Each year the cheese industry generates billions of pounds of whey that must be disposed of. Ultrafiltration has provided the cheesemaker with a means of concentrating the protein component of whey into a value-added item with significant dollar value. Some solids, however, have a negative market value because it costs money to get rid of them.

A recently developed bioconversion system employing selected strains of yeast can convert these solids to ascorbic acid with a market value of about $10 per kilogram.

Certain strains of yeast can produce terpenes which impart a characteristic grape aroma and the odor of oils of interest in the wine and food industries. Because these strains use the lactose in whey as a sole carbon source, they could be used in fermentation systems to produce flavor components. The yeast biomass could be dried and used as single-cell protein supplements in animal feed.

Enzymatic treatment of food processing waste streams could produce materials readily metabolized by micro-organisms genetically engineered to produce antibiotics, hormones, or peptides of interest in the pharmaceutical or chemical industries. In the future, environmental and economic concerns will necessitate a reduction of food processing waste, better use of raw materials, and the processing of food residuals to new products that have value.

Rapid Detection Methods

Ensuring the safety of our food supply is an integral part of the food processing industry. Classical microbiological techniques for the enumeration and identification of disease agents and their toxins in foods are not always reliable and are often slow. Foods can already be in the marketplace before results are available. Biotechnology has been used to develop sensitive, reliable, and rapid detection methods to expedite this process.

One method involves DNA—deoxyribonucleic acid, the molecular basis of heredity in many organisms. Specific fragments of DNA from disease-causing micro-organisms that code for toxins or virulence factors have been used to create DNA probes which in hybridization analyses can detect those organisms in foods.

Commercial test kits for the detection of Salmonella are available and currrently being tested in field trials.

The identification of antigens by using monoclonal antibodies is another valuable tool in the biological monitoring of food. Monoclonal antibodies have been used to detect disease-causing micro-organisms, and they also help detect nonmicrobial components of food.

In the future, bioassays employing DNA probes and monoclonal antibodies will be developed for a host of food-borne disease agents and become a powerful diagnostic tool for the food processing industry

Modern Biotechnology in Food: Modern biotechnology and food quality

In Europe, a vast diversity of high quality foods provide the carbohydrates, fats, proteins, minerals and vitamins needed in the everyday diet of consumers. At the heart of food production is biotechnology. One aspect of biotechnology which has been used for centuries is the selective breeding of crop plants and farm animals to produce improved food. Another is fermentation, in use for millennia to produce fermented foods like cheese, bread, beer, sauerkraut and sausages.

The first use of gene technology two decades ago opened up the potential for many additional advances in both selective breeding and fermentation. Each specific step forward might be relatively small, but together they could add up to further improvements in the nutritional quality, appearance, flavour, convenience, cost and safety of foods.

Better raw materials ...

In improving raw food materials, many plant breeding programmes have been directed towards boosting yield or allowing more environmentally compatible agriculture by increasing the resistance of crops to viruses, pests or herbicides. Increasing yield has clear benefits in helping to feed the world's ever-increasing population and could provide cheaper food. Plants which are resistant to attack by insect pests and diseases would need fewer pesticide applications; resistant crops such as maize, tomatoes and potatoes are already being developed. Crops have also been produced with tolerance to modern, more environmentally compatible herbicides, with the aim of achieving optimal weed control with reduced levels of herbicide.

Today, there is increasing interest in improving the nutritional value, flavour and texture of raw materials. This could help encourage greater fruit and vegetable consumption in line with government guidelines on healthy nutrition.

A range of promising crop plants are being developed with:

•Improved nutritional value - Crops in development include soybeans with a higher protein content; potatoes with more nutritionally available starch and with an improved amino acid content; pulses such as beans which have been altered to produce essential amino acids; crops which produce beta-carotene, a precursor of vitamin A; and crop plants with a modified fatty acid profile. An example is a strain of oilseed rape which produces a special type of polyunsaturated fatty acid (the so-called w3-fatty acids). These have been linked to brain development and have potential in a range of speciality, clinical and infant foods.

•Better flavour - For example, types of peppers and melons with improved flavour are currently in field trials. Flavour can also be improved by enhancing the activity of plant enzymes which transform aroma precursors into flavouring compounds.

•Improved keeping properties with the aim of making transport of fresh produce easier, giving consumers access to nutritionally valuable whole foods and preventing decay, damage and loss of nutrients. Examples include the improved tomatoes now being sold in the US, and recently approved in the UK, which have been genetically altered to delay softening. Research is underway on making similar modifications to broccoli, celery, carrots, melon and raspberries. The shelf-life of some processed foods such as peanuts has also been improved by using raw materials with a modified fatty acid profile.

•Reduced levels of toxicants, allowing a wider range of plants to be used as food crops, such as the edible strain of sweet lupin which has been developed through conventional breeding techniques.

Improved food ingredients ...

Necessary changes to the key food ingredients, starches and oils, are usually made by processing. Biotechnology opens up the possibility of altering crop plants to produce exactly the type of ingredients needed:

•Starches- Plant breeders have introduced a bacterial gene into potato plants which increases the proportion of starch in the tubers whilst reducing their water content. This means that the potatoes absorb less fat during frying, giving low-fat chips. Sweeter potatoes have also been produced which have a higher sucrose content than traditional varieties.

•Oils- Both rapeseed and sunflower are being altered to produce more stable and nutritious oils, which contain linoleic acid instead of linolenic acid and have a lower saturated fat content. Rapeseed has also been modified to produce a high-temperature frying oil low in saturated fat.

Advances in processing and additives ...

Research underway at present aims to allow the production of better food raw materials by crop plants. However, some processing steps remain essential to bridge the gap between currently-available raw materials and the desired end-product.

Traditional biotechnology has played a major role in producing fermented foods - where desirable changes are produced by the action of micro-organisms or enzymes - of which over 3,500 different types exist around the world. In Europe and North America, bread, yoghurt and cheese are perhaps most familiar. In Africa, foods made from fermented starch crops like yams and cassava are more important, whereas in Asia, products derived from fermented soya beans or fish predominate.

Fermentation can make the food more nutritious, tastier or easier to digest, and it can enhance food safety.
It also helps to preserve food and to increase its shelf-life, reducing the need for additives. Genetically improved strains of microbes can make a major contribution to these desirable properties.

For many years, a wide range of additives, processing aids and supplements have been obtained from microbial sources by fermentation. Increasingly, modern biotechnology is being used here. Products include vitamins, citric acid, natural colourings, flavourings, gums and enzymes. Gums used as low-calorie thickening agents and low-calorie sweeteners from natural ingredients are also produced using modern biotechnology. Enzymes (see separate background paper) - the naturally-occurring catalysts responsible for literally all the biochemical processes of life - are used in applications such as bakery and cheese making to improve texture, appearance and nutritional value, and to generate desirable flavours and aromas.

A second area where biotechnology has advantages is in improving the processes by which food is produced. Here, it can be used to develop mild, highly specific processes using modified micro-organisms and purer, cheaper enzyme products. These can offer better productivity, cost-effectiveness and energy efficiency than existing processes. They can produce top-quality foods with a reduced need for additives such as flavourings, and can also reduce the environmental impact of food processing.

Specific areas of food processing where advances are being seen are:

•Bread-making, for which improved strains of yeast have been developed containing genes for production of other food processing aids, such as amylases, which give improved dough. Yeast can also be used to produce a range of enzymes for use in processes such as cheese production, where introducing a copy of a calf gene has given a strain of yeast which produces the enzyme, chymosin. Previously, this enzyme could only be obtained from the stomachs of calves.

•Fruit juice production, where juice yields from apples can be improved by adding pectinase enzymes. These are produced naturally by a strain of the mould Aspergillus. The rate at which the enzymes are made can be improved by transferring the gene for pectinase from one strain of the mould into a second strain with a higher capacity for enzyme production.

•Improved quality management and food safety, through a greater understanding of micro-organisms and enzymes in food production. A range of biological tools, such as monoclonal and polyclonal antibodies, will add to this impact through their use in a range of diagnostic tests aimed at enhancing the quality and safety of products and processes. These can potentially be used to monitor the presence of additives, toxins, pesticides, micro-organisms and antibiotics, and they will give quicker, more accurate detection than traditional laboratory processes.

Biotechnology - a definition

Biotechnology is any technique which uses living organisms or their components to make or modify products, to improve plants or animals or to develop micro-organisms for special uses.

Source: OECD

Gene technology - a definition

Gene technology includes any technique for the controlled modification or transfer of genes from one organisms to another to give a desired characteristic

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