IV. Technology Milestones in Food and Agriculture Chemists and chemical engineers have made many contributions to food and agriculture that allow us to raise, harvest, and consume abundant and nutritious food. At the turn of the nineteenth and twentieth century, an average kitchen table would be loaded with produce from the root cellar, garden, or local farm; butter from a churn; eggs from hens penned in the backyard; vegetables from the garden and meat stored in an icebox and cooked over a coal or wood stove. The last century has brought vast changes in how we get food on our tables by making our farms more productive and our food and water supplies readily available. Modern farmers have utilized new chemical advances to improve agricultural production with fertilizers and pesticides and to develop plentiful food supplies. Consumers have benefited from new technologies that have enhanced the flavor, appearance, availability, and nutritional value of their food. These advances in chemistry are helping to feed potentially all individuals of the world’s rapidly expanding population. IV.1. Fertilizers and Soil Nutrients Nitrogen fixation Haber-Bosch process Advances in chemical fertilizers Green Revolution and hybrid plants IV.2. Crop Protection and Pest Management Bordeaux method and fungicides DDT and pesticides Livestock protection Farm mechanization IV.3. Food Processing, Handling and Safety Saccharin and sweeteners Vitamins and minerals Preservation and manufacturing advances Food safety and quality control IV.4. Food Storing Food packaging Refrigerants and chlorofluorocarbons Microwave ovens Clean water Chronology
IV. Technology Milestones in Food and Agriculture Chronology 1881 The French Louis Pasteur discovers anthrax vaccine for sheep and hogs 1883Johan Gustav Kjeldahl Danish chemist developed a method to analyze the nitrogen content of any organic compound 1884 The French botanist Pierre M. A. Millardet invents the Bordeaux mixture to fight vineyard mildew 1901John F. Quenny, the founder of Monsanto Company manufactures Saccharin 1913 Two German chemists, Fritz Haber and Carl Bosch developed the process for the production of ammonia at industrial level 1913Elmer V. McCollum and Marguerite David discover Vitamin A in butter and egg yolks 1918 The firm Kelvinator launches the first successful compressor-operated refrigerator for home use 1933Milk fortified with Vitamin D is sold commercially 1939 The Swiss chemist Paul Mueller discovers the insecticidal qualities of DDT pesticide 1943 U.S. Department of Agriculture chemists develop aerosol dispersion for insecticides and farm applications 1953 Saran wrap for household use is introduced by the firm Dow 1964 The ‘Green Revolution’: Application of new hybrid plants and liquid soil fertilizers solves nutrition of Asia’s population 1972 DDT usage banned in the United States. (As first country on the world Hungary banned it in 1968) 1974Monsanto introduces its comprehensive and non-tilling Roundup herbicide 1990Novel fortifications in food and ‘nutriceutical’ products become commercially popular
IV.1. Fertilizers and Soil Nutrients Nitrogen fixation The nitrogen cycle Nitrogen fixation is an essential natural process in which microorganisms convert the otherwise less-reactive nitrogen into inorganic nitrogen compounds, which in turn first appear in nutritional chain as organic nitrogen compounds like proteins in plants. Since the beginning of twentieth century available soil nitrogen, first of all nitrates is normally deficient for intensive crop production, many commercial processes to produce nitrogen fertilizers, including the best known Haber-Bosch method for ammonia synthesis. The achievability of balanced soil chemistry was underscored by the 1956 development of the Kjeldahl method to analyze automatically the amount of existing nitrogen present in organic compounds. Unit for determining nitrogen content of organic materials by the Kjeldahl method
IV.1. Fertilizers and Soil Nutrients The Haber- Bosch process The supply of the expanding population by food at the end of nineteenth century raised a growing difficulty, since nitrogen content of the soils exhausted, whereas industrial support of nitrogen fertilizers remained unsolved. Some scientists expected a starvation worldwide. Therefore, a compelling task raised for production of nitrogen compounds utilizing nitrogen of the air. The solution came in 1908 from Germany, where Fritz Haber discovered the principles of ammonia synthesis, utilizing all physical and chemical resources available that time. The synthesis takes place on iron catalyst at high pressure and temperature. Carl Bosch, chemist at BASF (Badische Anilin- & Soda-Fabrik) commercialized the process by establishing the first, state-of-the-art, industrial-level production in 1913. This industrial process allowed for the expansion of both agriculture production and human population during the 20th century. Fritz Haber
IV.1. Fertilizers and Soil Nutrients Advances in chemical fertilizers Beginning in 1913, synthetic fertilizers are commercially produced to dramatically improve crop yields and production. Innovations in the basic production of chemical fertilizers have been made ever since, including the 1930 marketing of granulated fertilizers and the 1965 introduction of suspension fertilizers in the American market. In the 1970s, granulation was further refined to introduce fertilizers suitable for home use blending. The most recent innovations in commercial fertilizers include time-release encapsulation that avoids environmentally undesirable over fertilization.
IV.1. Fertilizers and Soil Nutrients Green Revolution and hybrid plants Since the 1870s, hybrid plants have been created to use desirable qualities to increase food production and quality. Organic chemistry identifies desirable plant qualities, translates those qualities to successive hybrids, and maximizes nitrogen uptake with chemical fertilizers. These advances led to the so-described ‘Green Revolution’, beginning when Mexico first became self-sufficient in wheat production in 1943. Much of Asia’s population was being fed using new hybrid plants and soil nutrient chemistry by 1964. American farmers are now embracing new kinds of hybrid plants, such as maize and potatoes that secrete a pesticide in their leaves and stems.
IV.2. Crop Protection and Pest Managament Bordeaux method and fungicides In 1882, French botanist Pierre M. A. Millardet employs an aqueous solution of copper sulfate and hydrated lime dissolved in water (Bordeaux mixture) to effectively combat mildew in French vineyards. The Bordeaux mixture now controls a number of fungi that attack crops. This also marked the first large-scale fungicide use and revolutionized chemical crop protection. Chemical innovations in agricultural fungicides continued with the introduction of dithiocarbamate fungicides in 1934 and strobilurin fungicides in 1996. Pierre M. A. Millardet
IV.2. Crop Protection and Pest Managament DDT and pesticides Pesticides shield agricultural crops from harm by fungi, insects, and competition from other plants. In 1939, Paul Mueller developed the inexpensive insecticide DDT (dichlor-diphenyl-trichlorethan) to control potato beetles and other insects. DDT and similar pesticides controlled crop pests and insect-borne diseases for over twenty years. In the 1960s, public concerns about accumulation of DDT in human body, combined with increasing resistance in pest species led to the evolution of new pesticides and the decline of DDT. Today’s low-application pesticides provide greater economy for farmers, added worker safety, and are more environmentally friendly than ever before. DDT in combating malaria Thinned egg-shells caused by DDT
IV.2. Crop Protection and Pest Managament Livestock protection The treatment of animal disease, either by vaccination or medication, has increased the quality and quantity of the food supply. In 1881, Louis Pasteur successfully perfected techniques to vaccinate animals in order to induce immunity against the anthrax-causing organism. In 1981, the anti-parasitic Ivermectin fought a wide range of mites, worms, and other internal parasites that effect animal health. Current research is attempting to prevent bovine spongiform encephalopathy (BSE), the so called `mad cow disease’ that is believed to be caused by proteins in animal feed that harbor the infectious agent. Louis Pasteur Pasteur vaccinates animals
IV.2. Crop Protection and Pest Managament Farm mechanization Agricultural chemistry and farm mechanization have developed together over the last century, and they have dramatically increased farm efficiency and productivity. The Diesel-oil-powered tractor was developed by Benjamin Holt, the American inventor, in 1904 in conjunction with the need for efficient application technologies for agricultural chemicals (fertilizers, pesticides) and water. The crawler tractor developed by Holt Today’s tractors, cultivators, combines reapers, irrigation machines, computer-based application technology, and sophisticated GPS software are all enabled by chemical innovations such as petrochemical fuels, structural materials (metal alloys and advanced plastics), tire technology, and computing electronics.
IV.3. Food Processing - Handling and Safety Saccharin and sweeteners Artificial sweeteners created using chemistry aid both diabetics and dieters in controlling their sugar intake. In 1901, John F. Quenny manufactured the artificial sweetener Saccharin. In 1967, the manufacturing of high-fructose corn syrup using a patented enzyme to increase the fructose sweetness of corn syrup from 14% to 42% began and quickly became the sweetener for all major soft drinks. Aspartame was first sold in 1985 in the USA; this low-calorie intense sweetener marketed as NutraSweet was developed in 1955 as a possible anti-ulcer drug. Originally packaged Saccharin
IV.3. Food Processing - Handling and Safety Vitamin additives Understanding food biochemistry has revolutionized nutrition by offering cures for dietary deficiency and malnutrition caused by lack of vitamins. Chemistry has made great advances in this field, as shown by examining the first vitamin to be understood. In 1913 the first, in butter and egg yolks discovered vitamin was vitamin A (beta-carotene), an essential nutrient for vision and protection of epithelia. Its chemical structure was determined in 1931, and it was first synthesized in 1947. The Hungarian biochemist Albert Szent-Györgyi isolated hexuronic acid (ascorbic acid) from adrenal glands in 1928 that is known as vitamin C. In 2001, genetically-modified ‘golden rice’ that produces pro-vitamin A arrives in Asia to fight blindness and other deficiency diseases.
IV.3. Food Processing - Handling and Safety Preservation and manufacturing advances The roots of food chemistry are going back to the German Justus Liebig, who first made meet extract at the middle of nineteenth century. Advances in preservation and manufacturing techniques have allowed us to create our meals from processed foods. As food chemistry fueled industrial practices, many processed foods were developed. New technologies extended the shelf life of food, including freeze-drying (liophilisation) (1906), deep-freezing foods (1920), precooking frozen foods (1939), and making concentrates from fluids (1946). The one-time placard of Liebig’s meat extract
IV.3. Food Processing - Handling and Safety Food safety and testing Any raw agricultural product or prepared food can be contaminated and might possibly affect human health. Contaminations may occur during preparation, cooking, serving and storage. To control food safety, chemical advances include rapid test methods enabling to detect microbial food contaminants and control of food-borne epidemics. Illnesses from the most common food-borne pathogens have been reduced by 20% from 1997 to 1999 in the USA.
IV.4. Food Storing Food packaging Packaging food with plastics, metal, glass, and ceramic technologies help to preserve food during sale, shipping, and preparation. Ralph Wiley invented industrial saran polymer in the 1930s, and household Saran wrap was introduced in 1953 to provide an excellent barrier to oxygen, moisture, aroma, and chemicals under extreme humidity and temperature conditions. Saran wrap is a copolymer of vinylidene chloride and vinyl chloride. Other innovations include utilization of aluminum cans for foods and beverages (1960s), and of PET (polyethylene terephthalate) as recyclable container packaging to replace glass or aluminum (1970s).
IV.4. Food Storing Refrigerants and chlorofluorocarbons Since being introduced for home use in 1918, refrigeration has altered food preservation by providing the ability to transport and store fresh foods safely. Early 1920s refrigerators were unpopular after the sulfur dioxide coolant proved toxic. The solution was Freon 12, a chlorofluorocarbon (also referred to as a CFC, CCl2F2) compound made into a refrigerant gas by Thomas Midgley and Charles Kettering in 1931. Refrigerators quickly became standard in homes, restaurants, and grocery stores. Freon’s role is now being discontinued because of its role in the destruction of the earth’s ozone layer. Icebox (1890) and household refrigerator by Kelvinator (1926)
IV.4. Food Storing Microwave owens Household appliances in the 20th century have eliminated much of the everyday labor of food preparation, and one innovation fueled by chemical advances was the microwave oven. In 1945, Percy L. Spencer was reportedly standing near an operating radar transmitter at Raytheon when a candy bar in his pocket began to melt. Fascinated, he replicated this experience with popcorn, and the microwave oven was born. His Radarange debuted later that decade in industrial kitchens. Today, World War II-type microwave transmitters, called magnetrons, still form the heart of this popular appliance.
IV.4. Food Storing Clean water Advances in chemistry have ensured safe water supplies that are free from bacteria, viruses, and other harmful contaminants. Innovations include using carbons to remove bad taste and odor, other ingredients to soften the water and remove heavy metals, and modern technology for water treatment, supply, and distribution. Chlorine disinfection in water treatment systems was underway by 1910, and household bleach was introduced in 1913. Chlorine-based disinfectants remain an excellent method for protecting kitchens and food-processing facilities from food-borne diseases. Molecule model of hypochlorous acid