The industrialized food scientific background

Food microbiology is the branch of science that studies microorganisms that inhabit, grow and contaminate food, with emphasis on those that deteriorate or spoil food. These microorganisms cause harm to men, as well as pathogenic microorganisms or pathogens, which can be present in food and cause various diseases. However, there are other microorganisms, such as probiotics and those used in the production of food, such as cheese, pickles, bread, beer, vinegar, salami, and wine, which are introduced into foods due to their beneficial effects.

Until 200 years ago, the preparation of fermented food and its conservation was done empirically, as the microorganisms role in these processes was unknown. This situation began to change more markedly with the Louis Pasteur work. In 1857, demonstrated that the milk acidification is caused by microorganisms (lactic acid bacteria) and in 1860, he destroyed undesirable microbes from wine and beer using heat, a process that was later called pasteurization and is widely used today. Due to the importance of his work, Pasteur is known as the founder of microbiological science and food microbiology. He is also attributed to experiments with the famous swan-neck bottles that finally refuted the theory of spontaneous generation.

After that, microbiological developments and discoveries began to advance more quickly. Microbes were implicated in various diseases, heat-resistant spores were discovered, toxins were identified, and at the end of the 18th century, governments started creating legislation focused on food safety and quality.

Food microbiology has gained importance with the study of diseases cause by food and the growth of international food trade. In 1888, A. A. Gartner demonstrated than Salmonella enteritidis was the biological agent responsible for contamination in food. Other agents were discovered later: Shigella dysenteriae (K. Shiga, 1898); Salmonella chloreacius (Salmon, 1900); Bacillus spp (1906); Bacillus cereus (1946); and many others, including fungi and viruses. This process of discovering microorganisms is continuous, as new biological agents associated with food contamination are always discovered. Recently arisen agents are called emergent.

In 1930, G. M. Dack and collaborators discovered that the bacterium Staphylococcus spp produced toxins, which were actually responsible for the negative effects observed in the body. After them, several bacterial toxins were discovered, such as botulin, produced by the Clostridium botulinum and responsible for causing botulism, and fungal toxins (mycotoxins), such as aflatoxin, produced by Aspergillus flavus. Therefore, there are two situations: one in which the biological agent was ingested together with food and is active in the body (infection) and another in which only the active toxin is present in the body (intoxication).

From these discoveries, attention turned to food production, that is, it was essential to understand how contamination occurred and to develop practices to eliminate or control it, including the analyses. Them, some important benchmarks point to this direction:

– 1905: establishment of standard method for water analysis and milk analysis.

– 1958: recommendation of methods for microbiological analyses.

– 1962: creation of the FAO/WHO program and the International Commission on Microbiological Specifications of Foods – ICMSF.

– 1967: creation of the Latin American Subcommittee – LAS do ICMSF.

– 1969: publishing of the first standard of the Good Manufacturing Practices – GMP, designed to food, demonstrating the importance of creating a legislation specific for the sector. In Brazil, the GMP for foods were implemented by ANVISA Decree no. 326 in 1997.

– 1971: An important control tool is made public, Hazard Analysis and Critical Control Points – HACCP.

– 1989 to 1992: publishing of “HACCP principles for food production”

– 1993: Codex announces guidance for HACCP implementation.

– 1995: The U.S. Department of Agriculture (USDA) determines that all animal processing and slaughtering plants must develop and implement a HACCP program within 3 years.

– 2005: publishing of ISO 22000, an international standard that defines the requirements of a food safety management system, covering all organizations in the food chain, from the harvest to the consumer’s tablepublicação da ISO 22000, norma internacional que define os requisitos de um sistema de gestão de segurança de alimentos, abrangendo todas as organizações da cadeia alimentar, desde a colheita até a mesa do consumidor.

Currently, the foods industry applies an integrated tools, such as, Good Manufacturing Practices (GMP) and the Standard Sanitizing Operational Procedures (SOP) are important to prevent hazards. GMP and SOP are also prerequisites for the HACCP system implementation , which brings objectivity to the systems, allowing to strictly monitor critical points in the processes, that is, those that present higher risk, prioritizing a preventive instead of reactive approach, and reducing the operational costs. The quality control is a mandatory regulatory activity through which national or local authorities can ensure the availability of food that is adequate, safe and compliant with labeling requirements as provided by law.

In addition to the mandatory safety and quality practices, many industries have obtained a certification by ISO 22000 standard, that in addition to reinforce the safe food production, it enables them to export their products.

Food toxicology studies the adverse effects caused by chemical agents present in the food, whether contaminants or chemical substances used specifically as preservers, sweeteners, flavorings, both synthetic or natural.

When Paracelsus, at the beginning of the 16th century, postulated that the difference between what cures and what poisons is the dose, he established some theoretical references of toxicology as a scientific discipline, to which there was a later universal convergence. But it was only in the 19th century that toxicology was consolidated as a modern science, taking advantage of the development of chemistry, physiology and microbiology. Nowadays, it represents an area of vital importance in establishing parameters and conditions in which food can be ingested without causing harm to health.

The main parameter for the study of food toxicology is the ADI (Acceptable Daily Intake), as it allows predicting whether or not there will be harm to those who use a certain food.

ADI is the dose of the ingested chemical agent that does not produce statistically or biologically significant increases in the frequency or severity of adverse effects in the exposed population. Effects may be produced by this dose, but are not considered to be adverse.

Before calculating the ADI, it is necessary to know the non-observed adverse effect level (NOEL). To obtain NOEL, the highest possible dose of an additive is given to the most sensitive animal species for most of its life, with no toxic or adverse effects. It is expressed in mg/Kg/day.

Then, NOEL calculated for tha animal is divided by a safety factor, usually 100. For example, if NOEL obtained for the animal species used in the toxicological test was 100 mg/Kg/day, the ADI for humans will be 1 mg/Kg/day.

Example: The cyclamate ADI is 11 mg/Kg/day, it means that an individual with 80 Kg can intake up to 880 mg of cyclamate a day, a much lower than the quantity usually consumed.

Food chemistry is the science that studies the food composition, the chemical changes undergone by it during processing and storage, and the compounds introduced into it intentionally or accidentally, such as additives and contaminants. Food has a very large number of components, with water, proteins, fats or lipids and carbohydrates being present in greater quantity. Other components present in smaller quantities are minerals, vitamins and nucleic acids.  Food chemistry is also related to biochemistry and nutrition.

Chemistry began its strong development in the second half of the 18th century, especially after the year 1785, a period in which there was a real revolution in the area, especially in France. At that period, the main chemical elements were discovered and analytical methods, which allowed the testing of old and new ideas quantitatively and scientifically, were developed. In 1785, for example, Claude Berthollet discovered that the steam coming out of decomposing animals was ammonia and that it was composed of 17% hydrogen and 83% nitrogen.

Between 1790 and 1794, Lavoisier studied the processes of combustion food and cellular respiration using sophisticated equipment he created and called calorimeters, and concluded that the heat produced came from the slow combustion of organic matter, a process that released CO2, H2O and about 2,000 calories/day.

Still at the late 18th century, Scheele, a Swedish pharmacist, discovered chlorine, glycerol, and isolated citric acid, tartaric acid, and malic acid from fruits.

In the early part of the 19th century, Justus Liebig classified food into nitrogenous (albumin, casein, meat, and blood) and non-nitrogenous (fats, carbohydrates, and alcoholic beverages). In 1847 he published what was perhaps the first book on food chemistry, entitled “Researches on Chemistry of Food”.

Thanks to the parallel development of chemistry, microbiology, physiology, and nutrition, by the end of the 19th century, the food main chemical constituents were already known.

After World War II, studies on food composition were increasing, to the point that FAO created conditions for the elaboration of regional tables, through a international cooperation process. During the 1970s and 1980s there was a great advance in the area of food chemical analysis and more accurate and reliable methods of identification were developed, such as HPLC (High Pressure Liquid Chromatography). At the same time, the relationships between diet, health and disease were increasingly evident.

After that, the computing development enabled a rapid development of food chemistry, as well as other sciences, as it supported the development of increasingly practical and reliable equipment.

Another wave of development experienced by chemistry is provided by nanotechnology.

Biotechnology can be defined as the set of knowledge that allows the use of living organisms or parts of them (cells, organelles, molecules) to produce goods and services.

Biotechnology comprises different areas of knowledge such as microbiology, chemistry, genetics, physiology, cell biology, biochemistry, informatics and robotics, among others.

With the development of recombinant DNA technology, from the 1970s, modern biotechnology began, which allowed the cloning genes from one species to another, giving rise to genetically modified organisms, the GMO. That fact has caused a truly revolution in the biotechnology, as it enabled a more precise approach of genetic changes, speeding up the results obtainment and reducing costs.

Modern biotechnology has driven the computing development, resulting in an impressive advance of the called omics science (genomics, proteomics, metabolomics). The sequencing of all human genomes genes and many other living beings is an example of this advance.

For further information (link with BIT biotechnology)

It studies the food production, storage, packaging, preservation and quality assurance processes. You can also work with the technological processes general management and in the development of procedures and machines related to food production.

According to the Brazilian Association of Food Engineers (www.abea.com.br) : “It is a specific area of knowledge capable of encompassing all elements related to food industrialization, and that can enhance the development of this branch at all levels, through the professional with this training; whether in the training of professionals, in subsidizing the elaboration of policies, in research projects, in the performance within companies in the sector, as well as in collaboration with the preservation of public health (technical standardization, guidance and inspection)”.

Nanotechnology can be defined as technology that works at the nanometer scale, that is, dimensions of atoms or molecules. It usually works with structures measuring between 1 and 100 nanometers in at least one dimension.

Nanotechnology is causing a revolution in several areas of knowledge. In food, there are important regulatory aspects that need to be addressed, but it is already being used in various stages of the production chain such as processes, transport, packaging, and distribution.

The possibilities for developing food ingredients involving nanotechnology are enormous and could contribute to generating concrete benefits for consumers.

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It studies nutrients and toe food behavior in the human body. It coordinates food in many institutions such as schools, companies, hospitals, spas, etc., seeking for a healthy diet and according to people’s needs.

Lavoisier is considered the “Father of Nutrition” for having studied, between the processes of food combustion and cellular respiration, within 1790 and 1794, using sophisticated equipment created by him and called calorimeters. From his work, it became clear that our body’s source of energy was the controlled food combustion, with the release of CO2, H2O and about 2,000 calories/day.

At the beginning of the 19th century, Françoise Magendie studied gelatin for 10 years and, after conducting several experiments, he concluded that it was not a complete food. At that time, scientists believed in the existence of a food that could meet all the needs of an organism. Later, it was discovered that, with the exception of breast milk, there is not a complete food a all, which forces us to have a varied diet to obtain all the chemical compounds that our body needs.

In the 1830s, Jean Baptiste Bussingault discovered that leguminous plants (soybean, beans, etc.) were capable of using nitrogen from the atmosphere in their metabolism. Justus Liebig, on the other hand, concluded that animals convert carbohydrates into fat and are therefore also able to reduce organic matter.

In the first half of the 19th century, John Young, William Beaumont and Claude Bernard studied the digestion process intensively and made important contributions to the field of physiology and nutrition.

In 1746, James Lind discovered that lemons and oranges recovered sailors from scurvy. In the period within 1845 and 1871, they found that potatoes, fresh vegetables, and fruit juices also have an anti-scurvy effect. Only many year after it was discovered that ascorbic acid (vitamin C) was the anti-scurvy agent.

In the first third of the 20th century, a period known as the age of vitamins, several diseases were associated with specific substances, forming the baseline for the development of nutrition. As it was the case for night blindness (lack of vitamin A), rickets (lack of vitamin D) and beriberi (lack of vitamin B1 or thiamine).

Soon after this phase, physiology, nutrition, biochemistry and biology had a rapid development, mainly due to the introduction of the use of microorganisms as a model of studies. Microorganisms provided it very well to this because they grow and multiply rapidly, take up little space, and enable the environmental variables controlling. The bacterium Escherichia coli and the yeast Saccharomyces cerevisae were the most studied.

The comprehensive study of microorganisms also enabled the emergence of modern biotechnology, which occurred with the discovery of restriction enzymes in the early 1970s, a fundamental step in the development of recombinant DNA techniques.

In the last decades, nutrition had a strong development, driven by the growth of functional foods and the creation of nutrigenomics/nutrigenetics, the result of the union of nutrition with genomics/genetics.