Food and biological process engineering

Creating article "Food and biological process engineering" Since both food engineering and biological process engineering are separate and well-defined things, I'm assuming this article should discuss overlap between food engineering and biological process engineering.

Thus I should do the following

• Prepare relevant background on food engineering (check out article Food engineering)
  • Found other source (https://www.sciencedirect.com/science/article/pii/B978012385881800001X)
• Prepare relevant background on biological engineering (check out article Biological engineering)
  • Cornell page also talks about biological engineering (https://bee.cals.cornell.edu/research/biological-engineering)
• Identify areas of overlap between the two things
  • Food safety
    • fda article: https://www.fda.gov/downloads/Food/FoodborneIllnessContaminants/UCM545175.pdf
    • Chapter 3: https://www.sciencedirect.com/science/article/pii/B9780123858818000033
    • Food safety engineering
  • Food storage
  • Waste management

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Creating, processing, and storing food to support the world's population requires a combination of many fields, one of such combinations is biological engineering processes within food engineering. Food safety in particular requires extensive biological study to understand the microorganisms involved and how they effect humans. However, other aspects of food engineering, such as food storage and processing, also require extensive biological knowledge of the food and possible microorganisms that inhabit the food. This food microbiology knowledge becomes biological engineering when systems and processes are created to maintain desirable food properties and microorganisms while providing mechanisms for eliminating the unfavorable or dangerous ones.

Food safety

This figure illustrates the pathway of food preservation followed by lactic acid bacteria involving Nisin, as well as the pathway of food preservation followed by salt. Additionally, the hurdle effect of food preservation, such as by adding lactic acid bacteria and salt to a food product, is illustrated and described.

An important biological engineering task within the realm of food safety is the elimination of microorganisms responsible for food-borne illness. Food and waterborne diseases are recognized as one of the most serious public health concerns in the world. The risk of these diseases have risen throughout the years, mainly due to the mishandling of raw food, poor sanitation, and poor socioeconomic conditions. In addition to diseases caused by direct infection by pathogens, some food borne diseases are caused by the presence of toxins produced by microorganisms in food. There are four main types of microbial pathogens which contaminate food and water: viruses, bacteria, fungi, pathogenic protozoa and helminths.

Several bacteria, such as E. coli, Clostridium botulinum, and Salmonella enterica, are well-known and are targeted for elimination via various industrial processes. Though bacteria are often the focus of food safety processes, viruses, protozoa, and molds are also known to cause food-borne illness and are also of concern when designing processes to ensure food safety. Although the goal of food safety is to eliminate harmful organisms from food and prevent food-borne illness, detecting said organisms is another important function of food safety.

Monitoring and detection

The goal of most monitoring and detection processes is the rapid detection of harmful microorganisms with minimal interruption to the processing of food products. An examples of a detection mechanism that relies heavily on biological processes is usage of chromogenic microbiological media.

Chromogenic Microbiological Media

Chromogenic microbiological media use colored enzymes to detect the presence of certain bacteria. In conventional bacteria culturing, bacteria are allowed to grow on a medium that supports many strains. Since it is hard to isolate bacteria, many cultures of different bacteria are able to form. To identify a particular bacteria, scientists must rely on other characteristics of cultures of that bacteria, before performing further tests, such as serology tests to find antibodies formed in organisms as a response to infection. To cut down on the need for further tests and to make the identification of certain bacterial colonies easier, chromogenic microbiological media use enzymes that produce colored dyes as they interact with certain microbes. Chromogenic media plates thus use particular color-producing enzymes that are targeted for metabolism by a certain strain of bacteria, hopefully allowing for easy identification of colonies of that bacteria. Typically, the chromogenic plates must also incorporate additional enzymes that will be processed by other bacteria. This prevents false identification of other bacterial colonies, since these colonies are producing additional colors that distinguish them from the target bacteria.

Visit this link

https://www.condalab.com/pdf/Chromogenic%20Media%20FAQS%202.pdf

Just summarize chromogenic stuff and do not do more, mention fda reference

Also used this link:

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2672.2007.03442.x

Mechanisms

Food safety has been practiced for thousands of years, but with the rise of heavily industrial agriculture, the demand for food safety has steadily increased, prompting more research into the ways to achieve greater food safety. A primary mechanism that will be discussed in this article is heating of food products to kill microorganisms, as this has a long history and is still extensively used. However, more recent mechanisms have been created such as application of ultraviolet light, usage of ozone, and irradiation of food.

Heating

A report given to the Institute of Food Technologists states that thermal processing of food has been used for thousands of years. A notable step in development of heat application to food processing is pasteurization, developed by Louis Pasteur in the nineteenth century. Pasteurization is used to kill microorganisms that could pose risks to consumers or shorten the shelf life of food products. Primarily applied to liquid food products, pasteurization is regularly applied to fruit juice, beer, milk, and ice cream. Heat applied during pasteurization varies from around 60 (degrees C) to kill bacteria to around 80 (degrees C) to kill yeasts. Most pasteurization processes have been optimized recently to involve several steps of heating at various temperatures and minimize the time needed for the process. (cite the handbook of pres, chapter 23)

Basic drawing of an ammonia compressor. Ammonia compressors are used in many factories to cool food products.

A more severe food heating mechanism is thermal sterilization. While pasteurization destroys most bacteria and yeast growing in food products, the goal of sterilization is to kill almost all viable organisms found in food products including yeast, mold, bacteria, and spore forming organisms. Done properly, this process will greatly extend the shelf life of food products and can allow them to be stored at room temperature. As reported in The Handbook of Food Preservation (http://www.cold.org.gr/library/downloads/Docs/Handbook%20of%20Food%20Preservation.PDF, CITE), thermal sterilization typically involves four steps. Firstly, food products are heated to between 110-125 (degrees C), and then the products must be given time for the heat to travel through the material completely. After this, the temperature must be maintained long enough to kill microorganisms before the food product is cooled to prevent cooking. In practice, though complete sterility of food products could be achieved, the intense and extended heating needed to accomplish this could reduce the nutritive value of the food products, thus, only a partial sterilization is performed. (chapter 24)

Low-Temperature Process

Chapter 16: Food Process Engineering and Technology

Low-temperature processes, also play an essential role in food processing and storage. During this process, microorganisms and enzymes are subjected to low temperatures. Unlike heating, chilling does not destroy the enzymes and microorganisms but simply reduces their activity which is consistent as long as the temperature is maintained. It ceases to function when the temperature is raised. It follows that, unlike heating, the effect pf preservation by cold is not permanent; hence the importance of maintaining the cold chain throughout the shelf life of the food product. (Chapter 16 pg, 396)

It's important to note that there are two distinct low temperature processes: chilling and freezing. Chilling is the application of temperatures within the range of 0 to 8 degrees C, while freezing is usually below 18 C. Refrigeration does slow spoilage in food, and reduces the risk of bacterial growth, however it does not improve the quality of the product.

Irradiation

(chapter 32 of handbook of food pres)

(chapter 3, 2.1.3 of handbook of farm, dairy)

Food irradiation is another notable biological engineering process to achieve food safety. Research into the potential utilization of ionizing irradiation for food preservation started in the 1940's as an extension of studies on the effect of radiation on living cells. The FDA approved usage of ionizing radiation on food products in 1990. This radiation removes electrons from atoms, and these electrons go on to damage the DNA of microorganisms living in the food, killing the microorganisms. Irradiation can be used to pasteurize food products, such as seafood, poultry, and red meat, thus making these food products safer for consumers. Some irradiation is also used to delay fruit ripening processes, which also can kill microorganisms that accelerate the ripening and spoilage processes of produce. Low dosages of radiation can also be used to kill insects living in harvested crops, as the radiation will stunt the insects' development at various stages and damage their ability to reproduce.

Food storage and preservation

Meat that has been gas flushed; a technique used for modified atmosphere packaging.

Food storage and preservation is a key component of food engineering processes and relies heavily on biological engineering to understand and manipulate the organisms involved. Note that the above food safety processes such as pasteurization and sterilization destroy the microorganisms that also contribute to deterioration of food products while not necessarily posing a risk to people. Understanding of these processes, their effects, and the microorganisms at play during food those food processing techniques is a very important biological engineering task within food engineering. Factories and processes must be created to ensure that food products can be processed in an efficient and effective manner, which again relies heavily on biological engineering expertise.

Another aspect of biological engineering necessary for food preservation is the preservation of fresh produce and grain. Biological engineering is important to the preservation of fresh produce because most fruits and vegetables are living organisms from the time of harvest to the time of consumption. Before harvesting, understanding of plant ontogeny, or origin and development, and the manipulation of these processes are key components of the industrial agriculture process. Understanding of plant developmental cycles govern how and when plants are harvested, impact storage environments, and contribute to creating intervention processes. Even after harvesting, fruits and vegetables undergo respiration, transpiration, and ripening. Understanding and controlling these natural plant processes should be achieved to prevent food spoilage, sprouting or growth of produce during storage, and reduction in quality or desirability, such as through wilting or loss of desirable texture. (chapter 2 of handbook food pres)

When considering food storage and preservation, the technologies of modified atmosphere and controlled atmosphere are widely used for the storage and packing of several types of foods. They offer several advantages such as delay of ripening and senescence of horticultural commodities, control of some biological processes such as rancidity, insects, bacteria and decay, among others. Controlled atmosphere (CA) storage refers to atmospheres different than normal air and strictly controlled during all time. This type of storage manipulate the CO₂ and O₂ levels within gas-tight stores of containers. Modified atmosphere (MA) storage refers to any atmosphere different from normal air; typically by mixing CO₂, O₂, and N_2.

Waste management

(chapter 23 section 5, handbook of farm)

Another biological engineering process within food engineering involves the processing of waste produced in the processes of producing food. Though it may fall more within the realm of environmental engineering, understanding how organisms in the environment will respond to the waste products is important for assessing the impact of the processes and comparing waste processing strategies. It is also important to understand which organisms are involved in the decomposition of the waste products, and the byproducts that will be produced as a result of their activity.

In a more direct application, biological waste processing techniques are used to process organic waste and some can even produce useful byproducts. There are two main processes by which organic matter is processed via microbes: aerobic processes and anaerobic processes. These processes convert organic matter to cell mass through synthesis processes of microorganisms. Aerobic processes occur in the presence of oxygen, take organic matter as input, and produce water, carbon dioxide, nitrate, and new cell mass. Anaerobic processes occur in the absence of oxygen and produce less cell mass than aerobic processes. An additional benefit of anaerobic processes is that they also generate methane, which can be burned as a fuel source. Design of both aerobic and anaerobic biological waste processing plants requires careful control of temperature, humidity, oxygen concentration, and the waste products involved. Understanding of all aspects of the system and how they interact with one another is important for developing efficient waste management plants and falls within the realm of biological engineering.

Further reading

• Gustavo V. Barbosa-Canovas, Liliana Alamilla-Beltran, Efren Parada-Arias, Jorge Welti-Chanes (2015) Water Stress in Biological, Chemical, Pharmaceutical and Food Systems. New York, NY : Springer New York : Imprint: Springer. ISBN 978-1-4939-2578-0
• Jamuna Aswathanarayn & Rai, V. Ravishankar (2015). Microbial Food Safety and Preservation Techniques. Boca Raton : CRC Press Taylor & Francis Group. ISBN 9781138033801