User:Isaacsrach/sandbox

Very good evaluation Rachel.

Overall excellent edits, but here are some suggestions:

Not sure "Some bacterial spores may need to be separately treated with acid to prevent their reproduction." what this sentence means. How will spores be treated? Or do you mean the food should be treated to prevent outgrowth of spores?

Also review the last sentence in this paragraph, and modify in light of the previous paragraph as follows: During pascalization, the food's proteins are denatured, hydrogen bonds are broken, and noncovalent bonds in the food are disrupted, while the product's primary and secondary structure remains intact. Because pascalization is not heat-based, covalent bonds are not affected, causing no change in the food's taste. This also means that HPP does not destroy vitamins, maintaining the nutritional value of the food.

Article Evaluation

Joule heating

• Is everything in the article relevant to the article topic? Is there anything that distracted you?
  • Only one statement about food processing, nice images and organization
• Is the article neutral? Are there any claims, or frames, that appear heavily biased toward a particular position?
  • Neutral article, but heavily focused on the physics of how it works
• Are there viewpoints that are overrepresented, or underrepresented?
  • Not descriptive about applications in food science
• Check a few citations. Do the links work? Does the source support the claims in the article?
  • The links work and are far more descriptive/extensive than the sentence about food processing
• Is each fact referenced with an appropriate, reliable reference? Where does the information come from? Are these neutral sources? If biased, is that bias noted?
  • It is referenced with information provided by The Ohio State University, but not in a journal article or book.
• Is any information out of date? Is anything missing that could be added?
  • A lot more information could be added about food processing such as: types of food used, pieces of equipment, effects on microorganisms/food quality.
• Check out the Talk page of the article. What kinds of conversations, if any, are going on behind the scenes about how to represent this topic?
  • Conversations are about adding new material about power and clarifying wording of material
• How is the article rated? Is it a part of any WikiProjects?
  • "Start-class"
  • WikiProjects Physics
• How does the way Wikipedia discusses this topic differ from the way we've talked about it in class?
  • This article goes more in depth on the science behind the electrical conductance and less about the application of this technology, especially in the food science realm

Article Edits

Pascalization

Previous text about food

Uses

• Spoilage microogoranisms and some enzymes can be deactivated by HPP, which can extend the shelf life while preserving the sensory and nutritional characteristics of the product . HPP can pasteurize or sterilize food products, decrease processing time, reduce energy usage, and also reduce waste . The treatment occurs at low temperatures and does not include the use of food additives. From 1990, some juices, jellies, and jams have been preserved using pascalization in Japan. The technique is now used there to preserve fish and meats, salad dressing, rice cakes, and yogurts. HPP is now being used to preserve fruit and vegetable smoothies and other products such as meat for sale in the UK. An early use of pascalization in the United States was to treat guacamole. It did not change the guacamole's taste, texture, or color, but the shelf life of the product increased to thirty days, from three days without the treatment. However, some treated foods still require cold storage because pascalization does not stop all enzyme activity caused by proteins, some of which affects shelf life. In recent years, HPP has also been used in the processing of raw pet food. Most commercial frozen and freeze-dried raw diets now go through post-packaging HPP treatment to destroy potential bacteria and viruses contaminants, with salmonella being one of the biggest concerns.

copied from pascalization

Process

• In pascalization, food products are sealed and placed into a steel compartment containing a liquid, often water, and pumps are used to create pressure. The pumps may apply pressure constantly or intermittently. The application of high hydrostatic pressures (HHP) on a food product will kill many microorganisms, but the spores of some bacteria may need to be separately treated with acid to prevent their reproduction. Pascalization works especially well on acidic foods, such as yogurts and fruits, because pressure-tolerant spores are not able to live in environments with low pH levels. The treatment works equally well for both solid and liquid products.
• During pascalization, the food's proteins are denatured, hydrogen bonds are fortified, and noncovalent bonds in the food are disrupted, while the product's main structure remains intact. Because pascalization is not heat-based, covalent bonds are not affected, causing no change in the food's taste. High hydrostatic pressure can affect muscle tissues by increasing the rate of lipid oxidation, which in turn leads to poor flavor and decreased health benefits.
• Because hydrostatic pressure is able to act quickly and evenly on food, neither the size of a product's container nor its thickness play a role in the effectiveness of pascalization. There are several side effects of the process, including a slight increase in a product's sweetness, but pascalization does not greatly affect the nutritional value, taste, texture, and appearance. As a result, high pressure treatment of foods is regarded as a "natural" preservation method, as it does not use chemical preservatives.

copied from pascalization

Updated text about food

• should break up into sections about food
• add citations to previous work
• Process
  • In pascalization, food products are sealed and placed into a steel compartment containing a liquid, often water, and pumps are used to create pressure. The pumps may apply pressure constantly or intermittently. The application of high hydrostatic pressures (HHP) on a food product will kill many microorganisms, but the spores are not destroyed. of some bacterial spores may need to be separately treated with acid to prevent their reproduction. HPP inactivates microorganisms by reducing cell volume, increasing cell membrane permeability, and by denaturing cell membrane proteins and DNA. Pascalization works especially well on acidic foods, such as yogurts and fruits, because pressure-tolerant spores are not able to live in environments with low pH levels. The treatment works equally well for both solid and liquid products.
  • During pascalization, the food's proteins are denatured, hydrogen bonds are fortified, and noncovalent bonds in the food are disrupted, while the product's main structure remains intact. Because pascalization is not heat-based, covalent bonds are not affected, causing no change in the food's taste. This means that HPP does not destroy vitamins, maintaining the nutritional value of the food. High hydrostatic pressure can affect muscle tissues by increasing the rate of lipid oxidation, which in turn leads to poor flavor and decreased health benefits.

Joule Heating

Previous text about food

• Some food processing equipment may make use of Joule heating: running current through food material (which behave as an electrical resistor) causes heat release inside the food. The alternating electrical current coupled with the resistance of the food causes the generation of heat. A higher resistance increases the heat generated. Ohmic heating allows for fast and uniform heating of food products, which keeps the high quality in foods. Products with particulates heat up faster in Ohmic heating (as compared to conventional heat processing) due to higher resistance.
• copied from joule heating

Updated text about food

Food Processing

Joule heating (Ohmic Heating) is an HTST, aseptic process that runs an alternating current of 50-60 Hz through food. Heat is generated through the electrical resistance of the food. As the product heats up, electrical conductivity increases linearly. A higher electrical current frequency is best as it reduces oxidation and metallic contamination. This heating method is best for foods that contain particulates suspended in a weak salt containing medium due to their high resistance properties. Ohmic heating allows for a maintained quality of foods due to the uniform heating that decreases deterioration and over-processing of food.

Benefits

Ohmic heating has similar benefits than other rapid heating methods. This method can destroy microorganisms achieving sterility through electroporation of cell membranes, membrane rupture from the voltage drop across cell membranes, and cell lysis.

Ideal Food Products

• liquid based products:
  • thick soups
  • sauces
  • stews
  • salsa
  • fruit in a syrup medium

In particulate foods, the particles heat up faster than the liquid when they have a higher electrical conductivity. This allows for the liquid to remain undamaged while the product still undergoes heat processing. Below are some examples of different electrical conductivity values of certain foods to display composition and salt concentration affect electrical conductivity.

Electrical conductivity of selected foods

Food	Electrical Conductivity (S/m)	Temperature (°C)
Apple Juice	0.239	20
Beef	0.42	19
Beer	0.143	22
Carrot	0.041	19
Carrot Juice	1.147	22
Chicken meat	0.19	20
Coffee (black)	0.182	22
Coffee (black with sugar)	0.185	22
Coffee (with milk)	0.357	22
Starch solution (5.5%)
(a) with 0.2% salt	0.34	19
(b) with 0.55% salt	1.3	19
(c) with 2% salt	4.3	19

Limitations

Ohmic heating is highly influened the electrical conductivity of the product. Dependent of the position of the electrodes, the food can have locations of overprocessing and underprocessing. Fats, oils, alcohols, bone, and crystalline structures cannot be heated directly by ohmic heating due to their low electrical conductivity values.

Group Project

see user:mille504/sandbox