Microwave popcorn is a convenient meal consisting of popcorn without popcorn in sealed and sealed paper bags intended to be heated in a microwave oven. In addition to dry corn, the bag usually contains cooking oil with enough saturated fat to compress the room temperature, one or more spices (often salt), and natural or artificial flavorings or both. With a variety of flavors, there are many different providers.
Video Microwave popcorn
Design
The bag is usually partially folded when placed in a microwave, and expands as a result of the vapor pressure of the heated kernel.
The design of microwave popcorn bags is specifically locked to avoid scratched kernels, unwanted effects that occur when the kernel appears heated above 300 ° F (149 ° C).
Susceptor, usually a laminated metalized film onto a paper bag, absorbs microwaves and focuses heat on the film interface, ensuring the heat distribution is focused on the hard coating layer to heat so that the untreated kernel is uniformly distributed before use. appears, thus ensuring a sense of flattening throughout the product. In addition, some popcorn is flawed and will not appear due to possible damage to the shell, which allows steam to escape. This seedless kernel is known as "old waiter" or "old maid".
The initial design of patented popcorn bags was patented by American company General Mills in 1981 (US Patent # 4,267,420).
Maps Microwave popcorn
Security issues
Treatment in the package design is necessary for food safety.
The safety issue is the cooking time given on the packaging does not apply to all microwave ovens. Set the timer and come back later, after the timer alarm is heard, can cause popcorn to burn and smoke badly. The popcorn microwave maker suggests that people who cook popcorn live near the oven to observe popcorn while cooking, and pop out the popcorn when the intermediate time appears more than a few seconds.
Concerns about microwave popcorn bags have increased in recent years in terms of waste and their harmful effects on the environment. One study showed that food packaging accounts for nearly two-thirds of the total volume of packaging waste. In addition, the coating materials used in microwave popcorn bags can have a negative effect on the environment. Researchers have detected toxic chemicals in the bag, such as perfluorinated compounds (PFCs) and their potential precursors. PFC is environmentally persistent, bioaccumulative, and potentially harmful. Among PFCs, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) have been reported to be toxic. The perfluorocarboxylic acid precursor (PFCA) proved to be more toxic than the PFCA itself. In addition, due to the persistence and mobility of PFOA, it has been detected in water, soil, air, and wildlife. To minimize the harmful effects of PFC on the environment, people have developed many treatment methods to remove them from aqueous solutions.
Hazardous chemicals
Researchers have detected many PFCs in microwave popcorn bags used as coating materials for oil resistance and moisture. The most commonly studied PFCs are PFOA and PFOS. The amount of PFOA in some microwave popcorn bags is determined to be as high as 300 ug kg -1 . In addition to PFOA and PFOS, Moral et al. also determines other perfluorocarboxylic acids (PFCAs) in popcorn packaging, including perfluoroheptanoic (PFHpA), perfluorononanoic (PFNA), perfluorodecanoic (PFDA), perfluoroundecanoic (PFUnA), and perfluorododecanoic (PFDoA) acids.
PFC is toxic, can not decompose and stay in the environment continuously. PFC accumulation in living organisms can have adverse effects on laboratory animals, aquatic life and humans. A study in rats has found that PFOA can induce liver, testes, and pancreatic tumors. Exposure to PFOS to mice can also cause abnormal glucose and lipid homeostasis during gestation and lactation. PFC has been found to inhibit communication systems and gene transcription in mice. In addition, a study also showed that PFOA exposure was associated with kidney and testicular cancer in people living near a chemical plant. PFOA and PFOS may also cause membrane damage associated with apoptosis and DNA damage to aquatic organisms (especially in fish) and negative effects on the rate of rotifer population growth.
Due to PFOA toxicity, major US producers voluntarily terminate PFOA production by the end of 2015. In addition, the use of substances in contact with ethanol containing ethyloroalkyl is no longer authorized by the US Food and Drug Administration (FDA). ) regulation in January 2016. However, although the production of PFOA and PFOS is reduced, the production of fluorotelomer-based chemicals applied to food contact paper is still increasing. Some compounds, such as polifluoroalkyl phosphate (PAP) or fluorotelomers (FTOH) surfactants, have been used in some brands of microwave popcorn bags. The compounds are PFCA precursors, and the evidence shows that they are more toxic than PFCA itself. Furthermore, they can also be degraded into PFCA, and therefore lead to an increase in PFCA concentrations in the environment and produce adverse effects.
Environmental impact
Due to the high energy bonds of C-F (531.5kJ/mol) in PFC, PFC is highly resistant to natural biodegradation. Once PFC is released into the environment, they become contaminants. The evidence shows that water, air, soil, and wildlife have been contaminated by PFCs. For example, PFOA concentrations of up to 0.9 micrograms per liter (Âμg/L) in several wells in Minnesota between 2004 and 2008, and 0.4 Âμg/L were interim health advisers for PFOA in drinking water developed by EPA in 2009. In addition, Giesy and Kannan detect PFCs in fish, birds, and marine mammals around the world. People also detect PFOA in media and arctic biota.
Due to the large amount of microwave popcorn bag production, they also become a significant source of contaminants (PFC) to the environment. Due to layered paper drainage and manufacturing activity, PFOA has also been detected in wastewater and biosolids. Land near the landfill is also contaminated by PFOA.
Remediation Method
To reduce the destructive impact of PFC on the environment, people have developed many technologies to remove PFC from aqueous solutions, including adsorption, ion exchange, membrane separation, photochemical oxidation, ultrasonication, bioremediation, plasma oxidation, and other techniques. This technology requires harsh maintenance conditions, causes high energy consumption, and can not be applied on a large scale. Electrochemical oxidation (EO) is a promising technique for removing PFC from contaminated wastewater. It has many advantages, such as relatively lower energy consumption, lighter conditions, and higher removal efficiency.
Electrochemical oxidation mechanism
The EO mechanism and the PFCA and PFSA lines are listed below. In the beginning, the carboxylic acid group or the PFC sulfonate transfer the electrons to the anode, and the radical PFC (C n F 2n 1 COOÃ, Â · or C n 3 Ã, Â ·) is formed. PFC radicals are unstable, and perfluoroalkyl radicals (C n F 2n 1 Ã, Â ·) are produced. Then, C n F 2n 1 Â · Radicals react with OH, O 2 , and H 2 O in four possible routes as shown in Cycle A, Cycle B, Cycle C and Cycle D. The detailed reaction process is as follows:
C n F 2n 1 COO - -> C n F 2n 1 COO? E -
C n F 2n 1 COO? -> C n F 2n 1 ? CO 2
C n F 2n 1 SO 3 - -> C n F < sub> 2n 1 SO 3 ? e -
C n F 2n 1 SO 3 ? H 2 O-> C n F 2n 1 ? SO 4 2 - 2H
In Cycle A:
C n F 2n 1 Ã, Â Â · OH -> C n F 2n 1 OH
C n F 2n 1 OH Ã, Â · OH -> C n F 2n 1 OÃ Â Â · H 2 O
C n F 2n 1 O 2n-1 n < 2 O
In Cycle B:
C n F 2n 1 OH -> C n-1 F 2n-1 CFO HF
C n-1 F 2n-1 CFO H 2 O -> C n-1 F 2n-1 COO - HF H
C n-1 F 2n-1 CFO Ã, Â · OH -> C n F 2n sub> 2 HÃ Â Â ·
C n F 2n O 2 HÃ, -> C n-1 F 2n-/sub> COOÃ, Â · HF
In C C:
C n n 2n 1 Ã, Â
C n F 2n 1 OOÃ, Â · R F COOÃ, Â · -> C n F 2n 1 OÃ, Â · R F COÃ, Â · O 2
C n F 2n 1 O 2n-1 n < 2 O
COF 2 H 2 O -> CO 2 2HF
In cycle D, volatile fluorinated organic contaminants are released.
The EO technique also has several disadvantages, such as the high cost and complexity of the regulation and operation of electrochemical cells. Due to this loss, the EO has not yet been commercialized.
Some microwave ovens have a special mode designed for cooking popcorn, which uses factory timing and power level settings, or that use moisture or sound sensors to detect when popping has finished.
See also
- Corn kettle
- List of popcorn brands
- Popcorn Maker
Note
External links
- The popcorn microwave patent dispute between General Mills and Hunt-Wesson
Source of the article : Wikipedia
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