Recent Methods of Analysis for Aflatoxins in Foods and Feeds
Sampling and Sample Preparation :
Sampling and sample preparation remain a considerable source of error in the analytical identification of aflatoxins. Thus, systematic approaches to sampling, sample preparation, and analysis are absolutely necessary to determine aflatoxins at the parts-per-billion level . In this regard, specific plans have been developed and tested rigorously for some commodities such as corn, peanuts, and tree nuts; sampling plans for some other commodities have been modeled after them. A common feature of all sampling plans is that the entire primary sample must be ground and mixed so that the analytical test portion has the same concentration of toxin as the original sample.
Solid-Phase Extraction :
All analytical procedures include three steps: extraction, purification, and determination. The most significant recent improvement in the purification step is the use of solid-phase extraction.Test extracts are cleaned up before instrumental analysis(thin layer or liquid chromatography) to remove coextracted materials that often interfere with the determination of target analytes.
Thin-Layer Chromatography :
Thin layer chromatography (TLC) , also known as flat bed chromatography or planar chromatography is one of the most widely used separation techniques in aflatoxin analysis. Since 1990, it has been considered the AOAC official method and the method of choice to identify and quantitate aflatoxins at levels as low as 1 ng/g. The TLC method is also used to verify findings by newer, more rapid techniques .
Liquid Chromatography :
Liquid chromatography (LC) is similar to TLC in many respects, including analyte application, stationary phase, and mobile phase. Liguid chromatography and TLC complement each other. For an analyst to use TLC for preliminary work to optimize LC separation conditions is not unusual. Liquid chromatography methods for the determination of aflatoxins in foods include normal-phase LC (NPLC), reversed-phase LC (RPLC) with pre- or before-column derivatization (BCD), RPLC followed by postcolumn derivatization (PCD), and RPLC with electrochemical detection.
Immunochemical Methods :
Thin layer chromatography and LC methods for determining aflatoxins in food are laborious and time consuming . Often, these techniques require knowledge and experience of chromatographic techniques to solve sepatation and and interference problems. Through advances in biotechnology, highly specific antibody-based tests are now commercially available that can identify and measure aflatoxins in food in less than 10 minutes. These tests are based on the affinities of the monoclonal or polyclonal antibodies for aflatoxins. The three types of immunochemical methods are radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA), and immunoaffinity column assay (ICA).
Confirmation of Identities of the Aflatoxins :
Although analytical methods might consist of different extraction, clean-up, and quantitation steps, the results of the analyses by such methods should be similar when the methods are applied properly. Since the reliability of the quantitative data is not in question, the problem still to be solved is the confirmation of identity of the aflatoxins. The confirmation techniques used involve either chemical derivatization or mass spectrometry (MS).
Nabil Saad. (2004). Aflatoxins: Occurrence and Health Risks. Retrieved July 4, 2008 from ansci.cornell.edu Website: http://www.ansci.cornell.edu/plants/toxicagents/aflatoxin/aflatoxin.html
Saturday, July 05, 2008
Aflatoxins in human health
Aflatoxins and Human Health
Humans are exposed to aflatoxins by consuming foods contaminated with products of fungal growth . Such exposure is difficult to avoid because fungal growth in foods is not easy to prevent . Even though heavily contaminated food supplies are not permitted in the market place in developed countries, concern still remains for the possible adverse effects resulting from long-term exposure to low levels of aflatoxins in the food supply . Evidence of acute aflatoxicosis in humans has been reported from many parts of the world , namely the Third World Countries, like Taiwan, Ouganda, India, and many others . The syndrome is characterized by vomiting, abdominal pain, pulmonary edema, convulsions, coma, and death with cerebral edema and fatty involvment of the liver , kidneys , and heart.
Conditions increasing the likelihood of acute aflatoxicosis in humans include limited availability of food, environmental conditions that favor fungal development in crops and commodities, and lack of regulatory systems for aflatoxin monitoring and control.Because aflatoxins, especially aflatoxin B1, are potent carcinogens in some animals, there is interest in the effects of long-term exposure to low levels of these important mycotoxins on humans . In 1988, the IARC placed aflatoxin B1 on the list of human carcinogens. This is supported by a number of epidemiological studies done in Asia and Africa that have demonstrated a positive association between dietary aflatoxins and Liver Cell Cancer (LCC) . Additionally , the expression of aflatoxin-related diseases in humans may be influenced by factors such as age, sex, nutritional status, and/or concurrent exposure to other causative agents such as viral hepatitis (HBV) or parasite infestation.
Nabil Saad. (2004). Aflatoxins: Occurrence and Health Risks. Retrieved July 4, 2008 from ansci.cornell.edu Website: http://www.ansci.cornell.edu/plants/toxicagents/aflatoxin/aflatoxin.html
Humans are exposed to aflatoxins by consuming foods contaminated with products of fungal growth . Such exposure is difficult to avoid because fungal growth in foods is not easy to prevent . Even though heavily contaminated food supplies are not permitted in the market place in developed countries, concern still remains for the possible adverse effects resulting from long-term exposure to low levels of aflatoxins in the food supply . Evidence of acute aflatoxicosis in humans has been reported from many parts of the world , namely the Third World Countries, like Taiwan, Ouganda, India, and many others . The syndrome is characterized by vomiting, abdominal pain, pulmonary edema, convulsions, coma, and death with cerebral edema and fatty involvment of the liver , kidneys , and heart.
Conditions increasing the likelihood of acute aflatoxicosis in humans include limited availability of food, environmental conditions that favor fungal development in crops and commodities, and lack of regulatory systems for aflatoxin monitoring and control.Because aflatoxins, especially aflatoxin B1, are potent carcinogens in some animals, there is interest in the effects of long-term exposure to low levels of these important mycotoxins on humans . In 1988, the IARC placed aflatoxin B1 on the list of human carcinogens. This is supported by a number of epidemiological studies done in Asia and Africa that have demonstrated a positive association between dietary aflatoxins and Liver Cell Cancer (LCC) . Additionally , the expression of aflatoxin-related diseases in humans may be influenced by factors such as age, sex, nutritional status, and/or concurrent exposure to other causative agents such as viral hepatitis (HBV) or parasite infestation.
Nabil Saad. (2004). Aflatoxins: Occurrence and Health Risks. Retrieved July 4, 2008 from ansci.cornell.edu Website: http://www.ansci.cornell.edu/plants/toxicagents/aflatoxin/aflatoxin.html
Factors affecting the growth of aflatoxins and the occurance
From my research, i had found that:
Aflatoxins are found in:
In Raw Agricultural Products:
Aflatoxins often occur in plants in the field prior to harvest. Postharvest contamination can occur if crop drying is delayed and during storage of the crop if water is allowed to exceed critical values for the mold growth. Insect or rodent infestations facilitate mold invasion of some stored commodities.Aflatoxins are detected occasionally in milk, cheese, corn, peanuts, cottonseed, nuts, almonds, figs, spices, and a variety of other foods and feeds. Milk, eggs, and meat products are sometimes contaminated because of the animal consumption of aflatoxin-contaminated feed. However, the commodities with the highest risk of aflatoxin contamination are corn, peanuts, and cottonseed.
Factors Favourizing Aflatoxin Production
Fungal growth and aflatoxin contamination are the consequence of interactions among the fungus, the host and the environment. The appropriate combination of these factors determine the infestation and colonization of the substrate, and the type and amount of aflatoxin produced. However, a suitable substrate is required for fungal growth and subsequent toxin production , although the precise factor(s) that initiates toxin formation is not well understood . Water stress, high-temperature stress, and insect damage of the host plant are major determining factors in mold infestation and toxin production.
Similarly, specific crop growth stages, poor fertility, high crop densities, and weed competition have been associated with increased mold growth and toxin production. Aflatoxin formation is also affected by associated growth of other molds or microbes. For example, preharvest aflatoxin contamination of peanuts and corn is favored by high temperatures, prolonged drought conditions, and high insect activity; while postharvest production of aflatoxins on corn and peanuts is favored by warm temperatures and high humidity.
Nabil Saad. (2004). Aflatoxins: Occurrence and Health Risks. Retrieved July 4, 2008 from ansci.cornell.edu Website: http://www.ansci.cornell.edu/plants/toxicagents/aflatoxin/aflatoxin.html
Aflatoxins are found in:
In Raw Agricultural Products:
Aflatoxins often occur in plants in the field prior to harvest. Postharvest contamination can occur if crop drying is delayed and during storage of the crop if water is allowed to exceed critical values for the mold growth. Insect or rodent infestations facilitate mold invasion of some stored commodities.Aflatoxins are detected occasionally in milk, cheese, corn, peanuts, cottonseed, nuts, almonds, figs, spices, and a variety of other foods and feeds. Milk, eggs, and meat products are sometimes contaminated because of the animal consumption of aflatoxin-contaminated feed. However, the commodities with the highest risk of aflatoxin contamination are corn, peanuts, and cottonseed.
Factors Favourizing Aflatoxin Production
Fungal growth and aflatoxin contamination are the consequence of interactions among the fungus, the host and the environment. The appropriate combination of these factors determine the infestation and colonization of the substrate, and the type and amount of aflatoxin produced. However, a suitable substrate is required for fungal growth and subsequent toxin production , although the precise factor(s) that initiates toxin formation is not well understood . Water stress, high-temperature stress, and insect damage of the host plant are major determining factors in mold infestation and toxin production.
Similarly, specific crop growth stages, poor fertility, high crop densities, and weed competition have been associated with increased mold growth and toxin production. Aflatoxin formation is also affected by associated growth of other molds or microbes. For example, preharvest aflatoxin contamination of peanuts and corn is favored by high temperatures, prolonged drought conditions, and high insect activity; while postharvest production of aflatoxins on corn and peanuts is favored by warm temperatures and high humidity.
Nabil Saad. (2004). Aflatoxins: Occurrence and Health Risks. Retrieved July 4, 2008 from ansci.cornell.edu Website: http://www.ansci.cornell.edu/plants/toxicagents/aflatoxin/aflatoxin.html
Saturday, June 21, 2008
Legal limits of alflatoxins
I have research about the limits of alflatoxins, this is another website that i had found, so we can do some comparison.
Legal limits for Aflatoxins require that food for human consumption must contain less than 10mg/kg (parts per billion) of which only 5 ppb may be aflotoxin B1.
The Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act restricts Aflatoxins to a maximum of 50 ppb in animal feed. Exceptions are 20 ppb for lactating cows, calves, pigs, lambs and poultry. Piglets, chickens under laying age and lambs younger than 4 months have a limit of 10 ppb. Feed for cats, dogs, horses and ostriches must have less than 20 ppb. The aflotoxin problem has been extensively researched and these limits have been based largely on research results.
Reference:
Janice Limson. (2001). Maize our Staple Food: Should Toxins Concern us? Retrieved June 21, 2008 from scienceinafrica.co.za Website: http://www.scienceinafrica.co.za/2001/november/maize.htm
Legal limits for Aflatoxins require that food for human consumption must contain less than 10mg/kg (parts per billion) of which only 5 ppb may be aflotoxin B1.
The Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act restricts Aflatoxins to a maximum of 50 ppb in animal feed. Exceptions are 20 ppb for lactating cows, calves, pigs, lambs and poultry. Piglets, chickens under laying age and lambs younger than 4 months have a limit of 10 ppb. Feed for cats, dogs, horses and ostriches must have less than 20 ppb. The aflotoxin problem has been extensively researched and these limits have been based largely on research results.
Reference:
Janice Limson. (2001). Maize our Staple Food: Should Toxins Concern us? Retrieved June 21, 2008 from scienceinafrica.co.za Website: http://www.scienceinafrica.co.za/2001/november/maize.htm
About alflatoxins, its symptoms and limits
This is what i had research on,
I found that:
Aflatoxins, of which aflatoxin B1 (AFB1) is the most important, are produced mainly by the fungus Aspergillus flavus, that may grow on peanuts before or after harvesting and under poor storage conditions.
The tolerance levels of aflatoxins in human foodstuffs are regulated worldwide and in South Africa by Government Notice No. R 313 of 16 February 1990, Regulations Governing Tolerances for Fungus-Produced Toxins in Foodstuffs. According to these regulations, which are the responsibility of the DOH, the maximum legal level of total aflatoxins in foodstuffs is 10 micrograms per kilogram, of which 5 micrograms per kilogram (parts per billion) may be AFB1.
Health implications of exposure to aflatoxins can be divided into symptoms of acute poisoning (aflatoxicosis) and chronic long-term health effects. Although aflatoxins have been implicated in several episodes of acute human aflatoxicosis in various areas of the world, these have been reported at contamination levels in the milligrams per kilogram (parts per million) range, i.e. 1000 times higher than the legal tolerance levels. However, the major health implication and area of considerable international concern with respect to aflatoxin exposure is the cancer-causing (carcinogenic) properties of AFB1, in that long-term exposure to low levels of the toxin may cause liver cancer. This is the reason why aflatoxins are the most widely and severely regulated of all the mycotoxins. It is of great concern that the liver cancer risk increases significantly if a child suffering from hepatitis B virus (HBV) infection consumes aflatoxin-containing foodstuffs, due to the synergism between AFB1 and HBV in causing liver cancer.
The PSNP was launched in 1994, and in areas with poor control over tender specifications and inadequate enforcement of legal levels of aflatoxins in peanut butter during the past 7 years, may have increased the liver cancer risk in millions of previously disadvantaged school children. The risk may have been increased markedly if the children consumed the high levels of aflatoxins quoted in the news media, and particularly if they are carriers and/or subsequently become infected with HBV.
Reference:
South African Medical Research Council. (2008). Alfatoxin in Peanut Butter. Retrieved June 21, 2008 from mrc.ac.za Website: http://www.mrc.ac.za/promec/afloxin.htm
I found that:
Aflatoxins, of which aflatoxin B1 (AFB1) is the most important, are produced mainly by the fungus Aspergillus flavus, that may grow on peanuts before or after harvesting and under poor storage conditions.
The tolerance levels of aflatoxins in human foodstuffs are regulated worldwide and in South Africa by Government Notice No. R 313 of 16 February 1990, Regulations Governing Tolerances for Fungus-Produced Toxins in Foodstuffs. According to these regulations, which are the responsibility of the DOH, the maximum legal level of total aflatoxins in foodstuffs is 10 micrograms per kilogram, of which 5 micrograms per kilogram (parts per billion) may be AFB1.
Health implications of exposure to aflatoxins can be divided into symptoms of acute poisoning (aflatoxicosis) and chronic long-term health effects. Although aflatoxins have been implicated in several episodes of acute human aflatoxicosis in various areas of the world, these have been reported at contamination levels in the milligrams per kilogram (parts per million) range, i.e. 1000 times higher than the legal tolerance levels. However, the major health implication and area of considerable international concern with respect to aflatoxin exposure is the cancer-causing (carcinogenic) properties of AFB1, in that long-term exposure to low levels of the toxin may cause liver cancer. This is the reason why aflatoxins are the most widely and severely regulated of all the mycotoxins. It is of great concern that the liver cancer risk increases significantly if a child suffering from hepatitis B virus (HBV) infection consumes aflatoxin-containing foodstuffs, due to the synergism between AFB1 and HBV in causing liver cancer.
The PSNP was launched in 1994, and in areas with poor control over tender specifications and inadequate enforcement of legal levels of aflatoxins in peanut butter during the past 7 years, may have increased the liver cancer risk in millions of previously disadvantaged school children. The risk may have been increased markedly if the children consumed the high levels of aflatoxins quoted in the news media, and particularly if they are carriers and/or subsequently become infected with HBV.
Reference:
South African Medical Research Council. (2008). Alfatoxin in Peanut Butter. Retrieved June 21, 2008 from mrc.ac.za Website: http://www.mrc.ac.za/promec/afloxin.htm
Friday, May 09, 2008
Some hygiene codes for groundnuts
Hi,
I have loaded some hygiene codes for groundnuts in the blackboard. I'm not sure whether it is needed. I just load it for incase and for your information. Hope that it helps in some ways.
Feel free to take a look.
Thanks,
Vanessa
I have loaded some hygiene codes for groundnuts in the blackboard. I'm not sure whether it is needed. I just load it for incase and for your information. Hope that it helps in some ways.
Feel free to take a look.
Thanks,
Vanessa
Thursday, May 01, 2008
In the shelling plant
From the buying station, the peanuts travel to shelling plants. The peanuts are passed over a series of screens which separate any farm materials such as sticks and rocks from the peanuts and then separate the peanuts by size.
The peanuts are shelled and then inspected by a laser beam and by people to eliminate any immature kernels. The sheller then packs the peanuts into bags, boxes or railcars for delivery to product manufacturers.
In the peanut butter plant
The peanut butter manufacturers inspect the peanuts to ensure high quality then roast them in special ovens which provide an even roast. After roasting, the peanuts are fast-cooled by suction fans that circulate air quickly. Rapid cooling is necessary to halt the cooking process, retain an even color and prevent the loss of too much oil.
Another machine rubs the peanuts gently between rubber belts to remove the outer skin ~ this is called blanching. The kernels are split, the hearts removed and the peanuts are cleaned and sorted a final time.
Finally, the peanuts are ground in two stages (one long grinding would produce too much heat, damaging the flavor of the peanut butter). In the first stage, the peanuts are ground alone. In the second stage, salt, sweetener and stabilizer (to keep the oil from separating) are added.
How It's Made. Retrieved April 27, 2008 from peanutbutterlovers.com Website: http://www.peanutbutterlovers.com/howmade/index.html
From the buying station, the peanuts travel to shelling plants. The peanuts are passed over a series of screens which separate any farm materials such as sticks and rocks from the peanuts and then separate the peanuts by size.
The peanuts are shelled and then inspected by a laser beam and by people to eliminate any immature kernels. The sheller then packs the peanuts into bags, boxes or railcars for delivery to product manufacturers.
In the peanut butter plant
The peanut butter manufacturers inspect the peanuts to ensure high quality then roast them in special ovens which provide an even roast. After roasting, the peanuts are fast-cooled by suction fans that circulate air quickly. Rapid cooling is necessary to halt the cooking process, retain an even color and prevent the loss of too much oil.
Another machine rubs the peanuts gently between rubber belts to remove the outer skin ~ this is called blanching. The kernels are split, the hearts removed and the peanuts are cleaned and sorted a final time.
Finally, the peanuts are ground in two stages (one long grinding would produce too much heat, damaging the flavor of the peanut butter). In the first stage, the peanuts are ground alone. In the second stage, salt, sweetener and stabilizer (to keep the oil from separating) are added.
How It's Made. Retrieved April 27, 2008 from peanutbutterlovers.com Website: http://www.peanutbutterlovers.com/howmade/index.html
Microbial information on peanut butter
M. R. S. Clavero, R. E. Brackett, L. R. Beuchat* and M. P. Doyle
Center for Food Safety and Quality Enhancement, Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia, 30223-1797, USA
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WFP-45F4K7F-2H&_user=10&_coverDate=02%2F29%2F2000&_alid=732971454&_rdoc=1&_fmt=high&_orig=search&_cdi=6800&_sort=d&_docanchor=&view=c&_ct=1&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=40823d43355224806d8b3ad028c381ab
Abstract
Outgrowth of Clostridium botulinum spores followed by toxin production in peanut spread at Aw0·98, 0·96, 0·94 and 0·92 stored at 30°C under anaerobic or aerobic conditions for 0, 3, 7 and 16 weeks or 0, 1, 9 and 16 weeks, respectively, was investigated. Botulinal toxin was not detected in peanut spreads stored under anaerobic conditions for 16 weeks.
Peanut spreads at Aw0·98 and two of three samples at Aw0·96 stored aerobically became toxic after 9 and 16 weeks, respectively. Clostridium botulinum in peanut spread at Aw0·98 and 0·96 grew to populations of 106and 105cfu g−1, respectively, within 16 weeks. Lactic acid bacteria grew within 3 days in peanut spread at Aw0·98 and 0·96 stored under aerobic or anaerobic conditions. Regardless of Aw, populations of aerobic and anaerobic micro-organisms decreased in peanut spread stored under anaerobic conditions. Only slight decreases occurred in samples stored under aerobic conditions.
The pH of inoculated and uninoculated peanut spread at Aw0·98 and 0·96 increased from 4·8 to 7·0 within 16 weeks and was attributed to growth of Penicillium andMucor spp. Similarly, redox potential (Eh) of peanut spread stored under anaerobic conditions for 3 weeks, decreased as the Awwas increased. Significantly lower Eh values in peanut spread samples at Aw0·98 or 0·96 stored under aerobic conditions occurred within 1 week and/or 9 weeks compared to peanut spread at Aw0·92 or 0·94.
Peanut spreads were judged inedible due to growth of lactic acid bacteria and molds which resulted in ‘off’ aromas before toxicity developed, thus greatly minimizing the likelihood of consumption.
Center for Food Safety and Quality Enhancement, Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia, 30223-1797, USA
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WFP-45F4K7F-2H&_user=10&_coverDate=02%2F29%2F2000&_alid=732971454&_rdoc=1&_fmt=high&_orig=search&_cdi=6800&_sort=d&_docanchor=&view=c&_ct=1&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=40823d43355224806d8b3ad028c381ab
Abstract
Outgrowth of Clostridium botulinum spores followed by toxin production in peanut spread at Aw0·98, 0·96, 0·94 and 0·92 stored at 30°C under anaerobic or aerobic conditions for 0, 3, 7 and 16 weeks or 0, 1, 9 and 16 weeks, respectively, was investigated. Botulinal toxin was not detected in peanut spreads stored under anaerobic conditions for 16 weeks.
Peanut spreads at Aw0·98 and two of three samples at Aw0·96 stored aerobically became toxic after 9 and 16 weeks, respectively. Clostridium botulinum in peanut spread at Aw0·98 and 0·96 grew to populations of 106and 105cfu g−1, respectively, within 16 weeks. Lactic acid bacteria grew within 3 days in peanut spread at Aw0·98 and 0·96 stored under aerobic or anaerobic conditions. Regardless of Aw, populations of aerobic and anaerobic micro-organisms decreased in peanut spread stored under anaerobic conditions. Only slight decreases occurred in samples stored under aerobic conditions.
The pH of inoculated and uninoculated peanut spread at Aw0·98 and 0·96 increased from 4·8 to 7·0 within 16 weeks and was attributed to growth of Penicillium andMucor spp. Similarly, redox potential (Eh) of peanut spread stored under anaerobic conditions for 3 weeks, decreased as the Awwas increased. Significantly lower Eh values in peanut spread samples at Aw0·98 or 0·96 stored under aerobic conditions occurred within 1 week and/or 9 weeks compared to peanut spread at Aw0·92 or 0·94.
Peanut spreads were judged inedible due to growth of lactic acid bacteria and molds which resulted in ‘off’ aromas before toxicity developed, thus greatly minimizing the likelihood of consumption.
Saturday, April 26, 2008
Peanut roasting
Dry roasting uses an oven temperature of around 430°C, and the temperature of the peanuts raised to around 160°C for 40 to 60 minutes.
However the actual temperature varies between the peanut's condition and the desired end characteristics. In some of the roasting conveyer oven, there are the uses of hot countercurrent hot air, whereby the air roast the peanut kernels individually giving an even roast.
The roasted peanut are then cooled and blanched. In the cooling process, it occurs in the cooling boxes or on the conveyer belt whereby air was used to blow over the peanuts immediately after the roasting it. This process is very important as so to stop the roasting process thus giving a uniform quality. The blanching method such dry, water, spin, air impact was used to remove the peanut's skin and also moulds, dust and other foreign material.
Dry blanching is more commonly used in peanut butter production.
This is because it removes the kernel hearts which would affect the peanut butter flavour.
In dry blanching, the peabuts are heated to around 138°C for 25 minutes, so to crack and loosen the skins. The heated peanuts are then cooled and passed through the brushes or ribbed rubber belting to rub off the skins. The hearts of the peanuts would be separated from the cotyledons (peanut halves) by screening.
Water blanching passes the peanuts on conveyors through stationary blades that slit the peanut
skins. Hot water sprayers would then be used to loosen the peanuts' skins and the oscillating canvas-covered pads on the knobbed conveyor belts would removed the skins as the peanuts passed through. Water blanching also requires the drying of the peanuts back to a moisture content of aound 6 to 12 percent.
Spin blanching uses steam to loosen the skins of the peanuts. Steaming is followed by
spinning the peanuts on revolving spindles as the peanuts move, single file, down a grooved conveyor. The spinning process would unwraps the peanut skins.
Air impact blanching uses a horizontal drum (cylinder) in which the peanuts are placed and
rotated. The inner surface of the drum has an abrasive surface that aids in the removal of the skins as the drum rotates. Inside the drum are air jets that blow the peanuts counter to the rotation of the drum creating air impact which loosens the skin. The combination of air impacts and the abrasive surface of the drum results in skin removal. Either batch or continuous air impact blanching can be conducted.
Taken from:
Jasper Guy Woodroof, Peanuts: Production, Processing, Products, 3rd Edition, Avi
Publishing Company, Westport, CT, 1983.
Peanut processing. Retrieved April 23, 2008 from epa.gov Website: http://www.epa.gov/ttn/chief/ap42/ch09/final/c9s10-2b.pdf
However the actual temperature varies between the peanut's condition and the desired end characteristics. In some of the roasting conveyer oven, there are the uses of hot countercurrent hot air, whereby the air roast the peanut kernels individually giving an even roast.
The roasted peanut are then cooled and blanched. In the cooling process, it occurs in the cooling boxes or on the conveyer belt whereby air was used to blow over the peanuts immediately after the roasting it. This process is very important as so to stop the roasting process thus giving a uniform quality. The blanching method such dry, water, spin, air impact was used to remove the peanut's skin and also moulds, dust and other foreign material.
Dry blanching is more commonly used in peanut butter production.
This is because it removes the kernel hearts which would affect the peanut butter flavour.
In dry blanching, the peabuts are heated to around 138°C for 25 minutes, so to crack and loosen the skins. The heated peanuts are then cooled and passed through the brushes or ribbed rubber belting to rub off the skins. The hearts of the peanuts would be separated from the cotyledons (peanut halves) by screening.
Water blanching passes the peanuts on conveyors through stationary blades that slit the peanut
skins. Hot water sprayers would then be used to loosen the peanuts' skins and the oscillating canvas-covered pads on the knobbed conveyor belts would removed the skins as the peanuts passed through. Water blanching also requires the drying of the peanuts back to a moisture content of aound 6 to 12 percent.
Spin blanching uses steam to loosen the skins of the peanuts. Steaming is followed by
spinning the peanuts on revolving spindles as the peanuts move, single file, down a grooved conveyor. The spinning process would unwraps the peanut skins.
Air impact blanching uses a horizontal drum (cylinder) in which the peanuts are placed and
rotated. The inner surface of the drum has an abrasive surface that aids in the removal of the skins as the drum rotates. Inside the drum are air jets that blow the peanuts counter to the rotation of the drum creating air impact which loosens the skin. The combination of air impacts and the abrasive surface of the drum results in skin removal. Either batch or continuous air impact blanching can be conducted.
Taken from:
Jasper Guy Woodroof, Peanuts: Production, Processing, Products, 3rd Edition, Avi
Publishing Company, Westport, CT, 1983.
Peanut processing. Retrieved April 23, 2008 from epa.gov Website: http://www.epa.gov/ttn/chief/ap42/ch09/final/c9s10-2b.pdf
Friday, April 18, 2008
flowchart edited
Hey,
I have edited the flowchart for bolognese sauce.
Feel free to see whether it is ok.
Thanks.
I have edited the flowchart for bolognese sauce.
Feel free to see whether it is ok.
Thanks.
Saturday, April 12, 2008
New post in bb
Hey,
i have post up the flowchart to the file exchange section.
Feel free to go and take a look to see if there's any changes to be made.
Thanks!
i have post up the flowchart to the file exchange section.
Feel free to go and take a look to see if there's any changes to be made.
Thanks!
Friday, April 11, 2008
cookie recipe
Ingredients:
2 cups butter
4 cups flour
2 tsp. baking soda
2 cups granulated sugar
2 cups brown sugar
5 cups blended oatmeal (measure oatmeal & blend in blender to a fine powder)
24 oz. chocolate chips
1 tsp. salt
18 oz. Cadbury bar (grated)
4 eggs
2 tsp. baking powder
3 cups chopped nuts (your choice)
2 tsp. vanilla
Directions:
Cream the butter and both sugars.
Add eggs and vanilla; mix together with flour, oatmeal, salt,baking powder, and soda.
Add chocolate chips, Cadbury bar and nuts.
Roll into balls and place two inches apart on a cookie sheet..
Bake for 10 minutes at 375 degrees.
Yields 122 cookies.
References: Ampin. (2008). Famous Amos Secret Recipe Cookie. Retrieved April 11, 2008 from ampin.wordpress.com Website: http://ampin.wordpress.com/2006/10/15/famous-amos-secret-recipes-cookie/
Ingredients:
1/2 pound butter or margarine
1 cup brown sugar, light, packed
1 cup sugar
3 large eggs
3 cups biscuit baking mix (bisquick)
1 cup cornstarch
1/2 cup milk, skim, (non fat) powder
2 tablespoons coffee (powdered)
1 tablespoon cocoa powder (unsweetened)
1 tablespoon vanilla extract
12 ounces chocolate pieces (semi-sweet)
4 ounces pecans (chopped)
Directions:
With electric mixer, high speed, cream butter until light andfluffy.
Beat in sugars, beating until very creamy.
Beat in eggs, then each remaining ingredient, except chips and pecan.
When dough is smooth, work in chips and pecans with spoon.
Make grape-sized pieces of dough for each cookie, placing 1 inch apart on ungreased sheet.
Bake at 350 degrees for 14 minutes or until golden brown.
References: Metro.isp Inc & Sean Wenzel. (2007). Famous Amos Chocolate Chip Cookies. Retrieved April 11, 2008 from recipeland.com Website: http://www.recipeland.com/recipe/44748/
Ingredients:
· 1 cup white sugar
· 1 cup packed light brown sugar
· 1 cup butter
· 1 cup vegetable oil
· 1 egg
· 1 tablespoon milk
· 4 cups all-purpose flour
· 1 teaspoon salt
· 1 teaspoon cream of tartar
· 1 teaspoon baking soda
· 1 teaspoon vanilla extract
· 1/2 cup chopped walnuts 2 cups semisweet chocolate chips
Directions:
1. Thoroughly cream sugars, margarine, oil, egg, milk and vanilla.
2. Add dry ingredients, nuts and chocolate chips. Drop by teaspoon onto ungreased cookie sheets.
3. Bake at 350 degrees F (175 degrees C) for 8-12 minutes. (Cookies are light in color when done.)
References: Allrecipes.com. (2008). Famous Amos Chocolate Chip Cookies. Retrieved April 11, 2008 from allrecipes.com Website: http://allrecipes.com/Recipe/Famous-Amos-Chocolate-Chip-Cookies/Detail.aspx
2 cups butter
4 cups flour
2 tsp. baking soda
2 cups granulated sugar
2 cups brown sugar
5 cups blended oatmeal (measure oatmeal & blend in blender to a fine powder)
24 oz. chocolate chips
1 tsp. salt
18 oz. Cadbury bar (grated)
4 eggs
2 tsp. baking powder
3 cups chopped nuts (your choice)
2 tsp. vanilla
Directions:
Cream the butter and both sugars.
Add eggs and vanilla; mix together with flour, oatmeal, salt,baking powder, and soda.
Add chocolate chips, Cadbury bar and nuts.
Roll into balls and place two inches apart on a cookie sheet..
Bake for 10 minutes at 375 degrees.
Yields 122 cookies.
References: Ampin. (2008). Famous Amos Secret Recipe Cookie. Retrieved April 11, 2008 from ampin.wordpress.com Website: http://ampin.wordpress.com/2006/10/15/famous-amos-secret-recipes-cookie/
Ingredients:
1/2 pound butter or margarine
1 cup brown sugar, light, packed
1 cup sugar
3 large eggs
3 cups biscuit baking mix (bisquick)
1 cup cornstarch
1/2 cup milk, skim, (non fat) powder
2 tablespoons coffee (powdered)
1 tablespoon cocoa powder (unsweetened)
1 tablespoon vanilla extract
12 ounces chocolate pieces (semi-sweet)
4 ounces pecans (chopped)
Directions:
With electric mixer, high speed, cream butter until light andfluffy.
Beat in sugars, beating until very creamy.
Beat in eggs, then each remaining ingredient, except chips and pecan.
When dough is smooth, work in chips and pecans with spoon.
Make grape-sized pieces of dough for each cookie, placing 1 inch apart on ungreased sheet.
Bake at 350 degrees for 14 minutes or until golden brown.
References: Metro.isp Inc & Sean Wenzel. (2007). Famous Amos Chocolate Chip Cookies. Retrieved April 11, 2008 from recipeland.com Website: http://www.recipeland.com/recipe/44748/
Ingredients:
· 1 cup white sugar
· 1 cup packed light brown sugar
· 1 cup butter
· 1 cup vegetable oil
· 1 egg
· 1 tablespoon milk
· 4 cups all-purpose flour
· 1 teaspoon salt
· 1 teaspoon cream of tartar
· 1 teaspoon baking soda
· 1 teaspoon vanilla extract
· 1/2 cup chopped walnuts 2 cups semisweet chocolate chips
Directions:
1. Thoroughly cream sugars, margarine, oil, egg, milk and vanilla.
2. Add dry ingredients, nuts and chocolate chips. Drop by teaspoon onto ungreased cookie sheets.
3. Bake at 350 degrees F (175 degrees C) for 8-12 minutes. (Cookies are light in color when done.)
References: Allrecipes.com. (2008). Famous Amos Chocolate Chip Cookies. Retrieved April 11, 2008 from allrecipes.com Website: http://allrecipes.com/Recipe/Famous-Amos-Chocolate-Chip-Cookies/Detail.aspx
Sunday, April 06, 2008
product recall
I found website which contain information about product recall procedures.
Can take a look. Hope it helps in the project...
Website:
http://www.fda.gov/ora/compliance_ref/rpm/pdf/ch7.pdf
http://www.nfsmi.org/Information/recallmanual.pdf
Import Control and Food Safety Guidelines
Website:
http://www.cfs.gov.hk/english/import/import_icfsg_08.html
Can take a look. Hope it helps in the project...
Website:
http://www.fda.gov/ora/compliance_ref/rpm/pdf/ch7.pdf
http://www.nfsmi.org/Information/recallmanual.pdf
Import Control and Food Safety Guidelines
Website:
http://www.cfs.gov.hk/english/import/import_icfsg_08.html
Tuesday, April 01, 2008
About Avian Influenza (Bird Flu)
Avian Influenza (Bird Flu)
Avian Flu in Birds is Spreading in Asia and Other Countries
·Avian influenza - commonly called "bird flu" - is an infection caused by influenza viruses that occur naturally in birds.
·Wild birds can carry the viruses, but usually do not get sick from them. However, some domesticated birds, including chickens, ducks, and turkeys, can become infected, often fatally
·One strain of avian influenza, the H5N1 virus, is endemic in much of Asia and has spread into parts of Europe and Africa. Avian H5N1 infections have recently killed poultry and other birds in a number of countries.
·Strains of avian H5N1 influenza may infect various types of animals, including wild birds, pigs, and tigers.
·Symptoms in birds and other animals vary, but virulent strains can cause death within a few days.
References: Department of Health & Human Services, U.S. General Information. Retrieved April 1, 2008 from avianflu.gov Website: http://avianflu.gov/general/index.html
What is Bird Flu?
Bird flu is the common name for avian influenza. It is a disease of birds that is mostly found in wild birds. Sometimes bird flu can spread from wild birds to domestic poultry.
There are many strains or types of bird flu virus. Right now there is a type of bird flu virus – the H5N1 strain – that has made many birds and some people sick in other parts of the world.
Reference: Vermont Department of Health. (2005). Avian Influenza: Bird Flu Facts. Retrieved April 1, 2008 from healthvermont.gov Website: http://healthvermont.gov/prevent/flu/birdflu/birdflu.aspx
Avian Flu in Birds is Spreading in Asia and Other Countries
·Avian influenza - commonly called "bird flu" - is an infection caused by influenza viruses that occur naturally in birds.
·Wild birds can carry the viruses, but usually do not get sick from them. However, some domesticated birds, including chickens, ducks, and turkeys, can become infected, often fatally
·One strain of avian influenza, the H5N1 virus, is endemic in much of Asia and has spread into parts of Europe and Africa. Avian H5N1 infections have recently killed poultry and other birds in a number of countries.
·Strains of avian H5N1 influenza may infect various types of animals, including wild birds, pigs, and tigers.
·Symptoms in birds and other animals vary, but virulent strains can cause death within a few days.
References: Department of Health & Human Services, U.S. General Information. Retrieved April 1, 2008 from avianflu.gov Website: http://avianflu.gov/general/index.html
What is Bird Flu?
Bird flu is the common name for avian influenza. It is a disease of birds that is mostly found in wild birds. Sometimes bird flu can spread from wild birds to domestic poultry.
There are many strains or types of bird flu virus. Right now there is a type of bird flu virus – the H5N1 strain – that has made many birds and some people sick in other parts of the world.
Reference: Vermont Department of Health. (2005). Avian Influenza: Bird Flu Facts. Retrieved April 1, 2008 from healthvermont.gov Website: http://healthvermont.gov/prevent/flu/birdflu/birdflu.aspx
Safe to consume eggs and poultry?
Is it safe to consume chicken, turkey, duck and eggs?
Yes. there is no evidence that properly cooked poultry or eggs can be a source of infection for bird flu. Because other common diseases such as salmonella infection can be spread by eating undercooked poultry or eggs:
Reference: Vermont Department of Health. (2005). Avian Influenza: Bird Flu Facts. Retrieved April 1, 2008 from healthvermont.gov Website: http://healthvermont.gov/prevent/flu/birdflu/birdflu.aspx
Is it safe to eat poultry and eggs?
Yes, the poultry and eggs available in the market are safe to eat. Bird flu is transmitted to humans through close contact with infected live poultry. There is no evidence that bird flu can be spread to humans through the consumption of poultry and eggs.
Are there guidelines to cooking poultry?
Consumers are advised to eat food that is well-cooked. Thorough cooking helps to kill any harmful germs present. The eating of any raw or semi-cooked food, including eggs, comes with an inherent food safety risk.
Is it safe to handle raw poultry?
Yes, it is safe to handle raw poultry. Bird flu is transmitted to humans through close contact with infected live poultry. However, you should practice general food safety precautions such as separating raw from cooked food to avoid cross contamination which can cause food poisoning.
Reference: Agri-Food & Veterinary Authority of Singapore. (2005). FAQs: About Bird Flu. Retrieved April 1, 2008 from ava.gov.sg Website: http://www.ava.gov.sg/AVA/Templates/AVA-GenericContentTemplate.aspx?NRMODE=Published&NRORIGINALURL=%2fNewsEvents%2fHotTopics%2fBirdFlu%2findex%2ehtm&NRNODEGUID=%7b67B3B7E2-ABCD-4580-A437-019BCA8DCC91%7d&NRCACHEHINT=Guest#consumption
Eating Chicken and Poultry
Is it safe to consume chicken, eggs and other poultry?
Yes. The poultry and eggs available in the market are safe to eat. There is no evidence that you can get bird flu by eating chicken, eggs and other poultry products.
Is it safe to handle chickens, eggs and other poultry bought from the market or supermarket?
Yes, it is safe to handle them. However, you should still practise general food safety precautions such as separating raw food from cooked food, and washing your hands after preparing food.
Is it safe to consume raw or half-boiled eggs, and semi-cooked meat?
You should eat food that is well cooked. Eating any raw or semi-cooked food comes with an inherent food safety risk.
Reference: Ministry of Information, Communications and the Arts. (2005) Bird Flu FAQ. Retrieved April 1, 2008 from crisis.gov.sg Wesite:
http://www.crisis.gov.sg/FLU/BirdFlu/BirdFluFAQ/
Yes. there is no evidence that properly cooked poultry or eggs can be a source of infection for bird flu. Because other common diseases such as salmonella infection can be spread by eating undercooked poultry or eggs:
- Wash hands with soap and hot water after touching any raw meat.
- Clean cutting boards and counters used for food preparation right after use.
- Cook eggs and meat thoroughly. (Cook meat to an internal temperature of 165ยบ).
Reference: Vermont Department of Health. (2005). Avian Influenza: Bird Flu Facts. Retrieved April 1, 2008 from healthvermont.gov Website: http://healthvermont.gov/prevent/flu/birdflu/birdflu.aspx
Is it safe to eat poultry and eggs?
Yes, the poultry and eggs available in the market are safe to eat. Bird flu is transmitted to humans through close contact with infected live poultry. There is no evidence that bird flu can be spread to humans through the consumption of poultry and eggs.
Are there guidelines to cooking poultry?
Consumers are advised to eat food that is well-cooked. Thorough cooking helps to kill any harmful germs present. The eating of any raw or semi-cooked food, including eggs, comes with an inherent food safety risk.
Is it safe to handle raw poultry?
Yes, it is safe to handle raw poultry. Bird flu is transmitted to humans through close contact with infected live poultry. However, you should practice general food safety precautions such as separating raw from cooked food to avoid cross contamination which can cause food poisoning.
Reference: Agri-Food & Veterinary Authority of Singapore. (2005). FAQs: About Bird Flu. Retrieved April 1, 2008 from ava.gov.sg Website: http://www.ava.gov.sg/AVA/Templates/AVA-GenericContentTemplate.aspx?NRMODE=Published&NRORIGINALURL=%2fNewsEvents%2fHotTopics%2fBirdFlu%2findex%2ehtm&NRNODEGUID=%7b67B3B7E2-ABCD-4580-A437-019BCA8DCC91%7d&NRCACHEHINT=Guest#consumption
Eating Chicken and Poultry
Is it safe to consume chicken, eggs and other poultry?
Yes. The poultry and eggs available in the market are safe to eat. There is no evidence that you can get bird flu by eating chicken, eggs and other poultry products.
Is it safe to handle chickens, eggs and other poultry bought from the market or supermarket?
Yes, it is safe to handle them. However, you should still practise general food safety precautions such as separating raw food from cooked food, and washing your hands after preparing food.
Is it safe to consume raw or half-boiled eggs, and semi-cooked meat?
You should eat food that is well cooked. Eating any raw or semi-cooked food comes with an inherent food safety risk.
Reference: Ministry of Information, Communications and the Arts. (2005) Bird Flu FAQ. Retrieved April 1, 2008 from crisis.gov.sg Wesite:
http://www.crisis.gov.sg/FLU/BirdFlu/BirdFluFAQ/
Avian Influenza: Food safety
Tips for Food Safety
Raw poultry meat and poultry eggs may be contaminated by bacteria or viruses such as salmonellas or avian flu virus. The mainstay of prevention lies with thorough cooking, which can kill bacteria and viruses in food. According to the World Health Organization, there is no evidence that properly cooked poultry or eggs can be a source of infection. Therefore, the risk of contracting avian flu could be reduced by thorough cooking of poultry meat and poultry eggs.As a general precautionary measure, the public are advised to observe good personal, food and environmental hygiene at all times.
The following safety tips are useful:
Food Safety and public health significance: Avian influenza
There were concerns over the possibility that avian influenza could spread to human through the handling and consumption of contaminated poultry products and eggs. From the limited studies available, it appears that almost all parts of an infected bird are contaminated with the viruses. The virus can also be found inside and on the surface of eggs.
On the basis of current scientific evidence available, WHO holds the view that to date there is no epidemiological information to suggest that the disease can be transmitted through contaminated food or that products shipped from affected areas have been the source of infection in humans.
The avian influenza virus, however, can survive on contaminated raw poultry meat and can pass around through contaminated food products (e.g. frozen meat). Freezing and refrigeration is not effective in reducing the concentration or virulence of the virus on contaminated meat, but normal cooking (temperatures at or above 70 oC) will inactivate the virus.
As precautionary advice and in order to avoid known risks of food poisoning from Salmonella and other organisms, WHO, as well as other health authorities such as the European Food Safety Authority, reiterates that, whilst it is unlikely that H5N1 could be passed onto humans by raw meat or eggs, cooking food thoroughly would inactivate the virus and eliminate this potential risk.
Advice to public
Although there is no epidemiological information to suggest that the disease can be transmitted through the consumption of contaminated poultry products and eggs, proper handling and cooking of poultry provides protection against H5N1, as it does against other viruses and pathogens such as Salmonella.
Raw poultry meat and poultry eggs may be contaminated by bacteria or viruses such as salmonellas or avian flu virus. The mainstay of prevention lies with thorough cooking, which can kill bacteria and viruses in food. According to the World Health Organization, there is no evidence that properly cooked poultry or eggs can be a source of infection. Therefore, the risk of contracting avian flu could be reduced by thorough cooking of poultry meat and poultry eggs.As a general precautionary measure, the public are advised to observe good personal, food and environmental hygiene at all times.
The following safety tips are useful:
Handling
1. After handling live poultry, poultry products or eggs, wash hands thoroughly with soap or liquid cleanser.
2. Clean thoroughly all working surfaces, utensils and equipments that have been used for handling poultry products or eggs.
3. Use separate knives and chopping boards to handle raw food and ready-to-eat food.
4. Keep raw poultry meat in well covered container and then store it in the lower compartment of refrigerator. Keep ready-to-eat and cooked food in the upper compartment to avoid cross-contamination.
5. Wash eggs (with household detergent if required) if they are soiled with faecal matter or stained with dirt. Washed eggs should be consumed immediately.
6. Avoid consuming eggs with cracked shell as they are prone to be contaminated.
Consumption
1. Do not use raw or undercooked eggs for preparation of food that will not be cooked further.
2. Do not eat raw eggs or dip cooked food into any mixed sauce of raw eggs. Cook eggs thoroughly until the white and the yolk become firm.
3. Cook poultry thoroughly before consumption. The centre of poultry meat should reach 70oC continuously for at least two minutes.
4. If there are pinkish juices running from the cooked poultry or the middle parts of the bones are still red in colour, cook the poultry again until fully done.
Food Safety and public health significance: Avian influenza
There were concerns over the possibility that avian influenza could spread to human through the handling and consumption of contaminated poultry products and eggs. From the limited studies available, it appears that almost all parts of an infected bird are contaminated with the viruses. The virus can also be found inside and on the surface of eggs.
On the basis of current scientific evidence available, WHO holds the view that to date there is no epidemiological information to suggest that the disease can be transmitted through contaminated food or that products shipped from affected areas have been the source of infection in humans.
The avian influenza virus, however, can survive on contaminated raw poultry meat and can pass around through contaminated food products (e.g. frozen meat). Freezing and refrigeration is not effective in reducing the concentration or virulence of the virus on contaminated meat, but normal cooking (temperatures at or above 70 oC) will inactivate the virus.
As precautionary advice and in order to avoid known risks of food poisoning from Salmonella and other organisms, WHO, as well as other health authorities such as the European Food Safety Authority, reiterates that, whilst it is unlikely that H5N1 could be passed onto humans by raw meat or eggs, cooking food thoroughly would inactivate the virus and eliminate this potential risk.
Advice to public
Although there is no epidemiological information to suggest that the disease can be transmitted through the consumption of contaminated poultry products and eggs, proper handling and cooking of poultry provides protection against H5N1, as it does against other viruses and pathogens such as Salmonella.
As a general precautionary measure, the public are advised to observe good personal, food and environmental hygiene at all times. Among which the following good hygienic practices are of particular importance in avoiding the spread of the virus through food.
- Cook poultry meat and eggs thoroughly. Do not eat raw or undercooked eggs (including food items containing raw or undercooked eggs as ingredients).
- Avoid contaminating cooked or ready-to-eat foods with raw meat (e.g. do not handle both raw and cooked poultry without washing your hands in between).
- After handling poultry products or eggs, wash hands and food-contact surfaces thoroughly.
References: Food and Environmental Hygiene Department, H.K. (2008). Risk in Brief, Issue No. 22: Avian Influenza Viruses and Food Safety. Retrieved April 1, 2008 from fehd.gov.hk Website: http://www.fehd.gov.hk/safefood/report/avian_infl_virus/index.html
Notes on storage of eggs
Eggs -- Storage Time
Eggs should be kept refrigerated all the time. They should be stored in the original carton. They do not need washing before using.
Recommended storage time for eggs in the refrigerator is 3-5 weeks.
Boiled eggs will keep a week in the refrigerator. It is suggested they be left unshelled until ready to use. They seem to keep better and have better quality. Cooked egg dishes (like casseroles, deviled eggs) should be stored in the refrigerator and used within three days.
Raw egg whites will keep one week in the refrigerator and 12 months in the freezer. Egg yolks will keep 3 days in the refrigerator and 12 months in the freezer, but the yolks will thicken when frozen.
Reference: University of Illinois Board of Trustees. (2006). Eggs – Storage time. Retrieved March 31, 2008 from solutions.uiuc.edu Website: http://www.solutions.uiuc.edu/content.cfm?series=3&item=319&Parents=0%7C26%7C34%7C37
Storage of eggs
Eggs deteriorate as soon as they are laid and its quality would decrease at room temperature. Eggs stored at room temperature are found to deteriorate at a faster rate as compared to those stored in the refrigerator of about one week. To ensure the freshness of the whole or liquid eggs, refrigerated, frozen or dried are preferred.
The sizes of the air cells gap between the membranes indicate its age. As the larger the air cell, the egg ages due to the escaping of moisture and carbon dioxide.
Proper refrigeration of eggs helps to keep the eggs fresh and prevent microbial growth. Eggs are best kept in carton packaging with the large ends up. This prevents the air cells from moving towards the yolk. Eggs should not be wash, as this would remove the oil coating, which function to prevent microbial growth and moisture loss.
Shelf life of refrigerated eggs should remain its freshness for about one month. Separated egg yolks may be stored under water in the refrigerator, but should be used within two days. Egg whites should be kept tightly covered in a glass container, which could last for about four days.
Eggs are treated with a light coat of oil or plastic and stored in high humidity at low temperatures very close to the egg’s freezing point (29 ° to 32 °F/ -1.5 ° to 0 °C).
Reference: Brown A. (2004). Understanding Food. Davis Drive Belmont, U.S.A.; Wadsworth/Thomson Learning. Pgs. 246 - 247
Safety
Egg is the excellent medium for the growth of microorganisms. Strict sanitation standards are employed by the egg producers to maintain clean facilities. Such measures are effective in eliminating numerous potential hazards, however, they do not prevent the contamination of eggs by Salmonella enteritidis. This bacterium infects the yolk of the egg when the egg is being form and before the shell is made. Thus, sanitary handling has no effect on this bacterium.
The control of this bacterium must focus on sanitary procedures beginning from preventing the hens from being infected by this bacterium. Refrigeration of shell eggs in warehouses, transport trucks and retailers should be of temperature of 7.2 °C (45 °F) or colder, to promote the safety of eggs.
Even if the eggs are not contaminated by Salmonella enteritidis, they are still a perfect medium for the growth of most microorganisms with which they might become infected during food handling.
Reference: McWilliams M. (2005). FOODS experimental perspectives, Fifth edition. Upper Saddle River, N. J. : Pearson Prentice Hall. Pgs 404-405
Eggs should be kept refrigerated all the time. They should be stored in the original carton. They do not need washing before using.
Recommended storage time for eggs in the refrigerator is 3-5 weeks.
Boiled eggs will keep a week in the refrigerator. It is suggested they be left unshelled until ready to use. They seem to keep better and have better quality. Cooked egg dishes (like casseroles, deviled eggs) should be stored in the refrigerator and used within three days.
Raw egg whites will keep one week in the refrigerator and 12 months in the freezer. Egg yolks will keep 3 days in the refrigerator and 12 months in the freezer, but the yolks will thicken when frozen.
Reference: University of Illinois Board of Trustees. (2006). Eggs – Storage time. Retrieved March 31, 2008 from solutions.uiuc.edu Website: http://www.solutions.uiuc.edu/content.cfm?series=3&item=319&Parents=0%7C26%7C34%7C37
Storage of eggs
Eggs deteriorate as soon as they are laid and its quality would decrease at room temperature. Eggs stored at room temperature are found to deteriorate at a faster rate as compared to those stored in the refrigerator of about one week. To ensure the freshness of the whole or liquid eggs, refrigerated, frozen or dried are preferred.
The sizes of the air cells gap between the membranes indicate its age. As the larger the air cell, the egg ages due to the escaping of moisture and carbon dioxide.
Proper refrigeration of eggs helps to keep the eggs fresh and prevent microbial growth. Eggs are best kept in carton packaging with the large ends up. This prevents the air cells from moving towards the yolk. Eggs should not be wash, as this would remove the oil coating, which function to prevent microbial growth and moisture loss.
Shelf life of refrigerated eggs should remain its freshness for about one month. Separated egg yolks may be stored under water in the refrigerator, but should be used within two days. Egg whites should be kept tightly covered in a glass container, which could last for about four days.
Eggs are treated with a light coat of oil or plastic and stored in high humidity at low temperatures very close to the egg’s freezing point (29 ° to 32 °F/ -1.5 ° to 0 °C).
Reference: Brown A. (2004). Understanding Food. Davis Drive Belmont, U.S.A.; Wadsworth/Thomson Learning. Pgs. 246 - 247
Safety
Egg is the excellent medium for the growth of microorganisms. Strict sanitation standards are employed by the egg producers to maintain clean facilities. Such measures are effective in eliminating numerous potential hazards, however, they do not prevent the contamination of eggs by Salmonella enteritidis. This bacterium infects the yolk of the egg when the egg is being form and before the shell is made. Thus, sanitary handling has no effect on this bacterium.
The control of this bacterium must focus on sanitary procedures beginning from preventing the hens from being infected by this bacterium. Refrigeration of shell eggs in warehouses, transport trucks and retailers should be of temperature of 7.2 °C (45 °F) or colder, to promote the safety of eggs.
Even if the eggs are not contaminated by Salmonella enteritidis, they are still a perfect medium for the growth of most microorganisms with which they might become infected during food handling.
Reference: McWilliams M. (2005). FOODS experimental perspectives, Fifth edition. Upper Saddle River, N. J. : Pearson Prentice Hall. Pgs 404-405
Monday, March 31, 2008
Subscribe to:
Posts (Atom)