The determination of hemoglobin and myoglogin residues as a parameter for testing heat exposure in back bacon.
The use of an extraction of the heme pigments hemoglobin and myoglobin as a test for the heat exposure of back bacon was investigated by treating back bacon at varying temperatures of 50-70 degrees C and times of two to 180 minutes and observing the effect on the absorbance of heme pigment residue after nitrite oxidation. Absorbance at 409 nm was used in place of the more usual 540 nm to provide greater sensitivity in the detection of heme. A decrease in residual heme pigments was time-dependent, particularly at lower temperatures. In view of this factor and the complex nature of the heat exposure of a large block of back bacon, the application of this test would require a calibration of each process. Alternatively, limits to the amounts of heme pigment residue could be set. The heme pigment test is useful in its simplicity and overcomes difficulties associated with the coagulation and enzyme tests. (+info)
Injection site survey in Canadian-fed cattle: spring 1997.
A 2nd injection site survey was conducted during the spring of 1997 in Canadian-fed beef. The prevalence of lesions was 13.3% in top butts, 23.1% in blades, 9.1% in eye of rounds, 7.5% in outside rounds, and 1.4% in inside rounds. Losses were $8.05/head processed or $17 million annually. (+info)
Food safety in the 21st century.
The global importance of food safety is not fully appreciated by many public health authorities despite a constant increase in the prevalence of foodborne illness. Numerous devastating outbreaks of salmonellosis, cholera, enterohaemorrhagic Escherichia coli infections, hepatitis A and other diseases have occurred in both industrialized and developing countries. In addition, many of the re-emerging or newly recognized pathogens are foodborne or have the potential of being transmitted by food and/or drinking water. More foodborne pathogens can be expected because of changing production methods, processes, practices and habits. During the early 21st century, foodborne diseases can be expected to increase, especially in developing countries, in part because of environmental and demographic changes. These vary from climatic changes, changes in microbial and other ecological systems, to decreasing freshwater supplies. However, an even greater challenge to food safety will come from changes resulting directly in degradation of sanitation and the immediate human environment. These include the increased age of human populations, unplanned urbanization and migration and mass production of food due to population growth and changed food habits. Mass tourism and the huge international trade in food and feed is causing food and feedborne pathogens to spread transnationally. As new toxic agents are identified and new toxic effects recognized, the health and trade consequences of toxic chemicals in food will also have global implications. Meeting the huge challenge of food safety in the 21st century will require the application of new methods to identify, monitor and assess foodborne hazards. Both traditional and new technologies for assuring food safety should be improved and fully exploited. This needs to be done through legislative measures where suitable, but with much greater reliance on voluntary compliance and education of consumers and professional food handlers. This will be an important task for the primary health care system aiming at "health for all". (+info)
An audit of retail beef loin steak tenderness conducted in eight U.S. cities.
An audit of supermarkets in eight U.S. cities was conducted to characterize retail beef loin steaks with respect to grade, postfabrication aging, and tenderness and to provide an interim measure of progress in industry efforts to improve retail beef tenderness. Top sirloin steaks (n = 819) and strip loin steaks (n = 827 paired steaks) were purchased at retail markets in Atlanta, Chicago, Denver, Houston, Philadelphia, Phoenix, San Francisco, and Seattle and shipped to Colorado State University for measurement of shear force (both cut types) and evaluation by a trained sensory panel (strip loins only). Approximately 80% of the steaks originated from beef plants in Kansas, Texas, Nebraska, and Colorado. Postfabrication aging periods ranged from 2 to 87 d (mean = 20.8 d) for top sirloin steaks and from 2 to 91 d (mean = 19.2 d) for strip loin steaks, although most top sirloin (85%) and strip loin (91%) steaks were available for purchase 7 to 35 d after fabrication. The mix of quality grades was similar for both cuts: 60% Select, 31% "commodity" Choice, 6 to 7% "Certified" Choice, and 2 to 3% Prime. Shear force averaged 3.46 kg (SD = .74) for top sirloins and 3.05 kg (SD = .95) for strip loins; 75% of both steak types had shear force values between 2 and 4 kg. Postfabrication periods shorter than 7 d were associated with reduced (P < .05) tenderness, especially for top sirloin steaks. Higher quality grades were associated with greater (P < .05) tenderness (Prime > Choice > Select) for both cuts. Based on panel tenderness ratings, the approximate odds of obtaining a "slightly tough" or tougher strip loin steak at a retail supermarket were: 0 for Prime, 1 in 10 for "Certified" Choice, 1 in 5 for "commodity" Choice, and 1 in 4 for Select. Audit results suggest that tenderness characteristics of loin steaks have not changed materially since the National Beef Tenderness Survey was conducted in 1991 and that two primary focal points of the beef industry's efforts to improve tenderness should be 1) to prevent short-aged (< 7 d postfabrication) product from reaching consumers and 2) to identify methods for enhancing tenderness of Select and "commodity" Choice beef. (+info)
Surveying vendors of street-vended food: a new methodology applied in two Guatemalan cities.
Lack of reliable data about street vendors, who are difficult to survey, has hampered efforts to improve the safety of street-vended food. A two-phase method for sampling vendors, surveying first in areas of concentrated vending activity identified by local authorities and second in randomly selected areas, was developed and implemented in two Guatemalan cities where street-vended food had been implicated in cholera transmission. In a 4-day survey in Escuintla, 59 vendors (42 from phase 1, 17 from phase 2) were interviewed. They demonstrated good knowledge of food safety and cholera but unsafe practices, implying that more effective, practical training was needed. In a 6-day survey in Guatemala City, 78 vendors (77 from phase 1, 1 from phase 2) were interviewed. Sixty-eight (87 %) vendors stored water, usually in wide-mouthed vessels prone to contamination; this led to a field test of a new system for safe water storage. Useful information for public health planning and intervention can be gathered rapidly with this new method for surveying street vendors. (+info)
Determination of farm-level risk factors for abnormalities observed during post-mortem meat inspection of lambs: a feasibility study.
To investigate the feasibility of using information about the health and management of lambs on farms to predict the risk of gross abnormalities at post-mortem meat inspection, 6732 lambs from 30 different farms in Great Britain were followed through to slaughter in 1995/6. The farm-level data were collected during farm visits at the beginning of the study. Routine meat inspection findings for the lambs were obtained from the 10 participating abattoirs. The most common abnormalities found during post-mortem inspection were pneumonia/pleurisy (53% of cohorts), lungworm (40%), abscesses (30%), liver fluke (27%) and nephritis/nephrosis (27%). The farm-level risk factors associated with abnormalities at slaughter varied with the type of lesion. The most significant risk factor was the age of the lambs at slaughter. Lambs slaughtered at an older age were more likely to have an abnormality, especially pneumonia, abscesses and liver fluke. After age, environmental factors appeared to be better predictors of those cohorts that would have lesions at slaughter than health and disease control variables. However, a much larger study would be required to identify a set of farm-level factors that adequately discriminated between lambs with high and low risks of lesion at slaughter. At the end of the study, the farmers were informed of the meat inspection findings for their lambs and a third indicated that they would improve their animal husbandry as a result of the information. (+info)
Establishment of the PCR system specific to Salmonella spp. and its application for the inspection of food and fecal samples.
We established the PCR detection system specific to Salmonella species using Salmonella enterotoxin gene (stn). The detection limit was one bacterial cell per one gram of fecal and minced-meat samples using enrichment procedure by Tripticase soy broth or Salmonella enrichment broth, respectively. We concluded that this PCR system is useful for the practical application in the field of the public hygiene. (+info)
Prevalence of Escherichia coli O157:H7 from cull dairy cows in New York state and comparison of culture methods used during preharvest food safety investigations.
A number of protocols for the cultural detection of Escherichia coli O157:H7 in clinical fecal specimens have been proposed. In the present study direct plating of cattle feces was compared to three different broth enrichment protocols, i.e., a protocol with modified E. coli broth with novobiocin, a protocol with Trypticase soy broth with cefixime and vancomycin, and a protocol with Gram-Negative Broth with novobiocin, for their relative abilities to detect E. coli O157:H7 in feces. In all enrichment protocols, dilutions of the enrichment broths onto 150-mm sorbitol-MacConkey agar plates to which cefixime and tellurite were added were used along with reading of agar plates at both 24 and 48 h. Fecal samples came from a preharvest food safety project in which feces from New York cull dairy cattle from a northeastern packing plant along with experimentally inoculated adult dairy cow feces were tested. The performances of the broth enrichments were comparable to each other, but the broth enrichments were superior to direct plating in their ability to detect E. coli O157:H7. Regardless of the culture protocol used, recovery of E. coli O157:H7 is more likely from fresh fecal specimens than from frozen samples. An overall prevalence of E. coli O157:H7 fecal shedding by New York cull dairy cattle of 1.3% was found in specimens just before processing at the packing plant. (+info)