Pork Luncheon Meat Research Articles

4-Aminothiophenol capped halloysite nanotubes/silver nanoparticles as surface-enhanced Raman scattering probe for in-situ derivatization and selective determination of nitrite ions in meat product

Halloysite nanotubes loaded with 4-aminothiophenol capped silver nanoparticles (mHNTs-AgNPs4−ATP) composite was synthesized as a sensitive surface-enhanced Raman scattering (SERS) probe for the determination of nitrite ions in sausage and pork luncheon meat. The as-prepared composite was characterized by transmission electron microscope, X-ray diffraction spectroscopy and Fourier transform infrared spectroscopy. The as-synthesized mHNTs-AgNPs4−ATP composite with evenly distribution of AgNPs can provide in-situ derivatization site for sensitive and selective SERS detection of nitrite ions. Under acid condition, the 4-ATP capped on the AgNPs can be transformed into p,p’-dimercaptoazobenzene (DMAB) through nitrite-triggered diazo reaction. This efficient nitrite-triggered reaction can be used to detect nitrite via the characteristic peaks of DMAB at 1143 cm−1, 1392 cm−1, and 1434 cm−1. This SERS method has a wide logarithmic range of 0.0069–6.9 mg L−1, with detection limit of 0.78, 3.4, 0.51 μg L−1 at the peak of 1143 cm−1, 1392 cm−1, and 1434 cm−1, respectively. Besides, this method can be applied to detect nitrite ions in sausage and pork luncheon meat with relative standard deviation less than 10.3%, and the results were consistent with that analyzed by UV–Vis method. This method has good potential in efficient detection of meat product in food safety.

Staphylococci isolated from ready-to-eat meat – Identification, antibiotic resistance and toxin gene profile

The aim of this study was to analyse the staphylococci isolated from ready-to-eat meat products, including pork ham, chicken cold cuts, pork sausage, salami and pork luncheon meat, sliced in the store to the consumer's specifications, along with species identification and determination of antibiotic resistance. Genes encoding staphylococcal enterotoxins, staphylococcal enterotoxin-like proteins, exfoliative toxins, and toxic shock syndrome toxin 1 were also investigated. From the 41 samples, 75 different staphylococcal isolates were obtained. Based on PCR-RFLP analysis of the gap gene using AluI and HpyCH4V restriction enzymes, the isolates were identified as Staphylococcus equorum (28%), S. vitulinus (16%), S. carnosus (14%), S. succinus (11%), S. xylosus (11%), S. saprophyticus (9%), S. warneri (9%), S. haemolyticus (1%) and S. pasteuri (1%). The incidence and number of resistances to antimicrobials was found to be species but not source of isolation dependent. All S. xylosus, S. saprophyticus, S. haemolyticus and S. pasteuri isolates showed antibiotic resistance. A lower percentage of resistance was recorded for S. warneri (71%) and S. vitulinus (58%), followed by S. equorum (57%), S. carnosus (50%) and S. succinus (50%). The most frequent resistance was observed to fusidic acid (43%). The mecA gene was amplified in 4% of the staphylococci. However, phenotypic resistance to methicillin was not confirmed in any of these isolates. On the other hand, the mecA gene was not detected in any of 9% of the isolates resistant to cefoxitin. It was also found that among 75 isolates, 60 (80%) harbored from 1 to 10 out of 21 analyzed superantigenic toxin genes. The most prevalent genes were: sei (36% isolates) among enterotoxins, seln (32% isolates) among enterotoxin-like proteins and eta encoding exfoliative toxin A (37% isolates). The findings of this study further extend previous observations that, when present in food, not only S. aureus but also other species of staphylococci could be of public health significance.

Amerikamun: Consuming America and Ambivalence toward the U.S. Presence in Postwar Okinawa

After the U.S. victory in the Battle of Okinawa in 1945, devastated Okinawans lived off of U.S. military rations, including unfamiliar foods such as pork luncheon meat and corned beef hash. Okinawans incorporated these and other U.S.-made goods into daily life as “Amerikamun,” literally meaning “American products,” but loaded with postwar Okinawan perceptions of America, its military, and the social contexts of the goods themselves. Connotations have shifted over the postwar period, at times suggesting Okinawan appropriation of American power through consumption of “luxurious” (jōtō) U.S. goods, but throughout the postwar period reminding Okinawans of American domination during the occupation and the unwelcome aspects of continuous U.S. military basing. “American Village,” which is a hybrid, American-style shopping mall and resort, is a concretization of this ambivalence, as multiple generations of Okinawans now have the opportunity to inscribe and reinscribe the meaning of Amerikamun on their landscape.

Radio frequency heating of comminuted meats - considerations in relation to microbial challenge studies

Bacillus cereus and Clostridium perfringens vegetative cell and spore cocktails in maximum recovery diluent (MRD) were inoculated into pork luncheon meat to challenge a previously developed radio frequency (RF) cooking protocol. After RF cooking and cooling microbial enumeration results showed a reduction in B. cereus vegetative cell and spores of 5.4 and 1.8 log 10 cfu g −1, respectively while the corresponding reduction for C. perfringens vegetative cells and spores were 6.8 and 4.1 log 10 cfu g −1, respectively. However, post cooking temperatures within the product were lower than anticipated. Subsequent analysis of product thermal and dielectric properties indicated that MRD addition and compositional variations within meat ingredients altered thermal and dielectric properties which in turn contributed to reduced and less uniform temperatures. The study shows that for RF microbial challenge studies, adjustment of product formulation prior to MRD addition is critical to ensure a similar composition to the normal product and a true picture of microbial inactivation.

Prevalence of Listeria monocytogenes and Salmonella in Ready-to-Eat Food in Catalonia, Spain

Listeria monocytogenes and Salmonella are pathogenic bacteria that can contaminate food products during or after processing. Ready-to-eat (RTE) food does not undergo any treatment to ensure its safety before consumption, and therefore risk of foodborne disease must be considered if these pathogens are present in the food. To evaluate the prevalence of these pathogens in RTE food, 140 RTE fish product samples, 501 RTE meat product samples, 462 RTE dairy samples, and 123 RTE dishes and desserts, providing a total of 1,226 samples, were collected from retail stores and food industry and analyzed for the presence of L. monocytogenes. A total of 1,379 samples consisting of 187 RTE fish products and 569 RTE meat products, 484 RTE dairy products, and 139 RTE dishes and desserts were collected and analyzed for the presence of Salmonella. L. monocytogenes was isolated from 20% of frozen Atlantic bonito small pies, 7.9% of smoked salmon samples, 11.1% of the pork luncheon meat samples, 6.2% of frozen chicken croquettes, 16.9% of cured dried sausage samples, 12.5% of cooked ham samples, and 20% of cooked turkey breast samples. L. monocytogenes was also found to be present in 1.3% of fresh salty cheese samples and 15.1% of frozen cannelloni samples. Salmonella was isolated from 1.2% of smoked salmon samples, 1.5% of frozen chicken croquettes, 2% of cooked ham samples, and 11.1% of cured dried sausage samples. Overall, occurrence of these pathogens in RTE foods was similar to that previously reported in the literature.

Thermal inactivation of Bacillus cereus and Clostridium perfringens vegetative cells and spores in pork luncheon roll

The aim of this study was to design a thermal treatment(s) for pork luncheon roll, which would destroy Bacillus cereus and Clostridium perfringens vegetative cells and spores. B. cereus and C. perfringens vegetative and spore cocktails were used to inoculate luncheon meat. Samples were subjected to different temperatures and removal times. The decimal-reduction times ( D-values) were calculated by linear regression analysis ( D=−1/slope of a plot of log surviving cells versus time). The log 10 of the resulting D-values were plotted against their corresponding temperatures to calculate (−1/slope of the curve) the thermal resistance ( z-values) of each cocktail. The D-values for vegetative cells ranged from 1 min (60 °C) to 33.2 min (50 °C) for B. cereus and from 0.9 min (65 °C) to 16.3 min (55 °C) for C. perfringens. The D-values for B. cereus spores ranged from 2.0 min (95 °C) to 32.1 min (85 °C) and from 2.2 min (100 °C) to 34.2 min (90 °C) for C. perfringens. The z-values were calculated to be 6.6 and 8.5 °C for B. cereus vegetative and spores, respectively, and 7.8 and 8.4 °C for C. perfringens vegetative cells and spores, respectively. The D-values of B. cereus and C. perfringens suggest that a mild cook of 70 °C for 12 s and 1.3 min would achieve a 6 log reduction of B. cereus and C. perfringens vegetative cells, respectively. The equivalent reduction of B. cereus and C. perfringens spores would require the pork luncheon meat to be heated for 36 s at 105 and 110 °C, respectively. The results of this study provide the thermal inactivation data necessary to design a cooking protocol for pork luncheon roll that would inactivate B. cereus and C. perfringens vegetative cells and spores. The data may also be used in future risk assessment studies.

Spam: the evolution of a nuisance

Junk e-mail (spam) is twenty five years old — the first junk e-mail was sent on the Arpanet, the fore runner to the Internet, in 1978. Not that there has been any cracking open of the bottles of bubbly to celebrate. It did not receive the spam designation until ten years ago based on the Monty Python sketch in which customers of a restaurant are offered spam with everything. Ironically, companies that offer anti-spam software are being threatened with breach of trademark litigation if they include the word spam in the product title by the company that owns the spam trademark. (for those of you unacquainted with spam, it is a tinned pork luncheon meat that really took off during the Second World War which declined in popularity in the Sixties).

The effect of food texture on the replication of jaw movements in mastication

The effect of different food textures on the replication of jaw movements has been generally ignored. In this study, the jaw movements of 28 young male subjects were measured while they chewed two samples of three foods—pork luncheon meat, dried apple and roasted salted peanuts. Several parameters, that characterized each chewing cycle when viewed from a frontal projection, were measured, and the average value for each variable was calculated. Values for dried apple and pork luncheon meat did not differ significantly between trials. However, for the second trial with peanuts, the chewing cycle duration was shorter (the duration of the closing phase being less and the closing velocity greater). These changes may have been due to exercizing caution during the chewing of a hard food while gaining familiarity with its texture.

Light‐induced flavour deterioration. The effect of exposure to light of pork luncheon meat containing erythrosine

AbstractWhen exposed to fluorescent light (250–1000 1x) at 4°C, luncheon meat containing erythrosine undergoes marked flavour deterioration in a few hours which is perceived mainly as a loss of flavour. The effect increased with light intensity and time of exposure but is absent in luncheon meat without added colours or with Red 2G in place of erythrosine. The results are consistent with the unique ability of erythrosine (amongst artificial food colours) to act as a sensitiser of photo‐oxidation.

Stability of red food colours in the presence of nitrite in canned pork luncheon meat

AbstractThe stability of nine red food colours in pork luncheon meat products in the absence and presence of nitrite has been investigated. The extracted dyes were examined by visible and u.v. spectrophotometry and paper chromatography for changes due to processing and to the presence of nitrite. All the colours were destroyed to some extent but with nitrite more of the food colour survived. Subsidiary dye components and colourless fluorescent products were formed as a result of heat processing and in certain cases additional products were observed in the presence of nitrite.

Incidence of Putrefactive Anaerobic Spores in Meata

SUMMARYStudy of the incidence of putrefactive anaerobic spores in fresh and cured pork trimmings and in canned pork luncheon meat from several commercial meat packing plants in Iowa indicated that the level of contamination was very low. The mode of putrefactive anaerobic spores in fresh pork trimmings was less than 0.18 per gram and less than 1 per gram in cured pork trimmings and canned pork luncheon meat. The maximum spore count found in any sample tested was 51 spores per gram. Spore counts on samples from different plants were similar.

Biochemical and Serological Relationships of Putrefactive Anaerobic Sporeforming Rods Isolated from Porka

SUMMARYUnder anaerobic culture conditions, 120 cultures of sporeforming rods were isolated from fresh and cured pork trimmings and from pork luncheon meat; 22 of these proved to be obligate anaerobic putrefactive organisms. Studied by the Reed and Orr method of rapid identification, the following species were identified: Clostridium. tetanomorphum, Cl. novyi, Cl. carnis, Cl. paraputrificum, Cl. tetani, Cl. histolyticum, and Cl. sporogenes. One culture was similar to Clostridium sp. National Canners Association putrefactive anaerobe 3679 (PA 3679). Serological relationships were determined by using antisera for Cl. sporogenes and PA 3679. No cross agglutination was obtained between Cl. sporogenes and PA 3679. An organism identified biochemically as Cl. carnis agglutinated in dilutions of 1:5120 of PA 3679 antiserum, indicating a very close serological relationship. Several organisms revealed antigens in common with Cl. sporogenes. The organism with biochemical reactions similar to PA 3679 showed no serological relationship to the known species. Serological relationships correlated with heat resistance while biochemical reactions did not.

Effect of Cooking and Curing on Lysine Content of Pork Luncheon Meat: Three Figures

Effect of Cooking and Curing on Lysine Content of Pork Luncheon Meat: Three Figures