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The halal food market is globally growing along with the increased risk of adulteration. We proposed an amplification-free and mix-to-read CRISPR-Cas12-based nucleic acid analytical strategy allowing rapid identification and analysis of pork components, thus enriching the toolbox for ensuring halal food authenticity. We designed and optimized guide RNA (gRNA) targeting the pork cytochrome b (Cyt b) gene. gRNA allowed specific identification of the target Cyt b gene from pork components followed by activation of Cas12 protein to abundantly cleave single-stranded DNA probes with terminally labeled fluorophore and quencher groups, thus turning on fluorescence. The presence of the pork Cyt b gene thus can be mix-and-read- and only-one-step-detected, which may indicate the risk of halal food adulteration. The method allowed specific discrimination of pork meat from beef, mutton, and chicken and yielded a detection limit of 2.7 ng/μL of total DNA from pork meat. The reliability of the method was tested using the following processed meat products: halal foods beef luncheon meat and spiced beef and non-halal foods sausage and dried pork slices. The CRISPR-Cas12-based nucleic acid test strategy is promising for rapid food authentication.

The effect of addition moringa leaves extract (MLE) on physical, chemical and sensory properties of luncheon was investigated. Luncheon samples were supplemented with 0.5, 1.0 and 1.5% of MLE. Results showed that supplementation of luncheon with MLE increased its content of protein, fiber and antioxidants. Protein content ranged from 8.49% in control to 10.90% in luncheon sample with 1.5% MLE. Total phenolic content of MLE was ranged from 65 to 67 mg/100g (as Gallic acid equivalent) while, the scavenging effects of 100 µl of MLE were ranged from 79.51 to 88.57%. The thiobarbituric acid number (TBA) values increased for all the investigated luncheon samples gradually during storage period. The highest value for TBA was noticed in L1 (control sample 1) (0.5239) after four weeks of cold storage while, the lowest value was observed with luncheon meat containing 0.01% butylated hydroxytoluene (BHT) (L2) (0.1251) at zero storage. The total polyphenol contents and antioxidants activity increased in luncheon meat after the addition of moringa leaves extract. All the luncheon meat samples containing moringa leaves extract were generally acceptable.

Nowadays, there is a great interest regarding demand for foods with low-fat meat products to decrease the risk of nutritional diseases. Several strategies had been reported to reduce fat contents of meat products. The term fat replacer is used to describe a wide variety of products that replace some or all of the fat in foods. In the last years, chicken luncheon meat became one of the most commonly widely marketed and distributed meat products all over the world due to its delicious taste and cheap price. In this study, the chemical quality of the chicken luncheon meat produced either by; sun flower oil, sun flower oil and sodium alginate, sun flower oil, sodium alginate and rice flour, sun flower oil, sodium alginate, rice flour and gum Arabic as fat replacers was evaluated according to market reference toward production of new chicken meat luncheon of low fat, cholesterol and calories. The results revealed that application of fat replacers in cooked chicken luncheon meat enhanced the quality of saturated, monounsaturated and polyunsaturated fatty acids improving its nutritional value.

Background. Since the beginning of humanity, the global burden of foodborne disease has had a decimating effect on populations, with biogenic amines (BAs) and aflatoxins in meat products implicated. While many developed countries have legitimized safety levels for BAs using evidence-based guidelines to attain high food quality standards for consumers of meat products, developing countries are still battling against poor food quality checking. Purpose. This study examines the level of health risk of biogenic amines and aflatoxin in meat products by extracting and estimating their residues and determining their indices as a way of monitoring the potential health impacts of these residues on consumers of meat products. Methods. A total of 40 imported meat products sampled and randomly collected, representing imported luncheon meat, hot dog sausages, corned beef, and minced meat. Using recommended laboratory protocols, eight residues of BAs and aflatoxins were extracted. Results. Eight BAs, histamine, tyramine, tryptamine, cadaverine, putrescine, β-phenyl ethylamine, spermine, and spermidine, were extracted and determined in all tested samples. Tyramine levels in luncheon meat were found to be significantly higher than in other meat products, while significantly high cadaverine levels were reported in corned beef samples. The results of biogenic amine index (BAI) revealed that the quality of imported minced meat and imported hot dog samples was good (BAI 5 µg/kg) in imported luncheon meat and imported hot dog meat samples. Conclusion. The general results indicate that testing meat products for biogenic amines and aflatoxins is a very good indicator for monitoring the freshness and quality of meat products.

A total of 396 food samples (ready-to-eat meat and poultry products; shellfish and finfish products; some raw shell and finfish and meat products; salads and coleslaws; baked confectionary) was purchased from local retail outlets and examined for the presence of motile aeromonads. Of the food categories tested, shellfish had the highest incidence, with 66% positive. Vegetable products, luncheon meat, salami, pate, and poultry products had very low incidences, and no motile aeromonads were found in baked confectionary, some of which contained whipped cream. Beef, pork, lamb, sausage, and finfish products had incidences above 20%. Most of the strains isolated were Aeromonas hydrophila . Given the reported distribution, a public health problem may exist if motile aeromonads do cause gastrointestinal disease.

Title 9 of the Code of Federal Regulations establishes prescribed thermal treatment for a variety of meat and poultry products. These requirements are to ensure the destruction of harmful microorganisms and viruses that cause diseases in humans and livestock. The information presented in this review provides information relative to the current procedures used by the Food Safety and Inspection Service (FSIS) for monitoring the adequacy of heat treatment of meat and poultry products; and the research activities that have been and are currently being conducted to develop new and/or improved methods for determining the maximum internal temperature of meat and poultry products. Currently, FSIS is using a protein "Coagulation Test" for monitoring the maximum internal temperature (MIT) of both beef and pork products heat processed to temperatures lower than 65°C; a residual "Acid Phosphatase Activity Method" for determining the MIT of canned hams, canned picnics and canned luncheon meat, and a third method, known as the "Bovine Catalase Test", for the determination of catalase which gives a pass/fail indication at a cooking temperature of 62.8°C for rare roast beef and cooked beef. Since 1957, several attempts have been made to develop new and/or improved methods. These include an evaluation of the enzyme systems and various physical techniques. The lack of new and/or improved methods is not due to the lack of research efforts in this area, as evidenced by this review. The challenge is the development of a method which can accurately determine within ± 1.0°C the endpoint temperature in the temperature range (67.8 - 70.0°C) that is of most interest to FSIS.

This study aims to design metal food packaging with hazard analysis critical control point (HACCP). First, theory of HACCP was introduced in detail. Taking empty cans provided by Wuxi Huapeng Food Packaging Company as an example, we studied migration of bisphenol compounds in coating of food can to food stimulant. Moreover, packaging design of luncheon meat can was taken as an example to confirm whether HACCP system could effectively control migration of phenolic substance. Results demonstrated that, coating of such empty were more likely to contain multiple bisphenol compounds such as bisphenol A (BPA), and bisphenol A diglycidyl ether (BADGE) was considered as the leading bisphenol pollutant; food stimulant of different types, storage temperature and time could all impact migration of bisphenol compounds. HACCP system was proved to be effective in controlling hazards of phenolic substance in luncheon meat can and could reduce various phenolic substance indexes to an acceptable range. Therefore, HACCP can control migration of phenolic substance and recontamination of food and thus ensure food safety.

Listeria monocytogenes has long been associated with ready-to-eat foods, particularly with deli products. A retail deli is full of potential niches for L. monocytogenes to establish, and this poses a significant sanitation challenge. Retail sliced deli meat products, also known as luncheon meat or cold cuts, are subject to long home storage times under refrigerated conditions where L. monocytogenes can multiply; these commonly consumed ready-to-eat meats are high risk for getting cross-contaminated in the retail deli environment and causing listeriosis. This review considers elements of the retail deli environment which can affect the prevalence and persistence of L. monocytogenes that may lead to contamination of sliced meat, as well as the specific attributes associated with L. monocytogenes isolated from deli environments and decontamination measures assessed to reduce L. monocytogenes prevalence in deli environments. In deli environments, the ratio of L. monocytogenes to Listeria spp. is 2.4:1, and L. monocytogenes is found twice as frequently on non-food contact surfaces compared to food contact surfaces. Elements that may affect the likelihood of this pathogen persisting in the deli environment are sanitizer tolerance and biofilm formation ability; it is found that there are no differences in sanitizer tolerance between transient and persistent deli strains, but biofilm formation is a trait linked to persistence in L. monocytogenes isolated from delis. A major virulence factor in L. monocytogenes, full length internalin gene inlA, has a higher prevalence in retail deli isolates compared to the studied prevalence in all food isolatesbut closely resembles the prevalence in clinical isolates, suggesting that the retail deli is a major source of clinically recognized listeriosis cases. To combat this pathogen, the merits of daily intervention as well as deep cleans are discussed; increased employee commitment to cleaning programs and a greater food safety culture are related to improved retail deli cleanliness.

High sodium intake increases blood pressure and consequently increases the risk of cardiovascular diseases. In Australia, the best estimate of sodium intake is 3840 mg sodium/day, almost double the World Health Organization (WHO) guideline (2000 mg/day), and processed meats contribute approximately 10% of daily sodium intake to the diet. This study assessed the median sodium levels of 2510 processed meat products, including bacon and sausages, available in major Australian supermarkets in 2010, 2013, 2015 and 2017, and assessed changes over time. The median sodium content of processed meats in 2017 was 775 mg/100 g (interquartile range (IQR) 483&ndash, 1080). There was an 11% reduction in the median sodium level of processed meats for which targets were set under the government&rsquo, s Food and Health Dialogue (p &lt, 0.001). This includes bacon, ham/cured meat products, sliced luncheon meat and meat with pastry categories. There was no change in processed meats without a target (median difference 6%, p = 0.450). The new targets proposed by the current government&rsquo, s Healthy Food Partnership capture a larger proportion of products than the Food and Health Dialogue (66% compared to 35%) and a lower proportion of products are at or below the target (35% compared to 54%). These results demonstrate that voluntary government targets can drive nutrient reformulation. Future efforts will require strong government leadership and robust monitoring and evaluation systems.

Canned meat products are usually protected against C. botulinum by combinations of heat, NaCl and NaNO2. When meat products are reduced in NaCl for health reasons, they need a higher heat treatment to maintain same level of protection against C. botulinum. We describe a new tool for calculating the F-value, necessary to obtain equivalent safety for canned meat when reduced in NaCl, compared to the original combination of aqueous salt and F–value. The tool is valid for combinations of F–values between 0.51 and 3.25 and aqueous salt between 1.66 and 3.54%. The tool is available at http://dmripredict.dk.

The rate of foodborne illness caused by Listeria monocytogenes continues to exceed the Healthy People 2020 goal of 0.2 cases per 100,000 persons. Listeria infections are primarily sporadic, most cases caused by eating contaminated, ready-to-eat (RTE) foods including luncheon meats sliced in retail delis which have been implicated as being responsible for as many as 83% of these illnesses. Listeria specific antimicrobials incorporated in RTE luncheon meats to be sliced in retail delis would lower the risk to consumers by as much as 96%, especially for high-risk consumers. Walmart and Sam's Club stores (Bentonville, AR), large retailers of RTE meats sliced in their delis, have required all their suppliers of bulk RTE meats which could support the growth of Listeria to include a verified inhibitor that will not allow an increase in L. monocytogenes of more than 1 log during the intended shelf-life and storage of the product. We surveyed these suppliers and determined that six of 15 suppliers had not added inhibitors to their bulk luncheon meat for Walmart prior to the 2010 requirement. One supplier reported using inhibitors in 60% of their products prior to Walmart's mandate and now uses Listeria specific inhibitors in 100% of the bulk deli meats it produces, regardless of customer. Three of the five manufacturers who needed to reformulate their products reported additional benefits: the Listeria specific antimicrobials extended their products' shelf life, improved food safety and provided better protection for their customers.

O objetivo deste estudo foi desenvolver duas formulações de apresuntado contendo farinha de yacon e extrato de frutanos de yacon visando obter produtos de melhor qualidade nutricional e ricos em fibras alimentares. Os apresuntados foram elaborados substituindo-se a fécula de mandioca (1,73%) pela farinha de yacon e a água da formulação (37,85%) pelo extrato aquoso de frutanos. Os efeitos dessas substituições nas qualidades tecnológicas e sensoriais dos apresuntados foram avaliados comparando-os com um controle. Os resultados obtidos demonstraram existirem diferenças significativas entre as formulações e evidenciaram que a adição da farinha de yacon ao apresuntado originou uma formulação com menor teor de sódio, índice de amarelo, tonalidade, dureza, flexibilidade, adesividade e menores notas nos quesitos sabor e impressão global. Entretanto revelaram que o apresuntado elaborado com extrato de frutanos apresentou uma aceitabilidade semelhante ao controle, porém com menor dureza e maiores teores de potássio e fibras, originando um produto cárneo benéfico à saúde. The objective of this study was to develop two luncheon meat formulations containing yacon flour and yacon fructan extract, in order to obtain products with improved nutritional quality and rich in dietary fiber. The luncheon meats were prepared replacing the cassava starch (1.73%) with yacon flour, and the water used in the formulation (37.85%) with the aqueous fructan extract. The effects of these substitutions on the technological and sensory qualities of the luncheon meats were evaluated, comparing them with a control. The results obtained showed there were significant differences between the formulations. The addition of yacon flour to the luncheon meat resulted in a formulation with a lower sodium content, yellow index, hue, hardness, flexibility and adhesion and lower scores for the items of taste and overall impression. However, they showed that the luncheon meat prepared with the fructan extract presented an acceptability similar to that of the control, but with reduced hardness and higher levels of potassium and fiber, resulting in a meat product beneficial to the health.

Summary The different effects of pasteurization and fermentation on sulphamethazine (SMZ) and sulphachlorpyridazine (SCP) were investigated in two common German meat products, luncheon meat and raw fermented sausages. There was no decrease in sulphonamide concentration (5 μg g-1) in luncheon meat during the different stages of processing and storage (4°C up to 27 days). Less than 40% of the initial concentration remained in fermented sausages after ripening for 10 days in a climatized room. The sulphonamide content was reduced only if fermentation was involved in contrast with meat contaminated with other chemotherapeutic residues.

Summary Glucose accumulated in chub packed luncheon meat cooked at 66°C. Glucose was also released from pork starch slurries, but not similar slurries prepared with beef or mutton. The amylolytic activity of pork was not inactivated by heating at 60°C, and this thermostable activity appears to account for the accumulation of glucose in pasteurized chub packed luncheon meat stored under conditions that preclude bacterial growth.

Summary Five formulations for commercial luncheon meat were prepared and canned, then analysed for proximate composition, thiobarbituric acid (TBA) value, peroxide value, pH, acidity (% as free fatty acid, FFA) and subjected to sensory analysis. Small differences (P = 0.05) in the proximate composition were recorded, but all samples came within the required Jordanian Standard for the product. TBA values were the highest in luncheon meat containing the highest percentage of mechanically deboned chicken meat. The most preferred colour to the panel was achieved in samples containing the greatest percentage of beef heart and lowest fat content; these samples were also the juiciest. The highest scoring samples for sensory evaluation were those that contained beef flank, topside and heart.

The zinc [Zn] content of 71 Egyptian foods were analyzed using flame atomic absorption spectrophotometry (AAS). Levels (mg per kg edible portion) ranged from trace amounts of 1.1 in oranges to 40 in luncheon meat. The daily Zn intake was estimated to be 8.5 mg per adult subject, bread being the major Zn contributor (36%). The phytate concentration was chemically determined in foods of plant origin. Mean [phytate]/[Zn] molar ratios for baladi bread, stewed faba beans and composite food samples amounted to 4.2, 28.0 and 3.46, respectively.

e-Caprolactam (CAP) is a monomer of nylon 6 used as food packaging for bologna sausage, turkey blanquettes, fowl breast, pâtes and ham luncheon meat. After polymerization a part of the monomer can remain in the packaging and migrate into the food. The aim of this work was develop and validate a single laboratory method to determine CAP in ethanol 95% that simulates fatty food characteristics. Thus, linear range was 2 to 32 mg/L of CAP, detection and quantification limits were 0.83 and 1.63 mg/L, respectively. Repeatability showed Hor Rat values lower than 2 while recovery range was 97.5 to 106.5%. The method was considered adequate for purpose.

A self-administered food frequency questionnaire (FFQ) was developed to indicate weekly consumption of 64 foods. Reliability, validity, and usefulness of the tool to define a protein eating pattern were determined. Adolescents (N = 1,108) completed the FFQ during the Bogalusa Heart Study. Two-hour and 2-week reliability measures demonstrated consistency of intake of specific foods. Frequency of foods obtained from seven consecutive 24-hour recalls was compared with frequency obtained from the FFQ. A mean 50% agreement for both frequency and quantity of food intake was observed. Geometric means showed differences in mean number of protein foods by age of adolescent but the only significant difference was for beef intake of 15-year-olds. White children reported more servings of beef, cheese, and vegetables with meat than did black children. Black children reported more servings of eggs, luncheon meat, pork, poultry, and total protein than did white children. Boys reported a greater frequency of total protein foods, specifically, eggs, milk, and poultry, than did girls. Significant correlations were noted between low-density-lipoprotein cholesterol and intake of eggs and luncheon meat. We were able to quantitate the reliability and validity of the FFQ and to use it to explore the association of specific eating patterns with cardiovascular disease risk.

Listeria monocytogenes is a common postprocess contaminant on ready-to-eat foods including premade ready-to-eat sandwiches. One popular type of sandwich product is the tortilla wrap, which contains sliced luncheon meats and cheeses rolled within a flour tortilla. This study determined the radiation resistance of L. monocytogenes surface inoculated onto two types of commercially available wheat flour tortillas, processed cheese slices, and deli turkey meat. The D 10 -values for L. monocytogenes (the radiation dose required to inactivate 1 log of the pathogen) were 0.27 kGy when inoculated onto two flour tortilla types, 0.28 and 0.30 kGy when inoculated onto two types of sliced processed cheeses, and 0.58 and 0.65 kGy when inoculated onto two types of sliced deli turkey meat. When two types of tortilla wraps were assembled from the individual components and L. monocytogenes was inoculated into the interfaces between the individual components, the D 10 -values were 0.27 to 0.37 kGy in the tortilla and cheese interfaces, 0.33 to 0.41 kGy in the cheese and turkey interfaces, and 0.25 to 0.33 kGy in the turkey and tortilla interfaces. The ability of ionizing radiation to reduce pathogen levels on the complex tortilla, cheese, and luncheon meat product was limited by the higher radiation resistance of L. monocytogenes when inoculated onto the ready-to-eat turkey-meat component.

The aim of the study was to assess the fat content in selected animal-origin products (ie. black pudding, luncheon, wiener, bacon) as well as certified reference material (MUVA RM700 Boiled Sausage) using two analytical methods. One of them was the fat extraction using a Soxhlet technique, and the other one - the extraction using carbon dioxide in supercritical state. Methods based on Soxhlet extraction have been and are at present used as reference. This conventional method is cheap and accurate, and this is why it has been the most used extraction technique worldwide for a number of decades. On the other hand some modern methods of fat determination are needed. Supercritical Fluid Extraction is quick, safe, and it eliminates any hazardous chemicals or solvents used in traditional extraction methods. For this purpose we used TFE 2000 fat analyzer (LECO Corporation). For the methods used the following validation parameters were determined: accuracy, precision, intermediate precision, correctness. The fat content in black pudding and luncheon meat ranged from 11.5 ± 4.5 g/100g (TFE) to 12.1 ± 0.0 g/100g (Soxhlet) and from 13.2 ± 0.5 g/100g (Soxhlet) to 13.8 ± 0.7 g/100g (TFE), respectively. For wiener samples we received values between 15.7 ± 0.4 g/100g (TFE) to 17.8 ± 0.1 g/100g (Soxhlet). The fat content in bacon samples ranged from 48.2 ± 2.5 g/100g (TFE) to 48.7 ± 0.7 g/100g (Soxhlet). The results received remain consistent with the values given in the Polish “Food Composition Tables”. The application of the methods described above for the determination of fat content in animal - derived products is dependent ie.: on the purpose of analysis, the amount of fat in food product sample and the time for receiving the results.

Studies on detection of lard in certain locally processed and imported meat products were carried out. The data showed that the palmitic acid enrichment factor could be used in detecting lard in meat products, as it markedly increases as lard percentage is increased. The data for unsaponifiable components revealed that beef luncheon meat contained a high percentage of lard, reaching 7% or more. Moreover, corned beef was shown to contain not less than 3% lard. Meanwhile, frankfurter-type sausages contained a rather high level of lard, reaching 13% or more. Based on IR data, imported meat products contained an ascending order of lard contamination; namely, 3%, 6% and 13% or more in corned beef, beef luncheon meat and frankfurter-type sausages, respectively.

Beliefs about the health value of 22 selected country (native) and store‐bought foods and preference (degree of like or dislike) for these foods were examined among 208 northern native Canadians (Indian and Metis) representing three generations (adolescents and young adults, middle adults, older adults). Ratings were obtained by use of five‐point Likert‐type scales presented in pictorial format. Of the 22 foods studied highest health value scores were assigned to vegetables, fruits, fish, and country meats, and lowest were assigned to modern snack foods. Preference scores were highest for moose, bannock, and caribou, and lowest for luncheon meat. Statistically significant differences (P < 0.05) among the three generations were found in the health scores of 9 foods and in the preference scores of 8 foods. Of the three age groups, older adults were least skeptical of the health value of modern snack foods. Northern native people perceive differences in the health value of foods. Preference for country foods...

Process pasteurization values for reference temperature 70 degrees C (P70) were calculated from the temperature profiles of 250 g luncheon meat chubs cooked under experimental conditions. A simple equation relating Process P70-value and the time and temperature of cooking was derived. With minimal cooking (P70 = 40) the surviving microflora (10(3)/g) wad dominated by species of Lactobacillus, Brochothrix and Micrococcus. These organisms were destroyed by more intensive cooking (P70 = 105), leaving a flora (10(2)/g) composed of Bacillus and Micrococcus species. The spoilage that developed after 14 d storage at 25 degrees C reflected the severity of the heat treatment received by each chub: with P70 between 40 and 90, a Streptococcus spoilage sequence occurred; with P70 between 105 and 120, a Bacillus/Streptococcus spoilage sequence occurred; with P70 of 135 and above, a Bacillus spoilage sequence occurred. Cooking to a P70 = 75 was adequate to reduce the surviving microflora to the 10(2)/g level associated with current good manufacturing practice.

Alkali extracted poultry protein obtained from mechanically separated poultry residues by aqueous extraction (pH 10.5) and acid precipitation (pH 5.5) was tested in all-chicken luncheon meats. The alkali extracted protein was included at 0–40% replacement for mechanically separated poultry used as the only meat ingredient. Texture measurements by Instron, drip loss and sensory evaluation data showed that the alkali extracted protein produced no significant differences in any of the luncheon meats at 20% or less replacement level. Differences in texture and flavour between the experimental products and a commercial all-chicken luncheon meat product were small even at the highest replacement levels used.

The shelf life at 25°C of chub-packed luncheon meat was inversely related to oxygen (O2) availability within the casing. With fibrous casings that are freely permeable to O2, shelf life was less than 3 d. With plastic casings of low O2 permeability, the shelf life was 7 d when air was trapped in the emulsion during the casing filling process, 14 d when air was not trapped (normal vacuum-stuffing) and greater than 28 d when vacuum-stuffed chubs were stored in hydrogen (H2). The initial spoilage bacteria, Bacillus spp., grew only at the surface unless air was trapped in the emulsion when growth occurred throughout the luncheon meat. Bacillus spp. failed to grow on luncheon meat stored under H2. Oxygen availability within the casing determined both the site and rate of microbial spoilage of chub-packed luncheon meat.

The relationship between sensory attributes and total numbers of bacteria was investigated in a study involving 600 samples of spiced luncheon meat. cooked salami, bologna, and chopped ham. The vacuum packaged products were purchased from 60 markets throughout the United States. Samples were subjected to microbiological and sensory evaluation within a few days after purchase and once a week during a 3-week refrigerated storage period. Based upon an off-flavor intensity scale of 1 = none to 7 = extremely strong, the samples having total plate counts (TPC) of< 104, 104, 105, 106, 107, and 108 per gram had mean taste panel scores (TPS) of 2.00, 2.25, 1.92, 2.06, 1.93, and 3.17, respectively over the 3-week storage period. A microbiological standard of 106 TPC would terminate shelf life of these products at 24–28 days after manufacture. Establishment of a total bacterial population of 108 per gram with a corresponding decrease in sensory quality did not occur until 46–60 days after manufacture.

A new approach to electronically counting microbial colonies is described. An experimental counter based on the theory, with no provision for calibration or setting of thresholds, returned counts comparing excellently with manual ones even in the presence of stained chicken, corn, tuna and luncheon meat debris, or highly coloured backgrounds of chocolate, paprika and turmeric. At the same time it accommodated illumination variations equivalent to at least four f-stops. In a few cases, where colonies were extremely difficult even for humans to distinguish, the counter returned poor counts; however, the new working principle permits it to alert the operator to the subject's dubious quality. The counter discriminated easily between two bacterial species on one plate, distinguishing and separately counting Aeromonas hydrophila (browny-yellow) and Citrobacter freundii (light yellow). It also identified and counted A. hydrophila in mixed culture by following the biochemical reactivity of colonies transferred across three substrates, counting only those which were positive on all three.

Canned shelf-stable luncheon meat containing varying amounts of sodium nitrite, prepared according to a commercial formula, was processed at 110°C to Fo = 0.4 and held at 35°C until nitrite was no longer detectable. The meat was then inoculated with spores of Clostridium botulinum separately heated to Fo = 0.4 and the cans were incubated at 30°C. Swelling of cans with concomitant toxin production was related directly to the size of the inoculum and inversely to the concentration of nitrite at time of manufacture. Meat containing 200 ppm of nitrite at time of manufacture (less than 2 ppm when inoculated) inhibited 1.43 log10more spores than meat that was manufactured without nitrite. It appears that an inhibitor, which we call Perigo-type Factor (PTF), is formed during commercial processing of shelf-stable luncheon meat that contains nitrite.

The 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.

When 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.

SUMMARY Study 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.

Ground pork was inoculated with spores of Clostridium botulinum types A and B and thermally processed. Factors which affected toxinogenesis were the number of spores, the concentrations of sodium chloride (salt) and sodium nitrite, and the amount of thermal processing. Meat inoculated with 1 spore per g and processed to Fo = 0.6 became toxic if salt and nitrite were omitted. In contrast, meat inoculated with 106 spores per g remained non-toxic after the same thermal process provided sufficient salt and nitrite were present, i.e., with a brine (% salt in the aqueous phase) of 6.1% and no added nitrite, with a brine of 4.6% and 300 ppm of added nitrite, or with intermediate concentrations of salt and nitrite. The amount of thermal processing required to prevent toxinogenesis in meat with 146 ppm of nitrite and 5.5% brine depended on the concentration of spores. An Fo of 0.15 did not prevent toxinogenesis in meat inoculated with 104 spores per g; an Fo of 0.3 prevented toxinogenesis with 104, but not with 106 spores per g; and an Fo of 0.6 prevented toxinogenesis in meat inoculated with 106 spores per g. However, when the brine was decreased to 4.8%, meat with 146 ppm of nitrite and 106 spores per g became toxic even after an Fo of 0.68. Viable spores of C. botulinum were recovered 18 months after processing although the meat remained non-toxic, and normal in appearance and odour during this period. It is probable that some shelf-stable cured meats are safe because of the scarcity of C. botulinum in the raw product.

Heat penetration data on canned corned beef and luncheon meat are presented. The effects of can size, retort temperature and composition on process requirements and quality are demonstrated and discussed.

Changes in residual nitrite content of 18 sausage products during storage for various lengths of time are reported. Most pre-packaged processed meats (storage temperature 5 ± 2 C) showed decreasing residual nitrite levels during storage. All dried meat products (storage temperature 24 ± 1 C) showed increasing residual nitrite levels during storage. Residual nitrite decreased with cooking for the three products evaluated.

Canned pork of the type known as spiced luncheon meat was found to contain an appreciable amount of vitamin B1 after the complete canning process. There were, however, losses of the original vitamin B1 in the raw meat during the retorting process used for cooking and commercially sterilizing the product. These losses were 55.3%, 55.6%, and 41.9% of the original vitamin in three series of packs examined. It was possible to fortify 6-lb. export packs of canned pork with synthetic thiamin to a level equal to, or above, that of the natural vitamin in raw meat. The destruction of synthetic added vitamin was no greater than that of natural vitamin under the conditions of this study.

SUMMARY Under 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.

Vacuum-packaged oven-roasted whole turkey breasts and sliced turkey breast luncheon meat are processed with and without potassium sorbate or sorbic acid. Through 12 days of accelerated storage at 10°C, the use of 0.26% sorbate reduced the psychrotrophic plate count in both products. In the main study conducted under commercial storage conditions of 4°C, the addition of 0.12% sorbic acid to the sliced product extended the time to reach 107 cells/g from 15 days in the controls to 42 days in the treated product. In oven roasted whole breasts, psychrotrophic counts in the controls were above 108 cells/cm2 after 14 days at 4°C while the sorbate pumped and dipped breasts were below that level through the 56-day storage period at 4°C. Organoleptic evaluations indicated no significant differences between control and sorbate-treated products.

The previously described headspace-gas chromatographic procedure for the determination of acrylonitrile (AN) in several foods, with N/P selective detection, has been modified to include packaged luncheon meats. The loss of AN during equilibration at 100°C in meat samples as well as the previously described loss in cold pack cheese and peanut butter has been studied. The loss of AN could be prevented by the addition of 10% phosphoric acid, which increases the acidity of the food-acid-salt slurry to pH 1.2-1.5. This acidification permits detection of AN at 2 ppb (5% FSD at 16 x 102 amp/mV) in all foods studied. AN was not detected in 10 samples of luncheon meat packaged in AN-based plastic which contained up to 2.6 ppm AN.

Growth of Clostridium botulinum from spores was inhibited in homogenates of luncheon meat produced commercially with varying amounts of sodium nitrite. The inhibition increased with increasing concentrations of nitrite present before the heating process but could not be accounted for by residual nitrite. It is concluded that a Perigo type inhibitor is formed during commercial processing of luncheon meat.

By using gas chromatography-mass spectrometry, seven volatile compounds were identified in vacuum-packaged sliced corned beef spoiled by Brochothrix thermosphacta under aerobic conditions. Acetoin and diacetyl appeared to be of major sensory significance.

Information is lacking on the ability of the common mold contaminant, Aspergillus flavus, to grow and produce aflatoxin in perishable foods at normal refrigerator temperatures. Because of public health interests we investigated the possibility of certain perishable foods contaminated with the mold developing an aflatoxin concentration under conditions of refrigeration. Cheddar cheese and luncheon-meat samples were inoculated with A. flavus ATCC 15517 and were refrigerated for 12 days at 4.4 or 7.2 C or incubated at 25 C for 12 days, Uninoculated cheese and meat samples were handled in the same manner. All samples were quantitatively analyzed by thin-layer chromatography for presence of aflatoxin. All samples; except those inoculated and incubated at 25 C, were negative for aflatoxin production. This indicated the mold would, not produce detectable aflatoxin in the tested foods when kept at normal refrigeration temperatures for 12 days.

The principal spoilage bacteria isolated from chub-packed luncheon meat stored at 25 °C have been identified as strains of Bacillus licheniformis and Streptococcus faecium. Bacillus licheniformis alone is responsible for those degradative changes (surface softening and discolouration, gas production and eventual product liquefaction) regarded as overt product spoilage. Streptococcus faecium metabolizes carbohydrate homofermentatively, and the resultant accumulation of lactic acid causes souring of the luncheon meat.

Summary Spices and packaging materials were exposed to γ-irradiation at a dose of 10 kGy. Luncheon meat was prepared with irradiated or non-irradiated spices and packaged in irradiated or non-irradiated packaging materials. Packaged luncheon meat was treated with 2 kGy. Irradiated and non-irradiated packaged luncheon meat were kept in a refrigerator (1–4 °C) for 12 months. Microbiological, nutritive and chemical characteristics of luncheon were evaluated after processing and during storage; whereas, sensory quality was evaluated only after irradiation. γ-Irradiation decreased the microbiological counts of spices, packaging materials and packed products and increased its shelf-life. No significant differences in moisture, protein, fat, pH value, total acidity, lipid peroxide and volatile basic nitrogen were observed as a result of irradiation. Sensory evaluation showed that all the combinations of treated luncheon meats were acceptable. However, the taste, odour, appearance and texture scores of irradiated packaged products were significantly lower than those of non-irradiated samples.

Studies were performed to investigate the effect of combinations of mild heat treatment ( F 0 ≈ 0.5) and γ-radiation (4 kGy) on the microbiological stability of canned luncheon meat inoculated with spores of Clostridium sporogenes. The effect of heat treatment plus irradiation and that of a combination of the reversed sequence were studied. For quantification of the combined effect of the sporocide physical treatments and the inhibition of the survivors by the antimicrobial chemical factors (reduced a w , nitrite, suboptimal pH.) of the product, the method proposed by Hauschild et al. 0 J. Fd Protect . 48 (1985), 197) was followed. Storage studies demonstrated the increased efficacy of combination treatments against bacterial spores. Pre-irradiation followed by heat treatment resulted in higher spore damage/inactivation than the opposite order of treatment. It is estimated that the number of safe packages may be increased in the experimental batch treated by 4 kGy irradiation plus F 0 ≈ 0.5 min heat treatment than that of the batch which has been heat-treated only.