An Enzyme Immunoassay Technique for Detection of Salmonellae in Meat and Poultry Products

A commercially available enzyme immunoassay (ELISA) in which a myeloma protein (MOPC 467) is used for detection of salmonellae was compared with two conventional cultural methods for detection of salmonellae in naturally contaminated meat and poultry products. Products tested included mechanically deboned poultry, chitterlings, poultry carcass rinsings, chicken necks, luncheon loaf emulsion, pork sausage and basturma. There was 100% agreement between ELISA and cultural methods. The ELISA technique is specific and rapid. Identification of Salmonella-contaminated meat and poultry products was accomplished in 2-3 days compared to the 4-6 days required by conventional cultural methods.     

EFFECT OF FREEZING AND PACKAGING METHODS ON SURVIVAL AND BIOCHEMICAL ACTIVITY OF SPOILAGE ORGANISMS ON CHICKEN

SUMMARY— A study was conducted to determine effects of freezing, thawing, and subsequent holding at about 5°C on survival or growth of aerobic bacteria on chicken packaged with various materials. Production of fluorescent pigment, and extracellular proteinase and lipase activities were used as indices of the ability of the organisms to produce spoilage. Growth of bacteria was determined by colony counts. Assays for proteolysis were made by means of a dye binding method; lipolysis of chicken fat was determined by titration of free fatty acids. Fluorescent pigment formation was evaluated by means of a photofluorometer. The influence of availability of oxygen on proteolytic and lipoytic spoilage of poultry was studied after chicken was packaged with materials having high or low oxygen permeability and by vacuum packaging. Fluorescent pigment production, proteofytic and lipolytic spoilage of chicken stored at 5°C was directly related to the availability of oxygen provided by the packaging procedure. Bacterial numbers paralleled increases in biochemical indices of deterioration. Freezing of chicken at −29°C for 35 days followed by defrosting and refrigerated storage increased the proportion of biochemically active psychrophiles on the surface of the meat. Vacuum packaging generally limited amount of spoilage as measured by the criteria specified. When samples were analyzed after alternate freezing and thawing, total aerobic bacterial counts were only slightly different from those on chicken frozen continuously for 22-25 days.     

HEAT STABILITY OF CHICKEN ACTOMYOSIN

The heat sensitivity of chicken actomyosin was determined under varying conditions of the pH and ionic environment and in the presence and absence of various additives. The emulsifying capacity of the protein was used as the index of heat damage. As the pH of the solvent was increased above 8.5, the stability of the protein increased. It was more stable in 0.6M KC1 than in 0.2M KCl. Up to 6% sucrose significantly improved the stability. Polyphosphates were beneficial in stabilizing the actomyosin. This information should facilitate development of methods of heat pasteurizing mechanically deboned chicken meat.     

EFFECTS OF BINDING SUBSTRATE, TYPE OF NONMEAT ADDITIVE AND METHOD OF TENDERIZING ON CURED CHICKEN ROLLS

Chicken rolls were manufactured using ground dark fowl meat or mechanically deboned poultry meat as a binding substrate, sodium caseinate or soya isolate and a meat block that was mechanically tenderized or chunked. Effects of these treatments on yield, chemical composition, sensory and texture profile attributes were evaluated in this study. Inclusion of soya isolate increased the cook yield and improved color over sodium caseinate (P < 0.05). Likewise, rolls containing ground-dark fowl meat were lighter in color than those made with mechanically deboned poultry meat. Rolls made with mechanically deboned poultry meat had greater chewiness, while those made with sodium caseinate had greater cohesiveness. Texture profile analysis indicated that mechanical tenderization was the predominant factor in producing a softer and more springy chicken roll. Sensory evaluation revealed that mechanical tenderization decreased chewiness as compared to cubing (P < 0.05).     

Application of enterocins as biopreservatives against Listeria innocua in meat products

The antilisterial effect of enterocins A and B in meat and meat products (cooked ham, minced pork meat, deboned chicken breasts, paté, and slightly fermented sausages [espetec]) have been shown. An infective dose of 5 to 10 most probable numbers (MPN)/g to simulate the counts of Listeria generally found in meat products was used. Enterocins at 4,800 AU/g reduced the numbers of Listeria innocua by 7.98 log cycles in cooked ham and by 9 log cycles in paté when stored at 7 degrees C for 37 days. In deboned chicken breasts stored at 70 degrees C for 7 days, 4,800 AU/cm2 of enterocins diminished the L. innocua counts in 5.26 log cycles when compared to the control batch. In minced pork meat held at 7 degrees C for up to 6 days, 1,600 AU/g kept L. innocua counts under 3 MPN/g, while the control batch reached 50 CFU/g. In espetec sausages, 648 AU/g diminished the number of L. innocua under 50 CFU/g from the fifth day until the end of the process (12 days) while the control batch kept the initial counts (3 x 104 CFU/g). This is the first report on enterocins showing an antilisterial effect in different types of meat products.     

Ocean Pout (Macrozoarces americanus): Nutrient Analysis and Utilization

Ocean pout (Macrozoarces americanus), an underutilized marine species, was subjected to nutrient analysis, frozen storage stability studies and minced fish flesh evaluation. The nutritional quality of protein was higher than the reference casein, based on the protein efficiency ratio. A 3:1 ratio of unsaturated to saturated fatty acids was observed, making the product susceptible to rapid rancidity development. Mineral composition was low in calcium, magnesium and manganese but high in sodium and zinc, in comparison to other species. A decrease in water-holding capacity and an increase in free fatty acid and thaw drip volume of frozen fillets was observed. Mechanically deboned meat was acceptable by sensory evaluation, after 4 wk of frozen storage at –15°C. The effect of washing minced flesh was observed in the semi-fried product.     

PHOSPHATE AND NON-MEAT PROTEIN INCORPORATION INTO SMOKED SAUSAGE PRODUCED FROM MECHANICALLY DEBONED POULTRY MEAT

The effects of sodium tripolyphosphate and type of non-meat protein binders on the quality of smoked sausage produced from mechanically deboned poultry meat (MDPM) without skin were studied. Higher cook yields were observed in sausages containing soy protein isolate, soy protein concentrate and sodium caseinate (P < 0.05). Addition of sodium tripolyphosphate, with or without non-meat protein binder, also increased cook yields (P < 0.05). Objective and sensory textural attributes of firmness, chewiness and springiness were not affected by type of binder, but incorporation of phosphate increased sausage firmness. All chicken sausage treatments were considered acceptable by the sensory panel.     

The effect of temperature on microbial growth in apple cubes packed in film and preserved by use of orange juice

Red delicious apple cubes were packed in fresh orange juice containing chemical preservatives (citric and ascorbic acid, potassium sorbate) and covered with plastic films of different gas permeabilities (polyethylene and EVA‐SARAN‐EVA) before storage at 4, 10 and 20 °C. The concentration of potassium sorbate in the product was optimized with respect to colour and microbial growth. Yeast and mould growth was modelled by Gompertz and linear equations to derive parameters such as lag phase, maximum microbial population and specific microbial growth or rates of decline. Activation energies for the specific growth rates were estimated from Arrhenius‐type equations and the time required to reach microbial counts of 10^6±0.2 CFU g^?1 was determined in all cases. At 4 °C, these values were longer than 25 days in all systems tested. The use of a low gas permeability film and an adequate potassium sorbate concentration extended storage life at higher temperatures.     

Fate of unirradiated Salmonella in irradiated mechanically deboned chicken meat.

Mechanically deboned chicken meat was irradiated at 0, 1.25 and 2.50 kGy (Cesium 137) and inoculated with Salmonella dublin ATCC 15480, Salmonella enteritidis ATCC 9186 or Salmonella typhimurium ATCC 14028. Samples were then stored at 5 degrees C and 10 degrees C and were subjected to microbiological analysis directly after irradiation and inoculation (time 0), and after 24, 72, 120, 168 and 216 h of storage. Samples stored at 20 degrees C were examined at time 0 and after 6, 12 and 24 h of storage. Irradiation at 1.25 and 2.50 kGy caused an average reduction in bacterial levels of 2.23 and 3.44 logs, respectively. S. dublin, S. enteritidis and S. typhimurium showed very small, insignificant changes in numbers, during storage of meat for 9 days at 5 degrees C. The final populations of S. dublin and S. typhimurium in samples irradiated before inoculation and stored at 10 degrees C or 20 degrees C were greater than the equivalent populations in samples which had not been irradiated before inoculation. Reduction of indigenous microflora in mechanically deboned chicken meat by irradiation may create better conditions for the growth of salmonellae and may thus increase the risk of salmonellosis when accidental contamination and temperature abuse occur after a radiation treatment. Therefore, irradiated mechanically deboned chicken meat should be properly refrigerated and protected against contamination.     

Characterization of Minced Meat Extracted from Blue Crab Picking Plant By-Products

Blue crab meat was mechanically extracted from picking-room byproducts to produce the following minced meat yields: 3.18%, white; 10.71%, mixed; 6.39%, claw, and 2.62%, leg. Each meat had distinct visual, textural, and flavor attributes. Aerobic plate counts of unpasteurized minced meat ranged from 10⁵ to 10⁷ CFU/g. Extraction within 1.5 hours of picking or icing of by-products prior to mechanical extraction stabilized microbial levels. Meat pasteurized at 80.6°C darkened or blued significantly less than meat processed at 83.3°C. Addition of citric acid-phosphate buffer to meat pasteurized at 80.6°C further reduced darkening of meats.     

Possible role of volatile amines as quality-indicating metabolites in modified atmosphere-packaged chicken fillets: Correlation with microbiological and sensory attributes

The present work evaluated the possible role of volatile amines as indicator(s) of poultry meat spoilage. Fresh chicken meat (breast fillet) was packaged in four different atmospheres: air (A), vacuum (VP) and two modified atmospheres (MAs), namely M1, 30%/65%/5% (CO₂/N₂/O₂) and M2, 65%/30%/5% (CO₂/N₂/O₂). All chicken samples were kept under refrigeration (4 ± 0.5 °C) for a period of 15 days. Of the four treatments, the VP and M1 and M2 gas mixtures were the most effective for delaying the development of aerobic spoilage microbial flora. Pseudomonas spp. in chicken samples stored under M2 gas mixture and VP were significantly lower than all the other samples after 15 days of storage. Of the remaining bacterial species examined, lactic acid bacteria (LAB), Brochothrix thermosphacta, were dominant in the microbial association of both aerobically- and MA-packaged chicken, while yeasts contributed to a much lesser extent in the final microbial flora of chicken meat. On the basis of microbiological data (TVC), shelf-life extensions of 2, 4 and 9–10 days were achieved by VP and M1 and M2 gas mixtures. Results of the present work showed that the limit of sensory acceptability (a score of 6) was reached for the aerobically, vacuum-packaged and M1 gas mixture chicken samples approximately on days 6–7 and 9–10, respectively. Based on sensory (taste) analysis and with regard to chicken spoilage and freshness, TMA-N and TVB-N limit values of acceptability, namely 10.0 mg N/100 g and 40 mg N/100 g for chicken samples stored in air, may be proposed as the upper limit values for spoilage initiation of fresh chicken meat stored aerobically. Interestingly, the M2 gas mixture sample did not reach these limit values throughout the 15 day storage period. The formation of volatile amines during chill storage of chicken meat, under the packaging conditions examined in the present study, seemed to be in good agreement with the increase in microbiological count (TVC) and sensory taste score except for the M2 gas mixture.     

Microbial growth and colour of minimally processed shiitake mushroom stored at different temperatures

The effect of storage temperature on the microbiological and sensory characteristics of minimally processed shiitake was investigated. Shiitake mushrooms were washed, sanitised, packed in polystyrene trays, overwrapped with plastic film and stored at 7, 10 or 15 °C. Microbial counts, polyphenoloxidase activity, external lightness ( L* ) and acceptance tests were conducted. Mesophilic, aerobic psychrotrophic bacteria, yeasts and moulds predominated during storage. Pseudomonas was detected after 10 days' storage showing an increase of, approximately, 7 log cycles at 15 °C. Mushroom rejection occurred when the microbial population was lower than 10⁶ CFU g⁻¹, suggesting that, other factors, such as browning, affect mushroom spoilage more than microbial activity. Mushrooms treated with citric or ascorbic acids maintained high L * value during 10 days. The shelf life of minimally processed shiitake mushrooms was 10 days at 7 °C, but less than 5 days at 10 °C, and approximately 3 days at 15 °C.     

SALT PREBLENDING AND INCORPORATION OF MECHANICALLY DEBONED CHICKEN MEAT IN SMOKED SAUSAGE

A smoked sausage product was made by incorporating mechanically deboned poultry meat (MDPM) without skin in combination with a 3:1 pork:beef mixture. The ratio of MDPM to pork:beef was 10:90, 30:70, 50:50 and 70:30. Effects of preblending the meat components 24 h prior to mixing and stuffing were also studied. The sausages were evaluated for proximate composition, cook yield and sensory acceptability. As the level of MDPM increased objective and sensory textural attributes of cohesiveness increased (P < 0.05) while firmness decreased. Preblending increased the firmness and chewiness of smoked sausages (P < 0.05). Sausages in all treatment combinations were well accepted by the sensory panelists, with a score of 6.9 or higher for overall reaction on a scale from 0 to 10, 10 being the most desirable.     

Development of Sausages Containing Mechanically Deboned Chicken Meat Hydrolysates

Pork meat sausages were prepared using protein hydrolysates from mechanically deboned chicken meat (MDCM). In terms of the color, compared to the controls before and after storage, the redness (a*) was significantly higher in sausages containing MDCM hydrolysates, ascorbate, and sodium erythorbate. After storage, compared to the other sausage samples, the yellowness (b*) was lower in the sausages containing ascorbate and sodium erythorbate. TBARS was not significantly different among the sausage samples before storage, whereas TBARS and DPPH radical scavenging activities were significantly higher in the sausagescontainingascorbate and sodium erythorbate, compared to the other sausage samples after 4 wk of storage. In terms of sensory evaluation, the color was significantly higher in the sausages containing MDCM hydrolysates, ascorbate, and sodium erythorbate, compared to the other sausage samples after 4 wk of storage. The “off‐flavor” and overall acceptability were significantly lower in the sausages containing MDCM hydrolysates than in the other sausage samples.     

The quality evaluation of frankfurter-type sausages from hand and mechanically deboned turkey meat

Zusammenfassung Im Rahmen dieser Untersuchungen wurde die Qualitätsbewertung von Brühwürsten aus verschiedenem hand- oder mechanisch entbeintem Putenfleisch durchgeführt. Es wurde festgestellt, daß das mechanisch entbeinte Putenfleisch ein ausgezeichneter Rohstoff für die Brühwurstherstellung ist, obwohl zwischen beiden (hand- oder mechanisch) Fleischarten Unterschiede bestehen. Die minderwertigste Qualität zeigten Brühwürste, die aus mechanisch entbeinten Putenschwingen oder Putenknochen mit Haut hergestellt wurden.

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The quality evaluation of frankfurter-type sausages from hand and mechanically deboned turkey meat

Summary A quality evaluation was made of frankfurter-type sausages made from hand and mechanically deboned meat from various parts of turkey carcasses. The results led to the conclusions that despite some differences in objective measurements of the sausage quality, mechanically deboned turkey meat can be considered as an exclusive meat raw material for the production of frankfurter-type sausages. The quality of sausages from mechanically deboned turkey meat from wings and frames with skin was the least satisfacory.

     

EARLY DETECTION OF CLOSTRIDIUM PERFRINGENS ENTEROTOXIN AND ITS RELATIONSHIP TO SENSORY QUALITY OF COOKED CHICKEN

Growth, sporulation, and enterotoxin formation by Clostridium perfringens NCTC 8239 were determined in chicken thigh meat incubated at 45°C for 1.5 h and 37°C for up to 12.5 h. With an inoculum of 10⁶ vegetative cells per g, the cell counts reached mean log ₁₀ 7.32/g after 6 h of incubation and remained in that range through 14 h. Heat-resistant spores (log₁₀ 2.48/g) were first detected at 4 h, and the number increased to log₁₀ 5.19/g at 14 h. Enterotoxin (0.19 μg/g) was first detected after 2 h of incubation (1.5 h at 45°C and 0.5 h at 37°C) in the absence of detectable sporulation, and the enterotoxin concentration increased to 0.76 μg/g after 14 h. Significant differences (p < 0.01) in the odor, color, and texture scores for inoculated versus uninoculated cooked chicken following 2 h incubation correlated with the production of enterotoxin and suggested that these parameters could be used as indices of chicken spoilage by C. perfringens.     

Anti-oxidant activity of added tea catechins on lipid oxidation of raw minced red meat, poultry and fish muscle

The comparative anti-oxidative effects of added tea catechins (TC) and α-tocopherol to raw minced red meat (beef and pork), poultry (chicken, duck and ostrich) and fish (whiting and mackerel) muscle on susceptibility to lipid oxidation were investigated during 10 days of refrigerated (4 °C) display. Fresh meats, poultry and fish, purchased from a local market, were trimmed to remove bones, skin and surface fat and minced through a 4 mm plate. The minced muscle of each species was treated with either the addition of 300 mg TC kg^–1 minced muscle (TC300) or 300 mg α-tocopherol kg^–1 minced muscle (VE300). Minced muscle without any additives served as control (C). Oxidative stability (TBARS) was measured at 3-day intervals. Total lipids, fatty acid composition, total iron and haem iron from minced muscle for each species were also analysed. The susceptibility of untreated minced muscle to lipid oxidation was in the decreasing order: mackerel > beef > duck > ostrich > pork ≥ chicken > whiting. This may be because of the different content of total fat, iron and fatty acid composition between species. The TC300 significantly ( P  < 0.05) reduced lipid oxidation compared with controls for all seven species as shown by lower TBARS values. The anti-oxidant potential of TC was two to fourfold greater than that of α-tocopherol at the same concentration and this potential was species dependent. The VE300 showed limited capacity in inhibiting lipid oxidation for pork, chicken, duck and whiting. The results obtained show that TCs are powerful natural antioxidants when used in minced muscle food.     

The Effect of Inhibitors and High Pressure Treatment to Prevent Melanosis and Microbial Growth on Chilled Prawns (Penaeus japonicus)

ABSTRACT: Ascorbic acid, citric acid, sodium benzoate, kojic acid, and 4-hexylresorcinol were evaluated alone and in combination as inhibitors of melanosis and microbial spoilage in prawns ( Penaeus japonicus ) under non-pressure and high-pressure conditions. Sodium benzoate and kojic acid was an effective combination for the inhibition of prawn melanosis. Alone and in combination with ascorbic or citric acid, 4-hexylresorcinol proved the most effective as inhibitors of melanosis and microbial spoilage in prawns. High-pressure treatment appeared to increase the melanosis process, but it did not alter the effect performed by inhibitors. Lower total count of microorganisms seemed to be obtained with the presence of ascorbic and citric acids under high-pressure treatment.     

Antioxidant Properties of Rosemary Oleoresin in Turkey Sausage

Rosemary oleoresin (20 ppm) was used as an antioxidant in turkey breakfast sausages prepared with 75% hand deboned turkey meat and 25% mechanically deboned turkey meat. It was compared to similarly formulated products with butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT, 200 ppm) and a control with no antioxidants. 2-Thiobarbituric acid-reactive substances in samples stored at 4°C demonstrated that rosemary oleoresin was comparable to a commercial blend of BHA/BHT/citric acid in suppressing lipid autoxidation. Sensory analysis was in agreement with these results. Analysis of volatile aroma compounds revealed the occurrence of oxidatively derived carbonyls in the sausages without antioxidants, while the antioxidant-treated sausages were essentially free from these carbonyls.     

QUALITY AND STORAGE STABILITY OF FRANKFURTERS CONTAINING 15% MECHANICALLY DEBONDED TURKEY MEAT

SUMMARY –Fresh and frozen stored mechanically deboned turkey meat was incorporated into frankfurters at the 15% level and compard to red meat frankfurters. Mechanically deboned turkey meat exhibited higher emulsifying capacity than beef but lower than pork on a protein basis. This trend for emulsifying capacity was reversed when reported on a total meat basis. Emulsion stability was not essentially affected by the addition of 15% mechanically deboned turkey meat in red meat frankfurters. Differences flavor tests, preference flavor tests, and TBA values indicated that frankfurters containing 15% mechanically deboned turkey meat were comparable to all red meat frankfurters in flavor stability if fresh deboned poultry meat is used. The use of mechanically deboned poultry meat, which had undergone 90 days of frozen storage, resulted in a significantly inferior product as indicated by flavor evaluation and TBA values. Color evaluation showed slight color fading of all frankfurter treatments during storage. Microbial loads in the three frankfurther treatments showed some increased in total counts during refrigerated storage.