Evaluation of the Antioxidant Potential of Hyssop (Hyssopus officinalis L.) and Rosemary (Rosmarinus officinalis L.) Extracts in Cooked Pork Meat

ABSTRACT: The objective of this work was to study the ability of rosemary and hyssop extracts to inhibit lipid oxidation and metmyoglobin formation in pork meat, thereby stabilizing meat color. We also evaluated their effects on iron release from the heme moiety of pork meat. Meat samples were blended with hyssop and rosemary extracts and cooked. The cooked meat was chopped into pieces and stored for 8 d at 4 °C. Heme iron, TBA values, metmyoglobin percentage, and meat color were calculated. Hyssop and rosemary were seen to inhibit lipid oxidation and degradation of heme pigments caused by cooking and storage. Both spices delayed metmyoglobin formation and stabilized the red meat color during storage of the cooked meat.     

Role of Reduced Hemochromes in Pink Color Defect of Cooked Turkey Rolls

Reflectance and absorbance spectrophotometric studies on commercial and laboratory samples showed that the pigments responsible for a pink color defect sometimes observed in freshly cut surfaces of cooked turkey rolls were reduced hemochromes, possibly nicotinamide-denatured globin hemochromes, rather than nitrosyl pigments. Oxidation-reduction potential measurements of meat systems showed that hemochrome formation was promoted by reducing conditions and prevented by oxidizing conditions. All constituents necessary for the production of pink color defect were present in turkey meat. The variable most affecting its appearance was the redox potential of the meat.     

Quantitative Detection of Poultry in Cooked Meat Products

ABSTRACT: There is a growing awareness of perceived harm from meat species adulteration, both intentional and accidental. The present study developed a monoclonal antibody (Mab)-based enzyme-linked immunosorbent assay (ELISA) for the quantitative detection of chicken and turkey meat adulterated in cooked (100 °C, 15 min) mammalian meat. The specificity of Mab 5D2 to different species (pork, beef, lamb, deer, horse, duck, chicken, and turkey) and tissues (serum, gizzard, heart, and liver) was studied by noncompetitive ELISA. The detection of cooked chicken in beef, and turkey in pork was accomplished by competitive and noncompetitive ELISAs. Both ELISAs were optimized to quantify cooked poultry in red meats. The new Mab-based ELISAs enabled the detection of cooked poultry in red meats at levels as low as 1% (v/v) or better. The correlation ( r > 0.994) between chicken or turkey concentrations and ELISA signals permitted the quantification of poultry adulterants in cooked non-poultry meats.     

Effect of irradiation and packaging conditions after cooking on the formation of cholesterol and lipid oxidation products in meats during storage

The effect of irradiation and packaging conditions on the content of cholesterol oxidation products (COPs) and lipid oxidation in cooked turkey, beef, and pork during storage was studied. Ground turkey leg, beef, and pork were cooked, packaged either in oxygen-permeable or oxygen-impermeable bags, and irradiated at 0 or 4.5 kGy. Lipid oxidation and COPs were determined after 0 and 7 days of storage at 4°C. Packaging of cooked meat was more important than irradiation in developing COPs and lipid oxidation in cooked meats during storage. 7-Hydroxycholesterol, 7β-hydroxycholesterol, β-epoxide, and 7-ketocholesterol were among the major COPs formed in cooked turkey, beef, and pork after storage, and their amounts increased dramatically during the 7-day storage in aerobic conditions. Irradiation had no significant effect on the amounts of any of the COPs found in cooked turkey and beef, but increased (P<0.05) the amounts of - plus 7β-hydroxycholesterol, β-epoxide, 7-ketocholesterol, and total COPs in aerobically packaged cooked pork. The amounts of COPs and lipid oxidation products (TBARS) closely related to the proportion of polyunsaturated fatty acids in meat. The results indicated that the composition of fats in meat is important on the oxidation rates of lipids and cholesterol, and packaging is far more important than irradiation in the formation of COPs and lipid oxidation in cooked meat.     

Extraction of Pigments from Mechanically Deboned Turkey Meat

Several extraction procedures were tested to lighten the color and improve textural characteristics of mechanically deboned turkey meat. An extensive extraction of heme pigments was achieved when 0.04M phosphate buffer with a pH of 8.0 was used. Lightness of MDTM increased by 51. I%, redness decreased by 64.0%, and yellowness increased by 26.0% over untreated raw MDTM when measured objectively. Sensory analyses of cooked patties made from extracted MDTM from necks and ground turkey breast indicated that breast meat products could be formulated with 5–20% washed MDTM without significantly affecting overall sensory quality.     

Meat species identification and Halal authentication using PCR analysis of raw and cooked traditional Turkish foods

The method performance characteristics of commercially available PCR kits for animal species identification were established. Comminuted meat products containing different levels of pork were prepared from authentic beef, chicken, and turkey. These meat products were analysed in the raw state and after cooking for 20 min at 200 °C. For both raw and cooked meats, the PCR kit could correctly identify the animal species and could reliably detect the addition of pork at a level below 0.1%. A survey of 42 Turkish processed meat products such as soudjouk, salami, sausage, meatball, cured spiced beef and doner kebap was conducted. Thirty-six samples were negative for the presence of pork (< 0.1%) and four were found to be correctly labelled as containing pork. However, one sausage sample was labelled as containing 5% beef, but beef DNA was not detected and a meatball sample labelled as 100% beef was found to contain chicken. Another turkey meatball sample was predominantly chicken.     

Acceptance and Species Identification of Turkey Steaks Prepared with Beef, Pork, Lamb, and Turkey Fat

Fabricated extruded steaks were prepared from turkey meat, salt, phosphate, and water plus 15% beef, pork, lamb, or turkey fat. The grilled samples recieved relatively high hedonic scores from a sensory panel. The flavor, juiciness, and overall quality of the samples made with pork, beef, and turkey fat were preferred significantly over the samples made with lamb fat. Panel members tended to consider all samples as being pork flavored. Beef, pork, or turkey fat could be used as the fat in a fabricated, extruded steak without affecting the relative acceptability of the cooked product.     

Identification of meat species by TaqMan-based real-time PCR assay

In this study, a convenient, sensitive and specific real-time PCR assay was described for the species identification and their quantification in raw and cooked meat products. Specific primers and TaqMan probes were designed on the mitochondrial ND2, ND5 and ATP 6-8 genes for donkey, pork and horse, respectively, and the performance of the method was tested. In the results, no cross-reaction was observed between the donkey and pork species specific primer-probe systems and non-target species (bovine, ovine, chicken and turkey). Only one cross reaction was observed between the horse species specific primer-probe set and 100 ng pork DNA at the ct 33.01 level (corresponding to 0.01 ng horse DNA). The real-time quantitative assay used in this study allowed the detection of as little as 0.0001 ng template DNA from pure meat for each species investigated and experimental meat mixtures. In conclusion, it can be suggested that the TaqMan probe assay used in this research might be a rapid and sensitive method for the routine meat species identifications studies in raw or cooked meat products.     

Growth/survival of natural flora and Aeromonas hydrophila on refrigerated uncooked pork and turkey packaged in modified atmospheres

To evaluate the growth/survival of natural flora and Aeromonas hydrophila on refrigerated normal low (pork) and high (turkey) pH meats packaged in modified atmospheres, A. hydrophila was inoculated onto fresh pork and turkey meat slices. Inoculated and control samples were packaged in modified atmospheres (100% N₂, 20/80 and 40/60 CO₂/O₂) or in air in plastic bags and kept at 1 and 7°C. Samples packaged in air showed a similar microbiological pattern to that usually observed in fresh meat stored aerobically. Packaging in modified atmosphere produced a strong inhibition of bacterial growth at 1°C, particularly in samples stored in CO₂/O₂enriched atmospheres. Aeromonas hydrophila grew on turkey and pork meat stored in 100% N₂at 1 and 7°C. Likewise, growth of this bacterium was detected on turkey stored in 20/80 CO₂/O₂at 7°C. No growth was observed in 40/60 CO₂/O₂in any meat at both temperatures assayed.     

Effect of Antioxidants and Cooking on Stability of n-3 Fatty Acids in Fortified Meat Products

ABSTRACT: This study was carried out to determine the effect of processing and cooking on n-3 polyunsaturated fatty acid (PUFA) stability and to determine the efficacy of antioxidants (ANTI) to minimize lipid oxidation in cooked n-3 PUFA-fortified meat products. An emulsion of n-3 PUFAs (25% algal oil) was incorporated into ground turkey, pork sausages, or restructured hams (500 mg n-3 PUFA/110 g meat) with or without an "antioxidant cocktail" containing citrate (0.5% w/w), erythorbate (1 g/kg product), and rosemary (0.2% w/w). Ground turkey and pork sausages were frozen 2 d, then cooked to 71°C, and stored at 4°C for 2 d. Cooked, restructured hams were sliced, vacuum packaged, and stored at 4°C, or frozen and thawed with subsequent storage at 4°C. Treatments were CON (control), n-3 (n-3 PUFAs), CON + ANTI and n-3 + ANTI. Products were analyzed for color, lipid oxidation (TBARS and peroxide values), and n-3 PUFA profile. TBARS of n-3 PUFA-fortified treatments in ground turkey and pork sausages increased with storage ( P < 0.05); there were no changes in TBARS for CON + ANTI and n-3 + ANTI groups ( P > 0.05). For restructured hams nitrite curing appeared to delay lipid oxidation such that antioxidant treatment effects were unobservable ( P > 0.05). Overall recovery of n-3 PUFAs after heat processing was 69% to 85%, and there was no effect of storage on n-3 PUFA concentration in raw or cooked products ( P > 0.05). Sensory scores for n-3 treated restructured hams were lower than controls ( P < 0.05). Results suggested that cooking resulted in some losses of n-3 PUFAs in fortified meat products and that an "antioxidant cocktail" protected against lipid oxidation during subsequent storage in non-cured meat products.     

Residual glutamic-oxaloacetic transaminase (GOT) activity in thermally processed poultry and poultry products as an indicator of end-point temperatures

Glutamic-oxaloacetic transaminase (GOT) activities in chicken and turkey thigh and breast meat samples, thermally processed at 60–84°C in a model heat-treating system, were evaluated for use as indicators of end-point cooking temperatures (EPT). Wings, breasts, thighs and legs from commercially cooked, whole, roasted chickens and commercially processed products containing chicken and turkey meat were analyzed also to determine if residual GOT activities would indicate compliance with recent FDA/FSIS EPT recommendations. Activities of samples processed in the model system decreased logarithmically with increasing temperatures. GOT activities were higher (P < 0·05) in thigh meat than breast meat in both chicken and turkey samples; activities were higher in turkey than chicken. GOT values for chicken thigh and breast meat at 74°C, the FDA/FSIS recommended EPT for use by food handlers and retailers, were 735 and 164 Sigma-Frankel units ml^?1 (SFU ml^?1), respectively. Values for turkey thigh and breast meat at this temperature were 1080 and 450 SFU ml^?1, respectively. The range of activities was 7–13 SFU ml^?1 in commercially prepared chicken products and 27–161 SFU ml^?1 in turkey products. Analysis of these products showed adequate cooking and compliance with FDA/FSIS recommended EPT for retail sale. These data indicate that residual GOT activity in processed poultry has potential for use as an indicator of EPT.     

Production and partial characterization of monoclonal antibodies specific to cooked poultry meat

Monoclonal antibodies (MAbs) specific to cooked poultry muscle proteins have been developed for the detection of poultry adulterants in cooked mammalian meat. Saline (0.85% NaCl) extract of heat-treated (100 °C, 15min) chicken muscle proteins was used to immunize mice for MAb development. The specificity of MAbs was tested against chicken antigen and protein extracts from seven other meat species (pork, beef, lamb, deer, horse, turkey and duck) by indirect enzyme-linked immunosorbent immunoassay (ELISA). The immunogenic components in the poultry protein extracts were determined by SDS-PAGE followed by immunoblotting. A total of six hybridoma cell lines that secrete IgG class MAbs have been developed: MAbs 3E12 and 1A5 were able to distinguish between cooked poultry and mammalian meats, MAbs 9C6 and 6F7 reacted strongly with cooked chicken only, and MAbs, 5D2 and 6G8, reacted with both cooked turkey and chicken but not other species. All six MAbs demonstrated a proportional increased ELISA response to respective adulterated poultry samples in pork over a 0-100% range of aduleration.     

Selective effect of the product type and the packaging conditions on the species of lactic acid bacteria dominating the spoilage microbial association of cooked meats at 4°C

The product type was shown to strongly affect the growth rate and the composition of the spoilage lactic flora during refrigerated (4°C) storage of cooked, cured meats, sharing their processing plant environment, day of production and film packaging conditions. Growth of lactic acid bacteria (LAB) under vacuum was more prolific on the product in the order: ham>turkey breast fillet>smoked pork loin>pariza>mortadella>bacon, and ham>frankfurters, manufactured in two industrial meat plants A and B, respectively. The Lactobacillus sakei/curvatus group prevailed in all products, except the non-smoked, boiled whole-meats, i.e. cooked ham and turkey breast fillet, where Leuconostoc mesenteroides subsp.mesenteroides predominated. Lactobacillus sakei was by far the most prevalent species in smoked whole-meats, i.e. pork loin and bacon. Emulsion sausages, i.e. pariza, mortadella and frankfurters, contained a more diverse lactic flora.Leuconostoc carnosum and Lc. citreum occurred in boiled, whole-meats and emulsion sausages, respectively.Weissella viridescens was isolated from smoked meat products only. A very good correlation between the LAB growth and types and important intrinsic factors, such as the product pH, moisture, salt (brine) concentration and cooking method could be observed. When ham and frankfurters from plant B were stored in air, yeasts and mainly Brochothrix thermosphacta became important members of the spoilage association. Growth of LAB was faster in air. The presence of oxygen resulted in a replacement ofLc. mesenteroides subsp. mesenteroides by other Leuconostoc spp. in ham, and in a shift of the spoilage flora from homo- to heterofermentative LAB species in frankfurters.     

Effects of Endpoint Temperature on the Internal Color of Pork Patties of Different Myoglobin Form, Initial Cooking State, and Quality

ABSTRACT: :The effects of several parameters on the development of internal cooked color in ground pork were evaluated. Patties were made from normal or pale, soft, and exudative (PSE) pork and the pigment converted to either oxymyoglobin or deoxymyoglobin. Patties from these 4 treatment combinations were cooked from the frozen or thawed states to 5 endpoint temperatures. PSE patties and those containing oxymyoglobin exhibited premature browning as they appeared cooked and were more (P < 0.05) tan at lower temperatures than normal patties or those with deoxymyoglobin which had a slightly pink internal color at 71 °C. Percentage myoglobin denaturation increased as cooking temperatures increased (P < 0.05) for both types of meat and was greater in patties containing deoxymyoglobin than in those with oxymyoglobin. Patties cooked frozen had lower a* values (P < 0.05) than thawed patties at every endpoint temperature.     

Carbon Monoxide as a Colorant in Cooked or Fermented Sausages

ABSTRACT:  The study aimed at substituting nitrite with carbon monoxide (CO) in cooked or fermented meat batter products by investigating color and color stability in myoglobin solutions, model meat systems, and full-scale hotdog and salami sausages of pork and beef. For cooked model meat systems and hotdogs at 75 to 80 °C core temperatures, direct flushing with a 1% CO gas mixture during the last stage of the batter chopping produced an initial red color equal to nitrite or more intense than with nitrite. For fermented model meat systems and salami sausages with a final pH of 4.7, pretreatment and storage of ground raw meat in a 1% CO mixture, and later use of the pretreated meat in batters, also formed an initial red color in the final products. The color stability during air and light display of cooked and fermented meat products with CO was inadequate compared to products with nitrite, although the red color of CO products was largely maintained by anaerobic packaging and storage. Spectra of carboxy- and nitrosomyoglobin at pH 4.7 demonstrated higher absorbance for carboxymyoglobin.     

Characterization of Extended Spectrum Β‐Lactamase Producing Enterobacteria and Methicillin‐Resistant Staphylococcus aureus Isolated from Raw Pork and Cooked Pork Products in South China

In this study, we assessed the co‐colonization with extended spectrum β‐lactamase producing Enterobacteria (ESBL‐E) and methicillin‐resistant Staphylococcus aureus (MRSA) in raw pork and cooked pork products in south China. In total, 240 raw pork and 240 cooked pork samples collected from supermarkets (n = 20) and local butcher shops (n = 20) in the city of Guangzhou (China) were investigated. Raw pork and cooked pork was more frequent colonization with ESBL‐E (7.5% in raw pork and 0.4% in cooked pork products) than with MRSA (4.2% in raw pork). Two of samples were contaminated with both tested types of multidrug‐resistant bacteria. High antibiotic‐resistance rate with wide spectrums of both ESBL‐E and MRSA isolated were observed. In ESBL‐E isolates, TEM (n = 15), CTX‐M‐1 (n = 3), CTX‐M‐9 (n = 1), and SHV (n = 1) genes were detected. TEM and SHV genes were associated with CTX‐M‐1 in 2 isolates, respectively. The CTX‐M‐9 gene of 1 isolate from cooked pork samples was found to be transferred to Escherichia coli J53 by conjugation. Detected MLST‐types of MRSA were livestock‐associated ST7 (n = 5) and ST9 (n = 4), as well as hospital‐acquired ST239 (n = 1), suggesting contamination from human source(s) during meat processing. These findings confirmed a contamination of raw pork and cooked pork with ESBL‐E and MRSA and emphasized the necessity of enforcing hygienic practices and specific detection of MRSA and ESBL‐producing bacteria in meat processing and storage.     

Consumers' sensory acceptability of pork from immunocastrated male pigs

Boar taint is the off-odour or off flavour of cooked pork. Currently, the most common method of controlling boar taint is surgical castration. However, immunocastration has been used in some parts of the world as an alternative to surgical castration. The aim of this study was to evaluate the sensory acceptability of meat from immunocastrated pigs (IM) compared with meat from females (FE), surgically castrated (CM) and entire males (EM). Twenty animals of each type were evaluated by 201 consumers in 20 sessions. Longissimus thoracis muscle of the different animals was cooked in an oven at 180 °C for 10 min. Consumers scored the odour and the flavour of the meat in a 9-point category scale without an intermediate level. There were no significant differences in consumer’s evaluation of meat from IM, CM, and FE. In contrast, EM meat presented a higher percentage of dissatisfied scores and was significantly (P < 0.05) less accepted than meat from CM, IM and FE. Consumers’ acceptability of EM meat was always lower, independently of its androstenone levels. However meat with low levels of androstenone was more accepted that meat with medium or high levels of this substance. It can be concluded that immunocastration produced pork that was accepted by the consumers, and was indistinguishable from pork from CM or FE.     

Identification of chicken,duck, pigeon and pig meat by species-specific markers of mitochondrial origin

In the present study, PCR based method for meat species identification of chicken, duck, pigeon and pig was achieved by developing species-specific markers. Using mitochondrial sequences species-specific primers were designed and the sizes of them were 256 bp, 292 bp, 401 bp and 835 bp for chicken, duck, pigeon and pig, respectively. The species-specific PCR products were sequenced to confirm the specificity of the product amplified. These markers were subsequently tested for cross amplification by checking them with beef, mutton, chevon, pork, rabbit, chicken, duck, turkey and pigeon meat. DNA markers developed in this study can help identify the species of fresh, cooked and autoclaved meat of chicken, duck and pigeon and fresh and cooked meat of pig. The process of identification is simple, economical and quick as compared to other methods such as RAPD, PCR-RFLP and sequencing method of species identification.     

Color Characteristics of Irradiated Vacuum-Packaged Pork, Beef, and Turkey

Changes in color of irradiated meat were observed to be species-dependent. Irradiated pork and turkey became redder due to irradiation but irradiated beef a* values decreased and yellowness increased with dose and storage time. The extent of color change was irradiation dose-dependent and was not related to myoglobin concentration. Visual evaluation indicated pork and turkey increased in red ness whereas beef decreased in redness as dose levels increased. Reflectance spectra showed that irradiation induced an oxymyoglobin-like pigment in pork and that both oxymyoglobin and metmyoglobin developed in beef as a result of irradiation.     

Myoglobin Analysis for Determination of Beef, Pork, Horse, Sheep, and Kangaroo Meat in Blended Cooked Products

This method allows the concurrent detection of several types of animal muscle meat in comminuted, cooked meat products. Meat proteins were dissolved in a solvent containing 8M urea and dithioerythritol and separated by electrofocusing on an ultra-thin polyacrylamide gel, containing urea. The proteins were then transferred to nitrocellulose by electroblotting and the blot was incubated with anti-human myoglobin serum, a linking antibody, peroxidase-antiperoxidase (PAP) immune complex, and enzyme-substrate. Detection of less than 10% pork, horse and sheep meat was possible in a beef-based meat product which had been heated to an internal temperature of 120°C for 5 min. The method is not suitable for detection of chicken and turkey meats.