Effects of irradiated phytic acid on antioxidation and color stability in meat models

Lipid oxidation and color stability of meats treated with irradiated phytic acid were investigated during storage for 2 weeks at 4 degrees C. The phytic acid in deionized distilled water (DDW) was degraded by irradiation at 10 and 20 kGy, and the irradiated phytic acid showed a strong antiradical activity. For measuring the antioxidant effects of irradiated phytic acid in food models, beef and pork were prepared with DDW (control), irradiated (10 and 20 kGy) or non-irradiated phytic acid, and ascorbic acid as a model system. Irradiated phytic acid significantly inhibited the lipid oxidation in meats compared to the control and ascorbic acid treated samples during storage (P < 0.05). The redness of the meats treated with phytic acid had a higher value than did the control and ascorbic acid treated samples, but a significant difference was not observed in the samples treated with phytic acid regardless of irradiation treatment. Irradiated phytic acid was also effective in inhibiting the loss of heme iron and metmyoglobin formation during storage. Results indicated that irradiation might be helpful for improving the antioxidant activity of phytic acid in meats.     

Influence of different dietary doses of n-3- or n-6-rich vegetable fats and alpha-tocopheryl acetate supplementation on raw and cooked rabbit meat composition and oxidative stability

This study evaluates the effects of replacing beef tallow added to rabbit feeds (3% w/w) by different doses (0%, 1.5% and 3% w/w) of n-6- or n-3-rich vegetable fat sources (sunflower and linseed oil, respectively) and alpha-tocopheryl acetate supplementation (0 and 100 mg/kg) on the fatty acid composition, alpha-tocopherol content, and oxidation levels [assessed by analyzing thiobarbituric acid (TBA) and lipid hydroperoxide values] in rabbit meat. We also measured these parameters after cooking and refrigerated storage of cooked rabbit meat. Both dietary alpha-tocopheryl acetate supplementation and the dose and source of fat added to feeds influenced meat fatty acid composition, modifying the n-6/n-3 ratio, which was more nutritionally favorable when linseed oil was used. Furthermore, the addition of linseed oil and the supplementation with alpha-tocopheryl acetate enhanced long-chain PUFA biosynthesis. However, the addition of 3% linseed oil increased meat oxidation, and although it was reduced by dietary supplementation with alpha-tocopheryl acetate in raw meat, this reduction was not as effective after cooking. Therefore, dietary supplementation with 1.5% linseed oil plus 1.5% beef tallow and with alpha-tocopheryl acetate would be recommended to improve the nutritional quality of rabbit meat.     

Effect of electron beam irradiation and storage at 5 degrees C on thiobarbituric acid reactive substances and carbonyl contents in chicken breast meat infused with antioxidants and selected plant extracts

This study evaluated the effectiveness of synthetic and natural antioxidants, green tea, commercial grape seed extracts/combinations, and TBHQ, with varying concentrations of lipid oxidation of nonirradiated and irradiated chicken breast meats stored at 5 degrees C for 12 days. Fresh boneless and skinless chicken breast meats were vacuum-infused with varying concentrations of antioxidants: green tea, grape seed extracts alone/in combination, and TBHQ. The irradiation dosage was 3.0 kGy. Carbonyl values of raw chicken meat and thiobarbituric acid reactive substances (TBARS) values of raw and cooked chicken meat were determined for 0-12 days at 5 degrees C storage. TBARS values for 0-12 days of storage at 5 degrees C ranged from 1.21 to 7.3 and 1.22 to 8.51 mg malondialdehyde/100 g chicken for nonirradiated and irradiated raw chicken, respectively. TBARS values of cooked chicken ranged from 2.19 to 35.83 and 2.45 to 45.72 mg malondialdehyde/100 g chicken for nonirradiated and irradiated chicken, respectively. Irradiation increased TBARS values of both controls and plant extracts. The carbonyl content in meat lipid ranged from 1.7 to 2.9 and 1.7 to 4.41 micromol acetophenone/10 g of nonirradiated and irradiated chicken meat, respectively, and meat protein ranged from 1.4 to 2.07 and 1.41 to 2.72 micromol/10 g meat. Infusion of chicken meat with selected plant extracts is an effective method to minimize lipid oxidation and volatiles developments caused by irradiation.     

Honey as a protective agent against lipid oxidation in ground turkey.

Lipid oxidation is a major deteriorative factor in meats. Sources of natural antioxidants that are as effective as commercially available antioxidants are desired. The objective of this research was to investigate honey as an inhibitor of lipid oxidation in ground poultry. The antioxidant content of different varieties of honey was investigated spectrophotometrically and honey's effectiveness in reducing oxidation of ground poultry determined by monitoring thiobarbituric acid reactive substances (TBARS). Buckwheat honey had the highest antioxidant content and acacia honey the lowest. Honeys of different floral sources differed in their protection against lipid oxidation. Buckwheat honey (5%, w/w) reduced TBARS approximately 70%, whereas acacia honey reduced TBARS approximately 34% at 3 days of storage at 4 degrees C. In comparison to butylated hydroxytoluene and tocopherol (0.02% of total fat), honey (at 5% of the weight of the meat) was much more effective at preventing oxidation. Honey has great potential as an antioxidant source and may result in greater acceptability of meat products and prevent negative health implications of oxidized meats.     

Preventing lipid oxidation during recovery of functional proteins from herring (Clupea harengus) fillets by an acid solubilization process

It has previously been found that a process based on solubilization at pH 2.7 gives high yields of herring muscle proteins with good functionality. In this study, the development of lipid oxidation during acid processing of herring mince was studied. It was tested how modifications of the process conditions and/or additions of antioxidants could prevent lipid oxidation during the actual process and then during ice storage of the protein isolates. Processing parameters evaluated were prewash of the mince, exposure time to pH 2.7, inclusion or exclusion of a high-speed centrifugation, and addition of antioxidants. Antioxidants tested were erythorbate (0.2%, 9.3 mM), sodium tripolyphosphate (STPP; 0.2%, 5.4 mM), ethylenediaminetetraacetic acid (EDTA; 0.044%, 1.5 mM), and milk proteins (4%). The first three antioxidants were added in the prewash or during the homogenization step, whereas milk proteins were added to the final precipitate. At time 0, all isolates were analyzed for pH, moisture content, and thiobarbituric reactive substances (TBARS). Selected isolates were also analyzed for lipid and protein content. Stability during ice storage was followed in terms of odor, TBARS, and color (a/b values). Extensive lipid oxidation took place using the "control" process without high-speed centrifugation. This was not significantly (p < or = 0.05) affected by a prewash or varied exposure time to pH 2.7. Including high-speed centrifugation (20 min, 10,000g) significantly (p < or = 0.05) reduced TBARS values, total lipids, a values and b values. Erythorbate alone, or in combination with STPP/EDTA, significantly (p < or = 0.05) reduced lipid oxidation during processing if added in the prewash or homogenization step. During ice storage, better stability was gained when antioxidants were added in both of these steps and when EDTA was used instead of STPP.     

Effects of vitamin E supplementation on lipid peroxidation and color retention of salted calf muscle from a diet rich in polyunsaturated fatty acids.

The color of fresh meat is one of the most important quality criteria of raw muscle foods. This red color is principally due to the presence of oxymyoglobin. The present study was undertaken to examine the effect of a diet rich in polyunsaturated fatty acids (PUFA), the addition of NaCl, and the influence of dietary supplementation with vitamin E on calf muscle oxymyoglobin oxidation (color) and lipid peroxidation. Vitamin E was added to the feed at a concentration of 4000 mg/day for 90 days before slaughter. This diet increased the alpha-tocopherol concentration in muscle membrane from 2.6-2.8 to 6.5-7.0 microg/g of fresh weight. It was found that the diet rich in PUFA and, especially, the addition of NaCl increased muscle lipid peroxidation and oxymyoglobin oxidation as indicated by the contents of thiobarbituric acid-reactive substances and substances that impaired color value readings during storage at 4 degrees C. Both undesirable reactions during storage were controlled very efficiently by the presence of a critically high concentration of alpha-tocopherol in the muscle tissues. The findings concerning the antioxidant activity of alpha-tocopherol in this study form additional evidence of its efficient protection against oxidative reactions during storage of muscle tissues and its potential to maintain a high nutritional value in them.     

Ionizing radiation and antioxidants affect volatile sulfur compounds, lipid oxidation, and color of ready-to-eat Turkey bologna

Bologna was processed from ground turkey breast meats containing one of four antioxidant treatments (none, rosemary extract, sodium erythorbate, and sodium nitrite). After it was cooked, the bologna was sliced, sealed in gas impermeable bags, exposed to 0, 1.5, and 3.0 kGy gamma-radiation, and then stored at 5 degrees C for up to 8 weeks. Thiobarbuturic acid reactive substances (TBARS), color, and volatile sulfur compounds were measured every 2 weeks during storage. Irradiation had no consistent effect on TBARS values. The rosemary extract and sodium nitrite inhibited, while erythorbate increased, TBARS values, independent of radiation dose or storage time. Irradiation promoted redness and reduced yellowness of the control (no antioxidant) bologna at weeks 0 and 2. The use of nitrite and rosemary extract inhibited the changes in color due to irradiation. Several volatile sulfur compounds (hydrogen sulfide, methanethiol, methyl sulfide, and dimethyl disulfide), measured using a pulsed flame photometric detector, increased with radiation dose. However, none of the antioxidants had any substantial effect on volatile sulfur compounds induced by irradiation. Our results suggest that antioxidants did not consistently affect irradiation-induced volatile sulfur compounds of turkey bologna although they did significantly impact color and lipid oxidation.     

包装形式对辐照冷却猪肉糜脂肪氧化的影响

本文研究了不同包装形式结合抗氧化剂对辐照冷却猪肉糜(猪五花肉)中脂肪氧化的抑制作用。添加抗氧化剂的冷却猪肉糜分别采取真空包装、无氧包装(N2+CO2)和气调有氧包装(O2+CO2+N2),然后经3kGy低剂量辐照,在4℃±1℃贮藏20d。分别在辐照的第0、5、10、15和20d对冷却猪肉糜脂肪氧化指标TBARS值、过氧化值进行测量。结果表明:添加抗氧化剂并结合真空包装能显著降低辐照猪肉糜中的脂肪氧化。因此在降低辐照及贮藏过程中冷却肉的脂肪氧化方面,真空包装要优于有氧包装。     

Antimicrobial and antioxidant effects of milk protein-based film containing essential oils for the preservation of whole beef muscle

Milk protein-based edible films containing 1.0% (w/v) oregano, 1.0% (w/v) pimento, or 1.0% oregano-pimento (1:1) essential oils mix were applied on beef muscle slices to control the growth of pathogenic bacteria and increase the shelf life during storage at 4 degrees C. Meat and film were periodically tested during 7 days for microbial and biochemical analysis. The lipid oxidation potential of meat was evaluated by the determination of thiobarbituric reactive substances (TBARS). The availability of phenolic compounds from essential oils was evaluated by the determination of total phenolic compounds present in the films during storage. Antioxidant properties of films during storage were also evaluated following a modified procedure of the N,N-diethyl-p-phenylenediamine colorimetric method. Oregano-based films stabilized lipid oxidation in beef muscle samples, whereas pimento-based films presented the highest antioxidant activity. The application of bioactive films on meat surfaces containing 10(3) colony-forming units/cm2 of Escherichia coli O157:H7 or Pseudomonas spp. showed that film containing oregano was the most effective against both bacteria, whereas film containing pimento oils seems to be the least effective against these two bacteria. A 0.95 log reduction of Pseudomonas spp. level, as compared to samples without film, was observed at the end of storage in the presence of films containing oregano extracts. A 1.12 log reduction of E. coli O157:H7 level was noted in samples coated with oregano-based films.     

Inhibition of hemoglobin-mediated oxidation of regular and lipid-fortified washed cod mince by a white grape dietary fiber

The effectiveness of a white grape dietary fiber concentrate (WGDF) against hemoglobin-mediated oxidation of washed cod mince, with and without 10% added herring oil, was evaluated during ice storage. WGDF was added at two different levels: 2 and 4% based on final weight. An ethanol extract with the ethanol extractable polyphenols (EPP) and the ethanol-extracted grape dietary fiber residue were also tested as antioxidants in the washed cod mince. The addition of WGDF to the model system completely and significantly (p 相似文献   

Effect of dietary dried tomato pulp on oxidative stability of Japanese quail meat

Ninety, 21-day-old, Japanese quail (Coturnix coturnix japonica) divided into three groups with five subgroups each were fed a basal diet that served as control or a basal diet containing 5 or 10% of dried tomato pulp (DTP), a byproduct of the tomato-processing industry. The DTP contained lycopene and beta-carotene at 281 and 24.3 mg kg(-)(1) of dry weight, respectively. On day 42 of age, birds were slaughtered, and carcasses were trimmed for breast meat. To assess the effect of dietary treatment on the oxidative stability of raw and cooked meat, raw meat was subjected to iron-induced lipid oxidation, whereas both raw and cooked meats were subjected to refrigerated storage at 4 degrees C. The extent of lipid oxidation was determined on the basis of the malondialdehyde (MDA) formed through the use of third-order derivative spectrophotometry. Results showed that after 6 and 9 days of refrigerated storage, MDA values in raw meat were increased. The increase was higher (P < 0.05) for the 10% DTP group and lower (P < 0.05) for the 5% DTP group, compared to control. An analogous oxidation profile was observed for cooked meat at 3, 6, and 9 days of storage. Iron-induced lipid oxidation of raw meat showed that the 10% DTP group as well as the control group exhibited MDA values that did not differ (P > 0.05) from each other at all time points, whereas the 5% DTP group presented MDA values that, although not differing from those of the other groups at 0 and 50 min, were significantly (P < 0.05) lower than those of the other groups at 100 and 150 min of iron-induced lipid oxidation. These results suggested that inclusion of dried tomato pulp in feed at a level of 5% exerted an antioxidant effect, whereas addition at level of 10% exerted a prooxidant effect. Mean alpha-tocopherol levels in the control, 5% DTP, and 10% DTP groups were 2.2, 2.1, and 1.4 mg kg(-)(1) of meat, respectively. Fatty acid analysis showed that the 10% DTP group had a higher (P < 0.05) content of total polyunsaturated fatty acids and a greater (P < 0.05) unsaturated/saturated fatty acid ratio compared to control. There might be an interaction between DTP and alpha-tocopherol that is of importance for the balance between pro- and antioxidative activities. Future experiments should be designed to explore the interaction between individual carotenoids and tocopherols in order to better elucidate their role in oxidative changes.     

Particulate metmyoglobin reducing activity and its relationship with meat color

There is controversy about the effect of storage time on metmyoglobin (MetMb) reducing activity in the sarcoplasmic fraction of meat and the role of this reducing activity in maintaining the color of red meat. The presence of metmyoglobin reducing activity in the myofibrillar fraction of muscle extracts was investigated as a possible reason for this controversy. NADH-dependent MetMb reducing activity was found in the particulate fraction of meat following sedimentation of a meat homogenate at 35 000g. There was 5.8 times more MetMb reducing activity in the particulate fraction compared with that of the sarcoplasmic (supernatant) fraction. The presence of metmyoglobin reducing activity in the myofibrils (MMRA), defined as the activity in the sediment after centrifugation of a meat homogenate at 2 000g, was confirmed. The myofibrillar fraction contained 63% of the total MetMb reducing activity available in the meat. The relationship between muscle MetMb reducing activities and meat color parameters was investigated in a beef patties system. The particulate MetMb reducing activity (PMRA) in beef patties was found to be a good indicator of the total metmyoglobin reducing activity in meat and was positively correlated with the color parameters of the patties, suggesting that PMRA may be associated with red meat color of meat patties.     

Bioactive components of caper (Capparis spinosa L.) from Sicily and antioxidant effects in a red meat simulated gastric digestion

An increasing body of evidence on the association between adherence to the Mediterranean diet and healthy status is being accumulated. Floral buds of Capparis spinosa L. are commonly used in the Mediterranean cuisine as flavoring for meat and other foods. The present study evaluated bioactive components and antioxidant activity of Sicilian capers stabilized in salt. Whereas alpha-tocopherol was absent, low levels of gamma-tocopherol and vitamin C were measured. With reference to one serving size (8.6 g of capers), rutin was 13.76 mg, isothiocyanates, recently acknowledged as anticarcinogen phytochemicals, were 42.14 micromol, total phenols were 4.19 mg of gallic acid equivalents (GAE), and the total antioxidant potential measured using the [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt (ABTS) cation radical decolorization assay was 25.8 micromol of Trolox equivalents. The antioxidative activity of a caper hydrophilic extract was assessed in a number of assays. The extract at 3.5 and 7.0 microM GAE exhibited a dose-dependent peroxyl radical scavenging activity in a methyl linoleate methanol solution oxidized by azo initiator, and reduced hypervalent iron myoglobin species formed from met-Mb an H 2O 2, at 180 microM GAE. The hydrophilic extract, at 70-280 microM GAE, caused a dose-dependent inhibition of lipid autoxidation in heated red meat, incubated with simulated gastric fluid for 180 min. In the same model rutin tested at a concentration corresponding to its content in the extract was ineffective, and alpha-tocopherol at 25 microM was poorly effective. The hydrophilic extract (70 microM GAE) prevented the consumption of the co-incubated alpha-tocopherol, whereas lipid oxidation was inhibited for the experimental time, suggesting cooperative interactions between extract components and the vitamin. The findings encourage the use of caper with foods that contribute oxidizable lipids in view of the association between dietary oxidized lipids and risk of oxidative stress-based diseases.     

Redox instability induced by 4-hydroxy-2-nonenal in porcine and bovine myoglobins at pH 5.6 and 4 degrees C

Myoglobin (Mb) redox stability affects meat color and is compromised by lipid oxidation products such as 4-hydroxy-2-nonenal (HNE). Pork lipids are generally more unsaturated and would be expected to oxidize readily and produce more oxidation products than beef. Supranutritional supplementation of vitamin E improves Mb redox stability of beef but not pork. The present study investigated HNE-induced redox instability in porcine and bovine myoglobins at 4 degrees C and pH 5.6. Oxymyoglobin (OxyMb) was incubated with HNE (0.075 mM porcine OxyMb + 0.5 mM HNE; 0.15 mM bovine OxyMb + 1.0 mM HNE). In porcine Mb, only monoadducts formed via Michael addition were detected after 72 h, whereas in bovine Mb both mono- and diadducts were identified. LC-MS-MS identified four histidine residues (His 36, 81, 88, and 152) of bovine Mb that were readily adducted by HNE, whereas in porcine Mb only two histidine residues (His 24 and 36) were adducted. These results suggested that the primary structure of bovine Mb predisposes it to greater nucleophilic attack by HNE and subsequent adduction than is suffered by porcine Mb.     

辐照处理提高猪肉火腿肠保鲜效果

辐照是一种非常有效的食品杀菌保鲜技术,近年来在即食肉制品保鲜方面的应用逐渐引起了人们的关注。为了探讨γ辐照技术对猪肉火腿肠的杀菌保鲜效果,试验采用1、3、5、7、9 k Gy 5个剂量分别对火腿肠进行辐照处理,辐照结束后样品在4℃条件下冷藏,然后跟踪测定其在冷藏过程中脂肪和蛋白质氧化、颜色、p H值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)以及菌落总数的变化,分析不同剂量辐照处理对火腿肠保鲜效果的影响。结果表明,辐照可以显著降低火腿肠脂肪和蛋白质的氧化稳定性,促进其在储藏过程中的氧化。1 k Gy剂量辐照对火腿肠的色泽影响不显著;3~9 k Gy剂量辐照,可以使样品的红度值(a*值)显著降低、亮度值(L*值)显著升高(P0.05),而在冷藏过程中a*值与L*值均随储藏时间的延长而降低,且高剂量辐照组要比低剂量组降低更快一些。火腿肠p H值受辐照影响不显著(P0.05),且在冷藏过程中所有处理组火腿肠的p H值变化也不显著,均在6.0~6.5范围内。5 k Gy剂量辐照即可对猪肉火腿肠中的微生物起到有效抑制作用。     

Influence of the addition of raspberry seed extract on changes in the volatile pattern of stored model breakfast cereal

Laboratory-prepared muesli-type breakfast cereal (mixture of oat flakes, wheat flakes, corn flakes, hazelnuts, raisins, sunflower seeds, and flax seeds) was subjected to accelerated storage test at 60 degrees C with or without the addition of red raspberry seed extract. The oxidative changes in muesli resulting in the formation of secondary oxidation products were evaluated using solid phase microextraction (HS-SPME) and solvent-assisted flavor evaporation (SAFE) to isolate volatiles and GC-MS and chromatography-olfactometry to quantify them and determine the key odorants. During 14 days of storage the total amount of volatile compounds changed from 1.0 mg/kg, in freshly prepared muesli, to 32 mg/kg after storage. The predominant compound was hexanal; its content during storage increased 20-fold, reaching 17 mg/kg. Red raspberry seed extract addition limited the rate of lipid oxidation, and the total amount of volatiles was estimated at 11 mg/kg and that of hexanal at almost 5 mg/kg. An elevated temperature of the storage test also influenced the crucial flavor compounds determined using aroma extract dilution analysis (AEDA). The flavor dilution factor (FD) values for volatile lipid oxidation products were lower in samples with red raspberry seed extract added.     

Consumption of oxidized oil increases oxidative stress in broilers and affects the quality of breast meat

A total of 120 4-week-old broiler chickens were allotted to 12 pens and fed one of three diets including control, oxidized diet (5% oxidized oil), or antioxidant-added diet (500 IU vitamin E) for 2 weeks. Blood samples were collected at the end of feeding trial, and breast muscles were sampled immediately after slaughter. Breast meats were also collected 24 h after slaughter and used for meat quality measurements. Oxidative stress in blood, lipid and protein oxidation, and sarcoplasmic reticulum Ca2(+)-ATPase (SERCA) activity of breast muscle were determined. The oxidized diet increased oxidative stress in blood and increased carbonyl content in breast meat compared with the other two dietary treatments (P < 0.05). Lipid oxidation of breast muscles with the antioxidant-supplemented diet was lower than that with the oxidized and control diet groups (P < 0.05). Meat from birds fed the oxidized diet showed higher drip loss after 1 and 3 days of storage and greater 0-1 h post-mortem pH decline (P < 0.05). Significant differences in specific SERCA activity in breast muscles from birds fed control and oxidized diets (P < 0.05) were detected. This suggested that dietary oxidized oil induced oxidative stress in live birds and increased lipid and protein oxidation in breast muscle. Decrease in SERCA activity in breast muscles due to oxidative stress in live animals accelerated post-mortem glycolysis, which sped the pH drop after slaughter and increased drip loss, indicating that oxidation of diet can cause PSE-like (pale, soft, and exudative) conditions in broiler breast muscles.     

Hemoglobin-mediated lipid oxidation and compositional characteristics of washed fish mince model systems made from cod (Gadus morhua), herring (Clupea harengus), and salmon (Salmo salar) muscle

The use of washed cod light muscle minces in mechanistic studies of hemoglobin (Hb)-mediated fish lipid oxidation has largely increased in the past 5 years. Although cod light muscle has a low level of intrinsic lipid oxidation catalysts, a prerequisite for a good oxidation model system, we believe it cannot fully mimic the oxidation kinetics taking place in other fish species being more susceptible to lipid oxidation. The aim of this study was to systematically investigate whether washed mince model systems useful in Hb-mediated oxidation studies could be prepared also from herring (Clupea harengus) and salmon (Salmo salar) light muscles. The kinetics of oxidation in the washed models was measured during ice storage (+/-Hb), and the results were related to compositional differences. Minces from cod, herring, and salmon light muscles were washed 3 times with 3 volumes of water and buffer. A 20 microM portion of Hb and 200 ppm streptomycin was then added, followed by adjustment of pH and moisture to 6.3 and 86%, respectively. Samples with or without Hb were then stored on ice, and oxidation was followed as peroxide value (PV), rancid odor, redness (a*) loss and yellowness (b*). Prior to storage, all minces and models were also analyzed for total lipids, fatty acids, alpha-tocopherol, proteins, Hb, Fe, Cu, and Zn. Hb-mediated lipid oxidation appeared within 2 days on ice in all models. Small differences in the oxidation rates ranked the models as herring > cod > salmon. These differences were ascribed to more preformed peroxides and trace elements in the herring model, and more antioxidants in the salmon model. Controls, without Hb, stayed stable in all cases except herring, where a very slight oxidation appeared, especially if the herring raw material had been prefrozen. In conclusion, fattier fish like dark muscle species and salmonoids are useful for making washed mince model systems and would be a better choice than cod if there is an interest in the oxidation kinetics of such species.     

Establishment and application of a fluorescent polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for identifying porcine,caprine, and bovine meats

A method of fluorescent Polymerase Chain Reaction-restriction fragment length polymorphism (PCR-RFLP) was applied as an analytical and quantitative tool for meat identification. Following alignments of the nucleotide sequences, an oligonucleotide primer pair was designed to amplify the partial sequences within the 12S ribosomal RNA (12S rRNA) gene of mitochondrial DNA from porcine, caprine, and bovine meats. No fragment can be amplified from dog, cat, fish, duck, goose, turkey, and chicken DNA with the primer pair. Using fluorescence sensor capillary electrophoresis, the species-specific DNA fingerprints of pork, goat, and beef were generated by restriction enzyme digestion following a fluorescence-labeling PCR amplification. Species identification was conducted on the meat mixtures. The reliably semiquantitative levels were below 1% for binary mixtures of pork, goat, and beef. Cooking and autoclaving of meats did not influence the generation of the PCR-RFLP profiles or the analytical accuracy.     

Far-infrared radiation increases the antioxidant properties of rice hull extract in cooked turkey meat

To determine the antioxidant effects of rice hull extract exposed to far-infrared radiation, the added extracts were compared with sesamol in cooked turkey breast. Rice hull extract showed antioxidant properties in cooked turkey breast by reducing lipid oxidation and volatile aldehydes. Far-infrared radiation increased significantly the antioxidant activities of rice hull extracts. Rice hull extract irradiated by far-infrared (FRH) had lower TBARS values and fewer volatile aldehydes (hexanal, pentanal, and propanal) than a non-irradiated extract (IRH) during the 3 days of aerobic storage. Addition of FRH at 0.2% (w/w) in turkey meat could reduce the amounts of volatile hexanal to 18-47% of the control during the storage. However, the antioxidant activities of rice hull extracts did not last as long as those of pure sesamol due to the relatively low concentration of phenolics, and the extracts had some peculiar odor. Addition of rice hull extracts also increased both a and b values of the samples due to its brown intensity.