Cobalt-60 and electron beam irradiation-induced lipid oxidation in largemouth bass (Micropterus salmoides).

BACKGROUND: Irradiation can cause lipid oxidation of fish. This study aimed to examine the effect of radiation (method, dose and dose rate) on the acid value (AV), peroxide value (PV), thiobarbituric acid reactive substances (TBARS) content and fatty acid profile of fresh and freeze-dried largemouth bass flesh. RESULTS: AV, PV and TBARS presented a dose-dependent increase in fish meat for both cobalt-60 (60 Co) and electron beam (EB) irradiation. With a 6 kGy dose of radiation, all measured indices in the 60 Co group were significantly higher than those in the EB group (P < 0.05 or P < 0.01). With a 3 kGy dose of radiation, AV, PV and TBARS in the 200 Gy min-1 dose rate group were significantly lower than those in the 2 and 80 Gy min-1 groups (P < 0.05). After 60 Co irradiation, AV, PV and TBARS in most fresh samples were significantly higher than those in freeze-dried samples (P < 0.01). And 60 Co irradiation decreased the unsaturated fatty acid (UFA) content in fresh samples and increased the UFA content in freeze-dried samples. Our study indicated that 60 Co irradiation, particularly at a low dose rate, accelerated lipid oxidation in fish meat. A large amount of muscle moisture enhances the amount of UFA loss in fish meat during 60 Co irradiation. CONCLUSIONS: A low dose (3 kGy) of EB irradiation, a high dose rate (200 Gy min-1 ) of 60 Co irradiation or freeze-drying treatment can alleviate the lipid oxidation of largemouth bass meat. © 2020 Society of Chemical Industry.

Molecular DNA-based detection of ionising radiation in meat.

BACKGROUND: Ionising radiation induces molecular alterations, such as formation of ions, free radicals, and new stable molecules, and cleavage of the chemical bonds of the molecules present in food. Irradiation-treated meat should be labelled to control the process and to ensure free consumer choice. Therefore, sensitive analytical methods are required to detect the irradiation dose. RESULTS: Meat samples were exposed to radiation doses of 0, 0.272, 0.497, 1.063, 3.64, 8.82 and 17.42 kGy in an industrial 60 Co gamma cell. Primers were designed to amplify 998, 498 and 250-base pair (bp) regions of the 18S rRNA gene of nuclear DNA from the irradiated samples. A new DNA-based method was developed to quantify the radiation exposed to the unstored meat and the meat stored at -20 °C for 3 and 6 months. The method was able to detect meat samples stored and unstored with dose limits of 1.063 and 3.64 kGy, respectively. CONCLUSION: The level of irradiation can be detected using primer pairs that target particularly different-sized sequences for DNA amplification by PCR. This method can be widely used for the analysis of not only meat samples, but also all biological materials containing DNA. © 2016 Society of Chemical Industry.

Pulsed Light Treatment of Different Food Types with a Special Focus on Meat: A Critical Review.

Today, the increasing demand for minimally processed foods that are at the same moment nutritious, organoleptically satisfactory, and free from microbial hazards challenges the research and development to establish alternative methods to reduce the level of bacterial contamination. As one of the recent emerging nonthermal methods, pulsed light (PL) constitutes a technology for the fast, mild, and residue-free surface decontamination of food and food contact materials in the processing environment. Via high frequency, high intensity pulses of broad-spectrum light rich in the UV fraction, viable cells as well as spores are inactivated in a nonselective multi-target process that rapidly overwhelms cell functions and subsequently leads to cell death. This review provides specific information on the technology of pulsed light and its suitability for unpackaged and packaged meat and meat products as well as food contact materials like production surfaces, cutting tools, and packaging materials. The advantages, limitations, risks, and essential process criteria to work efficiently are illustrated and discussed with relation to implementation on industrial level and future aspects. Other issues addressed by this paper are the need to take care of the associated parameters such as alteration of the product and utilized packaging material to satisfy consumers and other stakeholders.

Determination of free cholesterol oxide products in food samples by gas chromatography and accelerated solvent extraction: influence of electron-beam irradiation on cholesterol oxide formation.

BACKGROUND: The aim of this study was to develop an efficient method for cholesterol oxide product (COP) determination in irradiated and non-irradiated ready-to-eat foods with high water content by gas chromatography-flame ionisation detector after accelerated solvent extraction (ASE), and derivatisation with a silylating reagent. RESULTS: The ASE solvent was an 85:15 v/v petroleum ether/chloroform mixture at 40 °C and 1500 psi followed by solid phase extraction. The ASE method was compared with the established lixiviation method, proving an advantageous alternative which reduces analysis time by a factor of 15 and solvent volume by 50%, and minimises the use of chlorinated solvents. COP derivative structures were identified by gas chromatography coupled with mass spectrometry. Analytical characteristics were determined from standards and recoveries were 63-95%, establishing the validity of the method. CONCLUSION: The results obtained and their analysis by chemometric techniques established COP formation in food samples after e-beam irradiation. Increase in COP concentration depended on both irradiation doses and food composition, mainly water and fat content, although linear correlations among variables were not found. © 2016 Society of Chemical Industry.

Effectiveness of Protective Activities for Rehabilitation of the Forage Lands in Russia and Belarus Contaminated as a Result of the Chernobyl Accident.

Regularities of changes in the content of (137)Cs in green fodder during the remote period after the CNPP accident depending on application of agro-technical and agrochemical activities are analyzed. It is revealed that the use of mineral fertilizers reduces receipt of (137)Cs from the soil to forage and further to a food chain. It is also established that agrochemical activities are more effective than agro-technical ones.

Flexible thin-layer dielectric barrier discharge plasma treatment of pork butt and beef loin: effects on pathogen inactivation and meat-quality attributes.

The effects of a flexible thin-layer dielectric barrier discharge (DBD) plasma system using a sealed package on microbial inactivation and quality attributes of fresh pork and beef were tested. Following a 10-min treatment, the microbial-load reductions of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium were 2.04, 2.54, and 2.68 Log CFU/g in pork-butt samples and 1.90, 2.57, and 2.58 Log CFU/g in beef-loin samples, respectively. Colorimetric analysis showed that DBD-plasma treatment did not significantly affect L* values (lightness) of pork and beef samples, but lowered a* values (redness) significantly after 5- and 7.5-min exposures. The plasma treatment significantly influenced lipid oxidation only after a 10-min exposure. The texture of both types of meat was unaffected by plasma treatment. All sensory parameters of treated and non-treated samples were comparable except for taste, which was negatively influenced by the plasma treatment (P < 0.05). This thin-layer DBD-plasma system can be applied to inactivate foodborne pathogens. The observed minor deterioration of meat quality might be prevented by the use of hurdle technology.

Effects of strain and light intensity on growth performance and carcass characteristics of broilers grown to heavy weights.

Effects of genetic strain and light intensity on growth performance and carcass characteristics of broilers grown to heavy weights were investigated. The experimental design was a randomized complete block design. Treatment structure was a 2 × 5 factorial arrangement with the main factors being strain (Ross × Ross 308, Ross × Ross 708) and light intensity (25, 10, 5, 2.5, and 0.2 lx) with trial as replicates. In each of the 5 trials, chicks of 2 different strains of the same commercial hatchery were equally and randomly distributed into 10 environmentally controlled rooms (5 rooms/strain) at 1 d of age at 50% RH. Each room was randomly assigned 1 of 5 light intensities from 22 to 56 d of age. Feed and water were provided ad libitum. Birds and feed were weighed on 0, 14, 28, 42, and 56 d of age for growth performance. Humoral immune response was determined on d 28, whereas ocular and blood samples were performed on d 42 and 55, respectively. On d 56, 20 (10 males and 10 females) birds/strain from each room were processed to determine weights and yields. Genetic strain was significant (P ≤ 0.05) for most of the examined variables, where Ross × Ross 308 had better growth performance and meat yield in comparison with Ross × Ross 708. Although, there was no main effect of light intensity on growth performance and meat yield, results indicated that birds under 10 and 5 lx intensities showed slightly better growth performance and meat yield compared with birds under 25, 2.5, and 0.2 lx in both strains. There was no effect of strain and light intensity on ocular indices, immune response, plasma corticosterone levels, and mortality. This study shows the positive influence on profits to commercial poultry facilities that are using a low lighting environment to reduce energy cost, optimize feed conversion, and maximize production without compromising the welfare of the broilers.

Effects of ultraviolet light on biogenic amines and other quality indicators of chicken meat during refrigerated storage.

Radiation from UV-C has been demonstrated as a potential surface decontamination method in addition to several advantages over regular sanitation methods. However, UV-C radiation possibly affects the physicochemical properties of meat products. To determine the optimum exposure time for bacterial reduction, 39 chicken breasts, inoculated with a pool of Salmonella spp., were submitted to 3 levels of UV-C intensities (0.62, 1.13, and 1.95 mW/cm²) for up to 120 s. After the optimum exposure time of 90 s was determined, changes in the biogenic amines, total aerobic mesophilic bacteria, Enterobacteriaceae, lipid oxidation, pH, and instrumental color were evaluated in 84 chicken breasts that were irradiated (0.62, 1.13, and 1.95 mW/cm²) and stored at 4°C for 9 d. The groups treated with UV-C radiation exhibited an increase in tyramine, cadaverine, and putrescine contents (P < 0.05). The highest UV-C intensity (1.95 mW/cm²) promoted a decrease in the initial bacterial load, and extended the lag phase and the shelf life. The groups irradiated with 1.13 and 1.95 mW/cm² exhibited a more stable b* value than the other groups; similar trends for L*, a*, pH, and TBA reactive substance values were observed among all groups. The UV-C light was demonstrated to be an efficient alternative technology to improve the bacteriological quality of chicken meat without negatively affecting the physical and chemical parameters of chicken breast meat. Nonetheless, the increases on the biogenic amines content should be considered as an effect of the UV processing and not as an indicator of bacterial growth.

Changes of DNA quality and meat physicochemical properties in bovine supraspinatus muscle during microwave heating.

BACKGROUND: The responses of foods to microwave exposure are usually evaluated only in terms of physicochemical properties, thus undervaluing the importance of DNA in an authentication process by methods based on polymerase chain reaction (PCR). In this study, the time effect of microwave heating on some meat physicochemical properties and DNA quality has been investigated. RESULTS: Cooking loss, instrumental colour, pH and other physicochemical parameters varied significantly during microwave cooking, reaching the lowest/highest values after 2.5 min of cooking. The exposure of meat to microwaves was found to affect characteristically the quality of extracted DNA (i.e. yield, purity and degradation). PCR products of both mitochondrial and nuclear regions were successfully observed in all samples. However, the band for large fragments became progressively fainter as treatment time increased. CONCLUSIONS: Microwave heating caused physicochemical changes in bovine supraspinatus muscle and influenced characteristically the yield and integrity of the extracted DNA, indicating that an accurate DNA quantification and a rational choice of the genes (i.e. mtDNA versus nDNA, fragment size, etc.) to be amplified are fundamental in an authentication process by PCR-based methods.

Irradiation and additive combinations on the pathogen reduction and quality of poultry meat.

Reduction of foodborne illnesses and deaths by improving the safety of poultry products is one of the priority areas in the United States, and developing and implementing effective food processing technologies can be very effective to accomplish that goal. Irradiation is an effective processing technology for eliminating pathogens in poultry meat. Addition of antimicrobial agents during processing can be another approach to control pathogens in poultry products. However, the adoption of irradiation technology by the meat industry is limited because of quality and health concerns about irradiated meat products. Irradiation produces a characteristic aroma as well as alters meat flavor and color that significantly affect consumer acceptance. The generation of a pink color in cooked poultry and off-odor in poultry by irradiation is a critical issue because consumers associate the presence of a pink color in cooked poultry breast meat as contaminated or undercooked, and off-odor in raw meat and off-flavor in cooked meat with undesirable chemical reactions. As a result, the meat industry has difficulties in using irradiation to achieve its food safety benefits. Antimicrobials such as sodium lactate, sodium diacetate, and potassium benzoate are extensively used to extend the shelf-life and ensure the safety of meat products. However, the use of these antimicrobial agents alone cannot guarantee the safety of poultry products. It is known that some of the herbs, spices, and antimicrobials commonly used in meat processing can have synergistic effects with irradiation in controlling pathogens in meat. Also, the addition of spices or herbs in irradiated meat improves the quality of irradiated poultry by reducing lipid oxidation and production of off-odor volatiles or masking off-flavor. Therefore, combinations of irradiation with these additives can accomplish better pathogen reduction in meat products than using them alone even at lower levels of antimicrobials/herbs and irradiation doses. Effects of irradiation and additive combinations on the pathogen reduction and quality of poultry meat will be discussed in detail.

Effect of crust freezing applied alone and in combination with ultraviolet light on the survival of Campylobacter on raw chicken.

The application of crust freezing (CF) applied as a stand-alone treatment or in combination with ultraviolet (UV) light for reducing the level of artificially inoculated Campylobacter jejuni on raw chicken was investigated. CF air temperatures of -5, -15 and -27 °C (±3 °C) with freezing times of 70, 15 and 6 min, respectively, were used. The level of C. jejuni on chicken was also examined following subsequent refrigerated (0-4 °C) storage at 3 and 7 days. All CF treatments resulted in significant reductions compared to untreated controls (P < 0.05). Although combining CF with UV also resulted in significant reductions for C. jejuni, the combined treatments were generally no more effective than treatment by CF alone. Overall, the color of chicken drumsticks was not affected by CF treatments (P ≥ 0.05). In general, CF resulted in increased drip loss (P < 0.05), which increased over storage time and was greater at higher CF temperatures. The current study indicates that CF has potential for reducing the levels of C. jejuni by between 0.5 and 1.5 log(10) CFU/g and impacts minimally on the color of treated skin.

Irradiation in the production, processing and handling of food. Final rule.

The Food and Drug Administration (FDA) is amending the food additive regulations to increase the maximum dose of ionizing radiation permitted in the treatment of poultry products, to include specific language intended to clarify the poultry products covered by the regulations, and to remove the limitation that any packaging used during irradiation of poultry shall not exclude oxygen. This action is in response to a petition filed by the U.S. Department of Agriculture, Food Safety and Inspection Service (USDA/FSIS).

Irradiation in the production, processing and handling of food. Final rule.

The Food and Drug Administration (FDA) is amending the food additive regulations to provide for the safe use of a 4.5 kilogray (kGy) maximum absorbed dose of ionizing radiation to treat unrefrigerated (as well as refrigerated) uncooked meat, meat byproducts, and certain meat food products to reduce levels of foodborne pathogens and extend shelf life. This action is in response to a petition filed by the U.S. Department of Agriculture, Food Safety and Inspection Service (USDA/FSIS).

Factors influencing the dielectric properties of agricultural and food products.

Dielectric properties of materials are defined, and the major factors that influence these properties of agricultural and food materials, namely, frequency of the applied radiofrequency or microwave electric fields, and water content, temperature, and density of the materials, are discussed on the basis of fundamental concepts. The dependence of measured dielectric properties on these factors is illustrated graphically and discussed for a number of agricultural and food products, including examples of grain, peanuts, fruit, eggs, fresh chicken meat, whey protein gel, and a macaroni and cheese preparation. General observations are provided on the nature of the variation of the dielectric properties with the major variables.

Evaluation of radiation-induced compounds in irradiated raw or cooked chicken meat during storage.

The concentrations of hydrocarbons, 2-alkylcyclobutanones, and sulfur volatiles in irradiated (0 and 5 kGy) chicken meat samples (raw, precooked, and irradiated-cooked) were analyzed after 0 and 6 mo of frozen storage (-40°C) under oxygen-permeable packaging conditions. Two hydrocarbons [8-heptadecene (C(17:1)) and 6,9-heptadecadiene (C(17:2))], two 2-alkylcyclobutanones (2-dodecylcyclobutanone and 2-tetradecylcyclobutanone), and dimethyl disulfide were determined as radiation-induced detection markers in the irradiated raw and cooked chicken meats. Although irradiated-cooked samples produced fewer hydrocarbons and 2-alkylcyclobutanones than precooked irradiated samples, the number of individual hydrocarbons or 2-alkylcyclobutanones was still sufficient to detect radiation treatment even after 6 mo of storage at -40°C. Among sulfur volatiles, only dimethyl disulfide was found in meat after 6 mo of storage, indicating it has potential to be used an irradiation detection marker for frozen-stored meats under oxygen-permeable packaging conditions.

Effect of edible composite film based on chitosan and cumin essential oil-loaded nanoemulsion combined with low-dose gamma irradiation on microbiological safety and quality of beef loins during refrigerated storage.

This research was conducted to assess the combined effect of chitosan (Ch) film containing cumin essential oil nanoemulsion (CNE) and low-dose gamma irradiation (GI) at 2.5 kGy on microbiological safety and quality of beef loins during 21 days of chilled storage. The growth of mesophilic and psychrophilic bacteria, Enterobacteriaceae, and lactic acid bacteria were retarded in all treated groups (Ch, GI, Ch + CNE, Ch + GI, and Ch + CNE + GI groups) compared to control group during storage time. The treatments also slowed down the increasing level of total volatile basic nitrogen and pH during storage, while irradiation increased the levels of thiobarbituric acid reactive substances and protein carbonyls in beef loins. All treatments except Ch were effective to control the growth of inoculated pathogenic bacteria, including Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium, in loin samples. The combination of Ch + CNE + GI was the most effective treatment to control the population of microbial flora and inoculated pathogens, slow down some physicochemical changes, and enhance the storage life of beef loins. As a result, the combination of active chitosan film and low-dose gamma irradiation can ensure microbiological safety and is suggested for long time preservation of beef during chilled storage.

Impact of irradiation on the safety and quality of poultry and meat products: a review.

For more than 100 years research on food irradiation has demonstrated that radiation will make food safer and improve the shelf life of irradiated foods. Using the current food safety technology, we may have reached the point of diminishing returns even though recent figures from the CDC show a significant drop in the number of foodborne illnesses. However, too many people continue to get sick and die from eating contaminated food. New and under utilized technologies such as food irradiation need to be re-examined to achieve new levels of safety for the food supply. Effects of irradiation on the safety and quality of meat and poultry are discussed. Irradiation control of the principle microbial pathogens including viruses, the differences among at-risk sub-populations, factors affecting the diminished rate of improvement in food safety and published D values for irradiating raw meat and poultry are presented. Currently permitted levels of irradiation are probably not sufficient to control pathogenic viruses. Typical gram-negative spoilage organisms are very sensitive to irradiation. Their destruction leads to a significant increase in the acceptable shelf life. In addition, the destruction of these normal spoilage organisms did not provide a competitive growth advantage for irradiation injured food pathogens. Another of the main focuses of this review is a detailed compilation of the effects of most of the food additives that have been proposed to minimize the negative quality effect of irradiation. Most of the antimicrobials and antioxidants used singly or in combination produced an increased lethality of irradiation and a decrease in oxidation by-products. Combinations of dosage, temperature, dietary and direct additives, storage temperature and packaging atmosphere can produce meats that the average consumer will find indistinguishable from non-irradiated meats. A discussion of the production of unique radiological by-products is also included.

Methods for inactivation of Toxoplasma gondii cysts in meat and tissues of experimentally infected sheep.

This study utilized infectivity bioassays in cats and mice to assess the efficacy of inactivation of Toxoplasma gondii cysts in experimentally infected sheep meat and tissues subjected to chilling, freezing, heating, microwave cooking, and gamma ray irradiation. Heating at 60 degrees C or 100 degrees C for 10 minutes, freezing at either -10 degrees C for 3 days or -20 degrees C for 2 days, or irradiation at doses of 75 or 100 krad was sufficient to kill tissue cysts. Meanwhile, neither cooking in a microwave nor chilling at 5 degrees C for 5 days was sufficient to kill tissue cysts.

Optimization of goose breast meat tenderness by rapid ultrasound treatment using response surface methodology and artificial neural network.

The aim of this study was to develop a prediction model on tenderization of goose breast meat by response surface methodology (RSM) and artificial neural network (ANN). The experiments were operated on the basis of a three-level, three-variable (ultrasound power, ultrasound time, and storage time) Box-Behnken experimental design. Under RSM and ANN optimum conditions, experimental Meullenet-Owens razor shear (MORS) of meat (1862.6 g and 1869.9 g) was in reasonable agreement with predicted one. Nevertheless, better prediction capability of ANN was proved by higher R2 (0.996) and lower absolute average deviation = 4.257) compared to those for RSM (0.852 and 16.534), respectively. These results revealed that ANN was more accurate and much better than RSM model for the optimization of tenderness of meat. The optimum conditions of ultrasound power, ultrasound time, and storage time given by ANN were 812 W, 24.5 min and 25.7 hr, respectively. Under the optimized condition, the cooking loss of meat significantly decreased by ultrasound treatment compared with untreated meat. Lower cooking loss and MORS at the optimal condition were beneficial to meet the satisfaction of consumer and producers for meat factory.

Application of ultrasound in chicken breast during chilling by immersion promotes a fast and uniform cooling.

The initial objective of the study was to evaluate different operation modes (sweep and normal) and frequencies (25 and 130 kHz) of ultrasound in pre-chilling of breast chicken cylinders (BCC) immersed in water at 10 °C during 10 min. The second objective was to study the effect of the immersion time (5, 10, 15, 20, and 30 min) using the best operation mode and frequency obtained in the pre-chilling of the BCC in water at 10 °C. Pre-chilling was evaluated in both stages by infrared thermography, and the percentages of water absorption were determined in the second stage. The application of US at 130 kHz and normal operation mode provided a reduction of temperature on the surface of BBC higher (≈19.6%) than untreated samples. Also, compared to control, the US-treated samples in these conditions presented a more uniform cooling rate (≈22.3%) and higher water absorption (≈113%).