Preservation Of Meat Products Research Articles

Novel soy protein isolate films incorporated with phage CAM-21 show strong antimicrobial effects against E. coli O157:H7

Due to their specificity, bacteriophages are becoming more widely used as antibacterial agents in the food industry. However, their effectiveness in food is often compromised by food components that can lead to a loss of their biological activity. In this study, soy protein isolate (SPI)-based packaging films incorporated with Escherichia phage CAM-21 were developed using a solution casting method. CAM-21 was relatively stable at pH 3–11 and temperatures up to 55 °C after 1 h of incubation. It remained active on the surface of raw beef, ground beef, and baby spinach after 36 h at 4 °C. The distribution of CAM-21 in the films was uniform, and its incorporation did not affect the film microstructure. No significant impact on the color, water vapor permeability, opacity, and mechanical properties of the films was observed. The antimicrobial activity of CAM-21-incorporated films was significantly enhanced in beef products inoculated with E. coli O157:H7. CAM-21-containing films significantly decreased the number of bacteria on raw beef samples by up to 1.5 and 2.0 log CFU/g after 3 and 5 days of refrigerated storage, respectively. These findings suggest that SPI films containing Escherichia phage CAM-21 have potential as antimicrobial packaging materials for preserving meat products.

ZIF-67C@CeO2 Composite for the Electrochemical Non-Enzymatic Determination of Nitrite in Fish Dry Samples

Nitrite is widely present in the human environment, and it is one of the most common nitrogenous compounds in nature. However, Nitrite is often used as a preservative in meat products even though it has always been considered a carcinogen. Herein, dimethylimidazole was used as a ligand to coordinate Co2+ to prepare a metal-organic framework material- ZIF67, then the ZIF67 was added to the prepared cerium hydroxide to produce ZIF67C@CeO2 composite via high-temperature calcination. Furthermore, a novel ZIF67C@CeO2 composite modified glassy carbon electrode (ZIF67C@CeO2/GCE) was constructed to detect nitrite in fish dried samples. Scanning electron microscopy and X-ray diffraction were used to characterize the microstructure of the ZIF-67C@CeO2 composite. The experimental condition, such as applied potentials, load mass of composite, and pH value of electrolyte were optimized by electrochemical tests. In the optimal conditions, the linear range of the sensor for detecting nitrite is 0.3–1150 μM, and the detection limit (DL) is 0.102 μM. Moreover, the sensor possesses a good anti-jamming capability, repeatability, and reproducibility. The constructed sensor- ZIF-67C@CeO2/GCE showed excellent electrochemical performance and enabled the detection of nitrite in fish dried foods.

Leveraging supply chain collaboration with digital technologies for supply chain performance: an empirical investigation of Indian meat industries

SummaryThe meat industry plays a vital role in India's economy, contributing significantly to employment and GDP. In recent years, there has been a growing interest in digitalising the meat supply chain in India to address these challenges and enhance efficiency, transparency, and traceability. Digitalisation enables real‐time monitoring of environmental conditions, such as humidity and temperature, during storage and transportation, ensuring optimal preservation of meat products. Government initiatives, such as the Digital India programme and the Atma‐Nirbhar Bharat Abhiyan, provide support and incentives to foster digitalisation in the meat industry and other sectors. This study analysed the implementation of digital technologies and supply chain performance as the involvement of top management commitment is crucial while carrying out this task. It supports that the implementation of digital technologies would lead to an increase in supply chain collaboration and it further would lead to an increase in supply chain performance. This study will help robust and more unified supply chain by connecting the stakeholders digitally as well as by applying digital technologies for smooth industry operations.

Tubular Cellulose Composite as a Vehicle for the Development of Meat Products with Low Nitrite Content.

Nitrite salts are among the most used preservatives in meat products as they ensure their safe consumption. Despite their positive effects on food safety and stability, many side effects on human health have been reported, leading to the need to reduce their use. Therefore, the aim of this study is to produce veal products with low nitrite content through low diffusion of potassium nitrite and to study their microbiological characteristics. Edible tubular cellulose from leaf celery was produced and KNO2 was encapsulated in this material. This was achieved in two ways: by impregnation of tubular cellulose in a KNO2 solution under stirring and using starch gel as a stabilizer. Two samples of impregnated cellulose were applied on the surface of two veal samples of which one was stored at room temperature and the other at 3 °C. Similarly, two samples of cellulose with starch gel were applied on the surface of two veal samples of which one was stored at room temperature and the other at 3 °C. The KNO2 diffusion in different depths of the meat was measured and its effect on the microbiological characteristics of the meat was evaluated. Τhe experiment was carried out in duplicate. A satisfactory percentage of about 70 % of the initially encapsulated amount of KNO2 was diffused in the meat, while the rest remained in the pores of the delignified leaf celery. The migrating amount of KNO2 proved to be effective in preserving meat, as the microbiological load decreased significantly (especially within the first 12 h, from a decrease of 0.6 log CFU/g up to 2.4 log CFU/g). The demand for meat products with low nitrite content is constantly increasing and the results of the present study are promising for the development of this technology in scale-up systems and on an industrial scale. This innovative approach could lead to products with controlled diffusion of the preservatives.

Inhibitory effects of citral on the production of virulence factors in Staphylococcus aureus and its potential application in meat preservation

Foodborne diseases caused by Staphylococcus aureus contamination on meat and meat products has gained increasing attention in recent years, while the pathogenicity of S. aureus is mainly attributed to its virulence factors production, which is primarily regulated by quorum sensing (QS) system. Herein, we aimed to uncover the inhibitory effects and mechanisms of citral (CIT) on virulence factors production by S. aureus, and further explore its potential application in pork preservation. Susceptibility test confirmed the antibacterial properties of CIT against S. aureus, the minimal inhibitory concentration (MIC) was 0.25 mg/mL. Treatment with sub-MICs of CIT reduced the hemolytic activity by inhibiting the production of α-hemolysin, and staphylococcal enterotoxins (SEs) production was significantly inhibited by CIT in both culture medium and pork without affecting bacterial growth. Transcriptomic analysis indicated that the differentially expression genes encoding α-hemolysin, SEs, and other virulence factors were down-regulated after treatment with 1/2MIC CIT. Moreover, the genes related to QS including agrA and agrC were also down-regulated, while the global transcriptional regulator sarA was up-regulated. Data here demonstrated that CIT could inhibited S. aureus virulence factors production through disturbing QS systems. In a challenge test, the addition of CIT caused a remarkable inhibition of S. aureus population and delay in lipid oxidation and color change on pork after 15 days incubation at 4 °C. These findings demonstrated that CIT could not only efficiently restrain the production of S. aureus virulence factors by disturbing QS, but also exhibit the potential application on the preservation of meat products.

Prevalence and risk factors of Linguatula spp. in slaughter animals in Tabriz, Iran, and methods for nymphal stage inactivation

Linguatula is a food born zoonotic parasite in which carnivores and herbivores serve as final and intermediate hosts, respectively. Human infection with Linguatula spp. occurs following consumption of raw or undercooked infected internal organs of the intermediate host and/or consumption of water and/or vegetables contaminated with eggs released from final hosts. The aim of this study was to determine prevalence and risk factors of Linguatula spp. in sheep, cattle, buffalo, goats and camels slaughtered at the Tabriz abattoir, Iran. In addition, effect of temperature and sodium chloride (NaCl) on survival time of Linguatula spp. nymphs was assessed. For this purpose, 25,520 mesenteric lymph nodes from 2552 animals and the livers and lungs from 656 animals were collected randomly and examined. To evaluate the effect of temperature and NaCl on the survival of Linguatula spp. nymphs in infected livers and lungs, 30 g of each liver and lung with dimensions of 2 × 3 × 4 cm, were exposed to temperatures of −20, 10, 50, 60 and 72 °C and NaCl concentrations of 5 %, 10 %, 15 % and 20 % for 3, 6, 12, 24, 48 and 72 h, in triplicate. Based on the mesenteric lymph nodes, 25.7 % (656 of 2552 animals) were infected with Linguatula spp. Of the 656 liver and lungs assessed, 141 (21.5 %) and 62 (9.5 %) were infected with Linguatula spp., respectively. The rate of infection of mesenteric lymph nodes in all animals was significant with age (P < 0.05), with more older animals infected. In regards to sex, except for camels, more female animals were infected than male animals (P < 0.05). There was a significant difference in survival of nymphs based on temperature and/or NaCl and time (P < 0.0001). At 72 h, all temperatures assessed except 10 °C, resulted in all nymphs being inactivated. Sodium chloride was more effective against Linguatula spp. nymphs in livers than in lungs with 100 % efficacy only achieved against nymphs in livers at 20 % concentration after 48 h and at 10 and 15 % concentration after 72 h. Based on these results, heating and application of common salt as a food preservative in meat products reduces the survival time of Linguatula spp. nymphs and their use could decrease the risk of food-born microorganisms.

Effects of Natural Extract Mixtures on the Quality Characteristics of Sausages during Refrigerated Storage.

Owing to the residual toxicity and adverse health effects of chemical preservatives, there is an increasing demand for using natural preservatives in food. Although many natural extracts have been evaluated, research on their antibacterial effects remains insufficient. Therefore, this study aimed to explore the possibility of developing Psidium guajava, Ecklonia cava, and Paeonia japonica (Makino) Miyabe & Takeda extracts as natural food preservatives. Further, the effect of mixing these extracts on microbial growth and quality was evaluated during the refrigeration of sausages. Optimal mixing ratios were determined based on the minimum inhibitory and bactericidal concentrations of each mixed extract against the Listeria monocytogenes, Salmonella spp. and Escherichia coli. D-optimal mixing design optimization tool was further used to obtain an optimum mixing ratio of Formulation 1 (F1). The antibacterial activity of F1 increased with increasing concentration, with similar activities at 0.5% and 1%. The sausages with synthetic or natural preservatives showed significantly lower lipid oxidation than those of the control and grapefruit extract-treated sausages after 4 wk of refrigeration. Total plate counts were observed only in the control and treatment groups stored for 3 wk, and no significant effect of ascorbic acid was observed. Compared to the other samples, sausages with added natural extracts showed the highest overall acceptability scores initially and after 4 wk. Therefore, similar amounts of grapefruit seed and natural extracts had the same effect on microbiological analysis and lipid rancidity during sausage storage. Hence, this mixture can serve as a potential natural preservative in meat products.

Antimicrobial ingredients of Zanthoxylum motuoense and potential in fresh pork meat preservation

Zanthoxylum motuoense (Tibetan prickly ash, MTHJ), different from the Chinese prickly ash species, is distributed only in the Tibet. Now the chemical characterization and antibacterial activity of MTHJ extracts were analyzed for the first time. As a result, Schinifoline (12), γ-Fagarine (8), (2E,7E,9E)-6 S-Hydroxy-N-(2-methylpropyl)-11-oxo-2, 7, 9-Dodecatrienamide (6), and Neoechinulin A (17) were found to be the major different factors by untarget LC-MS metabolomics together with quantitative analysis on target. These four compounds were also the major antibacterial constituents. Then, the antimicrobial activity of MTHJ fractions was evaluated with colony forming units (CFU), fluorescence microscopy imaging, SEM and investigating the potential food preservation. Nutritional composition, colour and sensory evaluation of extract-treated samples were evaluated along storage time. The results suggested the MTHJ may be used for meat products preservation, and the scores were significantly higher for its unique flavor, which offered a promising choice for food safety, preservation and reducing foodborne illness.

Public health hazards of some preservatives in meat products

Public health hazards of some preservatives in meat products

CURRENT TRENDS IN THE APPLICATION OF VACCINIUM MYRTILLUS AND ARONIA MELANOCARPA AS NATURAL PRESERVATIVES IN MEAT AND MEAT PRODUCTS: A REVIEW

"In the contemporary food industry, preservation of meat and meat products remains a paramount concern for ensuring safety, quality, and extended shelf life. Against the backdrop of consumer demand for natural and clean-label food additives, this comprehensive review investigates the current trends in utilizing Vaccinium myrtillus (bilberry) and Aronia melanocarpa (chokeberry) extracts as natural preservatives in meat and meat products. The review begins by elucidating the intrinsic antioxidant and antimicrobial properties of these berry extracts, emphasizing their relevance in the preservation of meat products. Recent research highlights their efficacy in reducing lipid oxidation, extending the shelf life of meat products, and inhibiting microbial proliferation. Furthermore, it explores various application methods, including their incorporation into meat matrices and the development of edible coatings, shedding light on innovative techniques and emerging technologies. The practicality of deploying these natural preservatives in meat processing is substantiated through industrial applications and illustrative case studies. Recognizing the promise of these natural preservatives, the review acknowledges the hurdles faced, including formulation optimization, cost-effectiveness, and consumer perceptions. Overcoming these challenges is crucial for their widespread adoption. The review concludes by summarizing key findings and underscores the pivotal role of Vaccinium myrtillus and Aronia melanocarpa in shaping the landscape of meat preservation while ensuring consumer safety and satisfaction."

Characterization, antioxidant, and sausage preservation effects of ethanol extract from lotus seed peel powder

The ethanol extract from lotus seed peel powder (EEL) were characterized, and its antioxidant and sausage preservation effects were investigated in this study. Chemical composition, UV and FTIR spectra of EEL, 70% ethanol-soluble matter (70-DF), and precipitate (70-PF) showed similar trends to some extent, indicating their similar chemical composition. Then, their antioxidant potentials were confirmed that EEL exhibited stronger DPPH· scavenging capacity, FRAP, and lipid peroxidation inhibitory activities than those of 70-DF and 70-PF. Correlation analysis also indicated phenolics as the main antioxidant components of EEL. Hence, catechin, epicatechin, rutin, phlorizin, and gallic acid were identified as the dominant phenolics of EEL. Throughout the chopping, roasting, cooking and pasteurization processes, EEL could protect the color, maintain the pH value, and decline the total volatile base nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) values of sausages. Following 18 days of storage at 25 °C, supplementation with EEL reduced the TVB-N and TBARS values of sausages, while pH value showed an opposite trend. The present study found that EEL could prolong the shelf life of sausages via inhibiting the oxidation of lipids and proteins, which would promote the utilization of lotus seed peel powder as a substitute for nitrites to preserve meat products.

Production cooked sausages with the addition of iodized salt

Iodine deficiency in the biosphere, mainly in the soil, leads to endemic goiter and other iodine deficiency disorders. As shown by numerous studies, this disease affects over 1 billion people in the world. Endemic goiter and much of the territory of Ukraine, including the Vinnytsia region. Presented current research study of recipes and technologies on system-cooked sausages. Currently, boiled sausage enjoys relatively high demand among the population because it is significant for most people, giving it an advantage. Innovation activity represents one of the most effective directions. It should facilitate the development of innovative activity that promotes penetration into new markets and production growth. Today, the most essential and effective innovative organizational and technical measures introduced in sausage production can be considered are the use of new recipes for manufacturing products and the installation of new equipment, which can significantly reduce the cost of manual labor and power inputs and improve product quality and reduce the share of marriage. Sausage production is seen as a thermochemical method of preserving meat products. For each type of sausage, set production process-approved technological instructions and recipes. Strict adherence to recipes, specialized instructions, and sanitary regimes is a prerequisite for obtaining high-quality links. Crucial in the production of sausages is raw. The primary raw materials are beef and pork. Occasionally, use lamb and horsemeat. Equally important is the creation of a new generation of products that have general strengthening and preventive action. The components of these products can protect the body from the harmful effects of the environment and the emergence of human diseased cells. The constant lack of iodine leads to a reduction in the synthesis and secretion of the primary thyroid hormone - thyroxine. The role of thyroid hormones in the body is extremely high, and most of the vital functions are performed by their participation. The main physiological effects of thyroid hormone are stimulating synthesis, growth, development, and differentiation of tissues. Developed products to include microorganisms that can synthesize biologically active structures (antibodies, receptors, hormones) that contribute to the removal or destruction of harmful decay and systems, thereby preventing human disease.

The efficiency of Lactiplantibacillus plantarum S61 strain as protective cultures in ground beef against foodborne pathogen Escherichia coli.

The aim of the study was the bio-control effectiveness of the Lactiplantibacillus plantarum S61 strain, isolated from traditional fermenting green olives, against Escherichia coli B805 in ground beef. The bio-control effect of L. plantarum S61 against E. coli B805 was evaluated in ground meat during storage under refrigeration at 4°C. The results showed that L. plantarum S61 reduced the biomass of pathogenic bacteria (E. coli) in ground meat during 10 days of storage at 4°C. Moreover, the treatment with L. plantarum S61 has no adverse effect on the sensory properties of ground meat after 10 days of storage at 4°C. The treatment with L. plantarum S61 and storage at 4°C effectively decreases the growth and risk of pathogenic bacteria in ground meat and, consequently, increases the product's shelf life. Therefore, the application of L. plantarum S61 during the storage of ground meat beef may help reduce the use of chemical preservatives in meat products. Consequently, L. plantarum S61 can be applied as a bio-control agent against spoilage and pathogenic bacteria in meat and meat products.

Design, Fabrication and Performance Evaluation of Mixed-Mode Solar Tunnel Dryer for Buffalo Meat by Forced Convection

In the context of Nepal, the consumption, as well as preservation of meat products, has been in practice for ages. The primitive approach - open sun drying technique- a technique for preserving meat for longer, can contaminate the meat. In addition, the meat in direct contact with UV rays also degrades the quality of meat which may not be suitable for consumption. Exposing the meat to the open air causes the evaporation of its moisture, leading to a decline in flavour and an extended duration for the dehydration of the meat product. The alternative technique - mixed mode solar tunnel dryer - is a revolutionary method to undertake the challenges, which uses both solar heated air and direct solar energy. This paper majorly includes the design, fabrication and performance evaluation of a solar mixed-mode tunnel dryer by forced convection for buffalo meat. The purposed system was designed for drying 4 kg of meat for humid sub-tropical climatic conditions with an estimated design drying time of 7 hrs 44 mins. The designed system includes a collector of area 2 m2, a drying chamber, and a DC fan. The recorded parameters were incident solar irradiance, air temperature, relative humidity of the air, and moisture content of meat at equal intervals. Reducing the moisture content in buffalo meat to 26.78% by weight in the month of November, took a total of 14 hrs with maximum collector efficiency of 29.79%.

Complete Genome Sequencing and Bacteriocin Functional Characterization of Pediococcus ethanolidurans CP201 from Daqu.

This study aims to sequence the whole genome of Pediococcus ethanolidurans CP201 isolated from Daqu and determine the anti-corrosion ability of bacteriocins on chicken breast. The whole genome sequence information of P. ethanolidurans CP201 was analyzed, and its gene structure and function were explored. It was found that gene1164 had annotations in the NR, Pfam, and Swiss-Prot databases, and was related to bacteriocins. The exogenous expression of the bacteriocin gene Pediocin PE-201 was analyzed based on the pET-21b vector and the host BL21, and the corresponding bacteriocin was successfully expressed under the induction of IPTG. After purification by NI-NTA column, enterokinase treatment, membrane dialysis concentration treatment, and SDS-PAGE electrophoresis, the molecular weight was about 6.5kDa and the purity was above 90%. By applying different concentrations of bacteriocin to chicken breast with different levels of contamination, the control of pathogenic bacteria, the ordinary contamination level (OC) group, and the high contamination level (MC) group could be completely achieved with 25mg/L bacteriocin. In conclusion, the bacteriocin produced by the newly isolated CP201 can be applied to the preservation of meat products to prevent the risk of food-borne diseases.

N-nitrosamines in processed meats: Exposure, formation and mitigation strategies

Nitrite and nitrate have been widely used in the preservation of meat products for the effective antimicrobial action against several pathogenic bacteria such as Clostridium botulinum, Salmonella and mesophilic bacteria. However, they can further react with secondary amines in meat products and produce noxious compounds called nitrosamines during thermal processing. N-nitrosamines are divided into volatile N-nitrosamines and non-volatile N-nitrosamines, among which volatile N-nitrosamines are a group of highly hazardous chemical carcinogens whose carcinogenicity and teratogenicity have led to widespread concern. Owing to their occurrence in daily diet, it is of great significance to suppress their formation and toxicity on human health without causing adverse effects on food flavors. In this paper, the formation mechanism and toxicity of nitrosamines are provided. Potential mitigations can be carried out from the perspectives of precursors in raw materials, processing conditions as well as exogenous additives. Moreover, promoting the degradation of nitrosamines is an effective approach. The potential health risks associated with nitrosamines are described. Different intervention substances, such as polyphenols, vitamins and various plant extracts are summarized, discussing their impact on various toxicity of nitrosamines. The purpose of this review is to provide theoretical guidance on the control of nitrosamines generation and deleterious effects, so as to promote the development of meat processing and practical production.

Influences of flavonoids from Sedum aizoon L. on biofilm formation of Pseudomonas fragi.

Pseudomonas fragi (P. fragi) is one of the main categories of bacteria responsible for the spoilage of chilled meat. In the processing and preservation of chilled meat, it is easy to form biofilms on the meat, leading to the development of slime on the meat, which becomes a major quality defect. Flavonoids, as one of the critical components of secondary plant metabolites, are receiving increasing attention for their antibacterial activity. Flavonoids in Sedum aizoon L. (FSAL), relying on its prominent antibacterial activity, are of research importance in food preservation and other applications. This article aims to investigate the effect of FSAL on the biofilm formation of P. fragi, to better apply FSAL to the processing and preservation of meat products. The disruption of cellular structure and aggregation properties by FSAL was demonstrated by the observation of the cellular state within the biofilm. The amount of biofilm formation was determined by crystal violet staining, and the content of polysaccharides and proteins in the extracellular wrapped material was determined. It was shown that the experimental concentrations of FSAL (1.0 MIC) was able to inhibit biofilm formation and reduce the main components in the extracellular secretion. The swimming motility assay and the downregulation of flagellin-related genes confirmed that FSAL reduced cell motility and adhesion. The downregulation of cell division genes and the lowering of bacterial metabolic activity suggested that FSAL could hinder bacterial growth and reproduction within P. fragi biofilms. KEY POINTS: • FSAL inhibited the activity of Pseudomonas fragi in the dominant meat strain • The absence of EPS components affected the formation of P. fragi biofilms • P. fragi has reduced adhesion capacity due to impaired flagellin function.

Potential of pectin-chitosan based composite films embedded with quercetin-loaded nanofillers to control meat associated spoilage bacteria

Increasing consumer demands for healthy, minimally processed, contamination-free food with extended shelf life have exerted pressure on the food industry to search for more effective and biodegradable packaging materials against spoilage agents. Pectin-chitosan based nanocomposite films were developed and evaluated for the impacts of antimicrobial-loaded nanofillers [(quercetin-loaded nano-liposomes (QNLs)] on the physico-mechanical, thermal, and antibacterial properties against meat-associated spoilage pathogens. QNLs were observed with an average size of 191 ± 7 nm by dynamic light scattering with a negative zeta-potential value of −37 ± 5.7 mV. Scanning electron microscopy revealed round and smooth surface morphology of QNLs. FTIR spectroscopic analyses confirmed the encapsulation of quercetin in liposomes via weak electrostatic or hydrophobic interactions. The addition of nanofillers in composite films increased the tensile strength (9.74 ± 0.26 MPa) and Young's modulus (24.17 ± 0.64 MPa) of the nano-active films as compared to active films (2.49 ± 0.02 MPa and 5.04 ± 0.04 MPa), respectively. Similarly, opacity (3.10 ± 0.04) and moisture content (31.03% ± 1.81%) values of nano-active films were lesser as compared to non-active films (5.35% ± 0.07% and 84.24% ± 0.45% respectively) owing to the hydrophobic nature of QNLs. Thermal analyses performed by TGA and DSC confirmed the thermal stability of nano-active films. Nano-active films exhibited excellent antimicrobial potential (spot-on-lawn and quantitative food application assays) against multidrug-resistant meat pathogens including Escherichia coli, Listeria monocytogenes and Salmonella enterica. Hence, pectin-chitosan based nano-active films have promising applications for the preservation of meat products from spoilage bacteria.

Influence of alternating magnetic field on the quality of beef and its protein during cold storage

SummaryMagnetic field is an appropriate physical field, it can be used as a process parameter for the preservation of meat products. In this study, fresh beef was subjected to an alternating magnetic field of 2 mT during cold storage at 4°C, then microbial indicators, physicochemical properties of beef samples and its protein indicators were investigated. The results showed that the alternating magnetic field could inhibit the microbial growth on beef sample, and TVB‐N content, drip loss and characteristic putrefactive amine were lower than the control. The total bacterial count and TVB‐N value of beef samples in the control exceeded the threshold value on the 8th day, respectively, while the samples in the alternating magnetic field exceeded the threshold value on the 13th day. Meanwhile, it demonstrated that the field could delay the transformation of free amino acids to biogenic amines and inhibit the accumulation of bitter amino acids, so maintaining its nutritional characteristics. With the extension of storage period, the sulfhydryl content of beef myofibrillar proteins subjected to alternating magnetic field was lower than that of the control. It demonstrated that the protein oxidation of samples was inhibited, which would also be the reason the Ca2+‐ ATPase activity of myofibrillar proteins was maintained at a low level during the period. Furthermore, the upward trend of carbonyl group content was delayed. It provides a reference for the application of alternating magnetic field on cold storage of meat.

Nitrite and Nitrate Residue in Non-Heat Treated Meat Products Marketed in East Azerbaijan Province

Background: Nitrite and nitrate salts are used as preservatives in meat products to prevent the growth of pathogen organisms such as Clostridium botulinum. Nitrogen salts additives create the desired color in meat products. However, the use of these salts accelerates nitrosamine production and increases the risk of carcinogenesis. Hence, nitrate and nitrite consumption rate should be according to the approved standards. This analytical study is designed to determine nitrate and nitrite residue of non-heat-treated meat products including hamburger and kebab in East Azerbaijan Province, Iran during 2015-2020. Methods: 120 samples of non-heat-treated meat products from different brands were randomly collected. They consisted of 60 products manufactured in East Azerbaijan province and 60 products imported from other provinces. Nitrate and Nitrite residues in non-heat-treated meat products including hamburger and kebab were determined by spectrophotometric method. Results: Results showed that the residue levels of nitrate and nitrite content regarding non-heat- treated meat products were less than maximum residual limits (MRLs) of national standards. The study also indicated that frozen non-heated meat products did not have any nitrogenous additive. Conclusion: The results of this research revealed that the frozen non-heat treated meat products including hamburger and kebab, produced or consumed in East Azerbaijan province during 2015-2020 did not have nitrate and nitrite additives. Continuous monitoring to ensure the compliance of meat products with the standards is necessary.