A review on the relation between grinding process and quality of ground meat.

This review is providing an overview of the actual and past research in the field of ground meat. The forces that are acting in the meat grinder are well understood. The higher the forces that are acting on the meat while grinding, the stronger the disintegration of the meat cells after the process. These forces can be calculated as energy transfer in meat grinders using specific mechanical energy (SME). The amount of non-intact cells (ANIC) can be used to describe the extent of disintegrated cells. Different methods are available to rate the quality of ground meat, which is mainly influenced by the raw material and processing. Over the past decades of industrialization, the landscape of ground meat production has changed. However, the effects of the process adjustments on the quality of ground meat are not yet sufficiently described in the literature.

Comparison of genetic variations between high- and low-risk Listeria monocytogenes isolates using whole-genome de novo sequencing.

In this study, genetic variations and characteristics of Listeria monocytogenes isolates from enoki mushrooms (23), smoked ducks (7), and processed ground meat products (30) were examined with respect to hemolysis, virulence genes, growth patterns, and heat resistance. The isolates that showed the highest pathogenicity and the lowest pathogenicity were analyzed to obtain the whole-genome sequence, and the sequences were further analyzed to identify genetic variations in virulence, low-temperature growth-related, and heat resistance-related factors. All isolates had ß-hemolysis and virulence genes (actA, hlyA, inlA, inlB, and plcB). At low temperatures, isolates with high growth (L. monocytogenes strains SMFM 201803 SD 1-1, SMFM 201803 SD 4-2, and SMFM 201804 SD 5-3) and low growth (L. monocytogenes strains SMFM 2019-FV43, SMFM 2019-FV42, and SMFM 2020-BT30) were selected. Among them, L. monocytogenes SMFM 201804 SD 5-3 showed the highest resistance at 60°C and 70°C. The strains SMFM 201804 SD 5-3 (high-risk) and SMFM 2019-FV43 (low-risk) harbored 45 virulence genes; 41 single nucleotide variants (SNVs) were identified between these two isolates. A comparison of 26 genes related to low-temperature growth revealed 18 SNVs between these two isolates; a comparison of the 21 genes related to heat resistance revealed 16 SNVs. These results indicate that the differences in the pathogenicity of L. monocytogenes SMFM 201804 SD 5-3 and L. monocytogenes SMFM 2019-FV43 are associated with the SNVs identified in virulence genes, low-temperature growth-related genes, and heat resistance-related genes.

Colour and pigment in raw ground meat incorporated crushed garlic during the refrigerated storage: Their relationship to lipolytic and volatilomic changes.

The effects of freshly crushed garlic incorporated in raw ground meat at different rates 0 % to 2 % on colour, pigment forms, TBARS, peroxide, free fatty acids and volatilomic were investigated during 96 h storage at 4 °C. With advancing storage time and increasing garlic rate from 0 % to 2 %, the redness (a*), colour stability, oxymyoglobin and deoxymyoglobin decreased, but metmyoglobin, TBARS, peroxide, free fatty acids (C6, C15-C17), and aldehydes and alcohols, especially hexanal, hexanol, benzaldehyde, increased. Principal component analysis based on pigment, colour, lipolytic and volatilomic changes classified successfully the meat samples. Metmyoglobin was positively correlated with lipid oxidation products (TBARS, hexanal), but the other pigment forms and colour parameters (a* and b* values) were negatively correlated. Increased metmyoglobin proportion and decreased redness and colour stability may be used as reliable indicators of lipid oxidation. Also, the incorporation of fresh garlic into ground meat was not promising to increase oxidative stability.

Novel biphasic gels can mimic and replace animal fat in fully-cooked coarse-ground sausage.

Four biphasic gels (BPG) were developed and tested as pork fat replacers in coarse-ground fully-cooked sausages. An oleogel (OG) phase (92.5% high-oleic soybean oil, 7.5% rice bran wax) and one of two hydrogel (HG) phases (water and 7% or 8% gelatin) were combined in 7:3 or 6:4 OG:HG ratios, for a total of four test formulations. Control sausages were formulated to 27.5% fat and stored at 0-2 °C for 98 d. BPGs allowed for fat reductions of up to 26%. Visually, all BPGs resembled pork fat. There were no differences in external L* and a* but, internally, controls were darker and redder. Except for one control, there were no differences in Texture Profile Analysis (TPA) hardness, cohesiveness, springiness, and chewiness. Warner-Bratzler Shear (WBS) force was highest in 6:4 samples, which were also highest in Sensory First Bite Firmness and lowest in Smoked Sausage Aroma and Smoked Sausage Flavor. TBARS values remained steady, with no rancid flavors detected by the sensory panel.

Calidad microbiològica de la carne picada y detección de patógenos en muestras ambientales de carnicerías de la ciudad de Tandil, provincia de Buenos Aires,Argentina / Microbiological quality of fresh ground beef and detection of pathogens in environmental samples taken from butcher shops in the city of Tandil, Buenos Aires Province, Argentina

Resumen Este estudio evaluó las condiciones higiénico-sanitarias de carnicerías de la ciudadde Tandil (provincia de Buenos Aires) mediante una estimación del riesgo basada en encuestasdirigidas a revisar las buenas prácticas de manufactura y de higiene de los establecimientos. Seutilizó una escala de 1 a 100 para clasificar a los establecimientos en las categorías de riesgoalto (0-40), riesgo moderado (41-70) y riesgo bajo (71-100). A su vez, se evaluó la presencia deSalmonella spp., Staphylococcus aureus, Escherichia coli productor de toxina Shiga (STEC) encarne bovina picada y en muestras ambientales como mesada, cuchilla, picadora y manos delcarnicero. Las muestras se tomaron una sola vez e inmediatamente se refrigeraron y transpor-taron al laboratorio para su análisis. En el período de estudio todas las carnicerías (100) fueronclasificadas como de «riesgo bajo¼ y con buenas condiciones higiénico-sanitarias. No obstante,el 75% de las muestras de carne picada no cumplió con al menos uno de los criterios microbiológicos establecidos en el Artículo 255 del Código Alimentario Argentino. Se sugiere estableceruna estrategia tendiente a identificar los desvíos e implementar un plan de mejoras continuasen las carnicerías de la ciudad de Tandil.

Abstract The aim of this work was to evaluate the hygienic-sanitary conditions of butcher shops in Tandil, Buenos Aires Province, by estimating the risk based on good manufacturing and hygiene practices, through surveys of the establishments. The analysis was performed using a scale of 1-100, and classifying them as high risk (0-40), moderate risk (41-70) or low risk (71-100). The presence of Salmonella spp., Staphylococcus aureus and Shiga toxin-producing Escherichia coli (STEC) from both, ground beef and environmental samples such as countertop, cleaver, mincer and butcher's hands, taken at butcher shops was also evaluated. Sampling was performed only once and immediately refrigerated and transported to the laboratory for analysis. All butcher shops evaluated (100) were classified as "low risk'' with good hygienic-sanitary conditions. However, 75% of the ground beef samples analyzed did not meet at least one of the microbiological criteria established in the Código Alimentario Argentino [Argentine Food Code], article 255. We propose to establish a strategy to identify deviations and implement a plan for continuous improvement in butcher shops of Tandil city.

Evaluation of heat treatment for inactivation of norovirus genogroup II in foods.

The effective food processing technology is a key step in eliminating human noroviruses in foods mainly due to their stability in diverse environmental conditions. The aim of this study was to evaluate the effect of rising temperatures for inactivation of norovirus genogroup (G) II and murine norovirus 1 in samples of tomato sauce (72-74 °C for 1 min) and ground meat (100 °C for 30 min). Spiking experiments were carried out in triplicate using TRIzol® reagent method associated with quantitative polymerase chain reaction (qPCR) TaqMan™ system combined with previous free RNA digestion. Success rate and efficiency recoveries of both viruses as well limit of detection of a method for each matrix were also conducted. The heat treatment applied here proved to be efficient to reduce the burden of norovirus GII in a range of 1-4 log10 genomic copies per gram (percentage ranging from 0.45 to 104.54%) in both matrices. The experiments in this study showed that the results of norovirus GII and murine norovirus 1 in tomato sauce and ground meat tested during thermal treatments cannot be generalized to other food matrices, since there may be food-specific protective effects, as the presence of different components, that can interfere in virus inactivation. Studies using different food matrices reinforce the importance to investigate viruses' inactivation thermal processes in foods due to the resistance of these viruses to adverse conditions, contributing to food security in food virology.

Effect of the type of packaging on the shelf life of ground rabbit meat.

Rabbit meat consumption has increased worldwide due to its health benefits in humans but few studies addressed the stability of this food matrix. The effect of two types of packaging (vacuum, VP; and polystyrene tray overwrap with PVC/polyvinyl plastic film, PT) was evaluated on the microbial stability (psychrotrophic; PSY, lactic acid bacteria; LAB, initial coliforms counts) and physicochemical (pH, thiobarbituric acid reactive substances (TBARS), total volatile basic Nitrogen (TBV-N), color and drip loss) changes of ground rabbit meat during its storage at 4 ± 1 °C. VP packaging delayed PSY growth, lipid oxidation, protein degradation and undesirable color changes compared to PT samples. Shelf life of ground rabbit meat in vacuum condition could be around 10 days of storage, while PT samples presented a shorter shelf life of around 5 days. However, sensory studies must be performed in order to assure the exact shelf life of the final product.

[Microbiological quality of fresh ground beef and detection of pathogens in environmental samples taken from butcher shops in the city of Tandil, Buenos Aires Province, Argentina]. / Calidad microbiológica de la carne picada y detección de patógenos en muestras ambientales de carnicerías de la ciudad de Tandil, provincia de Buenos Aires, Argentina.

The aim of this work was to evaluate the hygienic-sanitary conditions of butcher shops in Tandil, Buenos Aires Province, by estimating the risk based on good manufacturing and hygiene practices, through surveys of the establishments. The analysis was performed using a scale of 1-100, and classifying them as high risk (0-40), moderate risk (41-70) or low risk (71-100). The presence of Salmonella spp., Staphylococcus aureus and Shiga toxin-producing Escherichia coli (STEC) from both, ground beef and environmental samples such as countertop, cleaver, mincer and butcher's hands, taken at butcher shops was also evaluated. Sampling was performed only once and immediately refrigerated and transported to the laboratory for analysis. All butcher shops evaluated (100) were classified as "low risk" with good hygienic-sanitary conditions. However, 75% of the ground beef samples analyzed did not meet at least one of the microbiological criteria established in the Código Alimentario Argentino [Argentine Food Code], article 255. We propose to establish a strategy to identify deviations and implement a plan for continuous improvement in butcher shops of Tandil city.

Lipidomics profile of irradiated ground meat to support food safety.

Meat irradiation is considered as an effective treatment that expose the advantageous effects on meat preservation. This research, based on untargeted LC-HR orbitrap MS-based lipidomics strategy was meant to estimate the alterations in lipid profile of irradiated chicken, turkey and mixed (chicken, turkey and pork) ground meat in order to evaluate if exists any food safety issue concerning the lipidome alteration. Special attention was paid on oxidation triggered by irradiation. All three matrices exhibited a characteristic lipidome profile which was affected differently by five levels of irradiation intensity. Overall, 345 lipids categorized into 14 subclasses were identified. Remarkably, the oxidized glycerophosphoethanolamines and oxidized glycerophosphoserines were identified in irradiated turkey meat, while for all three categories a characteristic diacylglycerols profile was recognised. Our analytical approach highlighted that the estimation of qualitative variations in lipid portion might be valuable in food inspection purposes, especially when the samples from animal origin are suspected on irradiation treatment.

Investigation of Escherichia coli O157:H7 Survival and Interaction with Meal Components during Gastrointestinal Digestion.

Escherichia coli O157:H7 is responsible for foodborne poisoning, incriminating contaminated animal food and especially beef meat. This species can survive in the digestive tract, but, up to now, very few studies have considered its survival during the gastrointestinal digestion of meat. The present study aimed to investigate the survival of the pathogenic strain E. coli O157:H7 CM454 during the gastrointestinal digestion of ground beef meat and its interactions with meal components using a semidynamic digestive model. The CM454 strain in meat survived throughout digestion despite acidic pH (pH 2) and the presence of bile salts. The addition of nitrite and ascorbate in the digestion medium led to a decrease in strain survival. During digestion, a release of free iron was observed, which was accentuated in the presence of the CM454 strain. In addition, the strain modified the Fe2+/Fe3+ ratio, in favor of Fe2+ compared to the noninoculated meat sample. In the presence of nitrite, nitroso compounds such as nitrosamines, nitrosothiols, and nitrosylheme were formed. E. coli O157:H7 CM454 had no impact on N-nitrosation but seemed to decrease S-nitrosation and nitrosylation.

Preparation of on-package halochromic freshness/spoilage nanocellulose label for the visual shelf life estimation of meat.

In this work, grape anthocyanins (GA) were embedded in bacterial nanocellulose (BNC) by ex-situ method to fabricate an easy-to-use colorimetric label. The label revealed visible color responses to the pH buffers (2-11). According to the color parameter results [L*, a*, b*, and total color difference (TCD)], the label also presented appropriate color stability during the 60-day storage. During the application in minced beef, the label was bright red on the 1st day of storage at 4 °C. In accordance with the meat quality parameters [TVB-N, total mesophilic count, and sensory attributes], the label turned into purplish-red color on the 3rd and 5th days of storage (medium freshness meat) and turned into blue on the 7th day, representing the spoilage state. All the mentioned color changes could be distinguished by naked eyes. A strong Pearson's correlation coefficient was obtained between the TCD values and meat quality parameters, confirming the capability of the pH-sensing label to correctly distinguish the fresh meat from the spoiled meat.

Inactivation of Shiga Toxin-Producing Escherichia coli in Refrigerated and Frozen Meatballs Using High Pressure Processing.

High pressure processing (HPP) was evaluated to inactivate Shiga toxin-producing Escherichia coli (STEC) in raw meatballs. Ground meat (>90% lean) was inoculated (ca. 7.0 log CFU/g) with a rifampicin-resistant cocktail of eight STEC strains (O26:H11, O45:H2, O103:H2, O104:H4, O111:H-, O121:H19, O145:NM, and O157:H7). Inoculated ground beef, ground veal, or a mixture of ground beef, pork, and veal were separately mixed with liquid whole eggs and seasonings, shaped by hand into meatballs (40 g each), and stored at -20 or at 4 °C for at least 18 h. Samples were then exposed to 400 or 600 MPa for 0 to 18 min. There were no differences (p > 0.05) in pathogen reduction related to the species of meat used or for meatballs that were refrigerated (0.9 to 2.9 log CFU/g) compared to otherwise similar meatballs that were stored frozen (1.0 to 3.0 log CFU/g) prior to HPP treatment. However, less time was needed to achieve a ≥ 2.0 log CFU/g reduction at 600 MPa (1 to 3 min) compared to 400 MPa (at least 9 min). This work provides new and practically useful information on the use of HPP to inactivate STEC in raw meatballs.

Development of a Rapid On-Site Method for the Detection of Chicken Meat in Processed Ground Meat Products by Using a Direct Ultrafast PCR System.

ABSTRACT: In this study, we developed a rapid on-site detection method by using direct ultrafast PCR coupled with a microfluidic chip to identify the presence of chicken meat in processed ground meat products. Chicken-specific PCR primer targeting mitochondrial 16S rRNA gene was newly designed, and its specificity was confirmed against 17 other animal species and 4 different chicken meat samples from different countries of origin. The sensitivity of the chicken-specific ultrafast PCR was 0.1 pg of chicken DNA. To evaluate the limit of detection of the direct ultrafast PCR method, different percentages of chicken meat mixed with pork or beef were prepared. The limit of detection of the direct ultrafast PCR method for the chicken meat-pork and chicken meat-beef mixtures was 0.1% for both raw meat and autoclaved meat. This method was used for 15 commercialized processed ground meat products. In this method, the target sequence was successfully amplified, and the presence of chicken meat in processed ground meat products was identified within approximately 25 min, including the time for sample preparation. Thus, our study shows that this developed direct ultrafast PCR method is a rapid and accurate method for on-site detection of chicken DNA in commercial food products.

The effect of rosemary Extract and cold plasma treatments on bacterial community diversity in poultry ground meats.

To provide safer food, many technologies have been used to preserve food. One such technology is cold plasma, which can reduce viable bacterial counts in various food matrices. However, bacterial communities in food matrices before and after cold plasma treatment have not been investigated. In this communication, the EcoPlates™ were used to physiologically profile bacterial communities from poultry ground meat treated with rosemary, cold plasma or both. The cultures in the plates were incubated at 25 °C for seven days in an OmniLog® system. Responses of the bacterial communities to 31 chemicals were measured on formazan production. The results show that the three parameters of the Gompertz growth curves were observed in all samples, 2-hydroxybenzoic acid could not be used, while pyruvic acid methyl ester was used for a carbon source by the bacterial communities from all meat samples, each bacterial community metabolized different numbers of chemical compounds at different rates, and reduction of bacterial functional diversity was observed in the poultry meat samples treated with cold plasma and rosemary. In the future, investigations on whether the physiological profiling in bacterial communities be used as an indicator for effectiveness of cold plasma treatment of meat samples.

Quantitative Microbial Risk Assessment for Campylobacter jejuni in Ground Meat Products in Korea.

This study evaluated Campylobacter jejuni risk in ground meat products. The C. jejuni prevalence in ground meat products was investigated. To develop the predictive model, survival data of C. jejuni were collected at 4°C-30°C during storage, and the data were fitted using the Weibull model. In addition, the storage temperature and time of ground meat products were investigated during distribution. The consumption amount and frequency of ground meat products were investigated by interviewing 1,500 adults. The prevalence, temperature, time, and consumption data were analyzed by @RISK to generate probabilistic distributions. In 224 samples of ground meat products, there were no C. jejuni-contaminated samples. A scenario with a series of probabilistic distributions, a predictive model and a dose-response model was prepared to calculate the probability of illness, and it showed that the probability of foodborne illness caused by C. jejuni per person per day from ground meat products was 5.68×10-10, which can be considered low risk.

Antioxidant Activities of Sorghum Kafirin Alcalase Hydrolysates and Membrane/Gel Filtrated Fractions.

Sorghum has a significant amount of proteins, especially kafirin; however, limited information is available on evaluating its potential for peptide antioxidants. The objectives of this study were to: (1) investigate the effects of two key variables, enzyme-to-substrate ratio and reaction time on kafirin hydrolysis using Alcalase; (2) evaluate the antioxidant performances of the hydrolysates and fractions from membrane ultrafiltration and gel filtration; and (3) identify peptide sequences in the antioxidant fraction using MALDI-TOF/TOF MS. Kafirin hydrolysates prepared at enzyme-to-substrate ratio of 0.4 Au/g and 4 h had a good balance of antioxidant activity, yield, and economic efficiency. Medium-sized fraction of hydrolysates (5-10 kDa) from membrane filtration possessed the highest antioxidant activities among various fractions. The fraction also unveiled a good inhibition effect against lipid oxidation in emulsion and ground meat systems. Smaller-sized fraction (F3) collected through gel-filtration chromatography had significantly stronger antioxidant activities than other fractions, and 26 representative peptide sequences were identified in the fraction.

Genotypic and Phenotypic Characterization of Salmonella Isolated from Fresh Ground Meats Obtained from Retail Grocery Stores in the Brookings, South Dakota, Area.

Salmonella is one of the most common foodborne pathogens found in retail fresh meat products. The purpose of this study was to characterize the Salmonella that is found in common types of fresh ground meats available to consumers in grocery stores in the Brookings, South Dakota, area. Salmonella serotypes were detected in 50 (19%) of 261 retail fresh ground meat samples, with 2 (2%) of 115 ground turkey samples, 6 (14%) of 42 chicken samples, and 42 (40%) of 104 ground pork samples testing positive for Salmonella. The Salmonella isolates were sequenced using an Illumina MiSeq genome sequencer. The resulting genomic sequences were analyzed to determine the serotypes of the isolates and to detect the presence of virulence and antibiotic resistance genes. The Salmonella isolated from the ground meats belonged to 23 different serotypes. The predominant serotype isolated from ground chicken was Enteriditis (5 of 6, 83%). Among the ground pork isolates, the most common serotypes were the potential monophasic variant of Typhimurium (5 of 42, 12%), Uganda (5 of 42, 12%), Anatum (4 of 42, 10%), Derby (3 of 42, 7%), Infantis (3 of 42, 7%), and London (3 of 42, 7%). Among the 45 Salmonella isolates tested to determine their resistance to common veterinary antibiotics, 25 (56%) were found to be susceptible to all 14 antibiotics tested, 11 (24%) were resistant to 1 antibiotic, 4 (9%) were resistant to 2 antibiotics, 1 (2%) was resistant to 3 antibiotics, 2 (4%) were resistant to 4 antibiotics, 1 (2%) was resistant to 8 antibiotics, and 1 (2%) was resistant to 10 antibiotics. The most common antibiotic resistances observed in this study were to streptomycin (15 of 45, 33%), tetracycline (11 of 45, 24%), and sulfisoxazole (7 of 45, 16%). The results of phenotypic evaluation of antibiotic resistance profiles of Salmonella isolates correlated well with the antibiotic resistance genes detected in the genomic sequences of the isolates.

Colour and oxidative stability of mince produced from fresh and frozen/thawed fallow deer (Dama dama) meat.

Colour and oxidative stability of minced meat from fresh and frozen/thawed fallow deer was investigated. For the seven fallow deer harvested, half of the meat was minced fresh and half was frozen (-20°C) for 2months under vacuum prior to grinding. Surface colour attributes, myoglobin content and surface redox forms, pH and lipid oxidation of the mince were measured during eight days of display storage. Proximate composition was determined in mince on day 0, fatty acid composition on day 0 and 8. Freezing had no effect on the proximate composition or fatty acid composition of the mince. Frozen meat mince had lower (P≤0.05) total myoglobin content but higher (P≤0.05) decrease in redness (a*) during display storage, higher (P≤0.05) accumulation of metmyoglobin at the surface from day 2 and higher (P≤0.05) TBARS values. Results showed shorter colour and oxidative stability for frozen meat mince as compared to mince from fresh meat. Display storage however did not affect fatty acid composition.

Impact of Added Encapsulated Phosphate Level on Lipid Oxidation Inhibition during the Storage of Cooked Ground Meat.

The effect of levels (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) of added encapsulated (e) phosphate (sodium tripolyphosphate, STP; sodium hexametaphosphate, HMP; sodium pyrophosphate, SPP) on lipid oxidation inhibition during storage (0, 1, and 7 d) of ground meat (chicken, beef) was evaluated. The use of eSTP and eSPP resulted in lower and higher cooking loss (CL) compared to eHMP, respectively (P < 0.05). Increasing encapsulated phosphate level (PL) enhanced the impact of phosphates on CL in both chicken and beef samples (P < 0.05). Encapsulated STP increased pH, whereas eSPP decreased pH (P < 0.05). pH was not affected by PL. The highest orthophosphate (OP) was obtained with eSTP, followed by eSPP and eHMP (P < 0.05). The level of OP determined in both chicken and beef samples increased (P < 0.05) during storage. Increasing PL caused an increase in OP (P < 0.05). The highest reduction rate in the formation of thiobarbituric acid reactive substances (TBARS) and LPO for both meat species were obtained with eSPP, followed by eSTP and eHMP (P < 0.05). Increasing PL resulted in lower TBARS and LPO (P < 0.05). Findings suggest that encapsulated phosphates can be a strategy to inhibit lipid oxidation for the meat industry and the efficiency of encapsulated phosphates on lipid oxidation inhibition can be enhanced by increasing PL.

Epidemiological alteration in pathogens found in ground meat in Iran: unexpected predominance of vancomycin-resistant Enterococcus faecalis.

Colonization of the human and animal intestinal tract with potential pathogenic bacteria is correlated with the risk of contamination of food products. The current study analyzed the prevalence of Enterococcus faecalis and Escherichia coli O157H7 in ground meat in Ilam, Iran. Both index organisms were identified following standard food microbiological methods. For E. faecalis, the susceptibility to vancomycin was tested, and PCR was used to check for the vanA gene. E. faecalis was present in all 24 ground meat samples, with no E. coli O157H7 detected in samples. The analysis showed the presence of the vanA gene in 5/24 vancomycin resistant enterococci. In conclusion, this study for the first time demonstrates the presence of vancomycin-resistant enterococci in ground meat in Iran. This observation warrants further epidemiologic investigation and should be followed up in the future.