Evaluation and predictive modeling of shelf life of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures

Incorporation of hydrogen-producing magnesium into minced beef meat protects the quality attributes and safety of the product during cold storage

The impact of hydrogen (H2) producing magnesium (Mg) incorporation into minced beef meat (MBM) on the quality and safety of the product was investigated. The H2-producing Mg (H2-P-Mg)-incorporated MBMs were vacuumed (VP) and stored at 4 °C for 12 days. Other MBMs were vacuumed and gassed with H2 or N2. At the end of storage, the lowest browning index values were for H2 and H2-P-Mg samples. H2- PMg and VP methods generally decreased the counts of mesophilic and psychrotrophic bacteria and yeast molds and restricted the formation of thiobarbituric acid reactive substances and biogenic amines. Heat mapping, PCA, and multivariate analysis methods confirmed chemical analysis results. The volatile compounds were at their highest levels in the control samples at the end of storage, followed by H2, N2, H2-P-Mg, and VP samples. Using the H2-P-Mg method in MBM preparation could protect the quality characteristics and safety of the product during cold storage.

Advancements in Predictive Microbiology: Integrating New Technologies for Efficient Food Safety Models

Predictive microbiology is a rapidly evolving field that has gained significant interest over the years due to its diverse application in food safety. Predictive models are widely used in food microbiology to estimate the growth of microorganisms in food products. These models represent the dynamic interactions between intrinsic and extrinsic food factors as mathematical equations and then apply these data to predict shelf life, spoilage, and microbial risk assessment. Due to their ability to predict the microbial risk, these tools are also integrated into hazard analysis critical control point (HACCP) protocols. However, like most new technologies, several limitations have been linked to their use. Predictive models have been found incapable of modeling the intricate microbial interactions in food colonized by different bacteria populations under dynamic environmental conditions. To address this issue, researchers are integrating several new technologies into predictive models to improve efficiency and accuracy. Increasingly, newer technologies such as whole genome sequencing (WGS), metagenomics, artificial intelligence, and machine learning are being rapidly adopted into newer-generation models. This has facilitated the development of devices based on robotics, the Internet of Things, and time-temperature indicators that are being incorporated into food processing both domestically and industrially globally. This study reviewed current research on predictive models, limitations, challenges, and newer technologies being integrated into developing more efficient models. Machine learning algorithms commonly employed in predictive modeling are discussed with emphasis on their application in research and industry and their advantages over traditional models.

Fabrication of double layer nanoparticle infused starch-based thermoplastic food packaging system for meat preservation

The current work aims to produce nanoparticle-infused starch-based bioactive thermoplastic packaging films. The FeO and ZnO nanoparticles were examined to be potential active ingredients for the production of nanoparticle-infused bioactive thermoplastic packaging films. The bio-thermoplastic films infused with FeO and ZnO nanoparticles showed high oxygen scavenging and antimicrobial activity, respectively. Consecutively, both films were combined to form a double-layer Nano-Biothermoplastic packaging system for food preservation. The distribution and diffusion of nanoparticles in starch-based films were examined to be influenced by the amorphous character of starch and the swelling index of the film, respectively. The amorphous property of starch molecules showed a masking effect on the crystalline characteristics of nanoparticles in Nano-Biothermoplastic films. The diffusion of nanoparticles from the Nano-Biothermoplastic packaging system was found to influence the microbial, chemical, and color characteristics of mutton and chicken meat stored at 4 °C.

Antioxidant potential of coffee husks in fresh pork sausage

Coffee husks, a by-product of dry coffee processing, present a disposal problem in coffee-producing countries. Valorization of this residue is necessary to reduce its environmental impact and improve benefits to the producer. This study evaluated the antioxidant effect of coffee husks on physicochemical properties and sensory liking of fresh sausages packaged in aerobic (AEP) or modified atmosphere packaging (MAP) (20% CO2 + 80%N2). Fresh sausages were prepared with different antioxidants: no addition (control C), sodium nitrite (T2), sodium nitrite + sodium erythorbate + BHA/BHT blend (T3), sodium nitrite + coffee husk 1% (T4), sodium nitrite + coffee husk 2% (T5). Physicochemical properties (TBARs, carbonyl content, pH and instrumental color) were analyzed to evaluate the effect of added synthetic and natural antioxidants on fresh sausages. A sensory test (n = 100) was conducted to assess consumer liking of fresh sausages stored in AEP and MAP. The addition of coffee husks reduced lipid oxidation in fresh sausages, especially under MAP packaging, but did not affect carbonyl content. Consumers reported lower liking scores for products packed in MAP. The addition of coffee husks did not affect the degree of liking. Valorization of coffee husks as an antioxidant in fresh meat products is a viable natural option for the meat industry.

Bibliometric Review on the Volatile Organic Compounds in Meat

Meat flavor is an important aspect of meat quality that also influences consumer demand, and is therefore very important for the meat industry. Volatile organic compounds (VOCs) contribute in large part to the flavor of meat, and while increasing numbers of articles are published on this topic, reviews of these articles are very scarce. Therefore, our aim was to perform a bibliometric analysis of the scientific publications on VOCs in meat over the period 2000-2020. We selected 611 scientific sources from the Scopus database related to VOCs in meat (seafood excluded). The bibliometric information retrieved included journals, authors, countries, institutions, keywords, and citations. From this analysis, we drew up a list of the most important journals, authors, countries, and institutions, and the trends in VOC research on meat. We conducted a social network analysis (SNA) to identify the collaborations among the many authors and countries, and a keyword analysis to generate a network map of the authors' keywords. We also determined which meat species were most frequently chosen as research subjects, traced the evolution of the various methods/instruments used, and explored the research tendencies. Finally, we point out the need for further research in defining meat quality, improving meat flavor, identifying adulterants, and certifying the authenticity of meat.

Qualitative and Quantitative Detection of Food Adulteration Using a Smart E-Nose

Food adulteration is the most serious problem found in the food industry as it harms people's healths and undermines their beliefs. The present study is focused on designing and developing a smart electronic nose (SE-Nose) for the qualitative and quantitative fast-track detection of food adulteration. The SE-Nose methodology is comprised of a dataset, sample slicing window protocol, normalization, pattern recognition, and output blocks. The dataset pork adulteration in beef is used to validate the SE-Nose methodology. The sample slicing window protocol extracts the early part of the signal. The sample slicing window protocol and pattern recognition models (classification and regression models) together achieved the high-performance and fast-track detection of pork adulteration in beef. With classification models, the qualitative analysis of adulteration is measured, and with regression models, the quantitative analysis of adulteration is measured. An accuracy of 99.996% and an RMSE of 0.02864 were achieved with the SVM classification and regression model. The recognition time in detecting pork adulteration in beef with SVM models is 40 s. With the proposed SE-Nose methodology, the recognition time is reduced by one-third. To validate the classification and regression models, a 10-fold cross-validation method was used.

Vacuum Packaging Maintains Fresh Characteristics of Previously Frozen Beef Steaks during Simulated Retail Display

The impact of frozen storage on beef steaks prior to the retail setting may result in changes to the quality and safety of the packaged meat. Therefore, the objective of the current study was to evaluate fresh characteristics on previously frozen steaks during a simulated retail display. Steaks were allocated to one of three packaging treatments (MB, MDF, MFS) and stored frozen (−13 °C) for 25 days in the absence of light. After thawing, steaks were stored in a lighted retail case at 3 °C and evaluated for instrumental surface color, pH, purge loss, lipid oxidation, and microbial spoilage organisms throughout the 25-day fresh display period. There was an increase (p < 0.05) for aerobic plate counts and lipid oxidation from day 20 through 25 on steaks packaged in MFS and MDF, respectively. Steaks packaged in MB were redder (p < 0.05) and more vivid (C*) as storage time increased. Whereas lipid oxidation was greater (p < 0.05) throughout the entire display for steaks packaged in MFS and MDF. It is evident that barrier properties of MB limiting oxygen exposure of the steak preserved fresh meat characteristics after frozen storage. Results from the current study suggest that vacuum packaging films can aid in retarding detrimental effects caused by frozen storage after placing the steaks in fresh retail conditions.

Predictive modelling of TBARS changes in the intramuscular lipid fraction of raw ground pork enriched with plant extracts

The aim of the study was to develop and compare the predictive models of lipid oxidation in minced raw pork meat enriched with selected plant extracts (allspice, basil, bay leaf, black seed, cardamom, caraway, cloves, garlic, nutmeg, onion, oregano, rosemary and thyme) by investigation TBARS values changes during storage at different temperatures. Meat samples with extract addition were stored under various temperatures (4, 8, 12, 16, and 20°C). TBARS values changes in samples stored at 12°C were used as external validation dataset. Lipid oxidation was evaluated by the TBARS content. Lipid oxidation increased with storage time and temperature. The dependence of lipid oxidation on temperature was adequately modelled by the Arrhenius and log-logistic equation with high R² coefficients (0.98–0.99). Kinetic models and artificial neural networks (ANNs) were used to build the predictive models. The obtained result demonstrates that both kinetic Arrhenius (R² = 0.83) and log-logistic (R² = 0.84) models as well as ANN (R² = 0.99) model can predict TBARS changes in raw ground pork meat during storage.

Effect of temperature abuse on quality and metabolites of frozen/thawed beef loins

The objective of this study was to examine the effect of temperature abuse prior to cold storage on changes in quality and metabolites of frozen/thawed beef loin. The aerobic packaged samples were assigned to three groups: refrigeration (4°C) (CR); freezing (–18°C for 6 d) and thawing (20±1°C for 1 d), followed by refrigeration (4°C) (FT); temperature abuse (20°C for 6 h) prior to freezing (–18°C for 6 d) and thawing (20±1°C for 1 d), followed by refrigeration (4°C) (AFT). FT and AFT resulted in higher volatile basic nitrogen (VBN) values than CR (p<0.05), and these values rapidly increased in the final 15 d. Cooking loss decreased significantly with an increase in the storage period (p<0.05). In addition, cooking loss was lower in the FT and AFT groups than in the CR owing to water loss after storage (p<0.05). A scanning electron microscope (SEM) revealed that frozen/thawed beef samples were influenced by temperature abuse in the structure of the fiber at 15 d. Metabolomic analysis showed differences among CR, FT, and AFT from partial least square discriminant analysis (PLS-DA) based on proton nuclear magnetic resonance (¹H NMR) profiling. The treatments differed slightly, with higher FT than AFT values in several metabolites (phenylalanine, isoleucine, valine, betaine, and tyrosine). Overall, temperature abuse prior to freezing and during thawing of beef loin resulted in accelerated quality changes.

Vacuum Packaging Can Extend Fresh Color Characteristics of Beef Steaks during Simulated Display Conditions

Packaging technology is evolving, and the objectives of this study were to evaluate instrumental surface color, expert color evaluation, and lipid oxidation (TBARS) on beef longissimus lumborum steaks packaged in vacuum-ready packaging (VRF) or polyvinyl chloride (PVC) overwrap packaging. Paired strip loins (Institutional Meat Purchasing Specifications # 180) were cut into 2.54-cm-thick steaks and assigned randomly to one of two packaging treatments, VRF or PVC. Steaks packaged in VRF were lighter in color (p < 0.05) as the display period increased, whereas steaks packaged in PVC became darker (p < 0.05). Redness (a*) values were greater (p < 0.05) for PVC steaks until day 5, whereas VRF steaks had a greater (p < 0.05) surface redness from day 10 to 35 of the display period. Calculated spectral values of red to brown were greater (p < 0.05) for steaks in VRF than PVC. In addition, expert color evaluators confirmed VRF steaks were less brown and less discolored (p < 0.05) from day 5 to 35 of the display. Nonetheless, lipid oxidation was greater (p < 0.05) for PVC steaks from day 10 through day 35 of the display. Results from this study suggest that the use of vacuum packaging for beef steaks is plausible for maintaining surface color characteristics during extended display periods.

A Multi-Model Approach to Implement a Dynamic Shelf Life Criterion in Meat Supply Chains

The high perishability of fresh meat results in short sales and consumption periods, which can lead to high amounts of food waste, especially when a fixed best-before date is stated. Thus, the aim of this study was the development of a real-time dynamic shelf-life criterion (DSLC) for fresh pork filets based on a multi-model approach combining predictive microbiology and sensory modeling. Therefore, 647 samples of ma-packed pork loin were investigated in isothermal and non-isothermal storage trials. For the identification of the most suitable spoilage predictors, typical meat quality parameters (pH-value, color, texture, and sensory characteristics) as well as microbial contamination (total viable count, Pseudomonas spp., lactic acid bacteria, Brochothrix thermosphacta, Enterobacteriaceae) were analyzed at specific investigation points. Dynamic modeling was conducted using a combination of the modified Gompertz model (microbial data) or a linear approach (sensory data) and the Arrhenius model. Based on these models, a four-point scale grading system for the DSLC was developed to predict the product status and shelf-life as a function of temperature data in the supply chain. The applicability of the DSLC was validated in a pilot study under real chain conditions and showed an accurate real-time prediction of the product status.

Predictive Modeling of Thiol Changes in Raw Ground Pork as Affected by 13 Plant Extracts-Application of Arrhenius, Log-logistic and Artificial Neural Network Models

In this study, predictive models of protein oxidation, expressed as the content of thiol groups (SH), in raw ground pork were established and their accuracy was compared. The SH changes were monitored during, maximum, 11 days of storage at five temperature levels: 4, 8, 12, 16, and 20 °C. The effect of 13 plant extracts, including spices such as allspice, black seed, cardamom, caraway, cloves, garlic, nutmeg, and onion, and herbs such as basil, bay leaf, oregano, rosemary, and thyme, on protein oxidation in pork was studied. The zero-order function was used to described SH changes with time. The effect of temperature was assessed by using Arrhenius and log–logistic equations. Artificial neural network (ANN) models were also developed. The results obtained showed very good acceptability of the models for the monitoring and prediction of protein oxidation in raw pork samples. High average R² coefficients equal to 0.948, 0.957, and 0.944 were obtained for Arhhenius, log-logistic and ANN models, respectively. Multiple linear regression (MLR) was used to assess the influence of plant extracts on protein oxidation and showed oregano as the most potent antioxidant among the tested ones in raw ground pork.

Prediction of Thiol Group Changes in Minced Raw and Cooked Chicken Meat with Plant Extracts-Kinetic and Neural Network Approaches

Simple Summary

Demand for poultry meat (chickens and turkeys) is constantly increasing. The upward trend in the production and consumption of poultry meat has two reasons. The first is the financial aspect because chicken meat is relatively cheap. The second reason is the nutritional and health aspect. Although the meat has high nutritional, dietary, culinary, technological, and sensory values, it is very susceptible to undesirable changes during storage, mainly due to the growth of microflora but also due to lipid and protein oxidation. The use of plant extracts in food technology is multifunctional, as they exhibit antioxidant and antibacterial effects and have a beneficial effect on the texture of meat and meat products. Moreover, the antioxidant effect of compounds isolated from plants may influence consumer health. Antioxidants of plant origin can be used as an additive to animal feed, as well as a component of stuffing or marinating mixes for meat. In addition, they are used in the coating of raw materials or in active packaging for food products. So far, many studies have shown the positive effect of plant and plant extract addition to meat on the oxidative status of its protein. However, the predictive approach to protein oxidation in raw meat is still little described. This study has demonstrated the potential usefulness of the kinetic model as well as models based on artificial neural networks (ANNs) to the realistic prediction of protein oxidation expressed as thiol group (SH) changes in raw and cooked chicken meat during storage. Such predictive models allow us to predict oxidative changes in minced meat under different time and temperature conditions as minced meat is particularly susceptible to oxidation through exposure to oxygen during the mincing process itself and through the increased contact surface with oxygen. This knowledge is very useful in designing food products and predicting their shelf-life. Additionally, the effectiveness of various spices in the raw and cooked meat system were compared. Meat is a very complex system and, according to the research, there is no direct correlation between the anti-oxidant activity of the spice itself and its antioxidant effectiveness in the product.

Abstract

The aim of the study was to develop predictive models of thiol group (SH) level changes in minced raw and heat-treated chicken meat enriched with selected plant extracts (allspice, basil, bay leaf, black seed, cardamom, caraway, cloves, garlic, nutmeg, onion, oregano, rosemary, and thyme) during storage at different temperatures. Meat samples with extract addition were stored under various temperatures (4, 8, 12, 16, and 20 °C). SH changes were measured spectrophotometrically using Ellman’s reagent. Samples stored at 12 °C were used as the external validation dataset. SH content decreased with storage time and temperature. The dependence of SH changes on temperature was adequately modeled by the Arrhenius equation with average high R² coefficients for raw meat (R² = 0.951) and heat-treated meat (R² = 0.968). Kinetic models and artificial neural networks (ANNs) were used to build the predictive models of thiol group decay during meat storage. The obtained results demonstrate that both kinetic Arrhenius (R² = 0.853 and 0.872 for raw and cooked meat, respectively) and ANN (R² = 0.803) models can predict thiol group changes in raw and cooked ground chicken meat during storage.

Predictive Modeling of Changes in TBARS in the Intramuscular Lipid Fraction of Raw Ground Beef Enriched with Plant Extracts

The aim of the study was to develop and compare the predictive models of lipid oxidation in minced raw beef meat enriched with selected plant extracts (allspice, basil, bay leaf, black seed, cardamom, caraway, cloves, garlic, nutmeg, onion, oregano, rosemary and thyme) expressed as value changes of TBARS (thiobarbituric acid reactive substances) in various time/temperature conditions. Meat samples were stored at the temperatures of 4, 8, 12, 16 and 20 °C. The value changes of TBARS in samples stored at 12 °C were used as the external validation dataset. Lipid oxidation increased significantly with storage time and temperature. The rate of this increase varied depending on the addition of the plant extract and was the most pronounced in the control sample. The dependence of lipid oxidation on temperature was adequately modeled by the Arrhenius and log-logistic equation with high average R2 coefficients (≥0.98) calculated for all extracts. Kinetic models and artificial neural networks (ANNs) were used to build the predictive models. The obtained result demonstrates that both kinetic Arrhenius (R2 = 0.972) and log-logistic (R2 = 0.938) models as well as ANN (R2 = 0.935) models can predict changes in TBARS in raw ground beef meat during storage.

The Use of Modeling Tools to Better Evaluate the Packaging Benefice on Our Environment

Packaging play a key role on food quality preservation and shelf-life increase. Even if the link between shelf life and food loss has not yet clearly been formalized, it is generally observed that a well-designed packaging contributes to reduce food loss and waste and thus the corresponding useless negative impact that producing and distributing uneaten or inedible food has on our environment and economy. In order to anticipate the usage benefit of a given packaging, decision making tools are needed to be developed. While some authors' separately showed the importance of shelf life model, food loss and waste prediction model and Life Cycle Analysis, so far no connection was really made between them. In this context, this paper aims to analyze the different mathematical modeling approaches proposed in the available scientific literature, from the prediction of food shelf life gain thanks to well-designed packaging to the environmental benefice due to the decrease of food loss and waste. The article presents a review of 29 models developed on this thematic during the last two decades. The analyzed models were split in three categories: (1) the food shelf life models, (2) the models linking shelf life to food loss and waste, and (3) the Life Cycle Analysis including direct (production, processing and end of life) and indirect (food loss and waste) packaging environmental impacts. In one hand, the review showed that if many predicting approaches were conducted to assess food shelf life, only few of them were enough mechanistic (by coupling mass transfer to food deterioration) to be used in other conditions than the ones initially studied. Moreover, the consumers' practices and believes being strongly influent on the quantity of food waste at household, it should be more systematically integrated in the food loss and waste estimation for a fairer evaluation. On the other hand, this review highlighted that even if indirect environmental benefit of packaging, e.g., through food loss and waste decrease, is more and more integrated in life cycle analyses of the food packaging system, most of studies were only based on rough estimation and not on real quantification of the food loss and waste reduction obtained thanks to the well-designed packaging. Therefore, further research is needed to facilitate the representation/quantification of the links between shelf life increase for packed food, resulting food loss and waste reduction and environmental benefit to support the packaging sectors to choose and validate the best packaging solution to decrease the environmental impact of food/packaging system.

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.

Evaluation of microbiological, chemical, and sensory properties of cooked probiotic sausages containing different concentrations of astaxanthin, thymol, and nitrite

In this study, the effects of different concentrations of thymol and astaxanthin on control of Clostridium perfringenes and also microbial, chemical, and organoleptic properties of common and probiotic beef cooked sausages containing two levels of nitrite during storage at refrigerated condition during 45 days were evaluated. Based on findings, control group had significantly higher total volatile base nitrogen (TVB-N) than nitrite-, thymol-, and astaxanthin-treated samples. At the end of the storage time in control, thiobarbituric acid reactive substances (TBARS) value reached 1.96 mg/kg, while the values for treated samples remained lower than 1.63 mg/kg. Final count of lactic acid bacteria decreased approximately 1.67-3.79 log CFU/g in treated samples compared with the control group (p < .05). A reduction between 1.46 and 2.46 log CFU/g in C. perfringenes count was recorded for the treated samples in comparison with control group after 45 days of storage.

Developing a Commercial Antimicrobial Active Packaging System of Ground Beef Based on "Tsipouro" Alcoholic Distillate

The present study aimed to develop a commercial active packaging system of ground beef, by exploiting the antimicrobial and antioxidant properties of a traditional Greek alcoholic distillate called “tsipouro”. Commercial packages (500 g) were used and 40 mL of “tsipouro” was added in absorbent pads placed underneath the ground beef, while 10 mL was also mounted under the packaging film, facing the headspace. Samples were packaged in 80% O₂: 20% CO₂ and stored at 0, 4, 8, and 12 °C. Total Viable Counts, pseudomonads, Brochothrix thermosphacta, lactic acid bacteria, yeasts-moulds, pH, colour (L*, a*, b*), odour (buttery and acidic), and ethanol migration to ground beef (SPME/GC-FID) were determined. Moreover, mathematical models (square root and Arrhenius) describing the effect of temperature on determinant indicators of spoilage and quality deterioration like growth of dominant microorganisms and red colour reduction were developed and validated under non-isothermal conditions. B. thermosphacta dominated the microbial association of ground beef, while LAB were second in dominance, revealing a high growth potential at all assays. a* value (redness) was gradually decreased in controls, while samples treated with “tsipouro” showed more stable red colour during storage. Although ethanol was organoleptically detectable, especially at low storage temperatures (0–4 °C), it was rather perceived as a pleasant cool odour. Prediction by both models for microbial growth as well as those of Arrhenius model for reduction of a* value showed good agreement with the observations under non-isothermal storage. Overall, our study showed that the developed antimicrobial active packaging of ground beef based on “tsipouro”, combined with high oxygen MAP lead to an almost 2-fold shelf-life extension compared with controls during storage at chill and abuse temperatures.

Analysis of Microbiota Structure and Potential Functions Influencing Spoilage of Fresh Beef Meat

Beef is one of the most consumed food worldwide, and it is prone to spoilage by bacteria. This risk could be caused by resident microbiota and their alterations in fresh beef meat during processing. However, scarce information is available regarding potential spoilage factors due to resident microbiota in fresh beef meat. In this study, we analyzed the microbiota composition and their predicted functions on fresh beef meat. A total of 120 beef meat samples (60 fresh ground and 60 non-ground beef samples) were collected from three different sites in South Korea on different months, and the microbiota were analyzed by the MiSeq system. Our results showed that although the microbiota in beef meat were varied among sampling site and months, the dominant phyla were the same with shared core bacteria. Notably, psychrotrophic genera, related to spoilage, were detected in all samples, and their prevalence increased significantly in July. These genera could inhibit the growth of other microbes with using glucose by fermentation. The results of this study extend our understanding of initial microbiota in fresh beef meat and potential functions influencing spoilage and can be useful to develop the preventive measures to reduce the spoilage of beef meat products.

Antimicrobial Activity of Polylactic Acid Film Incorporated With Marjoram and Clove Essential Oils on Microbial and Chemical Properties of Minced Beef During Refrigerated Storage

Background: Active packaging is one of the new packaging technologies which causes interaction between packaging material and food with the aim of food shelf life extension while maintaining food safety and quality. Biodegradable films like polylactic acid (PLA) can be good alternatives to non-biodegradable plastics because of environmental pollution and concerns about the limitations of petroleum resources. Objective: This study was conducted to evaluate the efficacy of PLA film incorporated with marjoram and clove essential oils (EOs) (0.5 and 1% v/v) in maintaining the microbial and chemical quality of minced beef during refrigerated storage. Materials and Methods: Minced beef was packaged with PLA film incorporated with marjoram and clove EOs (0.5 and 1% v/v) alone and in combination and stored at refrigerator temperature for 10 days. Then, microbiological and chemical analyses were done at 0, 2, 4, 7 and 10 days of examination. Results: A reduction of 1 log CFU/g in total count was observed between groups with simultaneous use of EOs and control group (P<0.05) at day 7; however, there was not any significant difference between the mentioned groups at day 10. Active packaging with marjoram and clove EOs decreased the number of psychrotrophs in comparison to the control group and it was more evident at days 7 and 10. The number of Enterobacteriaceae in control and 1% clove EO/1% marjoram EO groups showed a difference of 3 log units at day 10. TVB-N of 1% clove EO/1% marjoram EO and 0.5% clove EO/1% marjoram EO showed significant differences from control at day 10 (P<0.05). Conclusion: The results of the current study have shown that the active PLA films can be a promising approach in order to maintain microbial and chemical quality of minced beef at refrigerator temperature for 10 days.

Effects of Chitosan on Clostridium perfringens and Application in the Preservation of Pork Sausage

The effects of chitosan with 95% deacetylation degree (DD95) on the spore germination, cell proliferation, and heat resistance of Clostridium perfringens CCRC 10,648 and CCRC 13,019 were investigated, and its application on pork sausage with sodium nitrite reduction was also evaluated. DD95 chitosan can strongly reduce the heat resistance of both strains. The D₈₀ and D₁₀₀ values for strain CCRC 13,019 decreased from 40.98 and 4.64 min to 39.21 and 3.26 min, respectively, as a result of adding 250 ppm DD95; meanwhile, addition of chitosan decreased the D₈₀ and D₁₀₀ values for CCRC 10,648 from 41.15 and 6.46 min to 39.52 and 3.78 min, respectively. In pork sausage, addition of 3000 ppm DD95 chitosan considerably slowed down the bacterial proliferation and volatile basic nitrogen production. There were no significant differences in color (L* and b* values), shearing force, and hardness in the pork sausages with or without DD95 chitosan during storage at 4 and 25 °C. However, the addition of DD95 chitosan in pork sausage significantly retarded the decrease of the a* value. Therefore, DD95 chitosan could reduce the concentration of sodium nitrite required in pork sausages for color retention.

Microbiological and physicochemical parameters for predicting quality of fat and low-fat raw ground beef during refrigerated aerobic storage

The aim of the current study was to identify quality indicators of fat (14.50 ± 0.75%) and low-fat (4.79 ± 0.63%) raw ground beef by monitoring changes in physicochemical and microbiological parameters during aerobic refrigerated storage, such as water-holding capacity, pH, thiols, carbonyl compounds, thiobarbituric acid reactive substances (TBARS), metmyoglobin, deoxymyoglobin, oxymyoglobin color indices, pseudomonads, Brochothrix thermosphacta, and total viable counts. Meat packaged in air-permeable polyethylene plastic film was stored under controlled isothermal conditions (0, 5, 10, and 15 °C). A population level of pseudomonads equal to 7.0 ± 0.5 log₁₀ colony forming units (CFU)/g was considered as the potential spoilage level. Using principal component analysis, samples were distinguished on the basis of their microbial load. A significant positive correlation between microbial population and carbonyls, metmyoglobin, TBARS, water-holding capacity, and a negative correlation with thiols and color parameters (L^* , chroma) were observed. Two different approaches were followed to estimate the quality status of samples: (i) the partial least square (PLS) regression with R² of 0.93 and root mean square error prediction of 0.44 for pseudomonads, using the above physicochemical characteristics as the dominant input variables, which allowed prediction of the microbiological status of ground beef regardless of time-temperature storage profile and fat content, and (ii) a square-root-type model (adjusted R² of 0.952) that satisfactorily predicted the growth of spoilage pseudomonads under isothermal and dynamic conditions, regardless of the above physicochemical changes. The above results suggest that depending on the available input data, the two modeling approaches can accurately (and complementarily) assess quality of aerobically stored ground beef. PRACTICAL APPLICATION: Changes in appearance and quality of fat and low-fat raw ground beef are associated with physicochemical alteration and/or microbial growth. The study provides two different modeling approaches that can be integrated in an intelligent interface of the refrigerator having specific colorimetric and/or temperature sensors, to evaluate in a convenience way the quality of stored meat thus reducing domestic waste: the partial least square model was based on physicochemical parameters (particularly chroma, metmyoglobin, and thiobarbituric acid reactive substances), while the square root model was based on the time-temperature conditions during storage.

Efficacy of lyophilized cell-free supernatant of Lactobacillus salivarius (Ls-BU2) on Escherichia coli and shelf life of ground beef

In the present study, the effect of different concentrations of cell-free supernatant (CFS; 10.00 and 35.00 mg g^-1) of Lactobacillus salivarius (Ls-BU2) on chemical, microbial and sensorial specifications of ground beef stored under the refrigerated condition was investigated. The antibacterial activity of CFS on Escherichia coli was also assessed. According to agar-disk diffusion method, CFS of Ls-BU2 revealed a promising antibacterial activity against E. coli in culture media compared to CFS of a well-known probiotic (L. acidophilus LA-5). In meat, CFS of Ls-BU2 showed a minimal effective concentration (MEC) of 35.00 mg g^-1 on E. coli, while CFS of L. acidophilus represented a MEC of 45.00 mg g^-1. The CFS of Ls-BU2 at 35.00 mg g^-1 concentration retained psychrophilic counts of meat at a lower value than maximum accepted level (7 log₁₀ CFU g^-1). In a similar trend, CFS of Ls-BU2 at 35.00 mg g^-1 concentration was also displayed high sensorial scores compared to other CFS-treated samples. In conclusion, we demonstrated that CFS of Ls-BU2 and to some extent CFS of L. acidophilus could act as a safe food additive for the control of bacterial pathogens and to extend the shelf life of ground beef.

Influence of storage and packaging method on chicken breast meat chemical composition and fat oxidation

The aim of this study was to determine the influence of storage conditions and packaging methods on chicken breast meat chemical composition and fat oxidation. In this study, chicken breasts available in retail sale were used for evaluation. The meat packed by three different methods (air packaging-AP, modified atmosphere packaging-MAP, and vacuum packaging-VP) was stored in a cooling room or a commercial display case for 9 D and tested for basic chemical composition, lipid oxidation (TBARS), and fatty acid composition. Meat in MAP during storage in the cooling room was characterized by higher (P ≤ 0.05) TBARS values as compared to meat packaged in AP and VP, respectively. The highest share in the fatty acid profile in chicken breasts was demonstrated by monounsaturated fatty acid, including cis C18:1 (n9 + n11) acid in the range from 31.86 to 34.66%. A high share of polyunsaturated acids was observed, including linoleic (C18:2 cis, cis) acid from 24.50 to 31.22% of all fatty acids. The simple relationship between the changes in the profile of fatty acids in meat packaged using different methods and in storage time was not determined, likely due to the variability of the composition of fatty acids in chicken breasts depending on the sample and the general low level of fat found in the meat.

Experimental accelerated shelf life determination of a ready-to-eat processed food

The most direct way to estimate the shelf life of a product is to conduct simulation tests which are time consuming and expensive. Conversely, accelerated shelf life tests can be successfully used for stable products having long expected shelf life. The aim of the study was directed to verify the possibility to apply an accelerated shelf life test to perishable food products having a short-expected shelf life, such as a new ready-to-eat processed food preparation, composed mainly by cereals, tuna and chicken, packed in thermo-sealed trays and pasteurised. Different samples of the product were stored in thermal abuse conditions, collected periodically and subjected to determinations of TVB-N, pH and sensorial characteristics. Q₁₀ and activation energy were calculated allowing to obtain a predictive evaluation of the product shelf life at the 4°C recommended temperature. The product shelf life was assessed at 26 days vs the 30 days expected by the manufacturer, showing the possibility to apply successfully ASLT for products having short shelf life, saving both time and money.

Kinetic models of quality parameters of spreadable processed Gouda cheese during storage

The aim of the study was to prepare mathematical models based on the Arrhenius equation as predictive tools for the assessment of changes in quality parameters during the storage of spreadable Gouda cheese at temperatures of 8, 20 and 30 °C. The activation energy value and the chemical reaction rate constant enabled the construction of kinetic models, which helped to estimate the direction and rate of changes. Moreover, the activation energy (E_a) of the quality parameters was used to determine the sequence of their vulnerability during storage. The value of activation energy corresponding to temperature changes resulted in the following order of susceptibility of the quality parameters: ΔC > ΔE ≈ water activity > texture parameters > pH > colour > sensory parameters > rheological parameters. The research showed limited applicability of the mathematical models for estimation of quality parameters referring to spreadable processed Gouda cheese.

Effects of vacuum and high-oxygen modified atmosphere packaging on physico-chemical and microbiological properties of minced water buffalo meat

OBJECTIVE

In this study, the effects of vacuum (VP) and high-oxygen modified atmosphere (80% O2+20% CO2) packaging (HiOx-MAP) on physico-chemical and microbiological properties of minced water buffalo meat were investigated.

METHODS

After minced meat preparation, samples were packaged under VP and HiOx-MAP and stored at 2°C±0.5°C for 14 days. Samples taken on certain days were subjected to total aerobic mesophilic bacteria, total aerobic psychrotrophic bacteria, lactic acid bacteria, Pseudomonas, Enterobacteriaceae and yeast-mold counts as well as pH, color (L*, a*, and b*) and thiobarbituric acid reactive substances (TBARS) analyses.

RESULTS

In minced water buffalo meat packaged under HiOx-MAP, TBARS value exceeded 1 mg malondialdehyde/kg on the 4th day of the storage. In VP samples, TBARS value remained close to initial TBARS value during storage. According to the findings, a* value was determined to be high in the HiOx-MAP samples within initial days of the storage. However, no significant changes in a* value were observed in VP samples during storage. In contrast, the mean value of L* was detected as higher in HiOx-MAP sample than VP samples. The count of psychrotrophic bacteria increased more than that of mesophilic bacteria during storage. The growth of Enterobacteriaceae and Pseudomonas was delayed in both the packaging methods. However, lactic acid bacteria exhibited more growth in VP samples compared to MAP samples.

CONCLUSION

The lipid oxidation proceeded faster than expected in minced water buffalo meat packed with HiOx-MAP method. This situation adversely affected the a* value. On the other hand, similar microbiological results were obtained in both packing methods.

Effect of temperature in domestic refrigerators on fresh-cut Iceberg salad quality and waste

The evolution of different quality parameters (firmness, weight loss, colour changes, microbial counts, consumer rejection) of packed fresh-cut Iceberg salad was assessed at 4, 8 and 12°C to simulate domestic refrigerators running at different conditions. The increase in storage temperature did not affect salad firmness and weight loss but increased colour changes, microbial growth and consumer rejection. A survey among Italian consumers was also carried out and demonstrated that fresh-cut salad was mainly consumed within the first 5days after purchasing. Consumer rejection data were combined with data relevant to the distribution of salad consumption over the days following product purchase, to estimate salad wasting risk. When salad was stored at 4 and 8°C, estimated wasted packages within the expiration date (7days) were <1%. By contrast, 13% of the packages was estimated to be wasted within 7days of storage at 12°C. Quantification of wasting risk is a necessary information to identify efficient and sustainable interventions to tackle food waste.