High-pressure processing and boiling water treatments for reducing Listeria monocytogenes, Escherichia coli O157:H7, Salmonella spp., and Staphylococcus aureus during beef jerky processing

Effect of freezing raw meat on the physicochemical characteristics of beef jerky

The effect of freezing raw meat on the quality characteristics of beef jerky was evaluated in the present study. Jerky was made using different types of raw beef (fresh, frozen, and frozen-thawed) with different curing times (6 h and 12 h). Frozen-thawed beef had a lower moisture content than fresh or frozen beef due to higher exudate loss (P < 0.05). Jerky made using frozen and frozen-thawed beef showed lower drying yield and higher shear force than jerky prepared using fresh beef (P < 0.05). Freezing raw beef decreased the fat content and increased the redness, yellowness, chroma, and hue values of jerky (P < 0.05). The microstructure of beef jerky was showed to increase the deformation and contraction of muscle fibers due to freezing. Longer curing times increased the moisture content of jerky made using frozen meat (P < 0.05). Jerky made using frozen or frozen-thawed meat was tough due to excessive fat and moisture loss.

Production of Marinated Chinese Lotus Root Slices Using High-Pressure Processing as an Alternative to Traditional Thermal-and-Soaking Procedure

Marinated vegetables are traditional cold dishes with a long history and special flavor in the Chinese deli market. However, the traditional thermal-and-soaking (TS) procedure often results in unreproducible flavor quality properties of marinated vegetables and waste of brine and time in production. A novel green and sustainable technique, high-pressure processing (HPP), has caught the attention of the food industry. In this study, the effects of HPP and TS treatment on the visual, flavor, textural, and microbiological qualities of Chinese marinated lotus root slices were investigated. Compared to the TS products, lighter color, more varieties of volatile compounds, and crunchier texture were detected in the HPP products. Throughout the 4 °C, 25 °C, and 45 °C shelf life challenges, the HPP products retained their original color and crunchiness better than the TS ones, whereas no significant differences were found in total viable counts (TVCs) in the first half of the shelf lives. The Arrhenius model under the first-order reaction of TVC deterioration showed a good fit to the shelf life of the HPP marinated lotus root slices. This study demonstrates that HPP may assist in making the best use of brine in a more time-efficient manner to improve the visual, flavor, and textural quality of traditional Chinese marinated lotus root slices.

Bactericidal effect of marinades on meats against different pathogens: a review

Marinades are seasoned liquids used to improve tenderness, palatability, flavor, color and/or texture of different meats. In addition to contribute to the sensory characteristics, marinates can inactivate food microorganism as well. The purpose of this study was to assess the current state of knowledge regarding the effect of marinades on meats and important food pathogens. Using a systematic review of literature, different types of marinades were evaluated, identifying its ingredients, concentrations, temperature, marinating time and their effect on Salmonella, Escherichia coli, Listeria monocytogenes, Campylobacter and Vibrio. Findings demonstrated that the use of marinades on meats not only prevents the growth of pathogens but also inactivates food pathogens. Most marinades were able to reduce < 3 log CFU/g of pathogens, and Vibrio populations demonstrated the highest reductions (> 4 log CFU/g). The pH was the most pronounced parameter influencing the pathogens inactivation, however, ingredients and storage temperature also affected pathogen reduction in marinades.

Macroalgae-Fortified Sausages: Nutritional and Quality Aspects Influenced by Non-Thermal High-Pressure Processing

The present work evaluated the nutritional impact of macroalgae flours used as new ingredients in fermented sausages and the feasibility of using high-pressure processing (HPP) as a non-thermal pasteurization methodology to keep the quality attributes of the new food products. A commercial macroalgae mix was used in the formulation of new macroalgae-fortified meat frankfurter sausages (F-MFS), macroalgae-fortified vegetable frankfurter sausages (F-VFS) and in macroalgae-fortified traditional Portuguese sausage "chouriço" (F-TPS), overall incrementing the contents of Mg, K, Ca, Mn and Fe and decreasing the Na/K ratio. The application of HPP allowed extending the shelf-life of frankfurters by about 3-fold and improved the safety of "chouriço" along 180 days of storage, keeping its microbial load below the detection limit. The prevention of microbial growth in F-MFS and F-VFS was accompanied by pH stability of the products. In addition, no significant detriment on surface color and fatty acids was observed between pressurized and non-pressurized sausages, allowing consolidating the suitability of HPP in seaweed-fortified fermented sausages.

Non-Thermal Methods for Ensuring the Microbiological Quality and Safety of Seafood

A literature search and systematic review were conducted to present and discuss the most recent research studies for the past twenty years on the application of non-thermal methods for ensuring the microbiological safety and quality of fish and seafood. This review presents the principles and reveals the potential benefits of high hydrostatic pressure processing (HHP), ultrasounds (US), non-thermal atmospheric plasma (NTAP), pulsed electric fields (PEF), and electrolyzed water (EW) as alternative methods to conventional heat treatments. Some of these methods have already been adopted by the seafood industry, while others show promising results in inactivating microbial contaminants or spoilage bacteria from solid or liquid seafood products without affecting the biochemical or sensory quality. The main applications and mechanisms of action for each emerging technology are being discussed. Each of these technologies has a specific mode of microbial inactivation and a specific range of use. Thus, their knowledge is important to design a practical application plan focusing on producing safer, qualitative seafood products with added value following today’s consumers’ needs.

Effect of fermentation and postcooking procedure on quality parameters and volatile compounds of beef jerky

In this study, jerky samples were prepared from seasoned beef with and without the addition of starter culture. They were then dried or fried and analyzed to identify the quality parameters and volatile flavor compounds. Samples (starter and control) were divided into drying (inoculated-drying, I-D; noninoculated-drying, N-D) and frying (inoculated-frying, I-F; noninoculated-frying, N-F) groups. Water activity (a w), lightness (L*), and redness (a*) values were significantly affected (p < .001) by the postcooking procedures (drying or frying). Hardness, chewiness, and resilience were significantly lower in the dried groups than in the fried groups (p < .05). The formation of volatile compounds was affected by cooking treatment, with the highest levels observed in the I-F group. After frying, the most abundant flavor compounds in the I-D and N-D groups were terpenes and sulfur-containing compounds, followed by aromatic hydrocarbons, ketones, and alcohols. The most common compounds among all groups were acetoin, D-limonene, anethole, styrene, and tetramethylpyrazine. Overall, the jerky in the I-F group had the best color and tenderness scores among all groups.

Texture of Fermented Summer Sausage With Differing pH, Endpoint Temperature, and High Pressure Processing Times

The objective was to evaluate the quality and texture of all-beef summer sausages produced with varying degrees of fermentation, endpoint cooking temperatures, and high pressure processing (HPP) hold times. Across 3 replications, sausages were fermented and (Process A) cooked to pH 4.6 and thermally processed to 54.4°C with smokehouse chilling, (Process B) cooked to pH 5.0 and thermally processed to 54.4°C with smokehouse chilling, (Process C) cooked to pH 5.0 and thermally processed to 54.4°C with rapid ice bath chilling, (Process D) cooked to pH 5.0 and thermally processed to 48.9°C with rapid ice bath chilling, and (Process E) cooked to pH 5.0 and thermally processed to 43.3°C with rapid ice bath chilling. After chilling, the sausages were sliced, layered, vacuum packaged, and subjected to HPP at 586 MPa for 0, 1, 150, or 300 s. Post HPP, the sausages were evaluated for objective color (n = 9), lipid oxidation (n = 9), water activity (n = 9), texture profile analysis (TPA; n = 15), sensory analysis (n = 9), and proximate analysis (n = 9). Neither process (combination of pH and endpoint temperature) nor HPP affected lipid oxidation (P = 0.45 and P = 0.69, respectively). Process A resulted in a lighter color (P &lt; 0.01) compared to the other process treatments. Additionally, Process A was less red (P &lt; 0.01) than all other process treatments, and Processes D and E were the reddest (P &lt; 0.01). TPA and trained sensory analysis indicated that, as endpoint temperature increased, so did sample hardness (P &lt; 0.05). Springiness, cohesiveness, and gumminess decreased (P &lt; 0.05) as the endpoint temperature decreased. Although springiness and gumminess increased (P &lt; 0.05) with longer HPP hold times, the panelists were unable to detect differences among samples with longer hold times. The use of HPP at 586 MPa for up to 300 s may be incorporated into manufacturing processes for semidry beef summer sausages with limited impacts on color and texture.

Quality and Safety of Fresh Chicken Fillets after High Pressure Processing: Survival of Indigenous Brochothrix thermosphacta and Inoculated Listeria monocytogenes

The effect of high-pressure processing (HPP) on Listeriamonocytogenes, the indigenous microbiota and the shelf-life of chicken fillets was evaluated. Chicken fillets were inoculated with different inocula (2, 4, and 6 log CFU/g) of a 4-strain cocktail of L. monocytogenes, vacuum-packed, processed or not with HPP (500 MPa/10 min) and stored at 4 °C and 12 °C. Total viable counts (TVC), L. monocytogenes, Pseudomonas spp., Brochothrix thermosphacta, lactic acid bacteria (LAB), Enterobacteriaceae and yeasts/molds were determined along with the pH and sensory analysis. Pulsed-field gel electrophoresis (PFGE) was used to monitor the succession of indigenous Brochothrix isolates and inoculated Listeria strains. The main spoilage microorganism of HPP-treated samples was B. thermosphacta detected after 3 days of storage. HPP decreased the inoculated Listeria population. For the low and medium inoculum case it was detected throughout the shelf-life at both temperatures in populations near to the detection limit or after enrichment. In the high inoculum case, the pathogen decreased ≥5-log cycles after HPP, while increased subsequently to 1.6 and 4.5 log CFU/g at 4 °C and 12 °C, respectively, by the end of the shelf-life. PFGE showed that Brochothrix isolates exhibited a significant diversity among control samples, whereas this was limited for the HPP-treated samples. The survival and distribution of different Listeria strains depended on the initial inoculum and storage temperature. In conclusion, HPP increased the shelf-life (for 5 and 4 days, at 4 °C and 12 °C, respectively) and enhanced the safety of chicken meat.

Applied and Emerging Methods for Meat Tenderization: A Comparative Perspective

The tenderization process, which can be influenced by both pre- and post-slaughter interventions, begins immediately after an animal's death and is followed with the disruption of the muscle structure by endogenous proteolytic systems. The post-slaughter technological interventions like electrical stimulation, suspension methods, blade tenderization, tumbling, use of exogenous enzymes, and traditional aging are some of the methods currently employed by the meat industry for improving tenderness. Over the time, technological advancement resulted in development of several novel methods, for maximizing the tenderness, which are being projected as quick, economical, nonthermal, green, and energy-efficient technologies. Comparison of these advanced technological methods with the current applied industrial methods is necessary to understand the feasibility and benefits of the novel technology. This review discusses the benefits and advantages of different emerging tenderization techniques such as hydrodynamic-pressure processing, high-pressure processing, pulsed electric field, ultrasound, SmartStretch^™ , Pi-Vac Elasto-Pack® system, and some of the current applied methods used in the meat industry.

Current Interventions for Controlling Pathogenic Escherichia coli

This review examined scientific reports and articles published from 2007 to 2016 regarding the major environmental sources of pathogenic Escherichia coli and the routes by which they enter the human gastrointestinal tract. The literature describes novel techniques used to combat pathogenic E. coli transmitted to humans from livestock and agricultural products, food-contact surfaces in processing environments, and food products themselves. Although prevention before contamination is always the best "intervention," many studies aim to identify novel chemical, physical, and biological techniques that inactivate or eliminate pathogenic E. coli cells from breeding livestock, growing crops, and manufactured food products. Such intervention strategies target each stage of the food chain from the perspective of "Farm to Table food safety" and aim to manage major reservoirs of pathogenic E. coli throughout the entire process. Issues related to, and recent trends in, food production must address not only the safety of the food itself but also the safety of those who consume it. Thus, research aims to discover new "natural" antimicrobial agents and to develop "multiple hurdle technology" or other novel technologies that preserve food quality. In addition, this review examines the practical application of recent technologies from the perspective of product quality and safety. It provides comprehensive insight into intervention measures used to ensure food safety, specifically those aimed at pathogenic E. coli.

Processing optimization of restructured jerky from sea rainbow trout frame muscle

This study determined optimal drying temperature and time on the moisture content, hardness, and overall sensory acceptance of restructured jerky from sea rainbow trout frame muscle (RJ-SRTF) using response surface methodology. The optimal drying conditions with respect to the above variables were 67.2°C for drying temperature and 8.6 h for drying time. The predicted values of response optimal conditions were 18.8 g/100 g for moisture content, 495.8 g/cm² for hardness, and a score of 7.2 for overall sensory acceptance. The actual values obtained in this experiment were 19.1±0.6 g/100 g for moisture content, 453.9±91.0 g/cm² for hardness, and a score of 7.4±0.5 for overall sensory acceptance. Both actual and predicted values were nearly identical. In conclusion, the models are adequately fitted to experimental data and suitable for optimization.