Over 21 days of cold storage, the quality and microbial composition of beef steaks in response to different high-CO2 packaging conditions achieved by flushing gas mixtures or embedding gas emitters into the packages were studied. The results revealed that the high levels of CO2, achieved by either the gas flushing or the CO2 emitter pads, effectively controlled the number of aerobic counts. The headspace CO2 increased quickly in response to using the CO2 emitter pads, and the meat samples presented different pH levels and surface color (a* and b*) values compared to the samples packaged with the gas flushing technique. Excessive accumulation of gas in the packages that contained CO2 emitters resulted in package swelling and higher levels of drip loss. The longest overall quality and attractive red color of the meat samples were observed when the packages were initially flushed with the headspace gas mixture containing high levels of oxygen. Overall, using CO2 emitters for meat packaging can be suggested when a topfilm with proper permeability to O2 and CO2 gases is used to regulate the internal CO2/O2 and gas/product ratios.

Cold plasma processing is a nonthermal approach that maintains food quality while minimizing the effects of heat on its nutritious qualities. Utilizing activated, highly reactive gaseous molecules, cold plasma processing technique inactivates contaminating microorganisms in food and packaging materials. Pesticides and enzymes that are linked to quality degradation are currently the most critical issues in the fresh produce industry. Using cold plasma causes pesticides and enzymes to degrade, which is associated with quality deterioration. The product surface characteristics and processing variables, such as environmental factors, processing parameters, and intrinsic factors, need to be optimized to obtain higher cold plasma efficiency. The purpose of this review is to analyse the impact of cold plasma processing on qualitative characteristics of food products and to demonstrate the effect of cold plasma on preventing microbiological concerns while also improving the quality of minimally processed products.

The application of food-grade microbial cultures to fresh meat products is a promising natural approach for meat shelf-life extension. However, before its adoption into commercial practice, it is essential to understand consumers' attitudes to this approach and the resulting marketed products. This study investigated Australian consumers' willingness to purchase and consume packaged fresh meat products with added microbial cultures for shelf-life extension. A national online survey of over 800 respondents was conducted. Results indicated that most Australian consumers would be willing to buy and eat such products, with 17.8% of respondents less likely to buy and 11.1% unwilling to eat these products. Respondents' purchasing and consumption decisions were influenced by demographic factors, their food and meat shopping and consumption behaviors, and the value, taste, and type of the meat product. Consumer acceptance may be improved by increasing their awareness of the potential use of microbial cultures as natural antimicrobials for food shelf-life extension.

This study investigated the effects of two commercial protective cultures, one containing Lactobacillus sakei (now Latilactobacillus sakei) and the other containing Staphylococcus carnosus and L. sakei, in vacuum-packaged minced beef (ground beef) to advance the understanding of this biopreservation approach for fresh meat shelf-life extension. The protective cultures’ effects on spoilage-related bacterial profiles over time were evaluated using both culture-dependent and culture-independent methods in premium (containing 7.7% fat) and standard (containing 19.2% fat) beef mince stored at 4 °C for 12 days. The culture-dependent method showed that in premium mince, the mixed culture containing S. carnosus and L. sakei significantly suppressed the growth of Enterobacteriaceae and Pseudomonas spp. The culture containing only L. sakei exhibited a slight inhibitory effect against these spoilage bacteria. In contrast, neither protective culture inhibited the spoilage bacteria in standard mince. The 16S rRNA gene sequencing indicated bacterial community changes by protective cultures. Photobacterium spp., a potentially important group of meat spoilage bacteria that were usually undetected in culture-dependent studies, were found to be abundant in this study. The protective cultures’ impact on other meat quality aspects was also assessed. The culture containing S. carnosus and L. sakei lowered the pH of both premium and standard mince more than the culture containing only L. sakei, and the mixed culture slightly decreased the redness of premium mince. These findings support the use of protective cultures for bacterial spoilage control and shelf-life extension of fresh red meat, but their application may be limited to lean or low-fat products.

With the fast-global development of packaging techniques, the potential antimicrobial effect of CO2, as a safe, cheap and readily available gas, makes it the integral component for packaging of meat products. The associated spoilage and/or pathogenic bacteria on raw meat may respond in different ways to elevated CO2 concentrations. The growth of some aerobic Gram-negative bacteria such as Pseudomonas spp. is significantly inhibited but some LAB bacteria may be allowed to grow faster and dominate the product. The antimicrobial efficacy of enriched CO2 packaging is attributed to the rate of CO2 solubility in the product which is itself affected by the level of headspace CO2, product pH, temperature and the ratio of headspace gas to product (G:P). This review, first, explores the varied range of beef and sheep meat spoilage and pathogenic bacteria and the intrinsic and extrinsic parameters that may influence the pattern of microbial growth and meat spoilage rate during storage. Then, the antimicrobial mechanism of elevated CO2 packaging will be discussed and the different approaches of achieving enriched CO2 packaging i.e. the traditional technique of flushing a desired gas mixture and/or using the new commercially developed CO2 emitters will then be compared in terms of their strengths, limitations and technical mode of action.

Banana peels (Cavendish and Nay poovan) in ripe and raw form were dried using tray drying (T), microwave (M), microwave-convection (MC) and freeze drying (F) with ultrasonication (U) and combined treatment of carbonation and ultrasonication (CU) as pretreatments. SEM analysis showed microscopic channels in samples after U treatment, which were more ravine after CU. Based on bulk density, tapped density, porosity, angle of repose, colour parameters, viscosity, CU + F was found best drying combination followed by CU + MC. For selected samples, relative water sorption changes induced by U and CU were positive as the sorption surface area increased after given pre-treatments. Peleg model fitted best to experimental data for sorption studies. The water plasticizing effect of U and CU treatments on glass transition temperature (Tg) was predicted using Gordon-Taylormodel. State diagram predicted critical moisture content (X-c), 0.106 kg H2O/kg dry matter and critical water activity (a(wc)), 0.525 at 16 degrees C. (C) 2021 Elsevier B.V. All rights reserved.

Protective cultures, as natural antimicrobials, have the ability to suppress the growth of spoilage bacteria and can potentially be used to extend the shelf-life of fresh meat and help reduce food waste. As there have been limited reports on the application of this approach in fresh red meat, the aim of this study was to evaluate the potential and practicality of this approach for red meat shelf-life extension based on the antimicrobial efficacy and quality impact of selected protective cultures. Two protective cultures (one containing Lactobacillus sakei and the other containing Staphylococcus carnosus and L. sakei) were applied to chill-stored (4 degrees C) vacuum-packaged lamb meat to determine their effects on spoilage bacteria as well as non-microbiological meat quality over a 20-day storage period. These protective cultures dominated the microbiota throughout storage and effectively suppressed the growth of common meat spoilage bacteria, Brochothrix thermosphacta, Pseudomonas spp., and Enterobacteriaceae. Meat color (measured in CIE L*a*b* color space) changed slightly in culture-treated samples in the later stage of storage, but the changes were not unacceptable based on previously reported thresholds for consumer accept-ability. The mixed culture containing additional S. carnosus exhibited a slightly stronger inhibitory effect against the spoilage bacteria but also caused more changes in meat color. Protective culture addition did not significantly affect meat pH, texture, or microstructure. Overall, these results demonstrated the potential of biopreservation using protective cultures for fresh red meat shelf-life extension.

Texture of meat is a critical factor in oral processing and bolus formation, especially for people suffering from dysphagia. The present study evaluated and compared the texture changes of beef semitendinosus muscles upon cooking, using sensory panelists and instrumental texture profile analysis. Cooking losses were also estimated. The correlation between instrumental and sensory parameters were established. Training with sensory texture profile enabled panelists to clearly identify and describe meat textural attributes except cohesiveness and springiness. Increased cooking temperature (65-85 degrees C) and time (30-60 min) significantly (p < .05) increased hardness, chewiness, and cook loss of beef whereas adhesiveness and juiciness decreased significantly. The correlation data showed significant positive correlations between instrumental and sensory hardness, chewiness, and adhesiveness and poor correlations between cohesiveness and springiness. Results show that the texture profile analyzer has a possibility to replace sensory analysis for hardness, chewiness, and adhesiveness; however, future work is needed to address cohesiveness and springiness of meat.

The D - optimal mixture design was used to optimize inclusions of hydrocolloids [carboxy methyl cellulose (CMC) 0-1% w/w, and tapioca starch (TS) 0-1% w/w] to create beef patties as a soft & bite-size food (level 6) according to the international dysphagia Diet Standardisation Initiative (IDDSI) guidelines. The effect of each ingredient and combination, on cooking properties and textural characteristics, were analysed. Results revealed that a combination of CMC and TS helped to improve the cooking yield and texture of beef patties. Optimization of ingredients obtained according to the maximum cooking yield, optimum colour, soft texture as per the IDDSI guidelines. Optimum formulation of patty contained beef 88.57%, CMC 0.89% and TS 0.02% with 0.87 desirability score. The beef patties containing hydrocolloids complied with the IDDSI fork pressure test. This test is recommended as a way to identify soft and bite-size foods for people with dysphagia.

Dysphagia is a medical condition that describes the difficulty of swallowing food, and texture modified food (TMF) is the best intervention for dysphagia. The relevant guidelines to identify dysphagia food are provided by the International Dysphagia Diet Standardization Initiative (IDDSI). Developing texture modified meat is a challenging task due to its fibrous microstructure and harder texture. Various meat tenderization attempts are therefore evaluated in the literature. Meat texture modification for dysphagia is not just limited to tenderization but should be focused on safe swallowing attributes as well. The application of hydrocolloids for designing TMF has a major research focus as it is a cost-effective method and offers an opportunity for careful control. The present review focuses on the meat texture modification attempts that have been used in the past and present, with special attention to the use of hydrocolloids. Several studies have shown improvements in texture upon the addition of various hydrocolloids; however, few studies have attempted to develop texture modified meat for people with dysphagia. This area has to be further developed along with the sensory evaluations conducted with the dysphagia population, to validate the industrial application of hydrocolloids to TMF.

International dysphagia diet standardisation initiative (IDDSI) is the most recent guideline for categorising texture modified food for people with dysphagia. Level 6 of the IDDSI guideline is known as soft & bite-sized, and the fork pressure test is the recommended test for this level. However, the result of this test is affected by the choice of fork and testing conditions. Therefore, the objective of this study was to mimic the standard IDDSI fork pressure test using a texture analyser with instrumentally controlled testing conditions. The data and observations made from the fork pressure test obtained using the texture analyser, correlated well (r = 0.948) with the those obtained from the standard IDDSI fork pressure test. The main effects for all testing conditions (food, crosshead speed, crosshead rest time, and sample position) had a significant effect (P < 0.05) on all three force-time curve parameters of the texture analyser except for crosshead rest time for the negative area (P = 0.116) and positive distance (P = 0.127), and crosshead speed for a positive distance of the curve (P = 0.069). The use of a texture analyser, with the protocol we developed, mimics the standard IDDSI test and it can be a more reliable alternative for industrial use and research purposes, to test foods designed for dysphagia sufferers.

Biopreservation is a recognized natural method for controlling the growth of undesirable bacteria on fresh meat. It offers the potential to inhibit spoilage bacteria and extend meat shelf-life, but this aspect has been much less studied compared to using the approach to target pathogenic bacteria. This review provides comprehensive information on the application of biopreservatives of microbial origin, mainly bacteriocins and protective cultures, in relation to bacterial spoilage of beef and lamb meat. The sensory effect of these biopreservatives, an aspect that often receives less attention in microbiological studies, is also reviewed. Microbial biopreservatives were found to be able to retard the growth of the major meat spoilage bacteria, Brochothrix thermosphacta, Pseudomonas spp., and Enterobacteriaceae. Their addition did not have any discernible negative impact on the sensory properties of meat, whether assessed by human sensory panels or instrumental and chemical analyses. Although results are promising, the concept of biopreservation for controlling spoilage bacteria on fresh meat is still in its infancy. Studies in this area are still lacking, especially for lamb. Biopreservatives need more testing under conditions representative of commercial meat production, along with studies of any possible sensory effects, in order to validate their potential for large-scale industrial applications.

Raw and ripe banana (Musa Cavendish) peel slices were dried by application of ultrasonication (U) and carbonation-ultrasonication (CU) as pre-treatments for tray drying (T) at 60 °C. Lesser drying time and higher diffusivity was noticed in CU + T dried samples followed by U + T and T dried samples. Model ‘Wang and Singh’ was identified as the excellently fitting model to experimental data. SEM images of dried samples revealed the microchannels formation due to U treatment, which were more couloir after CU treatment. Water and oil holding capacity (WHC and OHC) for raw peel powders was higher than ripened peel powders at 40, 60 and 80 °C. WHC and OHC increased significantly after U + T drying or CU + T drying as compared to T drying for ripe and raw peel powder samples. Back extrusion force (BEF) varied from 67.42 to 69.22 N and from 84.6 to 86.02 N for ripe and raw peel samples respectively. Given treatments resulted in lesser colour change and Browning Index. But U + T or CU + T treatment did not affect BEF significantly. CU + T was deemed to be the appropriate drying technique for ripe and raw banana peel drying.

The ability of Listeria monocytogenes isolates to survive within the food production environment (FPE), as well as virulence, varies greatly between strains. There are specific genetic determinants that have been identified which can strongly influence a strains ability to survive in the FPE and/or within human hosts. In this study, we assessed the FPE fitness and virulence potential, including efficacy of selected hygiene or treatment intervention, against 52 L. monocytogenes strains isolated from various food and food environment sources. Phenotypic tests were performed to determine the minimum inhibitory concentration of cadmium chloride and benzalkonium chloride and the sensitivities to five clinically relevant antibiotics. A genomic analysis was also performed to identify resistance genes correlating to the observed phenotypic resistance profiles, along with genetic determinants of interest which may elude to the FPE fitness and virulence potential. A transposon element containing a novel cadmium resistance gene, cadA7, a Tn916 variant insert in the hypervariable Listeria genomic island 1 region and an LGI2 variant were identified. Resistance to cadmium and disinfectants was prevalent among isolates in this study, although no resistance to clinically important antimicrobials was observed. Potential hypervirulent strains containing full length inlA, LIPI-1 and LIPI-3 were also identified in this study. Cumulatively, the results of this study show a vast array of FPE survival and pathogenicity potential among food production-associated isolates, which may be of concern for food processing operators and clinicians regarding L. monocytogenes strains colonising and persisting within the FPE, and subsequently contaminating food products then causing disease in at risk population groups.

The focus of this study was to compare the effectiveness of MALDI-TOF MS and partial 16S rRNA gene sequencing for the identification of bacteria isolated from VP lamb meat stored chilled at 5 ?C for 21 days, at the same time gaining insights into bacterial changes over time. The identity of bacterial isolates on non-selective and selective agars was determined by both methods and results compared. Results showed that total bacterial numbers increased over the 21 days (as expected) with Staphylococcus and Pseudomonas (day 0) being replaced by Carnobacterium, Brochothrix and members of the Enterobacteriaceae family by day 21. A high level of agreement (86?100%) for bacterial isolates? identity at genus level was observed between MALDI-TOF MS and partial 16S rRNA gene-based sequencing for isolates where identification was possible. With its cheaper cost and faster turnaround time, once optimized, MALDI-TOF MS could become a useful alternative to 16S rRNA genesequencing for the rapid identification of red meat bacterial isolates.

The original version of this chapter was inadvertently published with incorrect name of the first author as John Summer, and the same has been corrected as John Sumner.

The physiological transformations that happen during oral processing are complex and challenging to capture and measure; however, their knowledge can help design new products for people who struggle with mastication and swallowing. Here we relate chewing, saliva incorporation and bolus properties with initial meat texture. Three different textures (T1-tender, T2-intermediate, T3-tough) were created by cooking meat in different temperature time combinations and "ready-to-swallow" meat boluses were collected from 10 healthy individuals. Masticatory variables, saliva incorporation, and bolus mechanical and geometrical characteristics were analyzed. Meat texture showed significant effect on masticatory variables (number of chews and chewing duration) but not on saliva incorporation. Bolus mechanical characteristics (hardness, cohesiveness and adhesiveness) varied significantly (p < .05) with meat texture, where meat with a harder texture resulted in a harder bolus. Number of bolus particles changed significantly (p < .05) with increasing meat hardness, where harder meat produced more bolus particles. Significant (p < .05) intersubject variability was recorded for masticatory parameters and saliva incorporation. Mechanical and geometrical characteristics of "ready-to-swallow" meat bolus did not vary among subjects.

Listeria monocytogenes is a ubiquitous bacterium capable of colonising and persisting within food production environments (FPEs) for many years, even decades. This ability to colonise, survive and persist within the FPEs can result in food product cross-contamination, including vulnerable products such as ready to eat food items. Various environmental and genetic elements are purported to be involved, with the ability to form biofilms being an important factor. In this study we examined various mechanisms which can influence colonisation in FPEs. The ability of isolates (n = 52) to attach and grow in biofilm was assessed, distinguishing slower biofilm formers from isolates forming biofilm more rapidly. These isolates were further assessed to determine if growth rate, exopolymeric substance production and/or the agr signalling propeptide influenced these dynamics and could promote persistence in conditions reflective of FPE. Despite no strong association with the above factors to a rapid colonisation phenotype, the global transcriptome suggested transport, energy production and metabolism genes were widely upregulated during the initial colonisation stages under nutrient limited conditions. However, the upregulation of the metabolism systems varied between isolates supporting the idea that L. monocytogenes ability to colonise the FPEs is strain-specific.

This study evaluated the effect of addition of 14 different hydrocolloids that are commonly used in meat industry as texture modifiers, with a view to screen and categorise, hydrocolloid added beef patties within the International Dysphagia Diet Standardisation Initiative (IDDSI) levels of modified textures. Beef patties were made with 1% formulation for each hydrocolloid and were compared with control (no added hydrocolloid) samples. The effects were studied individually on cooking properties, colour and texture of beef patties, and samples were tested for compliance with the IDDSI guidelines. All hydrocolloids significantly (P < 0.05) increased the cooking yield of beef patties except modified corn starch. Compared to the control, diameter reduction was not significant in all treatments except for carboxymethyl cellulose (CMC) and xanthan gum. Patty texture was significantly (P < 0.05) altered with the addition of hydrocolloids by mostly decreasing hardness and cohesiveness. Adhesiveness increased with gum based and decreased with starch based hydrocolloids. Treatment of hydrocolloids brought lighter (L*) and yellower (b*) colour to the patties without significantly affecting the redness (a*) and pH of raw patties. Only two treatments (CMC and xanthan gum) complied with the IDDSI fork pressure test by squashing meat with the application of pressure and not returning to its original shape when pressure is released, thus categorised as potential level 6 (soft & bite-sized) diet in the IDDSI framework. However, both of these hydro colloids at 1% concentration did not give a proper structure to beef patties therefore further optimization of the beef patty mixture is recommended to develop patties with acceptable quality.

The use of protective cultures to inhibit spoilage bacteria is a promising natural preservation technique to extend the shelf-life of fresh meat. This study evaluated the effectiveness of six food-grade protective cultures (containing different combinations of Lactobacillus sakei, Pediococcus pentosaceus, Staphylococcus xylosus, and Staphylococcus carnosus) on naturally contaminated chill-stored (4 °C) lamb meat in different packaging systems. Only slight reductions of common meat spoilage bacteria Brochothrix thermosphacta, Pseudomonas spp., and Enterobacteriaceae were observed in culture-treated samples stored in modified atmosphere packaging (80% O2:20% CO2). Greater inhibitory effects were found in vacuum-packed lamb, with mixed cultures containing either L. sakei, S. carnosus, and S. xylosus or S. carnosus and L. sakei causing the most significant reductions. Protective cultures did not adversely affect meat color or pH. This study demonstrated the potential of protective cultures comprising lactic acid bacteria and coagulase-negative staphylococci in controlling microbial spoilage of lamb and, by inference, other types of meat as a natural solution for shelf-life extension.