Deterioration Of Meat Research Articles

H2S gas sensing based on CuNi MOFs derivative with TiO2 quantum dot decoration applied for meat freshness detection

As food safety issues have been widely revealed and exposed, the pursuit of food for people has shifted from food and clothing to fresh and healthy. Currently, there are many detection systems for detecting meat freshness on the market. However, most of the problems still exist are that they cannot be monitored in real time, cannot guarantee traceless monitoring, and the cost is high. To solve these problems, this work has built a portable meat freshness detection system based on copper oxide (CuO)/nickel oxide (NiO) doped titanium oxide (TiO2) quantum dot composites and added real-time monitoring and remote monitoring and finally packaged it into an intelligent food box. Real-time monitoring of the freshness of meat can be carried out in a specific range regardless of the space. Hydrogen sulfide (H2S) has always been an essential indicator of meat decay. Therefore, in this paper, an H2S gas sensor based on CuO/NiO doped TiO2 quantum dot composites material is designed and fabricated, which can effectively and quickly identify H2S. The gas sensor exhibits excellent gas sensing characteristics for H2S with a detection limit of 100 parts per billion (ppb) and has excellent selectivity and repeatability, which because of the presence of p-p type heterojunctions in CuO/NiO. In addition, the feasibility of the system and material for analyzing the meat deterioration process is demonstrated through the test of different meat samples. It is firmly believed that this new type of sensor mentioned in this paper can make contribution to food quality monitoring.

Nontargeted metabolomics reveals dynamic changes in the quality of fresh yak meat during ice-temperature preservation

Fresh yak meat is nutritious but susceptible to deterioration. The development of effective preservation techniques for fresh yak meat is highly important. In this study, the quality changes of fresh yak meat during ice-temperature (−1 °C) preservation and refrigerated (4 °C) preservation were evaluated. Within 15 days of preservation, the quality indicators of the yak meat preserved at ice temperature did not exceed the national standards, but the shelf life of the refrigerated meat was only 5 days. The TBARS, TVB-N, total viable counts of ice-temperature-treated meat were significantly lower than those of refrigerated meat. The dynamic changes in the metabolome of ice-temperature preservation meat were also investigated. A total of 2954 metabolites were annotated, and differentially regulated metabolites were mainly concentrated in amino acids and their metabolites, fatty acyls, benzene and its derivatives, aldehydes, ketones and esters, organic acids and its derivatives, etc. The significantly differentially regulated metabolites were mainly involved in protein and lipid oxidation. KEGG enrichment analysis revealed that the major metabolic processes involved in the deterioration of yak meat during ice-temperature preservation were purine metabolism, ABC transporters, biosynthesis of cofactors, biosynthesis of amino acids, nucleotide metabolism, glycerophospholipid metabolism, linoleic acid metabolism, and phenylalanine metabolism.

In-depth metaproteomics analysis reveals the protein profile and metabolism characteristics in pork during refrigerated storage

Alterations in microbiotas and endogenous enzymes have been implicated in meat deterioration. However, the factors that mediate the interactions between meat quality and microbiome profile were inadequately investigated. In this study, we collected pork samples throughout the refrigeration period and employed metaproteomics to characterize both the pork and microbial proteins. Our findings demonstrated that pork proteins associated with the catabolic process are upregulated during storage compared to the initial stage. Pseudomonas, Clostridium, Goodfellowiella, and Gonapodya contribute to the spoilage process. Notably, we observed an elevated abundance of microbial proteins related to glycolytic enzymes in refrigerated pork, identifying numerous proteins linked to biogenic amine production, thus highlighting their essential role in microbial decay. Further, we reveal that many of these microbial proteins from Pseudomonas are ribosomal proteins, promoting enzyme synthesis by enhancing transcription and translation. This study provides intrinsic insights into the underlying mechanisms by which microorganisms contribute to meat spoilage.

Comparative study of a liposome and emulsion system with cinnamon essential oil on the quality and proteolysis of refrigerated minced pork.

Essential oils have been recognized for their strong antibacterial property, making them an innovative approach for preserving meat. However, their chemical instability and direct impact on meat proteins limit their application. To overcome these limitations, various loading systems have been explored. This study aimed to compare the effect of cinnamon essential oil (CEO) loaded in a liposome and emulsion system on the proteolysis of minced pork and to evaluate the advantages of each delivery system in preventing microorganism-induced quality deterioration of meat. Minced pork treated with CEO-liposomes exhibited lower pH, total volatile basic nitrogen (TVB-N), and total viable count (TVC) values than CEO-emulsions and provided better protection against microorganisms. SDS-polyacrylamide gel electrophoresis (PAGE) analysis confirmed that CEO-liposome was more effective in protecting proteins from degradation. Moreover, CEO-liposome produced lower amount of bitter amino acids and harmful biogenic amines. Antibacterial mechanisms indicated that CEO-liposome exhibited a stronger inhibitory effect against major spoilage bacteria in meat products by increasing cell membrane permeability. The membrane damage was further supported by an increase in conductivity and the leakage of nucleic acids. Compared to the CEO-emulsion system, CEO-liposome emerged as an effective preservative for minced pork. These results provided important theoretical support for using a bioactive compound delivery system to prevent microorganism-induced quality deterioration in meat.

Effect of portulaca (Portulaca oleracea L.) extract on the quality and physicochemical attributes of vacuum-packed seasoned steaks during chilled storage.

Vacuum packaging has the ability to reduce oxidative deterioration and microbial-induced spoilage of meat. However, in an oxygen-free environment, it can lead to the development of an unappealing purplish-red color and a decrease in the water-holding capacity of meat, thereby impacting the overall meat quality. Portulaca oleracea L. (POL) is a homology of medicine and food known for its exceptional antioxidant and antimicrobial properties. The aim of our present study was to investigate the antioxidant and antimicrobial ability of n-butanol phase extract of POL and the effect of POL extract incorporation on the quality (water-holding capacity, shear force, color, and texture) and physicochemical (pH, total volatile base nitrogen, and total viable counts) attributes of vacuum-packed seasoned steaks at 4 °C over a 15-day period. Results showed that the POL extract had excellent antioxidant and antimicrobial capacity. Furthermore, the addition of POL extract significantly inhibited protein oxidation and microbial growth of steaks (P < 0.05), and improved the water-holding capacity, color properties, and tenderness (P < 0.05). Moreover, there were no significant differences (P > 0.05) in the color, water-holding capacity, or tenderness between the 0.5and 1 g kg-1 POL extract treatment groups compared to the sodium nitrite control group. These results indicate that POL extract had the potential to replace sodium nitrite due to its ability to hinder protein oxidation and microbial growth of vacuum-packed seasoned steaks, while enhancing the color, water-holding capacity, and tenderness of seasoned steaks. © 2024 Society of Chemical Industry.

Efeito do óleo essencial de Mentha piperita na conservação de carne refrigerada do peixe híbrido tambatinga

Abstract The search for safer foods has led to increased research attention to discover natural alternatives to synthetic additives that are used in the food industry. Natural preservatives, such as essential oils (EOs) from plants, could increase fish conservation and even positively affect human health. Therefore, the objective of the study was to evaluate the effect of Mentha piperita EO on the physicochemical characteristics and concentration of microorganisms in chilled tambatinga (Colossoma macropomum × Piaractus brachypomum) meat. Mentha piperita EO was prepared at three concentrations (0%, 0.25% and 0.50%) in a solution containing distilled water, propylene glycol and Tween. The meat samples remained immersed in this solution for 60 min; then, they were packed in plastic packages and stored under refrigeration (± 0.4 °C) for 14 days. During this storage, pH, total volatile nitrogenous bases (TVB-N), peroxides, thiobarbituric acid reactive substances (TBARS) and counts of strict and facultative aerobic mesophilic microorganisms were determined. The major constituents found in M. piperita EO were geranial (32.28%), neral (18.64%) and geranic acid (6.98%). None of the EO concentrations affected TVB-N, but there were some changes to the pH. Both 0.25% and 0.50% EO reduced the formation of peroxides and TBARS. The growth of microorganisms was reduced by treatment with 0.50% EO. Based on the findings, 0.50% EO was more effective in reducing the deterioration of meat kept refrigerated for up to 14 days.

Oxidative stability in meat (pectoralis major) of broiler orally supplemented with essential oils of allium sativum, Curcuma longa, Zingiber officinale, and Cinnamomum zeylanicum.

Lipid oxidation is a normal process in living muscles, but is escalated postmortem due to the loss of inherent antioxidant defense, which causes quality deterioration of meat. This study investigates the effects of essential oil (EO) supplementation to the drinking water of broiler chicken on physical properties, antioxidants, and lipid oxidation in Pectoralis major during frozen storage. Two hundred day-old chicks of arbo acre were allocated to five groups; control (T1) and the groups supplemented with: Allium sativum (T2), Curcuma longa (T3), Zingiber officinale (T4) and Cinnamomum zeylanicum (T5) at the level of 300ml/L into drinking water throughout a 49-d study. Thereafter, birds were slaughtered and breast meat excised for assessments during a 28-d storage period at 4 °C using standard procedure. The results show that cooking loss of Pectoralis major from T1 birds was not significantly (P > 0.05) different from that of T4, and were significantly higher than those of T2, T3, and T5 birds. Meat from T5 birds showed the lowest drip loss. The results for total antioxidant activity are not similar among sampling days. In general, control group showed inferior values, but T2 and T4 had greater values on days 0 and 28. The rate of lipid peroxidation increased with time; however, EOs administration markedly reduced the peroxidation rates compared to controls. The catalase activity of breast meat was significantly declined from day 14, but was enhanced as an effect of EO consumption especially in group T5 at 21 and 28 d. Supplementation of garlic, turmeric, and cinnamon EOs to broiler chickens increased glutathione peroxidase in breast meat on days 21 and 28, while turmeric EO enhanced superoxide dismutase up to 7 d. In conclusion, EOs are valuable supplements for broiler chickens and potent in enhancing meat quality and prolonging the shelf life.

Generalized and hetero two-dimensional correlation analysis of hyperspectral imaging combined with three-dimensional convolutional neural network for evaluating lipid oxidation in pork

Lipid oxidation is the main cause of meat deterioration. Hyperspectral imaging (HSI) technique has attracted attention as a non-destructive testing method. However, the complexity and overlap of the pork hyperspectral data lead to difficult band interpretation and computational overload. In this paper, a lightweight three-dimensional convolutional neural network (3D-CNN) model combined with two-dimensional correlation spectroscopy (2D-COS) analysis was proposed to monitor the lipid oxidation of frozen pork. Through the generalized 2D-COS analysis, the band interpretation of visible near-infrared (vis-NIR) HSI was established and the sequence of event changes caused by pork deterioration was monitored. It was found that sulfmyoglobin and oxymyoglobin were prone to change, and the decomposition of sulfmyoglobin and metmyoglobin occurred before the formation of oxymyoglobin. Moreover, the hetero 2D-COS analysis was used for the first time to correlate vis-NIR with fluorescence spectra to analyze more feature bands of vis-NIR HSI. A lightweight 3D-CNN regression model was developed for hyperspectral images of feature bands to quantitatively predict TBARS. It was found that 10 feature bands were obtained by integrating bands identified by generalized and hetero 2D-COS. The 3D-CNN model of these feature bands has yielded good results in predicting TBARS with R2p of 0.9214 and RMSEP of 0.0364 mg kg−1. Overall, this study provided a method for band assignment and interpretation of vis-NIR HSI and an end-to-end new approach for rapid and non-destructive monitoring of pork oxidative damage.

Sustainable Food Packaging with Chitosan Biofilm Reinforced with Nanocellulose and Essential Oils

Active packaging with biobased polymers aim to extend the shelf life of food and to improve the environmental sustainability of the food industry. This new concept was tested with samples of fresh poultry meat wrapped with chitosan reinforced with 2.5% of commercial nanocellulose (NC) incorporating 1% of essential oils (EO) from Aloysia citrodora (ACEO) and Cymbopogon citratus (CCEO). The performance of the bionanocomposites containing EOs was assessed and compared with unwrapped meat samples and samples wrapped with chitosan/NC, during a 13 day period of refrigerated storage for several physicochemical parameters related to food deterioration and microbial growth. Wrapping the meat with the chitosan/NC polymer helped to increase the shelf life of the meat. The incorporation of EOs added extra activity to the biocomposites, further delaying the meat deterioration process, by halting the lipid oxidation and the Enterobactereaceae growth until the 9th day. The composition of both EOs was similar, with the main components contributing to the increased activity of the biopolymers being geranial and neral. The performance of ACEO surpassed that of CCEO, namely on the Enterobactereaceae growth. This trend may be associated with ACEO’s higher phenolic content and the higher antioxidant activity of the compounds released by the ACEO biopolymers.

The Antioxidant and Antimicrobial Potential of Persian Indigenous Herbs as an Alternatives for Nitrate and Nitrite in the Preservation of Meat and Meat Products: An Overview

The consumption of animal products, including meat and meat products, has increased globally with increased household income. Spoilage by microbes, autolytic enzymes, and lipid oxidation can cause the deterioration of meat and meat products, which has a considerable economic and environmental impact. Meat curing, which includes the addition of salt, nitrite, and sometimes nitrate to fresh meat cuts, enables a preservative effect by removing moisture and reducing the water activity of the meat. Nitrates and nitrites have been traditionally used as curing agents in the production of cured meat products. Sodium and potassium nitrates and sodium and potassium nitrites are used in meat curing because they stabilize red meat color, inhibit some spoilage and food poisoning anaerobic microorganisms, delay the development of oxidative rancidity, and contribute to flavor development. The beneficial effects of adding nitrates and nitrites to meat products are the improvement of quality characteristics and microbiological safety. However, several studies have indicated that nitrates and nitrites intake should be limited owing to their potential carcinogenic effect on humans. Therefore, the consumer demand for natural or nitrate- and nitrite-free meat products remains high. There is a need to find alternative natural plant material that provides alternative antioxidant and antimicrobial activities since they are noncarcinogenic and reliable; they can substitute or reduce nitrates and nitrites with minimal or no quality compromise of sensory attributes and shelf-life. Hence in this overview, we focused on Persian indigenous herbs, their essential oil and extracts' chemical composition, and their relation to their antioxidant and antimicrobial activity to find out how the essential oils and extracts of the herbs can be applied to meat and meat as a natural substitute.

Colour Stability, Fatty Acid Profile, and Lipid Oxidation in Meat Stored in Modified Atmosphere Packaging from Light Lambs Fed with Concentrate with Carob Pulp (Ceratonia siliqua L.).

There is a growing interest in using by-products rich in polyphenols, such as carob pulp (Cp, Ceratonia siliqua L.), as a dietary source of antioxidants for animals. This study assesses the effects of including Cp in lambs' diet and meat display time (0, 7, 9, and 11 days) in modified atmosphere packaging on meat colour, fatty acid (FA) composition, tocopherol levels, and lipid oxidation values in the Semimembranosus muscle of 40 light lambs. The lambs were fed with concentrates supplemented with increasing Cp levels (0, 150, and 300 g/kg) for 45 days before slaughter. Metmyoglobin (MMb) and malondialdehyde (MDA) contents increased linearly with display time (p < 0.05), regardless of diet (p > 0.05). At 11 days of display, MMb (28 ± 0.8%) and MDA (0.6 ± 0.1 mg MDA/kg of meat) contents remained within the acceptable limits. The α-tocopherol content was lower in the 30% Cp group and meat (p < 0.05). Total saturated and monounsaturated FA contents (934 ± 64 and 823 ± 65 mg/100 g of meat, respectively) did not differ significantly among the groups. However, the meat from lambs fed with 30% Cp showed reduced levels of branched-chain FAs, while polyunsaturated FAs increased (p < 0.05) compared to the control lambs. The inclusion of Cp in the lamb's diet, up to 30%, did not lead to meat deterioration and improved certain quality parameters, including a healthier FA profile. These findings highlight Cp's potential as an alternative antioxidant source in animal diets.

Quality characteristics and moisture migration of refrigerated bullfrog (Lithobates catesbeiana) under slightly acidic electrolyzed water combined with composite preservative treatment

The aim of this study was to investigate the effects of allicin and antioxidant of bamboo leaves (AOB) with slightly acidic electrolyzed water (SAEW) pretreatment on the microbiological, physicochemical quality and moisture migration of bullfrog (Lithobates catesbeiana) during refrigerated storage. The results showed that slightly acidic electrolyzed water combined with composite preservative treatment (SAA) could effectively inhibit microbial proliferation in bullfrogs, which reflected by total viable counts (TVC). The analysis low-field nuclear magnetic resonance (LF-NMR), water holding capacity (WHC), magnetic resonance imaging (MRI), and drip loss demonstrated that SAA can keep the freshness of bullfrog meat by preventing water migration. Moreover, SAA treatment also retard the increase of pH, malondialdehyde (MDA), total volatile basic nitrogen (TVB-N), biogenic amines and K-value, which also delay the deterioration of bullfrog meat and maintain a good sensory score. In conclusion, this study proved that SAA treatment can be used as an effective treatment to sustain the quality of bullfrogs during refrigerated storage.

Antimicrobial and Antioxidant Edible Films and Coatings in the Shelf-Life Improvement of Chicken Meat.

Meat deterioration during processing, distribution, and display can compromise the quality and safety of products, causing several undesirable changes and decreasing products' shelf-life, which has a negative impact on the industry and consumers. In recent years, studies have been carried out using decontamination techniques and new packaging methodologies to overcome deterioration problems, increase sustainability, and reduce waste. Edible films and coatings obtained from biopolymers such as polysaccharides, proteins, and lipids, combined with active compounds, can be an alternative approach. This article focused on recent studies that used alternative biodegradable polymeric matrices in conjunction with natural compounds with antioxidant/antimicrobial activity on chicken meat. Its impact on physicochemical, microbiological, and sensory characteristics was evident, as well as the effect on its shelf-life. In general, different combinations of active edible films or coatings had a positive effect on the chicken meat. Different studies reported that the main results were a decrease in microbial growth and pathogen survival, a slowdown in lipid oxidation evolution, and an improvement in sensory quality and shelf-life (an increase from 4 to 12 days).

Photodynamic inactivation of spoilers Pseudomonas lundensis and Brochothrix thermosphacta by food-grade curcumin and its application on ground beef

This study evaluated the bactericidal effects of curcumin-mediated photodynamic inactivation (PDI) combined with citric acid on meat spoilage bacteria, and their preservative effects of refrigerated beef. After treatment of PDI (60 μM curcumin and 33.01 J/cm2) combined with 0.5 mg/mL citric acid, the populations of Pseudomonas lundensis and Brochothrix thermosphacta in PBS solution were reduced by 3.07 and 6.14 log CFU/mL, respectively, compared to 0.31 and 1.39 log CFU/mL for PDI. Combined treatment enhanced reactive oxygen species (ROS) activity in the two strains, and damaged their cell morphology, especially B. thermosphacta. With increasing curcumin concentration, the growth rate of spoilage bacteria was significantly inhibited (P < 0.05), and the changes of dominant spoilage species in bacterial community were retarded in aerobic-packaged and vacuum-packaged ground beef at 4 °C. Compared to the control, trichloroacetic acid-soluble peptide and total volatile basic nitrogen production were greatly restrained, and changes in pH values and brown color were apparently reduced for the combined treatment, which could extend the shelf life by 2 days. These results suggested the synergistic potency of PDI combined with citric acid against spoilage bacteria in meat products.Industrial relevance: The proliferation and spread of some psychrotrophs are major causes of quality deterioration and cross-contamination in fresh meat during cold chain. This study revealed that photosensitized curcumin combined with citric acid significantly decreased the survival of two psychrotrophic spoilage bacteria and extended the shelf-life of ground beef. Thus, curcumin-based PDI provides a new insight for the development of efficient and economic preservation in the meat processing industry.

Multi-task convolutional neural network for simultaneous monitoring of lipid and protein oxidative damage in frozen-thawed pork using hyperspectral imaging

Lipid and protein oxidation are the main causes of meat deterioration during freezing. Traditional methods using hyperspectral imaging (HSI) need to train multiple independent models to predict multiple attributes, which is complex and time-consuming. In this study, a multi-task convolutional neural network (CNN) model was developed for visible near-infrared HSI data (400–1002 nm) of 240 pork samples treated with different freeze-thaw cycles (0–9 cycles) to evaluate the feasibility of simultaneously monitoring lipid oxidation (thiobarbituric acid reactive substance content) and protein oxidation (carbonyl content) in pork. The performance of the commonly used partial least squares regression (PLSR) model based on the spectra after pre-processing (Standard normal variate, Savitzky-Golay derivative, and Savitzky-Golay smoothing) and feature selection (Regression coefficients) and single-output CNN model was compared. The results showed that the multi-task CNN model achieved the optimal prediction accuracies for lipid oxidation (R2p = 0.9724, RMSEP = 0.0227, and RPD = 5.2579) and protein oxidation (R2p = 0.9602, RMSEP = 0.0702, and RPD = 4.6668). In final, the changes of lipid and protein oxidation of pork in different freeze-thaw cycles were successfully visualized. In conclusion, the combination of HSI and multi-task CNN method shows the potential of end-to-end prediction of pork oxidative damage. This study provides a new, convenient and automated technique for meat quality detection in the food industry.

Antibacterial smart absorbent pad with Janus structure for meat preservation

In this work, an antibacterial smart absorbent pad with Janus structure was prepared to preserve and indicate the quality of meat. The pad had two layers, polyurethane (PU) nanofibers as the top hydrophobic layer and polyvinyl alcohol (PVA) nanofibers as the bottom absorbent layer. Polyhexamethylenebiguanide hydrochloride (PHMB) was added to the top layer as cationic antimicrobial agent because guanidine group could maintain its strong positive charge in alkaline environment, which keeps the antibacterial ability during meat spoilage that is a process of pH increasing. Besides, the juice of the meat can be absorbed to the bottom layer while the hydrophobic top layer in contact with meat remains dry, which can reduce the multiplication of bacteria. Furthermore, anthocyanin was added to the bottom layer as an indicator to detect spoilage of meat. The experiments show the new antibacterial indicator absorbent pad can effectively inhibit bacterial growth (less than 5 lg CFU/g after 8 days), prolong the shelf life of fresh meat (total volatile base nitrogen less than 20 mg/100 g) to 7 days when stored at 4 °C and indicate the deterioration of meat.

Effect of Different Genotypes and Harvest Times of Sage (Salvia spp. Labiatae) on Lipid Oxidation of Cooked Meat.

Lipid oxidation is the primary non-microbial reason for quality deterioration of meat and meat products. Lipid oxidation can be prevented or delayed by antioxidants. In this study, 15 sage (Salvia spp. Labiatae) extracts (five genotypes, three harvest times) were tested for their ability to reduce lipid oxidation (peroxide value (PV) and thiobarbituric acid reactive substances (TBARS)) in ground, uncured, cooked porcine and bovine meat (60%/40% mixture) during 14 days of refrigerated storage. Additionally, total phenolic content was determined, and the antioxidant capacity of the extracts was measured as radical scavenging activity (2,2-diphenyl-1-picrylhydrazyl assay), reducing power, and superoxide anion scavenging activity. All 15 sage extracts were able to reduce lipid oxidation, though showing expected differences depending on genotype and harvest time. The extracts of S. officinalis accession from Foggia, Italy performed better than the other genotypes when looking at the entire storage period and considering both PV and TBARS. Of the applied methods for determining antioxidant capacity, superoxide anion scavenging activity proved to be the best determinant of the ability of sage to reduce lipid oxidation in the meat sample.

Causes of Meat Deterioration and Preservation Methods

Humans have been practising the skill of meat preservation since the beginning of time, and this practice lives on in all of the foods we consume today. Primarily, meat preservation postpones the development of microorganisms like bacteria and fungi, so meat and its byproducts may sit on store shelves for longer without losing quality or flavour. Dysbiosis is the process by which any food, when exposed to organisms (bacterial and fungal), that degrade the products, changes from being edible to being inedible via denaturation of texture, color, and odor. Spoilage and a lack of storage skills during processing and analyzing generate a significant annual loss of meat and its byproducts for the economies of all countries. In general, organic material, lipid oxidation, and metabolic activity are the fundamental processes of meat deterioration. Traditional techniques for preserving food include drying, salting, pickling, and smoking, all of which aid in preservation when frozen. However, as time went on, new techniques for preserving food emerged, such as freezing, chilling, and irradiation, which significantly extended the period of preservation and made it easier to apply. Modern procedures, such as chilling and other freezing technologies, are used to preserve all manner of meat and meat products, extending their shelf life and improving their quality and texture by all but neutralizing the development of microorganisms.

Microbiological Changes during Long-Storage of Beef Meat under Different Temperature and Vacuum-Packaging Conditions

We evaluated a combination of two temperatures and two packaging materials for long-term storage of vacuum-packaged (VP) beef striploins. Microbial populations and microbiome composition were monitored during refrigerated storage (120 days between 0-1.5 °C) and refrigerated-then-frozen storage (28 days between 0-1.5 °C then 92 days at -20 °C) under low-O2 permeability VP and high-O2 permeability VP with an antimicrobial (VPAM). Pseudomonas (PSE) and Enterobacteriaceae (EB) counts in VPAM samples were significantly higher (p < 0.05) than in VP samples at 28, 45, 90, and 120 days of storage. Microbiome data showed that bacteria of the genera Serratia and Brochothrix were more abundant in VPAM samples at 120 days, while lactic acid bacteria (LAB) dominated in VP samples. Frozen temperatures inhibited microbial growth and maintained a relatively stable microbiome. Refrigerated and frozen VPAM samples showed the greatest difference in the predicted metabolic functions at the end of storage driven by the microbiome composition, dominated by PSE and LAB, respectively. Although no signs of visible meat deterioration were observed in any sample, this study suggests that VP meat refrigerated and then frozen achieved better microbiological indicators at the end of the storage period.

Effects of edible chitosan coating containing Salvia rosmarinus essential oil on quality characteristics and shelf life extension of rabbit meat during chilled storage

Rabbit meat is one of the most consumed meats throughout the world and is extremely susceptible to spoilage due to its high protein and moisture content. Natural preservatives with antioxidant and antibacterial properties are needed to maintain meat quality and increase its shelf life. This study examined the effect of 1% chitosan (CH), 0.2% rosemary (Salvia rosmarinus) essential oil (REO), and their combination on pH, total volatile basic nitrogen (TVB-N) and thiobarbituric acid (TBA) levels, and the microbial profile of rabbit meat stored over 12 days at 4 °C. During this time, changes in appearance, odor, and texture were also noted. The shelf lives of samples treated with only 1% CH coating, or in combination with 0.2% REO, were longer than those of untreated samples. These results showed that samples treated with both CH and REO were still acceptable until the 12th day and resulted in significantly lower meat demerit scores in these treated groups compared with untreated meat. In all groups, the pH, TVB-N, and TBA values increased over time, but these values were significantly higher (p < 0.05) in untreated samples. Microbial analysis results showed that chilled rabbit meat samples treated with combined 1% CH and 0.2% REO reduced Enterobacteriaceae, Pseudomonas, and Psychrotrophic counts. The experimental results demonstrated that using CH coating in combination with REO improved the quality of rabbit meat and could be an effective approach to reduce rabbit meat deterioration during chilled storage.