Effect of sodium alginate coating incorporated with nisin, Cinnamomum zeylanicum , and rosemary essential oils on microbial quality of chicken meat and fate of Listeria monocytogenes during refrigeration

Evaluation of phyto-gallic acid as a potential inhibitor of Staphylococcus aureus efflux pump mediated tetracycline resistance: an in-vitro and in-silico study

Plants contain many bioactive compounds with potent antibacterial and efflux pump inhibitory activity (EPI). In this study, gallic acid extracted from pomegranate molasses by analytical HPLC holds promise as an EPI drug for Staphylococcus aureus mediated tetracycline resistance, it lowered the bacterial resistance and reversed the mechanism via tet family efflux pump, using molecular technique and in-silico molecular docking analysis. Extracted gallic acid combined with tetracycline demonstrated a significant decrease in the minimal inhibitory concentration MIC compared to its single activity. Similarly, little growth and lower fluorescence of S. aureus were observed on ethidium bromide (2.5 mg/mL) agar plates, indicating a reversible efflux pump mechanism and a potent EPI activity. Molecular docking demonstrated a promising affinity binding energy between gallic acid and tet efflux genes, opening a new baseline in bacterial infection treatment. PCR for tetK and Qac A/B genes failed to show any relation between tet genes and gallic acid.

Bilayer coatings for extension of the shelf life of fish fillets: Incorporating seaweed sulfated polysaccharides in chitosan-alginate LbL structures

The aim of this study was to develop a new active coating of layer-by-layer (LbL) structure composed of alginate (as polyanions) and chitosan (as a polycation) containing sulfated polysaccharide (fucoidan) from Sargassum angustifolium, to protect rainbow trout fillets during refrigerated storage. Chitosan and alginate do not combine with each other as a homogeneous solution, so they are suitable for multilayer coatings. The results demonstrated that coating samples with chitosan and fucoidan significantly improved the quality of fish fillets and extended their shelf life from 6 to 16 days. The chemical values (TBARS and TVB-N) and bacterial growth (total viable count (TVC), total psychrophilic count (PTC), and lactic acid bacteria (LAB)) indicated lower levels in the LbL coating samples containing fucoidan compared to the alginate and control samples. Among the different coating samples, the LbL coating with fucoidan (AChF1) exhibited lower weight loss, improved chromaticity (L*, a*, and b*), and minimal changes in mechanical and sensory evaluations. Based on the findings, AChF1 was the most effective treatment for increasing the shelf life of rainbow trout fillets during refrigerated storage. Therefore, it has potential applications in the food packaging industry.

Role of marination, natural antimicrobial compounds, and packaging on microbiota during storage of chicken tawook

The aim of this study was to investigate the antimicrobial effect of marination, natural antimicrobials, and packaging on the microbial population of chicken tawook during storage at 4°C. Chicken meat was cut into 10 g cubes and marinated. The chicken was then mixed individually with 0.5% or 1% (w/v) vanillin (VA), β-resorcylic acid (BR), or eugenol (EU), and stored under aerobic (AP) or vacuum (VP) packing at 4°C for 7 d. The marinade decreased microbial growth as monitored by total plate count, yeast and mold, lactic acid bacteria, and Pseudomonas spp. by about 1 log cfu/g under AP. The combination of marinade and antimicrobials under AP and VP decreased growth of spoilage-causing microorganisms by 1.5 to 4.8 and 2.3 to 4.6 log cfu/g, respectively. Change in pH in VP meat was less than 0.5 in all treated samples including the control. Marination decreased the lightness of the meat (L*) and significantly (p < 0.05) increased the redness (A*) and yellowness (B*). Overall acceptability was highest for marinated samples with 0.5% BR.

Comprehensive Review on the Biocontrol of Listeria monocytogenes in Food Products

Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a group of human illnesses that appear more frequently in countries with better-developed food supply systems. This review discusses the efficacy of actual biocontrol methods combined with the main types of food involved in illnesses. Comments on bacteriophages, lactic acid bacteria, bacteriocins, essential oils, and endolysins and derivatives, as main biological antilisterial agents, are made bearing in mind that, using them, food processors can intervene to protect consumers. Both commercially available antilisterial products and solutions presented in scientific papers for mitigating the risk of contamination are emphasized. Potential combinations between different types of antilisterial agents are highlighted for their synergic effects (bacteriocins and essential oils, phages and bacteriocins, lactic acid bacteria with natural or synthetic preservatives, etc.). The possibility to use various antilisterial biological agents in active packaging is also presented to reveal the diversity of means that food processors may adopt to assure the safety of their products. Integrating biocontrol solutions into food processing practices can proactively prevent outbreaks and reduce the occurrences of L. monocytogenes-related illnesses.

Shelf life extending of probiotic beef patties with polylactic acid-ajwain essential oil films and stress effects on Bacillus coagulans

Meat and meat products are prone to the microbial and chemical spoilage, due to the high nutritional content. This study investigated the effect of polylactic acid (PLA) films incorporated with ajwain essential oil (AEO) on microbial (total viable count [TVC], psychrotrophic bacterial count [PTC], Enterobacteriaceae, Pseudomonas spp., yeast and mold (Y&M), and also Bacillus coagulans [BCG]), chemical (pH, peroxide value [PV], thiobarbituric acid-reactive substance [TBARS], and TVN values), and sensorial properties of beef patties, as well as survivability of BCG during refrigerated storage. Results showed that all microbial counts of samples were significantly increased, except BCG, during storage but the lowest TVC of samples was achieved in samples wrapped with PLA-1% AEO (8 log colony forming units per gram [CFU/g]) at 12th of storage, which is significantly lower than control treatments (10.66 log CFU/g). The best results in all treatments are those wrapped by PLA-1% AEO in all evaluated characteristics. At the final day of storage, PTC (8.82 log CFU/g), Enterobacteriaceae (5.05 log CFU/g), Pseudomonas spp. (9.08 log CFU/g), Y&M (4.69 log CFU/g), and also pH (4.5), PV (5.12 meq/kg), TBARS (2.92 MDA/kg), and TVN (14.43 mgN/100 g) values of PLA-1% AEO treatments were significantly lower than control samples. AEO-PLA films reduce the survival of BCG in raw patties, which reached 6.19 log CFU/g in PLA-1% AEO treatments, although increasing the concentration of AEO in packaging PLA films led to the maintenance of BCG viability during the cooking process by increasing the AEO in PLA films. Overall, results showed shelf life of beef patties is extended 3 days more (150%) by wrapping with PLA films incorporated with 1% AEO.

The effects of double gelatin containing chitosan nanoparticles-calcium alginate coatings on the stability of chicken breast meat

The effects of gelatin coatings (2% and 4%) containing chitosan nanoparticles (ChNPs; 1% and 2%), in combination with calcium-alginate coatings (CA; 2%), on quality attributes and shelf life of chicken breast meat were evaluated at 4°C for 12 days. The results indicated that double-active gelatin-calcium alginate coatings had significant (p < .05) effects on moisture and protein content. Incorporation of ChNPs into double gelatin-CA coatings led to significant reduction (p < .05) in TBARS, pH, and TVB-N values at the end of storage. The counts of total viable count (TVC), coliforms, yeasts, and molds were significantly (p < .05) lower in all coated samples, particularly in treated samples by 4% gelatin containing 2% ChNPs + 2% CA coatings (6.85, 6.78, and 5.91 log CFU/g, respectively, compared with 8.35, 8.76, and 7.71 log CFU/g in control) at the end of keeping time. The results of sensory attributes showed that the coated samples had higher overall acceptability scores compared with the untreated samples. A synergistic relationship between the concentrations of gelatin and ChNPs was observed in maintaining the quality characteristics of meat samples during storage. Therefore, this study aims to evaluate the performance of double gelatin coating containing ChNPs in combination with CA coating in the storage quality improvement of chicken breast meat stored for 12 days at 4 °C to develop novel and practical coatings for meat and meat products.

The Research Field of Meat Preservation: A Scientometric and Visualization Analysis Based on the Web of Science

Meat plays a significant role in human diets, providing a rich source of high-quality protein. With advancements in technology, research in the field of meat preservation has been undergoing dynamic evolution. To gain insights into the development of this discipline, the study conducted an analysis and knowledge structure mapping of 1672 papers related to meat preservation research within the Web of Science Core Collection (WOSCC) spanning from 2001 to 2023. And using software tools such as VOSviewer 1.6.18 and CiteSpace 5.8.R3c allowed for the convenient analysis of the literature by strictly following the software operation manuals. Moreover, the knowledge structure of research in the field of meat preservation was synthesized within the framework of "basic research-technological application-integration of technology with fundamental research," aligning with the research content. Co-cited literature analysis indicated that meat preservation research could be further categorized into seven collections, as well as highlighting the prominent role of the antibacterial and antioxidant properties of plant essential oils in ongoing research. Subsequently, the future research direction and focus of the meat preservation field were predicted and prospected. The findings of this study could offer valuable assistance to researchers in swiftly comprehending the discipline's development and identifying prominent research areas, thus providing valuable guidance for shaping research topics.

Characterization of Sodium Alginate-Based Films Blended with Olive Leaf and Laurel Leaf Extracts Obtained by Ultrasound-Assisted Technology

Due to environmental concerns, there is an increasing need to reduce the use of synthetic and non-renewable packaging materials to reduce waste and increase sustainability. This study aimed to characterise sodium alginate edible-based films (SA) incorporated with laurel leaf extract (LLE) and olive leaf extract (OLE) obtained by ultrasound-assisted extraction. Determination of total phenolic content, antioxidant, and antimicrobial activity was performed for the extracts and films. Also, thickness, tensile strength, elongation at break, modulus of elasticity, opacity and colour, moisture content, water vapour permeability (WVP), Fourier-transform infrared spectroscopy (FTIR) spectra, and surface morphology by scanning electron microscope (SEM) analyses were performed for the films. LLE yielded better results in terms of phenolic content (195 mg GAE/g), antioxidant (2.1 TE/g extract) and antimicrobial activity (MIC at 1% for Listeria monocytogenes and Staphylococcus aureus, and 1.8% for Enterococcus faecalis). For the films, the simultaneous incorporation of LLE 1% (w/v) and OLE 1% (w/v) resulted in a significant reduction of approximately 2 log CFU/g against S. aureus. The addition of LLE and OLE extracts also proved to improve barrier properties (lower WVP for SA films with LLE 1% + OLE 1%, 3.49 × 10-11 g m-1 s-1 Pa-1) and promoted changes in resistance and flexibility. The results demonstrated that active alginate-based films can be valuable for enhancing food preservation.

A critical review on biodegradable food packaging for meat: Materials, sustainability, regulations, and perspectives in the EU

The development of biodegradable packaging is a challenge, as conventional plastics have many advantages in terms of high flexibility, transparency, low cost, strong mechanical characteristics, and high resistance to heat compared with most biodegradable plastics. The quality of biodegradable materials and the research needed for their improvement for meat packaging were critically evaluated in this study. In terms of sustainability, biodegradable packagings are more sustainable than conventional plastics; however, most of them contain unsustainable chemical additives. Cellulose showed a high potential for meat preservation due to high moisture control. Polyhydroxyalkanoates and polylactic acid (PLA) are renewable materials that have been recently introduced to the market, but their application in meat products is still limited. To be classified as an edible film, the mechanical properties and acceptable control over gas and moisture exchange need to be improved. PLA and cellulose-based films possess the advantage of protection against oxygen and water permeation; however, the addition of functional substances plays an important role in their effects on the foods. Furthermore, the use of packaging materials is increasing due to consumer demand for natural high-quality food packaging that serves functions such as extended shelf-life and contamination protection. To support the importance moving toward biodegradable packaging for meat, this review presented novel perspectives regarding ecological impacts, commercial status, and consumer perspectives. Those aspects are then evaluated with the specific consideration of regulations and perspective in the European Union (EU) for employing renewable and ecological meat packaging materials. This review also helps to highlight the situation regarding biodegradable food packaging for meat in the EU specifically.

Effect of Sodium Nitrite, Nisin and Lactic Acid on the Prevalence and Antibiotic Resistance Patterns of Listeria monocytogenes Naturally Present in Poultry

The impact of treating minced chicken meat with sodium nitrite (SN, 100 ppm), nisin (Ni, 10 ppm) and lactic acid (LA, 3000 ppm) on the levels of some microbial groups indicating hygiene quality were investigated. Specifically, aerobic plate counts and culture-based counts of psychrotrophic microorganisms and enterobacteria were obtained. Additionally, the prevalence of Listeria monocytogenes and the resistance of 245 isolates from this bacterium to 15 antibiotics were documented. L. monocytogenes was isolated using the ISO 11290-1:2017 method and confirmed with polymerase chain reaction using the lmo1030 gene. Antibiotic resistance was established using the disc diffusion technique (EUCAST and CLSI criteria). Twenty-four hours after treatment, the microbial load (log10 cfu/g) was reduced (p < 0.05) relative to controls in those samples treated with LA, with counts of 5.51 ± 1.05 (LA-treated samples) vs. 7.53 ± 1.02 (control) for APC, 5.59 ± 1.14 (LA) vs. 7.13 ± 1.07 (control) for psychrotrophic microorganisms and 2.33 ± 0.51 (LA) vs. 4.23 ± 0.88 (control) for enterobacteria. L. monocytogenes was detected in 70% (control samples), 60% (samples receiving SN), 65% (Ni) and 50% (LA) (p > 0.05) of samples. All strains showed resistance to multiple antimicrobials (between 3 and 12). In all, 225 isolates (91.8%) showed a multi-drug resistant (MDR) phenotype, and one isolate (0.4%) showed an extensively drug-resistant (XDR) phenotype. The mean number of resistances per strain was lower (p < 0.01) in the control samples, at 5.77 ± 1.22, than in those receiving treatment, at 6.39 ± 1.51. It is suggested that the use of food additives might increase the prevalence of resistance to antibiotics in L. monocytogenes, although additional studies would be necessary to verify this finding by analyzing a higher number of samples and different foodstuffs and by increasing the number of antimicrobial compounds and concentrations to be tested.

An edible coating utilizing Malva sylvestris seed polysaccharide mucilage and postbiotic from Saccharomyces cerevisiae var. boulardii for the preservation of lamb meat

Currently, microbial bioactive substances (postbiotics) are considered a promising tool for achieving customer demand for natural preservatives. This study aimed to investigate the effectiveness of an edible coating developed by Malva sylvestris seed polysaccharide mucilage (MSM) and postbiotics from Saccharomyces cerevisiae var. boulardii ATCC MYA-796 (PSB) for the preservation of lamb meat. PSB were synthesized, and a gas chromatograph connected to a mass spectrometer and a Fourier transform infrared spectrometer were used to determine their chemical components and main functional groups, respectively. The Folin-Ciocalteu and aluminium chloride techniques were utilized to assess the total flavonoid and phenolic levels of PSB. Following that, PSB has been incorporated into the coating mixture, which contains MSM, and its potential radical scavenging and antibacterial activities on lamb meat samples were determined after 10 days of 4 °C storage. PSB contains 2-Methyldecane, 2-Methylpiperidine, phenol, 2,4-bis (1,1-dimethyl ethyl), 5,10-Diethoxy-2,3,7,8- tetrahydro-1H,6H-dipyrrolo[1,2-a:1',2'-d] pyrazine, and Ergotaman-3',6',18-trione, 12'-hydroxy-2'-methyl-5'-(phenylmethyl)-, (5'alpha) as well as various organic acids with significant radical scavenging activity (84.60 ± 0.62 %) and antibacterial action toward Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus aureus, and Listeria innocua as foodborne pathogens. The edible PSB-MSM coating effectively reduced microbial growth and increased meat shelf life (> 10 days). When PSB solutions were added to the edible coating, the moisture content, pH value, and hardness of the samples were also more successfully maintained (P < 0.05). The PSB-MSM coating inhibited lipid oxidation in meat samples considerably and diminished the formation of primary as well as secondary oxidation intermediates (P < 0.05). Additionally, when MSM + 10 % PSB edible coating was utilized, the sensory properties of the samples were maintained more well during preservation. As a significance, the use of edible coatings based on PSB and MSM is efficient in decreasing microbiological and chemical degradation in lamb meat during preservation.

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).

A Novel Edible Coating Produced from a Wheat Gluten, Pistacia vera L. Resin, and Essential Oil Blend: Antimicrobial Effects and Sensory Properties on Chicken Breast Fillets

Antimicrobial edible coatings can eliminate the risk of pathogen contamination on the surface of poultry products during storage. In this study, an edible coating (EC) based on wheat gluten, Pistacia vera L. tree resin (PVR), and the essential oil (EO) of PVR was applied on chicken breast fillets (CBF) by a dipping method to prevent the growth of Salmonella Typhimurium and Listeria monocytogenes. The samples were packed in foam trays wrapped with low-density polyethylene stretch film and stored at 8 °C for 12 days to observe the antimicrobial effects and sensory properties. The total bacteria count (TBC), L. monocytogenes, and S. Typhimurium were recorded during storage. The samples coated with EC, containing 0.5, 1, 1.5, and 2% v/v EO (ECEO), showed significant decreases in microbial growth compared to the control samples. The growth of TBC, L. monocytogenes, and S. Typhimurium was suppressed by 4.6, 3.2, and 1.6 logs, respectively, at the end of 12 days on the samples coated with ECEO (2%) compared to the uncoated controls (p < 0.05). Coating with ECEO (2%) also preserved the appearance, smell, and general acceptance parameters better than uncoated raw chicken (p < 0.05) on the fifth day of storage. In grilled chicken samples, ECEO (2%) did not significantly change the appearance, smell, and texture (p > 0.05) but increased the taste and general acceptance scores. Therefore, ECEO (2%) can be a feasible and reliable alternative to preserve CBFs without adversely affecting their sensory properties.

Potential of Essential Oils in the Control of Listeria monocytogenes

Listeria monocytogenes is a foodborne pathogen, the causative agent of listeriosis. Infections typically occur through consumption of foods, such as meats, fisheries, milk, vegetables, and fruits. Today, chemical preservatives are used in foods; however, due to their effects on human health, attention is increasingly turning to natural decontamination practices. One option is the application of essential oils (EOs) with antibacterial features, since EOs are considered by many authorities as being safe. In this review, we aimed to summarize the results of recent research focusing on EOs with antilisterial activity. We review different methods via which the antilisterial effect and the antimicrobial mode of action of EOs or their compounds can be investigated. In the second part of the review, results of those studies from the last 10 years are summarized, in which EOs with antilisterial effects were applied in and on different food matrices. This section only included those studies in which EOs or their pure compounds were tested alone, without combining them with any additional physical or chemical procedure or additive. Tests were performed at different temperatures and, in certain cases, by applying different coating materials. Although certain coatings can enhance the antilisterial effect of an EO, the most effective way is to mix the EO into the food matrix. In conclusion, the application of EOs is justified in the food industry as food preservatives and could help to eliminate this zoonotic bacterium from the food chain.

Application of Rosmarinic Acid with Its Derivatives in the Treatment of Microbial Pathogens

The emergence of the antimicrobial resistance phenomena on and the harmful consequences of the use of antibiotics motivate the necessity of innovative antimicrobial therapies, while natural substances are considered a promising alternative. Rosmarin is an original plant compound listed among the hydroxycinnamic acids. This substance has been widely used to fight microbial pathology and chronic infections from microorganisms like bacteria, fungi and viruses. Also, various derivatives of rosmarinic acid, such as the propyl ester of rosmarinic acid, rosmarinic acid methyl ester or the hexyl ester of rosmarinic acid, have been synthesized chemically, which have been isolated as natural antimicrobial agents. Rosmarinic acid and its derivatives were combined with antibiotics to obtain a synergistic effect. This review reports on the antimicrobial effects of rosmarinic acid and its associated derivatives, both in their free form and in combination with other microbial pathogens, and mechanisms of action.

Nisin: From a structural and meat preservation perspective

Nisin is a posttranslationally modified antimicrobial peptide that is widely used as a food preservative. It contains five cyclic thioethers of varying sizes. Nisin activity and stability are closely related to its primary and three dimensional structures. It has nine reported natural variants. Nisin A is the most studied nisin as it was the first one purified. Here, we review the sequence feature of nisin A and its natural variants, and their biosynthesis pathway, mode of action and application as a meat preservative. We systematically illustrate the functional domains of the main enzymes (NisB, NisC, and NisP) involved in nisin synthesis. NisB was shown to dehydrate its substrate NisA via a tRNA associated glutamylation mechanism. NisC catalysed the cyclization of the didehydro amino acids with the neighboring cysteine residues. After cyclization, the leader peptide is removed by the protease NisP. According to multiple sequence alignments, we detected five conserved sites Dha⁵, Pro⁹, Gly¹⁴, Leu¹⁶, and Lys²². These residues are probably the structural and functional important ones that can be modified to produce peptides versions with enhanced antimicrobial activity. Through comparing various application methods of nisin in different meats, the antimicrobial effects of nisin used individually or in combination with other natural substances were clarified.

Application of alginate polymer films and coatings incorporated with essential oils in foods: a review of recent literature with emphasis on nanotechnology

Food waste is one of the major challenges in food safety and finding a solution for this issue is critically important. Herein, edible films and coatings became attractive for scientists as they can keep food from spoilage. Edible films and coatings can effectively preserve the original quality of food and extend its shelf life. Polysaccharides, including starch and cellulose derivatives, chitosan, alginate and pectin, have been extensively studied as biopackaging materials. One of the most interesting polysaccharides is alginate, which has been used to make edible films and coatings. Incorporating essential oils (EO) in alginate matrices results in an improvement in some properties of the edible packages, such as antioxidant and antimicrobial properties. Additionally, the use of nanotechnology can improve the desirable properties of edible films and coatings. In this article we reviewed the antimicrobial and antioxidant properties of alginate coatings and films and their use in various food products.

The effects of novel alginate-lauric arginate coatings with temperature on bacterial quality, oxidative stability, and organoleptic characteristics of frozen stored chicken drumsticks

Although alginate has been reported to be used as an edible film and coating in food, to the best of our knowledge, this study is the first to investigate the individual effects of coatings, temperatures, storage times, as well as their interactions, on the bacterial quality, deterioration criteria, and sensory attributes of chicken drumsticks. To accomplish this, six groups of chicken drumsticks were treated with different coatings, temperatures, and storage conditions. The groups included 2 % alginate at 25 °C (Alg₂₅) and 50 °C (Alg₅₀), a mixture of 2 % alginate and 2 % LAE at 25 °C (M₂₅) and 50 °C (M₅₀), besides control untreated samples in distilled water at 25 °C (C₂₅) and 50 °C (C₅₀). The chicken drumsticks were stored at -18 °C for 3 months. The results showed that all treated chicken drumsticks induced a significant reduction in all bacterial counts, as well as a significant decrease in pH and thiobarbituric acid values, with an improvement in all sensory attributes, particularly in the M₂₅ and M₅₀ coated samples compared to the C₂₅ and C₅₀. Furthermore, exposing alginate and LAE to a temperature of 50 °C can increase their antimicrobial activity. In conclusion, the innovative combinations of LAE and alginate can be used successfully to decontaminate chicken carcasses in poultry processing plants.

Alginate Coating Charged by Hydroxyapatite Complexes with Lactoferrin and Quercetin Enhances the Pork Meat Shelf Life

In this work, the effect of an alginate-based coating loaded with hydroxyapatite/lactoferrin/quercetin (HA/LACTO-QUE) complexes during the storage of pork meat was evaluated. FT-IR spectra of HA/LACTO-QUE complexes confirmed the adsorption of QUE and LACTO into HA crystals showing the characteristic peaks of both active compounds. The kinetic releases of QUE and LACTO from coatings in an aqueous medium pointed out a faster release of LACTO than QUE. The activated alginate-based coating showed a high capability to slow down the growth of total viable bacterial count, psychotropic bacteria count, Pseudomonas spp. and Enterobacteriaceae during 15 days at 4 °C, as well as the production of the total volatile basic nitrogen. Positive effects were found for maintaining the hardness and water-holding capacity of pork meat samples coated with the activated edible coatings. Sensory evaluation results demonstrated that the active alginate-based coating was effective to preserve the colour and odour of fresh pork meat with overall acceptability up to the end of storage time.

Inhibition of spoilage bacteria on marinated chicken by essential oils under aerobic and vacuum packaging

"Chicken tawook" is a marinated boneless chicken entrée consumed in the Middle East. The aim of this study was to determine whether bioactive essential oil (EO) components carvacrol (CA), cinnamaldehyde (CI), and thymol (TH) would delay the growth of microorganisms causing tawook spoilage during aerobic (AP) or vacuum (VP) packed storage. The EOs at 1% and 2% were mixed individually with the marinade. The samples (10 g of chicken cubes with 1.2 g of marinade - with or without EOs) were stored in bags under AP and VP (Geryon^® ) for 7 days at 4 ± 1°C and abusive conditions (10 ± 1°C). Two control samples consisting of meat chunks and tawook without EO were used. The microflora numbers were greater at 10°C than at 4°C, and the marinade worked additively with AP against anaerobes, yeast and mold (Y & M) and lactic acid bacteria. It also worked additively with VP against aerobic bacteria recovered as Pseudomonas and the total plate count. EO components were observed to decrease microbial populations by a maximum of 4 to 6 log colony-forming unit (CFU)/g depending on the type of microorganism. The combined mixture of marinade and 2% EO (CA, CI, and TH) resulted in the greatest reductions of all spoilage microorganisms at 10°C under AP on the last day of storage. Overall, VP was more effective (p < 0.05) than AP in controlling microorganisms at both 4 and 10°C. This study provides an affordable and natural alternative for extending product life. PRACTICAL APPLICATION: The use of EOs in marinated chicken (tawook) is expected to help producers reduce spoilage and extend shelf-life of the product when stored at refrigeration temperatures. EOs provide a cheaper alternative and are naturally sourced. Vacuum packaging will increase the shelf-life of marinated chicken tawook and facilitate its storage and transportation.

The Effect of Sodium Alginate Coating Containing Citrus (Citrus aurantium) and Lemon (Citrus lemon) Extracts on Quality Properties of Chicken Meat

The effect of sodium alginate-based edible coating containing 2% citrus (Citrus aurantium) and lemon (Citrus lemon) extracts was evaluated on the chemical, antimicrobial, and sensory properties of samples during storage at 4°C. The results showed that coating with sodium alginate containing citrus and lemon extracts had a significant effect on the pH, TVN, PV, and TBA values of chicken meat ( $P<0.05$ ). The lowest PV and TBA values were observed in the coated sample containing sodium alginate with 2% citrus and lemon extracts (ALG + CAE + CLE), indicating the antioxidant activity of sodium alginate and extracts. Coating resulted in less growth of microorganisms in the samples. The lowest microbial counts were also observed in the sodium alginate containing 2% citrus and lemon extracts (ALG + CAE + CLE). The coated samples had good overall acceptability similar to the control treatment. In conclusion, sodium alginate containing citrus (C. aurantium) and lemon extracts (C. lemon) are suggested for coating meat products.

Chitosan edible coating incorporated with resveratrol and Satureja bachtiarica essential oil as natural active packaging: In vitro antibacterial and antioxidant properties, and its impact on the shelf life of fresh chicken fillet and growth of inoculated Escherichia coli O157:H7

The purpose of this study was to investigate the effects of chitosan coating containing resveratrol (RES) and Satureja bachtiarica essential oil (SEO) on the microbial quality, oxidative stability, and sensory properties of chicken meat as well as inoculated Escherichia coli O157:H7 during 12 day storage at 4 °C. The synergistic in vitro antioxidant effects between RES and SEO in chitosan coatings were observed. Moreover, chicken coated with chitosan solution containing RES 0.001% + SEO 2% indicated better results compared with the control group with the following scores (p≤0.05): Total viable count (6.11 log10 CFU/g), total psychrotrophic count (5.39 log10 CFU/g), Lactic acid bacteria (5.36 log10 CFU/g), pH (6.25), peroxide value (4.32 meq/kg lipid), thiobarbituric acid reactive substance (1.03 mg MDA/kg), sensory analysis (overall acceptability: 5.5), and inoculated E.coli O157:H7 (6.01 log10 CFU/g). The finding of the present study can contribute to the meat industry as a natural active packaging system.

The Caucasian Whortleberry Extract/Myrtle Essential Oil Loaded Active Films: Physicochemical Properties and Effects on Quality Parameters of Wrapped Turkey Breast Meat

In this research work, the effects of myrtle essential oil (MEO) and Caucasian whortleberry extract (CWE) as natural additives were investigated on mechanical, physico-mechanical and antimicrobial properties of gellan/polyvinyl alcohol (G/PVA) film. Then, optimal blend active films were used for the wrapping of turkey breast meat stored at low temperature (4 ± 1 °C) for 15 days and chemical and sensory properties of wrapped meats were evaluated. The addition of MEO and CWE decreased tensile strength and increased the strain at the break of the films (p ≤ 0.05). Additionally, with increasing the amount of MEO and CWE, the permeability to water vapor (WVP) and the moisture content (MC) of the films decreased (p ≤ 0.05). MIC test showed that MEO and CWE were effective against S. aureus, E. coli, S. typhimurium, and P. fluorescens. at the concentrations of 5-6 and 15-17 mg/mL, respectively. Different microbiological, chemical, and sensory tests indicated that active films significantly enhanced the shelf life of turkey breast meat (p ≤ 0.05). Therefore, based on our finding in this study, the use of these active and biodegradable packagings can be effective and useful for protecting the microbial and sensory quality of turkey breast meat.

Sodium alginate edible coating containing Ferulago angulata (Schlecht.) Boiss essential oil, nisin, and NaCl: Its impact on microbial, chemical, and sensorial properties of refrigerated chicken breast

This study aimed to investigate the effects of sodium alginate (ALG) coating incorporated with Ferulago angulata (Schlecht.) Boiss essential oil (FAEO, 10 and 20 mg/mL), nisin (N, 500 and 1000 IU/mL), and NaCl (2 %) on microbial (lactic acid bacteria, LAB; total viable bacteria, TVC; psychrotrophic bacteria; Pseudomonas; Enterobacteriaceae, and yeast and mold), chemical (pH, PV, TVB-N, and TBARS), sensory (color, odor, texture, and overall acceptance), and antioxidant properties of refrigerated (4 °C) chicken breasts. GC-MS analysis revealed that trans-β-ocimene (45.36 %) and α-pinene (18.01 %) constituted most of the components in FAEO. The antioxidant properties of FAEO were evaluated via the DPPH method. The IC₅₀ value of FAEO was 562 mg/mL. The results of antimicrobial evaluations indicated that there was no significant difference between control and ALG treatments (p > 0.05). The highest antimicrobial effect was associated with ALG + FAEO2 + N2 + NaCl treatment. The logarithmic reduction of the TVC, psychrotrophic count, Pseudomonas count, Enterobacteriaceae, LAB, as well as yeast and mold count in the ALG + FAEO2 + N2 + NaCl treatment were 1.40, 0.92, 1.20, 1.02, 0.88, and 1 log CFU/g, respectively compared to the control treatment. The initial level of TVB-N in the control treatment was 8.26 mg/100 g, which reached 42.84 mg/100 g at the end of the storage period. In ALG+ FAEO2 + N2 + NaCl treatment, the lowest TVB-N was observed, being 36.37 mg/100 g at the end of the storage period. The initial level of PV in the control treatment was 0.14 meq/kg, which reached 3.04 meq/kg at the end of the storage period. In the treatments containing FAEO, PV was lower than in other treatments, indicating the antioxidant properties of FAEO. There was a significant difference between control and other treatments in pH and TBARS evaluation (p < 0.05). The samples treated with FAEO had a lower pH than control. At the end of the storage period, the TBARS level in the control treatment reached 1.20 mg MDA/kg, while in the treatment of ALG+ FAEO2 + N2 + NaCl treatment, its level was 0.36 mg MDA/kg. The results of sensory properties indicated that in evaluating the color, odor, texture, and overall acceptance on the final days, treatments containing FAEO, nisin, and NaCl had higher scores due to their antimicrobial and antioxidant properties. In conclusion, this study indicated that adding FAEO, nisin, and NaCl to ALG coating would enhance the shelf-life of chicken meat.

Effects of Sodium Alginate Edible Coating with Cinnamon Essential Oil Nanocapsules and Nisin on Quality and Shelf Life of Beef Slices during Refrigeration

ABSTRACT

The effects of a new edible sodium alginate (SA) coating incorporating cinnamon essential oil nanocapsules (CEO-NPs) and nisin were investigated with beef slices in refrigerated storage for 15 days. All beef samples were analyzed for physicochemical properties (pH, weight loss, and total volatile base nitrogen) and antimicrobial activity against total bacteria. Changes in color parameters and sensory attributes of all beef samples also were evaluated. Incorporation of the complex of CEO-NPs and nisin into the SA coating retarded the growth of microorganisms and reduced lipid oxidation, as determined by pH, total volatile base nitrogen, and total bacteria counts. This treatment also extended the shelf life of beef slices to 15 days. The SA coating with CEO-NPs and nisin significantly reduced weight loss and improved color, odor, texture, and purge quality of the beef samples. These results suggest that treatment with the SA coating enriched with CEO-NPs and nisin can significantly retard the deterioration of beef slices, and the complex of CEO-NPs and nisin can improve antioxidant, antibacterial, and sensory properties of the SA coating. This new edible coating could be useful for preserving beef slices.

HIGHLIGHTS

Effect of nanocomposite alginate-based film incorporated with cumin essential oil and TiO2 nanoparticles on chemical, microbial, and sensory properties of fresh meat/beef

The environmental problems of synthetic plastics in food packaging have led researchers to synthesize biodegradable films. In this study, nanocomposite alginate‐based films containing TiO₂ nanoparticles (1%) and cumin essential oil (CEO, 2%) were fabricated and the potential of these films to protect beef from chemical [pH, total volatile base nitrogen (TVBN), peroxide value, and thiobarbituric acid reactive substances (TBA)] and microbial [total viable count, Enterobacteriaceae, lactic acid bacteria, Listeria monocytogenes, and Pseudomonas spp.] spoilage was evaluated during 24 days of storage (4°C). The active films significantly induced the reduction in lipid oxidation, microbial growth, and TVBN values, improved the sensory attributes of treated samples, maintained the redness of meats for a longer time, and increased the shelf life of beef from 4 to 16 days. The results of this study showed that TiO₂/CEO alginate‐based nanocomposite film has a great potential for application in meat and meat products.

Antimicrobial activity of essential oils and natural plant extracts against Listeria monocytogenes in a dry-cured ham-based model

BACKGROUND

Listeria monocytogenes is a widespread common contaminant in food production facilities during preparation, storage, and distribution, and minimally processed ready-to-eat products are considered at high risk of contamination by this bacterium. Increased antibiotic resistance has led researchers to search for plant-based natural alternatives to control pathogenic microorganisms. Among these products, essential oils and plant extracts have previously shown antimicrobial activity and are possible alternatives to manage food pathogens. In this study, commercial essential oils (cinnamon, clove, oregano, ginger, and thyme) and plant extracts (pomegranate, acorn, olive, strawberry tree, and dog rose) were tested against L. monocytogenes in a dry-cured ham-based model.

RESULTS

Essential oils and plant extracts were screened by agar diffusion and minimum inhibitory concentration for anti-L. monocytogenes activity. Cinnamon, pomegranate, and strawberry trees returned the strongest results and were therefore evaluated in a dry-cured ham-based medium assay with water activity of 0.93 or 0.95. The 10% essential oil of cinnamon was capable of completely inhibiting bacterial growth, while strawberry tree and pomegranate extract also showed antilisterial activity (P > 0.05). Water activity influenced the bacterial count of L. monocytogenes in a dry-cured ham-based medium.

CONCLUSIONS

There was a reduction in L. monocytogenes with the application of cinnamon essential oil but, because of the negative sensory impact of this particular compound in meat products, we suggest the use of pomegranate or strawberry tree for the biocontrol of Listeria in ready-to-eat products. © 2021 Society of Chemical Industry.

The Effect of Whey Protein Films with Ginger and Rosemary Essential Oils on Microbiological Quality and Physicochemical Properties of Minced Lamb Meat

Consumers’ constant search for high-quality and safe products, with the least possible preservatives and additives, as well as extended shelf life, has led industries to research and develop alternative forms of food preservation and packaging. The purpose of this research was the study of the effect of natural antimicrobials and, in particular, the essential oils of ginger (Zingiber Officinale Roscoe) and rosemary (Rosmarinus officinalis L.) on strengthening whey protein films’ properties. Whey protein isolate (WPI) films, alone and with incorporated essential oils (WPI + EO) at different concentrations were prepared and then examined for their possible effect on delaying the deterioration of minced lamb meat. Microbiological and physicochemical measurements were carried out to examine the meat’s shelf life. Results showed that films with 1% EO significantly improved the microbiological quality of meat. On day 11, total viable counts, Pseudomonas spp., Br. thermosphacta, lactic acid bacteria, Enterobacteriaceae, and yeasts remained low for films with 1% concentration of essential oil compared with 0.5%. Regarding, physicochemical properties the same pattern was observed for pH while oxidation degree was significantly reduced. Finally, color attributes measurements recorded fluctuations between samples, but overall, no considerable discoloration was observed.

Application of Gelatin Composite Coating in Pork Quality Preservation during Storage and Mechanism of Gelatin Composite Coating on Pork Flavor

Gelatin coating is an effective way to prolong the shelf life of meat products. Aiming at solving the problem of flavor deterioration during the storage of pork at room temperature, pork coating technology was developed to preserve the pork at 25 °C, and the comprehensive sensory analysis of vision, touch, smell, and taste was used to study the effect of coating on preservation of pork flavor. Herein, uncoated (control) and coated pork samples (including gelatin coating and gelatin coating incorporated with ginger essential oil) were analyzed to investigate the integrity of pork periodically during storage at 25 °C for weight loss, color, texture (springiness, chewiness, cohesiveness, gumminess, and hardness), microstructure, odor (electronic nose), taste (electronic tongue), volatile flavor substance, and taste ingredients. The results suggested that ginger essential oil (GEO) gelatin coating and gelatin coating can effectively inhibit the loss of water dispersion and slow down the oxidation reaction, coating treatments could significantly (p < 0.05) retarded the weight loss of pork slices, with values of 20.19%, 15.95%, 13.12% for uncoated, gelatin coated, and GEO-gelatin coated samples during 24 h of storage, respectively. Compared with control group, the color, texture, smell, and taste evaluations demonstrated that coating treatments had improved sensory and texture attributes during the storage period. Furthermore, the comprehensive results from the physical property assays (especially the texture), morphological assay and volatile odor assays showed that the GEO-fish gelatin composite coating had better preservation effect on pork flavor than the fish gelatin coating. The study suggests that the gelatin composite coating could be developed as a prospective active packaging to preserve pork meat at room temperature.

Green Coating Polymers in Meat Preservation

Edible coatings, including green polymers are used frequently in the food industry to improve and preserve the quality of foods. Green polymers are defined as biodegradable polymers from biomass resources or synthetic routes and microbial origin that are formed by mono- or multilayer structures. They are used to improve the technological properties without compromising the food quality, even with the purpose of inhibiting lipid oxidation or reducing metmyoglobin formation in fresh meat, thereby contributing to the final sensory attributes of the food and meat products. Green polymers can also serve as nutrient-delivery carriers in meat and meat products. This review focuses on various types of bio-based biodegradable polymers and their preparation techniques and applications in meat preservation as a part of active and smart packaging. It also outlines the impact of biodegradable polymer films or coatings reinforced with fillers, either natural or synthesized, via the green route in enhancing the physicochemical, mechanical, antimicrobial, and antioxidant properties for extending shelf-life. The interaction of the package with meat contact surfaces and the advanced polymer composite sensors for meat toxicity detection are further considered and discussed. In addition, this review addresses the research gaps and challenges of the current packaging systems, including coatings where green polymers are used. Coatings from renewable resources are seen as an emerging technology that is worthy of further investigation toward sustainable packaging of food and meat products.

Green Banana (Musa acuminata AAA) Wastes to Develop an Edible Film for Food Applications

In this study, edible packaging based on discarded green banana (Musa acuminata AAA) flour (whole banana and banana peel flours) was developed for food applications. Films were characterized in terms of film-forming ability, mechanical, barrier, thermal, microbiological, and sensory properties. The film forming solutions were studied for rheological properties. Two formulations were selected based on their film-forming ability: whole banana flour (2.5%), peel flour (1.5%) and glycerol (1.0 %, F-1.0 G or 1.5%, F-1.5 G). Adding 1.5% plasticizer, due to the hygroscopic effect, favored the water retention of the films, increasing the density, which also resulted in a decrease in lightness and transparency. Water activity shows no difference between the two formulations, which were water resistant for at least 25 h. DSC results showed a similar melting temperature (Tm) for both films, around 122 °C. Both films solutions showed a viscoelastic behavior in the frequency spectrum, being the elastic modulus greater in F-1.0 G film than F-1.5 G film at low frequency. F-1.0 G film was less firm, deformable and elastic, with a less compact structure and a rougher surface as confirmed by AFM, favoring a higher water vapor permeability with respect to F.1.5 G film. Microorganisms such as Enterobacteria and Staphylococcus aureus were not found in the films after a period of storage (1 year under ambient conditions). The F-1.0 G film with added spices (cumin, oregano, garlic, onion, pepper, and nutmeg) was tested for some food applications: as a snack (with or without heat treatment) and as a wrap for grilled chicken. The performance of the seasoned film during chilled storage of chicken breast was also studied. Sensory evaluation showed good overall acceptability of all applications. In addition, the chicken breast wrapped with the seasoned film registered lower counts (1-log cycle) than the control (covered with a polystyrene bag) and the film without spices. Green banana flour is a promising material to develop edible films for food applications.

Encapsulation of cinnamaldehyde: an insight on delivery systems and food applications

Cinnamaldehyde is an essential oil extracted from the leaves, bark, roots and flowers of cinnamon plants (genus Cinnamomum). Cinnamaldehyde has shown biological functions such as antioxidants, antimicrobials, anti-diabetic, anti-obesity and anti-cancer. However, poor solubility in water as well as molecular sensitivity to oxygen, light, and high temperature limit the direct application of cinnamaldehyde. Researchers are using different encapsulation techniques to maximize the potential biological functions of cinnamaldehyde. Different delivery systems such as liposomes, emulsions, biopolymer nanoparticles, complex coacervation, molecular inclusion, and spray drying have been developed for this purpose. The particle size and morphology, composition and physicochemical properties influence the performance of each delivery system. Consequently, the individual delivery system has its advantages and limitations for specific applications. Given the essential role of cinnamaldehyde in functional food and food preservation, appropriate approaches should be applied in the encapsulation and application of encapsulated cinnamaldehyde. This review systematically analyzes available encapsulation techniques for cinnamaldehyde in terms of their design, properties, advantages and limitations, and food application status. The information provided in this manuscript will assist in the development and widespread use of cinnamaldehyde-loaded particles in the food and beverage industries.

Effect of chitosan coating containing Nepeta pogonosperma extract on shelf life of chicken fillets during chilled storage

Chicken meat is highly susceptible to microbial and chemical spoilage due to its high moisture and protein content. The use of edible coatings contains herbal extracts with antioxidant and antibacterial properties that help to extend the shelf life of meat products. In this study, the effect of chitosan coating (2%) and Nepeta pogonosperma extract (NPe) (0.2% and 0.6%) and their combination on chemical properties (pH, peroxide value (PV), thiobarbituric acid index (TBARS), total volatile basic nitrogen (TVB-N)) and microbial (aerobic mesophilic and psychrotrophic microorganisms, lactic acid bacteria, Enterobacteriaceae and Pseudomonas sp.) of chicken fillets were studied over a 12-day refrigerated storage period compared to the control sample. The results of NPe DPPH radical scavenging activity (DRSA) showed that IC50 and total phenolic contents values were 94.65 μg/ml and 113.53 mg GAE/g extract, respectively. Statistical results showed that the rate of increase in pH, PV, TBARS, and TVB-N of all coated treatments were lower than control. Microbial analysis results showed a decrease in the growth of different bacteria in chitosan-treated combined with NPe compared to the control sample during chilled storage. Chicken fillets coated with chitosan and 0.6% NPe displayed a longer shelf life compared to other samples.