Use of various essential oils as bio preservatives and their effect on the quality of vacuum packaged fresh chicken sausages under frozen conditions

Intrinsic properties and extrinsic factors of food matrix system affecting the effectiveness of essential oils in foods: a comprehensive review

Essential oils (EOs) have been proved as natural food preservatives because of their effective and wide-spectrum antimicrobial activity. They have been extensively explored for potential applications in food industry, and substantial progresses have been achieved. However well EOs perform in antibacterial tests in vitro, it has generally been found that a higher level of EOs is needed to achieve the same effect in foods. Nevertheless, this unsimilar effect has not been clearly quantified and elaborated, as well as the underlying mechanisms. This review highlights the influence of intrinsic properties (e.g., oils and fats, carbohydrates, proteins, pH, physical structure, water, and salt) and extrinsic factors (e.g., temperature, bacteria characteristics, and packaging in vacuum/gas/air) of food matrix systems on EOs action. Controversy findings and possible mechanism hypotheses are also systematically discussed. Furthermore, the organoleptic aspects of EOs in foods and promising strategies to address this hurdle are reviewed. Finally, some considerations about the EOs safety are presented, as well as the future trends and research prospects of EOs applications in foods. The present review aims to fill the evidenced gap, providing a comprehensive overview about the influence of the intrinsic and extrinsic factors of food matrix systems to efficiently orientate EOs applications.

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.

Chitosan/alginate/pectin biopolymer-based Nanoemulsions for improving the shelf life of refrigerated chicken breast

This study investigated the use of nanoemulsions and various polymer coatings to enhance the quality and shelf life of chicken breast. This comprehensive study explored the antibacterial activity of essential oils (EOs) against Escherichia coli and Staphylococcus aureus, as well as the characterization of nanoemulsions (Nes) and nanoemulsion-based coatings. The antimicrobial potential of EOs, such as cinnamon, tea tree, jojoba, thyme, and black cumin seed oil, was evaluated against microorganisms, and thyme oil exhibited the highest inhibitory effect, followed by cinnamon and tea tree oil by disk diffusion analysis. The MIC and MBC values of EOs were found between 0.16-2.5 mg/mL and 0.16-5 mg/mL, respectively, while thyme EO resulted in the lowest values showing its antimicrobial potential. Then, the essential oil nanoemulsions (EONe) and their coatings, formulated with thyme oil, alginate, chitosan, and pectin, were successfully characterized. Optical microscope observations confirmed the uniform distribution of droplets in all (EONe), while particle size analysis demonstrated multimodal droplet size distributions. The EONe-chitosan coating showed the highest efficacy in reducing cooking loss, while the EONe-chitosan, EONe-alginate, and EONe-pectin coatings displayed promising outcomes in preserving color stability. Microbial analysis revealed the significant inhibitory effects of the EONe-chitosan coating against mesophilic bacteria, psychrophilic bacteria, and yeasts, leading to an extended shelf life of chicken breast. These results suggest the potential application of thyme oil and NE-based coatings in various industries for antimicrobial activity and quality preservation.

Bio-preservatives and essential oils as an alternative to chemical preservatives in the baking industry: a concurrent review

The use of chemical preservatives in the baking industry is a common practice to extend the shelf life of baked goods However, there is growing interest in natural alternatives due to worries about the security and potential health risks of these chemicals. The purpose of this concurrent review is to investigate the potential of using essential oils and bio-preservatives in place of chemical preservatives in the baking industry. With a focus on their efficiency in extending the shelf life of baked goods, the review includes a thorough analysis of the most recent research on the use of bio-preservatives and essential oils in food preservation. The findings suggest that bio-preservatives and essential oils can be effective in preserving baked goods and may offer a safer and more natural alternative to chemical preservatives. However, further research is needed to fully understand the potential of these natural alternatives and to optimize their use in the baking industry.

Quantification of Bioactive Metabolites Derived from Cell-Free Supernatant of Pediococcus acidilactici and Screening their Protective Properties in Frankfurters

The specific aims of the current study were to determine and quantify the bioactive compounds derived from the cell-free supernatant (CFS) of Pediococcus acidilactici and screen their protective effect in frankfurters by applying an edible coating. This was achieved by immersing the peeled frankfurters in the CFS (CFS: 50% and 100%) alone or in combination with chitosan (CH: 0.5% and 1%) solutions for 3 min. Untreated frankfurter samples (control) exceeded the maximum acceptable total viable count limit (7.0 log10) on the 14th day, whereas samples treated with 100% CFS + 1% chitosan reached the limit on day 28 during refrigerated storage (P < 0.05). This treatment provided a 14-day extension to the shelf life of frankfurters without causing any significant changes in color and sensory attributes (P > 0.05). Additionally, this treatment inhibited oxidation in the frankfurters, leading to no significant changes in TBA and TVB-N within this group during storage (P > 0.05). This protective effect was mainly attributed to the wide variety of bioactive compounds identified in the CFS, including a total of 5 organic acids, 20 free amino acids, 11 free fatty acids, 77 volatiles, and 10 polyphenols. Due to these bioactive compounds, CFS exhibited a strong radical scavenging capacity (DPPH: 435.08 TEAC/L, ABTS: 75.01 ± 0.14 mg TEAC/L; FRAP: 1.30 ± 0.03 mM FE/L) and antimicrobial activity against microorganisms primarily responsible for the spoilage of frankfurters. In conclusion, the results indicate that the CFS contains high levels of bioactive metabolites, and an edible chitosan coating impregnated with CFS can be utilized to extend the shelf life of frankfurters through its antimicrobial effects and oxidation stabilization.

Green label marinades: A solution to salmonella and campylobacter in chicken products?

Introduction

The presence of meat-borne pathogens entering the home remains a concern for consumers, despite advances made in improving antimicrobial interventions and systems within the processing line. Naturally antibacterial food ingredients including citrus juice and essential oils have been proven to inhibit the proliferation of microbial growth with varying success.

Aims

This study aims to investigate the antimicrobial and sensory effects of mixtures of essential oils, fruit juices and herbs at established Minimum Inhibitory Concentrations (MICs) for their biopreservative effect on general microbiota of chicken and against chicken challenged with selected pathogenic/surrogate microorganisms.

Materials and methods

Three marinade compositions were designed for use on chicken meat; lemon juice, thyme oil and black pepper (M1), lime juice, lemongrass oil and chilli paste (M2), and olive oil, oregano oil, basil oil and garlic paste (M3). These marinades were assessed for antibacterial effects against Salmonella enterica, Campylobacter jejuni and Listeria innocua on marinaded chicken drumsticks stored in aerobic conditions at 4 °C. Consumer tasting sessions were also conducted with a small focus group using selected final marinades.

Results

M1 and M2 were effective at significantly reducing initial pathogen carriage from 6 Log CFU/g to 2 Log CFU/g on refrigerated chicken meat as well as increasing the shelf-life of the product during cold-storage from 2 days to 7 days. However, consumer studies indicate that the flavours these marinades impart to treated products can be strong.

Conclusion

These findings indicate that these designed marinades have shown excellent potential to improve food safety as well as shelf-life for the consumer, particularly in settings where food safety is often compromised such as barbecuing or in care settings. However, further recipe optimisation is required to make these marinades acceptable to consumers.

Application of oleaster leaves (Elaeagnus angustifolia L.) essential oil and natural nanoparticle preservatives in frankfurter-type sausages: An assessment of quality attributes and stability during refrigerated storage

The effects of oleaster leave essential oil (OLEOs: 1000 and 2000 ppm) in combination with nisin nanoparticles (200 ppm) and ε-polylysine nanoparticles (2000 ppm) on the physicochemical, microbiological and sensory properties of the emulsion-type sausages without added chemical nitrite/nitrate salts were evaluated during 45 days of storage. Nanoparticle attributes were assessed, including encapsulation efficiency (EE%), zeta potential, nanoparticles size, FTIR analysis, and thermal stability (DSC). Overall, ε-PL nanoparticles (ε-PL-NPs) were thermally more stable and showed higher EE% (91.52%) and zeta potential (37.80%) as compared to nisin nanoparticles (82.85%) and (33.60%), respectively. The use of combined ε-PL-NPs (2000 ppm) + Ni-NPs (200 ppm) with oleaster leaves essential oil (2000 ppm) resulted in a higher pH value (5.88), total phenolic content (10.45 mg/100 g) and lower TBARS (2.11 mg/kg), and also decreased total viable bacteria (1.28 Log CFU/g), Clostridium perfringens (1.43 Log CFU/g), E. coli (0.24 Log CFU/g), Staphylococcus aureus (0.63 Log CFU/g), and molds and yeasts (0.86 Log CFU/g) count in samples at day 45 in comparison to the control (120 ppm nitrite). The consumers approved sensory traits in nitrite-free formulated sausages containing ε-PL-NPs and Ni-NPs combined with OLEOs.

Chitosan Coating Functionalized with Flaxseed Oil and Green Tea Extract as a Bio-Based Solution for Beef Preservation

Ecological and safe packaging solutions arise as pivotal points in the development of an integrated system for sustainable meat production. The aim of this study was to assess the effect of a combined chitosan (Ch) + green tea extract (GTE) + essential oil (thyme oil, TO; flaxseed oil, FO; or oregano oil, OO) coating on the safety and quality of vacuum-packaged beef during storage at 4 °C. An optimized bio-based coating formulation was selected (2% Ch + 2% GTE + 0.1% FO) to be applied to three fresh beef cuts (shoulder, Sh; knuckle, Kn; Striploin, St) based on its pH (5.8 ± 0.1), contact angle (22.3 ± 0.4°) and rheological parameters (viscosity = 0.05 Pa.s at shear rate > 20 s^-1). Shelf-life analysis showed that the Ch-GTE-FO coating delayed lipid oxidation and reduced total viable counts (TVC) and Enterobacteriaceae growth compared with uncoated beef samples over five days. In addition, Ch-GTE-FO coating decreased total color changes of beef samples (e.g., ∆E* = 9.84 and 3.94, for non-coated and coated Kn samples, respectively) for up to five days. The original textural parameters (hardness, adhesiveness and springiness) of beef cuts were maintained during storage when Ch-GTE-FO coating was applied. Based on the physicochemical and microbial characterization results, the combination of the Ch-GTE-FO coating developed was effective in preserving the quality of fresh beef cuts during refrigerated storage along with vacuum packaging.

Mānuka Oil vs. Rosemary Oil: Antimicrobial Efficacies in Wagyu and Commercial Beef against Selected Pathogenic Microbes

Essential oils possessing antimicrobial characteristics have acquired considerable interest as an alternative to chemical preservatives in food products. This research hypothesizes that mānuka (MO) and kānuka (KO) oils may possess antimicrobial characteristics and have the potential to be used as natural preservatives for food applications. Initial experimentation was conducted to characterize MOs (with 5, 25, and 40% triketone contents), rosemary oil (RO) along with kanuka oil (KO) for their antibacterial efficacy against selected Gram-negative (Salmonella spp. and Escherichia coli), and Gram-positive (Listeria monocytogenes and Staphylococcus aureus) bacteria through disc diffusion and broth dilution assays. All MOs showed a higher antimicrobial effect against L. monocytogenes and S. aureus with a minimum inhibitory concentration below 0.04%, compared with KO (0.63%) and RO (2.5%). In chemical composition, α-pinene in KO, 1, 8 cineole in RO, calamenene, and leptospermone in MO were the major compounds, confirmed through Gas-chromatography-mass spectrometry analysis. Further, the antimicrobial effect of MO and RO in vacuum-packed beef pastes prepared from New Zealand commercial breed (3% fat) and wagyu (12% fat) beef tenderloins during 16 days of refrigerated storage was compared with sodium nitrate (SN) and control (without added oil). In both meat types, compared with the SN-treated and control samples, lower growth of L. monocytogenes and S. aureus in MO- and RO- treated samples was observed. However, for Salmonella and E. coli, RO treatment inhibited microbial growth most effectively. The results suggest the potential use of MO as a partial replacement for synthetic preservatives like sodium nitrate in meats, especially against L. monocytogenes and S. aureus.

Antibacterial Activity of Selected Essential Oils against Foodborne Pathogens and Their Application in Fresh Turkey Sausages

Essential oils (EOs) isolated from different plant materials, namely Origanum majorana L., Satureja hortensis L., and Satureja montana L. (OMEO, SHEO, and SMEO, respectively), were used in fresh turkey sausage processing. The chemical composition and in vitro antimicrobial potential of selected EOs and their mixture were determined. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against foodborne pathogens (Escherichia coli, Salmonella Enteritidis, and Listeria monocytogenes) ranged in the interval of 0.44-7.1 µL/mL. Fresh turkey sausages were produced with EOs addition and marked as follows: TOMEO-0.150 µL/g OMEO; TSHEO-0.150 µL/g SHEO; TSMEO-0.150 µL/g SMEO; TEOM-0.050 µL/g OMEO, 0.050 µL/g SHEO and 0.050 µL/g SMEO, and control (C) (without EOs). Microbiological profile and biogenic amines content in fresh turkey sausages were recorded during storage. The selected EOs and their mixture efficiently reduced bacterial growth and biogenic amines formation and accumulation. The lowest Enterobacteriaceae count and total biogenic amine (BA) concentration were determined through treatment TSHEO. The results of this study show that selected EOs could be useful in fresh turkey sausage processing in order to improve safety and shelf-life.

Effect of Bamboo Essential Oil on the Oxidative Stability, Microbial Attributes and Sensory Quality of Chicken Meatballs

This study explores the efficacy of bamboo essential oil (BEO) incorporated at 15 ppm (T1, BEO-I) and 30 ppm (T2, BEO-II) on the overall physicochemical and oxidative stability, microbial deterioration, and sensory acceptability of meatballs stored for 20 days under refrigerated conditions. Analysis of various parameters, including physicochemical quality, color (CIE L*, CIE a* and CIE b*), generation of oxidative products (TBARS), microbial growth, and sensory acceptability of meatballs were evaluated at 5-day intervals. In addition, the total phenolics and flavonoid content of BEO were estimated, and fatty acids were determined by Gas chromatography (GC.) To gain insights into the biological activities of the BEO, antioxidant assays were determined in vitro using various methods. The antibacterial activity of BEO was also evaluated against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Vibrio cholera, Salmonella Typhimurium, Shigella flexneri, Proteus vulgaris, Escherichia coli and Klebsiella pneumoniae) bacterial strains. The BEO contained a good quantity of total phenolics and flavonoids. In addition, the oil exhibited very potent antioxidant activity scavenging reactive oxygen and other such species, effectively showing IC₅₀ at a very minimal concentration. Further, the BEO exhibited a strong antibacterial effect with MICs within 2 µL and MBCs from 5 to 7 µL for Gram-positive as well as Gram-negative bacteria, respectively. At both the concentrations used, BEO did not show any negative effect on the color of cooked meatballs but rather increased the microbiological and oxidative stability during the overall storage period. Meatballs treated with BEO had considerably reduced oxidative changes in terms of TBARS levels compared to the control. The total viable microbial count was lowest in BEO-treated meatballs and the highest in control. Both control and treated meatballs had a desirable flavor and good acceptability. The sensory attributes and aroma of treated meatballs were better and acceptable during the storage study, whereas the control samples were disliked by the panelists on 15th day. From this study, it can be concluded that bamboo essential oil could be used as a benign and non-toxic preservative to improve the quality and shelf life of cooked meatballs stored under refrigerated conditions.

Comparing the Effects of Thyme (Zataria multiflora) and Rosemary (Rosmarinus officinalis) Essential Oils on Microbiological, Physicochemical, and Sensory Properties of Vacuum-Packaged and Refrigerated Chicken Breast

This study aimed to compare the effects of thyme and rosemary essential oils (EOs) with vacuum packaging on shelf life extension and organoleptic properties of chicken breast meat. For this purpose, two concentrations of 0.1% and 0.3% (v/w) from thyme and rosemary EOs were added individually to fresh chicken breast samples, packed under vacuum conditions, and stored at 4°C for 12 days. All the samples were evaluated for microbiological, physicochemical, and sensory properties at 3-day intervals. The results showed that the thyme EO treatments, especially at 0.3% concentration, significantly reduced both total and psychrotrophic colony counts, and they were more effective in reducing microbial counts compared to rosemary EO treatments. Moreover, thyme EO significantly controlled Escherichia coli growth in treated samples. TBA values in treated samples with thyme EOs were significantly less than in rosemary EOs and control samples. Results indicated that rosemary EO treatments had the lowest pH during 12 days. Colorimetric and organoleptic analysis of the samples showed statistical differences on various days. In the EOs-treated chicken breasts, the color and texture of the samples improved compared to controls, but the taste and odor were not desired at the higher concentration of thyme and rosemary EOs.

Addition of Natural Extracts with Antioxidant Function to Preserve the Quality of Meat Products

Antioxidants are used to prevent oxidation reactions and inhibit the development of unwanted sensory characteristics that decrease the nutritional quality, acceptance, and shelf-life of processed meat products, improving their stability. Synthetic antioxidants, although efficient, are related to the development of diseases because they present toxic and carcinogenic effects. Thus, researchers and the meat industry are studying natural alternatives to synthetic antioxidants to be used in meat products, thus meeting the demand of consumers who seek foods without additives in their composition. These natural extracts have compounds that exert antioxidant activity in different meat products by different mechanisms. Thus, this review work aimed to gather studies that applied natural extracts derived from different plant sources as possible antioxidants in meat products and their action in preserving the quality of these products.

Effect of milk-derived bioactive peptides on the lipid stability and functional properties of beef nuggets

The present study was conducted to ascertain the beneficial effects of bioactive peptides on the oxidative stability and functional properties of beef nuggets. In this study, milk casein protein hydrolysates were extracted and incorporated into beef nuggets which were then subjected to different assessment parameters including oxidative stability, functional capability as well as microbial and physico-chemical quality tests were performed for determining the meat quality at different storage periods. The casein protein hydrolysate powder (CPH) was added at different concentrations in nuggets CPH 2%, 4%, 6% and 8%, with reference to storage period of 0, 5, 10 and 15 days at 4 °C. The results regarding total phenolic contents (TPC) and DPPH free radical scavenging assay showed a significant increased with respect to CPH powder and significantly decreased with respect to storage interval. The TVBN, TBARS and POV of the CPH powder incorporated raw beef nuggets also differed significantly within groups with storage time. Higher POV and TBARS were noticed in the CPH 8% incorporated beef nuggets. However, the raw beef nuggets that were made by the incorporation 8% CPH powder, maintained significantly lower level of TBARS at the end of the storage period in contrast with the levels of the control (CPH 0%). The results of the pH and Hunter color test also showed a significant difference with respect to different groups. The microbiological analysis of beef nuggets showed a significant decrease in the level of both the total aerobic and coliform counts and also indicated a decreasing trend in the level of contamination by these bacteria within the groups. This depicted that the casein protein hydrolysate powder (CPH) or simply, the peptide powder has the strong ability to decrease lipid oxidation and related shelf-life retarding natural processes occurring in the meat. It can also greatly enhance the functional properties of the raw meat (beef) and meat products. Thus, it is seen that the bioactive peptides (BAP’s) are a key factor in improving the oxidative stability and functional properties of beef nuggets.

Critical overview of the use of plant antioxidants in the meat industry: Opportunities, innovative applications and future perspectives

The number of articles devoted to study the effect of "natural antioxidants" on meat systems has remarkably increased in the last 10 years. Yet, a critical review of literature reveals recurrent flaws in regards to the rationale of the application, the experimental design, the characterisation of the plant sources, the discussion of the molecular mechanisms and of the potential benefits. The selection of the appropriate source of these antioxidants and the identification of their bioactive constituents, are essential to understand their mode of action and set effective and safe doses. The methodological approach should also be planned with care as the recorded effects and main conclusions largely depend on the accuracy and specificity of the methods. This article aims to critically review the recent advances in the application of plant antioxidants in meat and meat products and briefly covers current trends of innovative application and future trends.

Sodium chloride reduction in fresh sausages using salt encapsulated in carnauba wax

Carnauba wax was used in salt encapsulation, allowing sodium reduction in fresh sausages while maintaining the salty taste due to the inhomogeneous salt distribution. Four treatments were made, as follows: treatment C containing 2% non-encapsulated salt, and the treatments S_2.0%, S_1.5%, and S_1.0% containing 2, 1.5, and 1% encapsulated salt, respectively. The physicochemical parameters were within the standard regulations for all treatments, with the lower hardness and cohesiveness observed for S_1.0%. The treatments and the storage period (90 days) had no effect on a_w and instrumental color. Although a decrease in pH and an increase in lipid oxidation were observed during storage, the results were within acceptable levels. Concerning the consumers' perception of saltiness, the assessors reported no differences among the treatments C, S_2.0%, and S_1.5%. Thus, it is possible to reduce 25% salt in fresh sausages using the taste contrast technology.

Edible flower essential oils: A review of chemical compositions, bioactivities, safety and applications in food preservation

In the context of consumers' growing concerns and boycotts of artificial and harmful chemicals, satisfying the demands for good-quality food products possessing clean and safe images is a challenge for food industry. Due to natural and avirulent images, various bioactivities as well as potentials to be used as safer substitutes for chemical preservatives, flower essential oils (EOs) have aroused increasing interests in the recent past. Many literatures have verified the biological activities of flower EOs, and have given high value to the preservative potentials of flower EOs in food systems. In this work, a review is done on the most recent publications associating the chemical constituents, bioactivities (antibacterial, antifungal, antioxidant and anti-pest abilities) and safety of flower EOs. The effects of flower EOs on food flavor are also discussed. Finally, the current combined preservation applications of flower EOs and other technologies are summarized.

Nanoencapsulation of essential oils and their bioactive constituents: A novel strategy to control mycotoxin contamination in food system

Spoilage of food by mycotoxigenic fungi poses a serious risk to food security throughout the world. In view of the negative effects of synthetic preservatives, essential oils (EOs) and their bioactive constituents are gaining momentum as suitable substitute to ensure food safety by controlling mycotoxins. However, despite their proven preservative potential against mycotoxins, the use of EOs/bioactive constituents in real food system is still restricted due to instability caused by abiotic factors and negative impact on organoleptic attributes after direct application. Nanoencapsulation in this regard could be a promising approach to address these problems, since the process can increase the stability of EOs/bioactive constituents, barricades their loss and considerably prevent their interaction with food matrices, thus preserving their original organoleptic qualities. The aim of this review is to provide wider and up-to-date overview on recent advances in nanoencapsulation of EOs/bioactive constituents with the objective to control mycotoxin contamination in food system. Further, the information on polymer characteristics, nanoencapsulation techniques, factors affecting the nanoencapsulation, applications of nanoencapsulated formulations, and characterization along with the study on their release kinetics and impacts on organoleptic attributes of food are discussed. Finally, the safety aspects of nanoencapsulated formulations for their safe utilization are also explored.

Effects of virgin olive oil and grape seed oil on physicochemical and antimicrobial properties of pectin-gelatin blend emulsified films

The active emulsified blend films based on gelatin-pectin (5% w/w) containing virgin olive oil (VOO) (0.1-0.3 g/g biopolymer) and grape seed oil (GSO) (0.1-0.3 g/g biopolymer) were prepared by casting method. GSO showed slightly more decreasing effect than VOO on ultimate tensile strength (UTS) and strain at break (SAB) of blend films however; VOO had more reducing effect than GSO on the water vapor permeability (WVP). The scanning electron microscopy (SEM) images showed that incorporating 0.3 g GSO and VOO oils had not considerable effect on the morphology of the emulsified films. Atomic force microscopy (AFM) topography images indicated that adding of oils considerably could increase roughness of emulsified film. Fourier transforms infrared (FTIR) revealed that no new chemical bond formed by adding oils into biopolymer matrix. The minimum inhibitory concentration (MIC) of VOO, GSO and Savory essential oil (SEO) against four important spoilage bacteria showed that GSO had higher antibacterial effect than VOO however; both showed very lower antimicrobial effect than SEO. All active films showed lower inhibitory zone for S. aureus than S. typhimurium and P. fluorescence. The chicken breast fillets wrapped in the films containing VOO-GSO-SEO (0.15-0.15-0.02 g/g polymer) showed considerably lower total viable count (TVC), Pseudomonas spp., Enterobacteriaceae, E. coli 157:H7 and S. typhimurium count than the control one during 12 days storage. Also, it caused significant decrease in peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVB-N) of fillet samples.

Effect of porcine plasma hydrolysate on physicochemical, antioxidant, and antimicrobial properties of emulsion-type pork sausage during cold storage

This study evaluated the effect of porcine plasma hydrolysates (PPH) on the physicochemical, antioxidant, and antimicrobial properties of emulsion-type pork sausages. Five levels of PPH were added to sausages (CON, 0 g/kg; T1, 5 g/kg; T2, 10 g/kg; T3, 15 g/kg; and T4, 20 g/kg) and their chemical composition, purge loss, lipid oxidation, microbial count, pH, color, texture, and sensory properties were compared on day 1 and after 4 weeks of cold storage. At 4 weeks of storage, hardness, cohesiveness, and gumminess were highest in T3 (P < 0.05). The peroxide value increased in all treatments during the 4-weeks of storage (P < 0.05); however, it was not significantly different between CON, T2, and T3 (P > 0.05). The total aerobic plate count was the lowest in T4 at week 4 (P < 0.05). Therefore, PPH addition could improve the texture of the emulsion-type pork sausages, and an antimicrobial effect was expected following exposure to at least 20 g/kg PPH.

Assessing the potential and safety of Myrtus communis flower essential oils as efficient natural preservatives against Listeria monocytogenes growth in minced beef under refrigeration

In this research, the chemical composition and biological properties of Tunisian Myrtus communis (McEO) flowers were investigated. The antibacterial effect of McEO toward some bacteria was assessed, alone and in combination with nisin. The major components of McEO were α-pinene, 1,8-cineol, limonene, and linalool. McEO exhibited cytotoxicity toward HepG2 and MCF-7 cell lines. The microbiological data showed that Gram-positive bacteria were more susceptible to McEO. McEO had a bactericidal effect against L. monocytogenes. McEO is able to prevent lipid oxidation, microbial development at noncytotoxic concentrations, when used alone or in combination with nisin. It can improve sensory attributes within acceptable limits and improve the conservation of shelf life of minced beef meat during the 4°C storage period. The most potent preservative effect was obtained with the mixture: 0.8% McEO with 500 IU/g of nisin. This combination may be a good alternative for the development of natural preservatives.

Preservation of traditional Chinese pork balls supplemented with essential oil microemulsion in a phase-change material package

BACKGROUND

In this study, we evaluated the combined effect of cinnamon essential oil (CEO) microemulsions, and a temperature buffering package using phase-change material (PCM) microcapsules on the physicochemical property, lipid oxidation, and bacterial load of traditional Chinese pork balls (shi zi tou) during temperature fluctuation storage for 9 days.

RESULTS

Transmission electron microscope characterization revealed that n-tetradecane microcapsules possessed a core-shell spherical shape with a size ranging from 300 to 600 nm. The use of n-tetradecane microcapsule packaging was found to maintain cold storage temperature efficiently. After 9 days of storage, the combination of CEO microemulsions with n-tetradecane microcapsules did not lead to changes in the color parameters of pork balls. At day 9, n-tetradecane microcapsules, used alone or in combination with CEO microemulsions, showed lower thiobarbituric acid reactive substances (TBARS) values than the control group, while their combination exhibited the lowest pH and 1,1-diphenyl-2-picrylhydrazyl (DPPH) values. Furthermore, the combination treatment retarded the growth of total plate count, lactic acid bacteria, Enterobacteriaceae, and Staphylococcus spp. after 4 and 9 days.

CONCLUSIONS

The combinations of CEO microemulsions and PCM microcapsules could extend the shelf-life of cooked pork products, suggesting a feasible strategy for meat preservation. © 2020 Society of Chemical Industry.

Bio-preservative effect of blends of essential oils: natural anti-oxidant and anti-microbial agents for the shelf life enhancement of emulsion based chicken sausages

This work explores the efficacy and potential of four different blends of essential oils as bio-preservative for enhancement of shelf life of emulsion based ready-to-eat chicken sausages. Pre-optimized levels of four different blends of essential oils: 0.25% each of B-1, B-2, B-3 and 0.125% of B-4, were tried in the chicken sausages. Four different treatments along with control were then aerobically packaged and stored under refrigerated (4 ± 1 °C) conditions. An increase in pH and TBARS value was found to be significantly lower in the case of B-2 products. Significantly higher values for DPPH activity (% inhibition) and total phenolic content (µg/g) were also observed for B-2 products which indicated that B-2 products had better oxidative stability. Further, B-1 and B-2 products were observed with significantly lower microbial count; however, B-4 products received slightly higher sensory scores than B-2. It was found that B-1, 2 and 3 (each at 0.25%) and B-4 (0.125%) enhanced the shelf life of chicken sausages by 13-14 days, 16-17 days, 10-11 days and 6-7 days, respectively under refrigerated (4 ± 1 °C) storage.

Impact of use of byproducts (chicken skin and abdominal fat) on the oxidation of chicken sausage stored under freezing

Fresh chicken sausage is a meat product with high consumption in the world. The addition of a lipid source (other than abdominal fat), such as chicken skin, is considered an alternative to harnessing slaughter byproducts in the preparation of processed meat products. The aim of this study was to evaluate the impact of use of skin and/or abdominal fat on chicken sausages and their effect on oxidative stability of chicken sausages during freezing storage. Three formulations with chicken meat added of abdominal fat (SF), or chicken skin (SS), or chicken fat and skin (SFS) were elaborated. Chemical composition, fatty acid profile, instrumental color and texture, oxidative stability of lipids and proteins, and sensory acceptability of chicken sausages were determined. SS formulation showed lower lipid and protein oxidation and softness during storage. Consumers showed greater preference and high purchase intent for SFS formulation, which showed average values of chemical composition and oxidation of chicken sausages stored under freezing. Therefore, the combined addition of lipid sources, skin, and abdominal fat is recommended for use in chicken sausages, considering that the addition of fat improves the sensory characteristics of chicken sausages and skin minimizes the oxidative effects of storage. PRACTICAL APPLICATION: The combined addition of skin fat and abdominal fat is recommended for use in chicken sausages as it does not interfere with consumer acceptability and further ensures nutritional quality during freezing storage. In addition, it is an alternative to using a byproduct of chicken slaughter, bringing economic advantages to the industry and less environmental damage to the world.

Valorization of Chicken Feet By-Product of the Poultry Industry: High Qualities of Gelatin and Biofilm from Extraction of Collagen

In this research, products with high quality were obtained from natural sources. The sensorial qualities, chemical characterization, and physical properties of gelatin extracted from chicken feet were compared with commercial gelatins. The extraction process was performed using acetic acid on a concentration ranging from 0.318% to 3.682%, processing time between 1.0 h and 8.4 h and extraction temperature between 43.3 °C and 76.8 °C. After the end of each assay, the yield was measured. Results showed that, under the best conditions, the collagen extraction yield was above 8%, and comprised 78.525 g/100 g of protein. Collagen analyzed by ICP-MS was composed of 99.44% of macro-minerals that are of great importance to human health. ATR-FTIR analysis showed that approximately 70.90% of the total protein from chicken feet is collagen, whereas, in commercial gelatin, only 30.31% is collagen. When comparing chicken gelatin with commercial gelatin, most sensory attributes were similar and chicken gelatin gained acceptance by more than 80% of the consumers. Additionally, the collagen films obtained from chicken feet and swine showed water absorption, odors, and texture characteristics similar to commercial material, such as latex and celofane. Consequently, due to its similarity to human skin, it is possible to apply it as a biocurative.

Microbial Growth and Biogenic Amine Production in a Balkan-Style Fresh Sausage during Refrigerated Storage under a CO2-Containing Anaerobic Atmosphere: Effect of the Addition of Zataria multiflora Essential Oil and Hops Extract

Fresh sausages are highly perishable, and the preservatives allowed in these types of meat preparations are limited. Balkan-style fresh sausages were prepared in triplicate without antimicrobials (Control), with an aqueous hops extract (30 mL/kg), with Zataria multiflora Boiss essential oil (1 mL/kg), or a combination of both (15 and 0.5 mL/kg, respectively), and refrigerator-stored under a 20% CO₂ and 80% N₂ atmosphere. The spoilage microbial growth, i.e., lactic acid bacteria (LAB), Brochothrix thermosphacta, Enterobacteriaceae, Micrococcaceae, molds and yeasts, the pH value, and the production of biogenic amines in the sausages were monitored weekly and compared with a control sausage during a 35-day storage period. Furthermore, 349 colonies of presumptive LAB (isolated from the De Mann, Rogose-Sharpe agar plates) were identified using a MALDI-TOF-based method. Growth levels to ≈ 9 Log colony forming units (CFU) per g were reached by LAB, with a predominance of Lactobacillus sakei. Enterobacteriaceae and B. thermosphacta also showed significant growth (up to 6 Log CFU/g). Biogenic amine levels increased, and tyramine values overcame 250 mg/kg. The study could not demonstrate a significant effect of antimicrobial source treatments in any of the characteristics studied, and thus, the shelf-life of sausages.

Producing an Emulsified Meat System by Partially Substituting Pig Fat with Nanoemulsions that Contain Antioxidant Compounds: The Effect on Oxidative Stability, Nutritional Contribution, and Texture Profile

The objective of this study was the incorporation of a water-oil (W/O) nanoemulsion for the partial substitution of pig fats and the addition of antioxidant compounds in an emulsified meat system (EMS). The nanoemulsion was formulated with orange essential oil and cactus acid fruit (xoconostle). The treatments were different percentages (0, 1, 2, 3, 4, and 5%) of the nanoemulsion for the substitution of pig fat in the EMS. The proximal analysis (moisture, protein, fat, and ash), texture profile (hardness, cohesiveness, springiness, and chewiness), phenolic compounds and antioxidant capacity 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and 2-thiobarbituric acid reactive substances (TBARS) were evaluated. All variables showed significant differences (p < 0.05). The results for protein, fat, and ash exhibited increments with the addition of the nanoemulsion, and moisture loss was reduced. The profile showed increments in hardness and chewiness. The addition of the nanoemulsion incremented the phenolic compounds and antioxidant capacity (DPPH and ABTS), decreased production of Malonaldehyde, and reduced lipid oxidation. The result of the addition of the nanoemulsion in the EMS is a product with a substantial nutritional contribution, antioxidant capacity, and excellent shelf life.