The use of bioactive properties of sage preparations to improve the storage stability of low-pressure mechanically separated meat from chickens2

Essential Oils and Their Combination with Lactic Acid Bacteria and Bacteriocins to Improve the Safety and Shelf Life of Foods: A Review

The use of plant extracts (e.g., essential oils and their active compounds) represents an interesting alternative to chemical additives and preservatives applied to delay the alteration and oxidation of foods during their storage. Essential oils (EO) are nowadays considered valuable sources of food preservatives as they provide a healthier alternative to synthetic chemicals while serving the same purpose without affecting food quality parameters. The natural antimicrobial molecules found in medicinal plants represent a possible solution against drug-resistant bacteria, which represent a global health problem, especially for foodborne infections. Several solutions related to their application on food have been described, such as incorporation in active packaging or edible film and direct encapsulation. However, the use of bioactive concentrations of plant derivatives may negatively impact the sensorial characteristics of the final product, and to solve this problem, their application has been proposed in combination with other hurdles, including biocontrol agents. Biocontrol agents are microbial cultures capable of producing natural antimicrobials, including bacteriocins, organic acids, volatile organic compounds, and hydrolytic enzymes. The major effect of bacteriocins or bacteriocin-producing LAB (lactic acid bacteria) on food is obtained when their use is combined with other preservation methods. The combined use of EOs and biocontrol agents in fruit and vegetables, meat, and dairy products is becoming more and more important due to growing concerns about potentially dangerous and toxic synthetic additives. The combination of these two hurdles can improve the safety and shelf life (inactivation of spoilage or pathogenic microorganisms) of the final products while maintaining or stabilizing their sensory and nutritional quality. This review critically describes and collects the most updated works regarding the application of EOs in different food sectors and their combination with biocontrol agents and bacteriocins.

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

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

Isolation, Bioactive Potential, and Application of Essential Oils and Terpenoid-Rich Extracts as Effective Antioxidant and Antimicrobial Agents in Meat and Meat Products

Using food additives (e.g., preservatives, antioxidants) is one of the main methods for preserving meat and meat product quality (edible, sensory, and technological) during processing and storage. Conversely, they show negative health implications, so meat technology scientists are focusing on finding alternatives for these compounds. Terpenoid-rich extracts, including essential oils (EOs), are remarkable since they are generally marked as GRAS (generally recognized as safe) and have a wide ranging acceptance from consumers. EOs obtained by conventional or non-conventional methods possess different preservative potentials. Hence, the first goal of this review is to summarize the technical-technology characteristics of different procedures for terpenoid-rich extract recovery and their effects on the environment in order to obtain safe, highly valuable extracts for further application in the meat industry. Isolation and purification of terpenoids, as the main constituents of EOs, are essential due to their wide range of bioactivity and potential for utilization as natural food additives. Therefore, the second goal of this review is to summarize the antioxidant and antimicrobial potential of EOs and terpenoid-rich extracts obtained from different plant materials in meat and various meat products. The results of these investigations suggest that terpenoid-rich extracts, including EOs obtained from several spices and medicinal herbs (black pepper, caraway, Coreopsis tinctoria Nutt., coriander, garlic, oregano, sage, sweet basil, thyme, and winter savory) can be successfully used as natural antioxidants and antimicrobials in order to prolong the shelf-life of meat and processed meat products. These results could be encouraged for higher exploitation of EOs and terpenoid-rich extracts in the meat industry.

Application of Natural Preservatives for Meat and Meat Products against Food-Borne Pathogens and Spoilage Bacteria: A Review

Meat and meat products are excellent sources of nutrients for humans; however, they also provide a favorable environment for microbial growth. To prevent the microbiological contamination of livestock foods, synthetic preservatives, including nitrites, nitrates, and sorbates, have been widely used in the food industry due to their low cost and strong antibacterial activity. Use of synthetic chemical preservatives is recently being considered by customers due to concerns related to negative health issues. Therefore, the demand for natural substances as food preservatives has increased with the use of plant-derived and animal-derived products, and microbial metabolites. These natural preservatives inhibit the growth of spoilage microorganisms or food-borne pathogens by increasing the permeability of microbial cell membranes, interruption of protein synthesis, and cell metabolism. Natural preservatives can extend the shelf-life and inhibit the growth of microorganisms. However, they can also influence food sensory properties, including the flavor, taste, color, texture, and acceptability of food. To increase the applicability of natural preservatives, a number of strategies, including combinations of different preservatives or food preservation methods, such as active packaging systems and encapsulation, have been explored. This review summarizes the current applications of natural preservatives for meat and meat products.

Alleviation of Lead Stress on Sage Plant by 5-Aminolevulinic Acid (ALA)

Oxidative stress is imparted by a varying range of environmental factors involving heavy metal stress. Thus, the mechanisms of antioxidant resistance may advance a policy to improve metal tolerance. Lead as a toxic heavy metal negatively affects the metabolic activities and growth of medicinal and aromatic plants. This investigation aimed to assess the function of 5-aminolevulinic acid (ALA) in the alleviation of Pb stress in sage plants (Salvia officinalis L.) grown either hydroponically or in pots. Various concentrations of Pb (0, 100, 200, and 400 µM) and different concentrations of ALA (0, 10, and 20 mg L^-1) were tested. This investigation showed that Pb altered the physiological parameters. Pb stress differentially reduced germination percentage and protein content compared to control plants. However, lead stress promoted malondialdehyde (MDA) and H₂O₂ contents in the treated plants. Also, lead stress enhanced the anti-oxidative enzyme activities; ascorbate peroxidase superoxide, dismutase, glutathione peroxidase, and glutathione reductase in Salvia plants. ALA application enhanced the germination percentage and protein content compared to their corresponding controls. Whereas, under ALA application MDA and H₂O₂ contents, as well as the activities of SOD, APX, GPX, and GR, were lowered. These findings suggest that ALA at the 20 mgL^-1 level protects the Salvia plant from Pb stress. Therefore, the results recommend ALA application to alleviate Pb stress.

Natural Anti-Microbials for Enhanced Microbial Safety and Shelf-Life of Processed Packaged Meat

Microbial food contamination is a major concern for consumers and food industries. Consumers desire nutritious, safe and “clean label” products, free of synthetic preservatives and food industries and food scientists try to meet their demands by finding natural effective alternatives for food preservation. One of the alternatives to synthetic preservatives is the use of natural anti-microbial agents in the food products and/or in the packaging materials. Meat and processed meat products are characteristic examples of products that are highly perishable; hence natural anti-microbials can be used for extending their shelf-life and enhancing their safety. Despite several examples of the successful application of natural anti-microbial agents in meat products reported in research studies, their commercial use remains limited. This review objective is to present an extensive overview of recent research in the field of natural anti-microbials, covering essential oils, plant extracts, flavonoids, animal-derived compounds, organic acids, bacteriocins and nanoparticles. The anti-microbial mode of action of the agents, in situ studies involving meat products, regulations and, limitations for usage and future perspectives are described. The review concludes that naturally derived anti-microbials can potentially support the meat industry to provide “clean label”, nutritious and safe meat products for consumers.

Sage (Salvia officinalis L.) Essential Oil as a Potential Replacement for Sodium Nitrite in Dry Fermented Sausages

This study investigates the effects of sodium nitrite replacement by the sage essential oil (SEO), on the physico-chemical, microbiological and sensory quality of dry fermented sausages (DFS) during 225 days of storage. The SEO (0.00, 0.05 and 0.10 µL/g) was added in DFS batters formulated with different levels of pork back fat (15% and 25%) and sodium nitrite (0, 75 and 150 mg/kg). The inclusion of SEO had no negative impact on pH, color (instrumental and sensory) and texture parameters. Total plate counts were lower than 6 log CFU (colony forming units)/g in all samples throughout the storage. Furthermore, the addition of SEO at concentration of 0.05 µL/g provided acceptable TBARS (2-Thiobarbituric acid reactive substances) values (<0.3 mg MDA (malondialdehyde)/kg) in the samples produced with reduced levels of sodium nitrite (0 and 75 mg/kg) without negative alternations on sensory attributes of odor and flavor. Generally, our findings confirmed that the usage of SEO could be a good solution to produce healthier DFS with reduced levels of sodium nitrite.

Properties of Salvia officinalis L. and Thymus serpyllum L. Extracts Free and Embedded into Mesopores of Silica and Titania Nanomaterials

This study evidenced the nanoconfinement effect on polyphenolic extracts prepared from Salvia officinalis L. and Thymus serpyllum L. into the mesopores of silica and titania nanomaterials on their radical scavenging capacity and antimicrobial potential. The ethanolic and hydroalcoholic extracts obtained either by conventional or microwave-assisted extraction were characterized in terms of total polyphenols, total flavonoids, and chlorophyll content, as well as radical scavenging activity by consecrated spectrometric determinations. The phytochemical fingerprint of extracts was analyzed by high-performance liquid chromatography-photodiode array detector. Salvia officinalis extracts exhibited better radical scavenging capacity and antimicrobial potential than Thymus serpyllum extracts. The mesoporous MCM-41 silica and titania nanomaterials, prepared by the sol-gel method, were characterized by small- and wide-angle powder diffraction, FTIR spectroscopy, nitrogen adsorption-desorption isotherms, scanning electron microscopy and transmission electron microscopy, while the materials containing embedded extracts were analyzed through Fourier-transform infrared spectroscopy, N₂ sorption measurements, and thermal analysis. All extracts free and embedded in mesoporous matrix exhibited high radical scavenger properties and good bactericidal activity against several reference strains. It was proved that by embedding the polyphenolic extracts into mesopores of silica or titania nanoparticles, the phytochemicals stability was enhanced as the materials containing extract exhibited higher radical scavenger activity after 3-6 months storage than that of the free extracts. Additionally, the extract-loaded material showed mild improved antimicrobial activity in comparison with the corresponding free extract.

Research Note: Microbial inactivation of raw chicken meat by supercritical carbon dioxide treatment alone and in combination with fresh culinary herbs

The objective of the present study was to assess the potential synergistic effect between supercritical carbon dioxide (SC-CO₂) and fresh culinary herbs (Coriandrum sativum and Rosmarinus officinalis) on the microbial inactivation of raw chicken meat. The microbiological inactivation was performed on Escherichia coli and natural flora (total mesophilic bacteria, yeasts, and molds). High pressure treatments were carried out at 40°C, 80 or 140 bar from 15 to 45 min. Microbial inactivation had a strong dependence on treatment time, achieving 1.4 log CFU/g reduction of E. coli after 15 min, and up to 5 log after 45 min, while a pressure increase from 80 up to 140 bar was not significant on the microbial inactivation. Mesophilic microorganisms were strongly reduced (>2.6 log CFU/g) after 45 min, and yeasts and molds were below the detection limits of the technique (<100 CFU/g) in most cases. The combination of fresh herbs together with SC-CO₂ treatment did not significantly increase the inactivation of either E. coli or natural flora, which was similar to the SC-CO₂ alone. The synergistic effect was obtained on the inactivation of E. coli using a proper concentration of coriander essential oil (EO) (0.5% v/w), while rosemary EO did not show a significant effect. Color analysis after the treatment showed an increment of lightness (L*), and a decrease of redness (a*) on the surface of the sample, making the product visually similar to cooked meat. Texture analysis demonstrated the modification of the texture parameters as a function of the process pressure making the meat more similar to the cooked one.