Biological properties of Thymus zygis essential oil with emphasis on antimicrobial activity and food application

Natural Antimicrobials: A Clean Label Strategy to Improve the Shelf Life and Safety of Reformulated Meat Products

“…As in all food industries, the chemical degradative reactions, spoilage, and pathogenic microorganisms are the main cause of economic losses for the meat industry, which also constitute an important consumer health risk [ 41 , 49 ]. In addition to these problems, pathogenic bacteria are a major concern in the meat industry, since foodborne diseases constitute a global health problem [ 49 ]. Similarly, microbial spoilage is the main food damage, and 40% of this spoilage occurs at the retail and consumer levels [ 50 ].…”

“…Another important aspect is that many bacteria strains can bind to environmental or food contact surfaces and form an extracellular matrix (biofilms), which contribute to >80% of human infections [ 49 ]. In addition to this problem, biofilms provide microorganisms with additional resistance due to the impossibility of accessing them directly, which prevents antimicrobial compounds, antibiotics, or disinfectant agents from exerting their bactericidal action [ 54 ].…”

“…Furthermore, it is important to note that the complex membrane of Gram-negative bacteria (with a protective outer lipopolysaccharide envelope) makes it difficult for some preservatives to perform their antimicrobial action through the mechanisms discussed in the next sections [ 47 ]. For example, these lipopolysaccharides present in the Gram-negative membrane repel essential oils, while the bioactive molecules can easily penetrate through the Gram-positive bacterial membrane due to their lipophilic character [ 49 ]. Therefore, it is expected that Gram-negative bacteria are less susceptible to the action of natural antimicrobials than Gram-positive bacteria [ 50 ], even though several natural antimicrobials exhibit a strong inhibition of both Gram-positive and Gram-negative bacterial growth.…”

“…In contrast to resins, several essential oils (cinnamon, sage, rosemary, oregano, basil, thyme, clove, nutmeg, menthol coriander, ginger, and lavender essential oils) and their active compounds (vanillin, carvacrol, citral, cinnamaldehyde, linalool, carvone, eugenol, thymol, and limonene) have been generally considered as GRAS [ 79 , 112 ], and some of them were approved as food additives in the USA., such as lemon balm, basil, clove, vanilla, thyme, and coriander [ 49 ]. Thus, essential oils were proposed and approved for use in the food industry.…”

“…More than sixty active molecules were described by multiple authors, but the most common were thymol carvacrol, p-cymene, and linalool, but other compounds, such as γ-terpinene, terpinen-4-ol, α-terpinene, β-myrcene, camphene, geraniol, borneol, α-terpineol, camphor, limonene, β-pinene, trans-caryophyllene, borneol, α-himachalene, γ-elemene, and sabinene hydrate were also identified in medium–high amounts [ 49 , 84 , 90 ]. These volatile compounds presented a strong inhibition effect against L. monocytogenes , S. aureus , E. coli , and S. typhimurium , while having no antimicrobial activity against P. aeruginosa [ 49 ]. Additionally, high inhibition against the growth of B. licheniformis , L. innocua , P. fluorescens , P. vulgaris , and P. putida was seen [ 84 ].…”