They possess inhibitory activity against Gram-positive than Gram-negative bacteria [ 59 , 60 ]. Essential oils have high vapor pressure and are able to reach pathogenic microorganism through gas or liquid phases. Many investigations have proved the antimicrobial efficiency of essential oils against several pathogenic and spoilage microflorae.
However, the efficiency of essential oils depends upon the pH, storage temperature, and concentration of oxygen [ 61 ]. Some of the antimicrobial compounds that are present in spices and herbs are eugenol, thymol, thymol and carvacrol, vanillin, allicin, cinnamic aldehyde, and allyl isothiocyanate that are, respectively, present in cloves, thyme, oregano, vanilla, garlic, cinnamon, and mustard [ 26 ].
Essential oils possess antimicrobial activities against several pathogenic microorganisms present in meat, including both Gram-positive and Gram-negative bacteria [ 62 ].
Many studies have been conducted to analyze the effects of essential oils extracted from sources such as oregano, rosemary, thyme, basil, garlic, and clove, when used alone or in combination with other essential oils [ 4 , 63 ].
Essential oils extracted from herbs and spices were found to be effective against several pathogenic microorganisms. Studies showed the antimicrobial activities of 14 essential oils clove, oregano, rosemary, pepper, nutmeg, liquorice, turmeric, aniseed, cassia bark, fennel, prickly ash, round cardamom, dahurian angelipca root, and angelica against four meat spoilage and pathogenic bacteria L.
Antimicrobials from herbs and spices are widely used by the industry, and government agencies have approved them to be safe [ 64 , 65 ]. Pseudomonas bacteria are responsible for the unacceptability of meat sausages. The use of thymol extracted from thyme and oregano as an antimicrobial inhibits the growth of Pseudomonas in sausages [ 53 ].
Researches show that Marjoram, mustard, cinnamon, lemon grass, and rosemary extracts have inhibitory effects against E. The oregano essential oils have antibacterial activities against E. The main component in the essential oil of oregano is carvacrol Some other studies show that S.
Sodium nitrite has been used as a preservative in meat and meat products, but researches showed that if it is used in combination with oregano essential oils, it will slow down the growth of bacteria more efficiently than sodium nitrite alone [ 14 ]. The amount of EOs used in meat and meat products should be higher than the dose used in in vitro conditions because of the interaction with components of meat. Antimicrobial essential oils can be used directly or as polyethylene oxide PEO -based antimicrobial packaging [ 69 ].
Another research showed that the addition of oregano essential oils at a concentration of 0. In vitro tests detected the antibacterial activity of oregano oil against S. Mustard and horseradish essential oils also have antimicrobial activities against Gram-negative bacteria. Major antimicrobial agent in both is allyl-isothiocyanate [ 71 — 73 ]. When applying the antimicrobials in meat or meat products, depending upon the properties and type of pathogen, some EOs are more effective than others.
Rosmarinus officinalis L. Carnosic acid and carnosol are the major antimicrobial components of rosemary and are effective against both Gram-negative and Gram-positive bacteria. In meat and meat products, rosemary oil has high antibacterial activity against L. Thyme essential oils have high antimicrobial activity owing to the presence of different compounds. Thyme oils are effective against L.
When added at a dose level of 0. In vitro antimicrobial activity of thyme essential oil has been tested against E. Research has been conducted to find out the antimicrobial activity of clove oil against L. Thymol essential oil from thyme at a concentration of — mg is used in fresh minced beef in combination with modified atmosphere packaging against different microorganisms and also increases the shelf life of beef [ 26 , 29 ].
Sage essential oil is used at a concentration of 0. Rosemary or Chinese mahogany , , and ppm is used to increase fresh chicken sausage [ 14 , 69 , 79 ]. Antimicrobial agents, though very effective against microbial population and able to extend the quality and shelf life of meat and meat products, should be added with care because they can cause some side effects. Many essential oils like thymol and eugenol can cause mucous membrane irritation, if used in higher concentrations.
In vitro studies of various essential oils like carvacrol, carvone, thymol, and so on show a mild to moderate toxic effects [ 30 ]. Some essential oils can cause allergy or some can have photoactive molecules which can cause phototoxic reactions [ 80 , 81 ]. Many fruits and vegetables are nowadays well known to have antimicrobial effect against different pathogenic and spoilage microbes due to their contents of phenolic and organic acids.
Fruit peels that are mostly discarded also contain antimicrobial compounds [ 30 , 82 ]. Research showed that the antimicrobial activity of orange peel and capsicum was due to the presence of phenolic compound coumaric acid [ 83 ].
In minced beef, the extracts of capsicum annum have inhibitory effect against S. The minimum dose level of capsicum extract was 1.
Pomegranate extract reduces the growth of E. The peel of pomegranate contains different phenols and flavonoids that have great antimicrobial activity against Gram-positive bacteria. Peel extracts have inhibitory effects against S. The addition of pomegranate peel extract to chicken meat products increases its shelf stability by 2—3 weeks during chilled storage and its extract is also effective in controlling oxidative rancidity in these chicken products [ 7 , 62 ].
Citrus peel extract, lemon grass, and lime peel extracts were investigated for their antimicrobial activities in meat and meat products. The extracts showed high potential of antibacterial activity against B. Hot water extract of lemon fruit peels, seeds, and juices displayed promising evidence of antibacterial activity against bacteria E.
Garlic is a potential inhibitor for food pathogens. The use of garlic can increase the shelf life and decrease the possibilities of food poisoning and spoilage in processed foods. Garlic extract has antimicrobial activity due to the presence of an organic sulfur compound allicin, which acts as a growth inhibitor for both Gram-positive and Gram-negative bacteria including E.
Garlic aqueous extract has antibacterial properties against S. The antimicrobial effect of onion extract on the fresh beef fillet meat was investigated. Microbiological quality of the samples was investigated during storage for 9 days. Increasing concentrations of onion extract significantly affected E. Antimicrobial efficacy of curcumin, one of the active components of the Curcuma longa turmeric plant, was evaluated against food pathogens in a minced meat medium.
Today, many fresh products are available commercially with best nutritional profile and low cost of production. Consumers also prefer consuming fresh meat and meat products, but a limit for the commercial availability of fresh meat is its low storage life because of high moisture contents that cause the growth of pathogenic and spoilage microorganisms [ 87 ]. To avoid this, the spoilage use of antimicrobials is one of the best ways to increase the shelf life of these perishable food products especially meat and meat products.
The use of antimicrobial films and coatings dates back to twelfth century. The only difference between film and coating is its thickness. There are many ways of applying these antimicrobials on food products to enhance the natural appearance and safety of fresh meat and meat products like spray or spread of antimicrobials on meat [ 88 , 89 ].
By the combination of different preservation techniques, researchers have been successful in achieving the objectives related to microbial quality storage life of perishable products. The addition of natural antimicrobials in combination with modified atmosphere packaging and refrigeration has proven to show the best results.
Antimicrobials can also be added in coatings and films to be used in meat and meat products [ 88 , 90 ]. The use of antimicrobials in edible films and coatings is an emergent technique that is helpful in enhancing the quality and safety aspect of food. This technique includes a control release of antimicrobial agents in effective concentration in the food product, when required. The use of oregano essential oil EO as natural antimicrobial in combination with modified atmosphere packaging and refrigeration highly enhances the storage life of fresh beef or chicken during storage.
Whey protein isolate coatings containing antimicrobial agents like oregano EO, 3-polylysine, or sodium lactate were used on fresh beef under refrigeration, which was evaluated against the progression of microflora like Pseudomonas bacteria [ 91 ]. By using 1. Both Pseudomonas spp. Carvacol and cinnamon aldehydes, the main active compounds of oregano and cinnamon essential oils, were evaluated for their antimicrobial activity; they were incorporated in edible films based on apple puree containing 1.
These films inactivated the autochthonous spoilage microflora of chicken [ 89 ]. Whey protein isolates-based edible films were evaluated for antimicrobial activities with different essential oils. These films showed high effectiveness against L.
Oregano containing carvacrol as antimicrobial agent and clove containing eugenol EOs were highly effective against S. Coatings act as barrier against oxygen transfer leading to growth inhibition of aerobic bacteria. Chitosan has been used as an antimicrobial agent and also as a coating and wrapper in salami and film and coating combined with lauric arginate and nisin to reduce L. Similarly, milk protein coatings are used in beef in combination with oregano essential oils against E.
Similarly, chitosan coatings in combination with oregano oil at a concentration of 0. Gelatin films are used in Turkey bologna in combination with nisaplin-based films GNF 0. Chitosan coatings in different molecular weights and viscosities 14, 57, or mPa were used in Atlantic cod fish against psychotropic bacteria. Whey protein coatings were used in smoked fish in combination with Lactoperoxidase system 0—0. Gelatin films were used in sardine pilchardus in combination with oregano extracts against Enterobacter bacteria.
Alginate, carrageenan, pectin, gelatin, or starch coatings were also used in smoked salmons in combination with sodium lactate against a mixture of L. All the researches and studies conducted till now have proved that the use of synthetic preservatives to increase the shelf life of food and food products is in any way harmful for the human health, so there is a call for the use of natural products as preservatives to increase the quality and shelf stability of the food and food products.
Natural antimicrobials contain all the qualities to be used as preservatives especially in meat and meat products, and plants are the main source of these antimicrobials. Samples were withdrawn at 0, 1, 2, 3, 5, 8, 10 minute intervals. All neutralized dilutions were surface-spread in petri dishes with tryptone soy agar with Tween-lecithin.
When assays were carried out with organic matter, such matter was added to the disinfectant solution. Essential clove oil at 0. Assays were performed with Escherichia coli and Staphylococcus aureus as a representative scenario of a Gram positive and a gram negative response. The linear regression of death was performed with Microsoft Office Excel program. The results of the survivors log have been adjusted as to time, by linear regression. The values of death rate constant for each temperature and concentration are shown in Table 1.
Figure 1 shows the effect of clove oil concentration 0. The concentration coefficient n has been calculated as:. Kinetic of bacterial inactivation by essential clove oil at two concentrations. The relationship with the death constant at two different temperatures shows an approximately linear correlation This factor plays a highly variable role from one compound to another. For the same product, the temperature coefficient varies depending on the microorganism involved, but does not influence the concentration of the product.
The temperature coefficients Q 1 of essential clove for E. Figure 3 show that adding organic matter to the disinfecting solution does not compromise antimicrobial activity. In the case of Staphylococcus aureus , albumin shows the greatest interference, as they needed 10 minutes to reach the reduction of 5 log cycles in the bacterial population 3 min are required in the absence of organic matter.
Influence of organic matter on bactericidal effect of clove oil. The inactivation curves presented biphasic kinetics, although the curve for Escherichia coli in the presence of 0. A fast reduction in the viable count was detected during the first 3 to 5 minutes afterward the count remained constant.
Escherichia coli demonstrated a marked sensitivity showing a 6. The concentration exponent quantifies the dilution effect in the antimicrobial activity 14 , 8. Thus, halving the concentration will increase the time 1- fold to reach the same end point against Staphylococcus aureus , while against Escherichia coli it will increase 4 times.
The inactivation kinetics depends on the temperature. This activity increase must be considered in the application of clove essential oil as antiseptic. Any increase in temperature is linked to increased sensitivity due to the fact that membrane permeability of small molecules is due in part to the fluidity of the lipid layer. Gil and Suisted 10 have shown that the temperature modifies cell permeability which affects the proportion of unsaturated fatty acids.
When permeability increases protection against a germicidal agent entry is reduced so clove essential oil can be dissolved in the membrane and accumulate with consequent damage to the membrane. The results observed with the bacterial strains suggest that there is a direct relationship between the damage caused through a membrane and cell death 2. At bactericidal concentrations the primary mechanism of action of eugenol is disruption of the cytoplasmic membrane, which increases its non-specific permeability 9.
The results show that organic matter reduces antibacterial activity, although it maintains its bactericidal efficacy: indeed, at 10 min, the bacterial population was reduced by 5 logarithmic orders in the presence of albumin. It can be noted that the reduction degree of antimicrobial activity of the different types of assayed substances varies from one microorganism to another.
It has already been shown in other studies 5 , 11 that reduction of antimicrobial activity by organic matter shows variations between bacterial species. This variation was related with the structure cell wall, which shows significant differences in constitution and, consequently, differences in the capacity of combination with organic material and thus prevention of bactericidal capacity. Also, the interaction between antimicrobial agents and organic matter can result in a form less easily absorbed by different microorganisms.
In addition, the results obtained suggest that the characteristics of organic substances play an important role in the bactericide agent inactivation; this can be explained by the chemical composition of the interfering substance, high concentrations of proteins can cause significant interference with bactericidal solution activity Different authors have explained that such differences within the interference degree could be found in both solubility and protein content of the different types of organic matter 11 , 7.
Clove essential oil can be considered as a potential antimicrobial agent for external use because it is not markedly inactivated by dilution or affected by organic matter. The design of clinical trials will determine its effectiveness in medical and dental practice. National Center for Biotechnology Information , U. Journal List Braz J Microbiol v.
Braz J Microbiol. Published online Jun 1. Author information Article notes Copyright and License information Disclaimer. Mailing address : Hygiene, Faculty of Pharmacy and Biochemistry.
University of Buenos Aires. Argentina, Junin — Buenos Aires Argentina. All the content of the journal, except where otherwise noted, is licensed under a Creative Commons License. This article has been cited by other articles in PMC.
Abstract Clove essential oil, used as an antiseptic in oral infections, inhibits Gram-negative and Gram-positive bacteria as well as yeast. Keywords: clove essential oil, concentration coefficient, organic matter, antibacterial activity. Bacterial death kinetics Determination of bactericide effect was performed according Briozzo et al 1. Influence of organic matter Essential clove oil at 0. Statistical Analysis The linear regression of death was performed with Microsoft Office Excel program.
Table 1 Kinetic parameters of bactericidal reaction. Microorganism Log k r2 n Escherichia coli 0. Open in a separate window. Figure 1. Figure 2. Figure 3. It can be noted that the reduction degree of antimicrobial activity of the different types of assayed substances varies from one microorganism to another It has already been shown in other studies 5 , 11 that reduction of antimicrobial activity by organic matter shows variations between bacterial species.
Briozzo J. Antimicrobial activity of clove oil dispersed in concentrated sugar solution. Broxton P. Study of the antibacterial activity some polyhexamethylene biguanides towards Escherichia coli ATCC Burt S.
Essential oils: their antibacterial properties and potencial applications in foods—a review. Food Microbiol. Chaib K. The chemical composition and biological activity of clove essential oil, Eugenia caryophyllata Syzigium aromaticum L. Myrtaceae : a short review.
Dorman H. Antimicrobial agents from plants: antibacterial activity of plant volatile oils. Neutralization of the activity of eight disinfectants by organic matter. Gilbert P. Assessment of resistance towards biocides following the attachment of micro-organisms to, and growth on, surfaces. Appl Microbiol. Gill A.
0コメント