Addition Of Oregano Essential Oil Research Articles

Screening of Essential Oils for the Inhibition of Enterobacter ludwigii Isolated from Tomato Fruits

Tomato is perishable and requires preservation to extend its shelf life. In this study, we conducted selection processes to identify essential oils that can help to avoid spoilage and deterioration during tomato storage and extend the shelf life. Thereafter, we determined the phosphatase activity assay, potassium ion concentration, and electron microscopy to study the antibacterial mechanism of essential oil. We found that Enterobacter ludwigii W01 was the dominant spoilage bacterium in tomatoes with cracked and curled skin. We selected oregano essential oil from 12 essential oils (oregano essential oil, lemon essential oil, osmanthus essential oil, cypress wood essential oil, tea tree essential oil, licorice essential oil, Baili essential oil, white camphor essential oil, Shancang seed essential oil, rosemary essential oil, rose essential oil, and cinnamon essential oil) which could significantly inhibit the activity of E. ludwigii W01. However, the diameter of the inhibition zone for Wh, Te, Cy, Li, Rm, Le, and Os is 0 mm, the diameter of the inhibition zone for Ba, Sh, and Ro was less than 1.0 mm, whereas the diameter of the inhibition zone for Ci and Or was greater than 2.0 mm. The diameter of the suppression circle for Ci and Or was greater than 2.0 mm, while Ci was lesser than Or. Oregano essential oil can damage the cell wall of E. ludwigii W01, leading to the leakage of the alkaline phosphatase stored between the cell wall and the cell membrane which can increase the alkaline phosphatase activity in the bacterial solution. Meanwhile, the addition of oregano essential oil significantly altered the cellular morphology of E. ludwigii W01. Spraying the surface of fresh tomato fruits with 1 MIC (0.125%) of oregano essential oil prolonged the storage time to 15 days, without significant changes in its sensory attributes. Those results indicated that oregano essential oil was a potential preservative for tomatoes.

Effect of oregano essential oil against selective microorganisms in raw mutton

The current study was conducted to ascertain the impact of various concentrations of oregano essential oil on the microbial population in raw mutton. The experiment was conducted using a complete randomized design (CRD) with six (6) treatments as T0 , T1 , T2 , T3 , T4 , T5 and three (3) replications. The drop plate method was utilized to detect the presence of certain microorganisms. The outcomes showed that adding oregano oil reduced the microbial population in samples. Colony-forming units gradually decreased where T5 being the lowest number of colony-forming units. There was a highly significant difference (p<0.0001) in the colony-forming unit of Staphylococcus epidermidis and Proteus vulgaris. For Klebsiella pneumonia, there was a significant reduction (p<0.01) of the microbes among samples. On the other hand, Staphylococcus epidermidis significantly outperformed Proteus vulgaris in terms of growth inhibition. In light of the findings, it is possible to conclude that the addition of oregano essential oil at a 200 µl level reduces the microbial population of raw mutton.

Use of Nile tilapia (Oreocromis niloticus) processing residues in the production of pâtés with the addition of oregano (Origanum vulgare) essential oil.

The effect of the use of Nilo tilapia filleting residues in the production of pâtés with the addition of oregano essential oil stored for 90 days at 4 °C was evaluated. For that, 5 treatments were performed as follows: TSA-control treatment; TES with the addition of sodium erythorbate; and formulation TOE1 with 600 ppm oregano essential oil; TOE2 with 1000 ppm essential oil; and TOE3 with 1400 ppm essential oil. The pâtés showed adequate technological and physicochemical characteristics and microbiological counts within the legislation standards. No significant differences were observed in the luminosity of the pâté formulations during storage, and the addition of oil contributed to the increase in a* values and stability of b* values. Regarding the lipid and protein oxidation, TOE3 showed lower values at the end of the shelf-life. The addition of essential oil did not affect the hardness and cohesiveness of the products. The fatty acids in greater amounts in the samples were linoleic, oleic, palmitic, and stearic acids. The analysis of biogenic amines indicated that only the treatments with the highest amounts of sodium erythorbate (TES and TOE1) showed losses of spermidine. It was observed that decreasing the inclusion of sodium erythorbate and increasing the inclusion of oregano essential oil resulted in a drop in cadaverine values. A total of 46 volatile compounds were detected in the samples with the highest amount of free fatty acids and all the formulations were well accepted sensorially.

Effects of Essential Oil and/or Encapsulated Butyrate on Fecal Microflora in Neonatal Holstein Calves.

This study was conducted to investigate the effects of feeding oregano essential oil, butyrate, and its mixture on the intestinal microbial diversity of calves. A completely randomized experimental design was used. Sixty-four healthy neonatal Holstein female calves with birth weight ≥ 35 kg were randomly divided into one control and three treatments (16 calves per group). The control group was fed normally, and the treatment group was fed oregano essential oil, butyrate, and their mixture, respectively. The experiment lasted for 70 days, and the lactation period lasted for 56 days. On days 55 and 70, rectal fecal samples from five calves were collected from each group for 16S rRNA amplification and sequencing. The results showed as follows: (1) the three treatments had no significant effects on the intestinal microbial community diversity, community uniformity, and community pedigree diversity of calves (p > 0.05). (2) At the phylum level, Firmicutes, Bacteroidota, Spriochatetota, Actinobacteriota, Firmicutes, and Bacteroidota gates of the main bacteria were detected in feces. (3) At the genus level, the top ten species with relative abundance detected are: norank_ F_Muribaaculaceae, Ruminococcus, unclassified_ F_ Lachnospiraceae, UCG-005, Prevotelaceae_NK3B31_Group, Prevotella, Bacteroides, Rikenellaceae_RC9_Gut_Group, and Faecalibacterium, Alloprevotella. (4) LEfSe analysis results show that the species with significant differences in the control group were f__Lachnospiraceae, o__Lachnospirales, o__Coriobacteriales, and c__Coriobacteriia, g__Megasphaera; in the essential oil group were g__Lachnospiraceae_AC2044_group, o__Izemoplasmatales, g__norank_f__norank_o__Izemoplasmatales, and f__norank_o__Izemoplasmatales; in the sodium butyrate group were g__Lachnospiraceae_NK4A136_group, and g__Sharpea, g__Fournierella; in the mixed group were g__Flavonifractor, and g__UBA1819. (5) The functional prediction analysis of calf gut microbes, found on the KEGG pathway2, shows that essential oil significantly improved membrane transport, Sodium butyrate inhibits lipid metabolism and improves the body's resistance to disease. (p < 0.05). (6) The effects of each treatment on the intestinal microbial structure of calves did not last for 14 days after the treatment was stopped. In conclusion, the addition of oregano essential oil, butyrate, and its mixtures to milk fed to calves can modulate the microbial structure, and it is recommended that oregano essential oil and butyrate be used separately, as a mixture of the two can increase the rate of diarrhea in calves.

Effects of oregano essential oil and capsicum extract supplementation on slaughter characteristics, meat quality, and fatty acid composition of lambs

The aim of this study was to evaluate the effect of oregano essential oil (OEO) and capsicum oleoresin extract (CAO) supplementation on lamb slaughter characteristics, meat quality, and fatty acid composition. In the study, 18 male and 18 female lambs were divided into three equal groups for a 56- day feeding period. The first group was fed the control diet, while the other groups were fed a control diet containing either 300 mg OEO/kg or 300 mg CAO/kg of diet. Feeding OEO or CAO had no effect on the slaughter and carcass quality of the fattening lambs. However, when compared to the female lambs, the male lambs were found to have higher slaughter weights, hot and cold carcass weights, and dressing percentage, while having lower back fat thickness. In addition, OEO substantially increased the intramuscular fat. Dry matter, protein, pH24, meat colour (L*, a*, and b*), drip loss, and cooking loss were not affected by dietary treatment or sex. The addition of OEO or CAO to the diets did not change the meat lipid oxidation or sensory quality characteristics at different storage times. However, meat from the female lambs was found to have thiobarbituric acid reactive substances (TBARS) values lower than that of the meat from the male lambs after 2 d and 4 d of storage. However, the female lamb meat was more preferred in terms of flavour and general acceptance. The ΣMUFA, ΣPUFA, ΣUFA, Σn-6, Σn-3, and Σn-6/Σn-3 contents of the lamb meat were not affected by the dietary treatment. As a result, the inclusion of 300 mg of oregano essential oil/kg of DM in lamb diets is considered appropriate because of its significant contributions to the fat composition of lamb meat.

Effects of Dietary Oregano Essential Oil on Cecal Microorganisms and Muscle Fatty Acids of Luhua Chickens.

This experiment was conducted to investigate the effects of oregano essential oil on the cecal microorganisms and muscle fatty acids of Luhua chickens. One hundred and twenty 49-day-old healthy dewormed Luhua chickens were randomly divided into four groups with three replicates per group and ten chickens per replicate. The corn-quinoa and soybean meal diets were supplemented with 0 (Q8 group), 50 (QO50 group), 100 (QO100 group) and 150 mg·kg-1 (QO150 group) of oregano essential oil, respectively, and the experiment lasted for 75 days. The composition of intestinal flora was detected by Illumina sequencing of the 16S rRNA V4 region, and the composition and content of fatty acids in the muscles were analyzed by gas chromatography. The results showed that dietary oregano essential oil can effectively increase the contents of elaidic acid (C18:ln9t), polyunsaturated fatty acids (PUFAs) and n-3 polyunsaturated fatty acids (n-3 PUFAs) in breast muscle tissues. However, the fatty acid composition and PUFA content in leg muscle tissues were not significantly improved. According to a 16S rRNA high-throughput sequencing analysis, dietary oregano essential oil supplementation with a certain concentration can change the cecal microbial community composition of broilers. At the phylum level, Elusimicrobia in the QO150 group was significantly lower than that in Q8 group (p &lt; 0.05). At the genus level, Phascolarctobacterium, Parasutterella and Bilophila in the experimental groups (QO50, QO100 and QO150) were significantly lower than those in the Q8 group (p &lt; 0.05). An enrichment analysis of the microbial function found that the amino acid metabolism, energy metabolism, metabolism, signal transduction and genetic information processing were mainly enriched in the experimental groups, which promoted the digestion and absorption of nutrients and enhanced intestinal barrier functioning. An analysis of the association between fatty acids and microbes found that the abundance of microbiota was significantly correlated with partially saturated fatty acids (SFAs) and unsaturated fatty acids (UFAs) (p &lt; 0.05). In conclusion, the dietary addition of oregano essential oil can effectively improve cecal microbial community composition, promote the digestion and absorption of nutrients, and enhance intestinal barrier functioning. It can significantly improve the content of some fatty acids, and there was a certain correlation between caecum microorganisms and fatty acid deposition in muscles.

In Vitro Antioxidant, Antimicrobial, Anticoccidial, and Anti-Inflammatory Study of Essential Oils of Oregano, Thyme, and Sage from Epirus, Greece.

Origanum vulgare subsp. hirtum, Thymus vulgaris, and Salvia fructicosa are aromatic plants commonly found in Mediterranean countries and are traditionally used in Greece as a remedy for humans, since they are well known as potent antibacterial, antioxidant, and anti-inflammatory agents. Essential oils (EOs) derived from plants cultivated in the mountainous region of Epirus, Greece, were investigated for their inhibitory activity against key microorganisms with relevance to avian health, while also assessing their antioxidant and anti-inflammatory activity. The total phenolic content (TPC) of the EOs was estimated according to the Folin−Ciocalteu method, while the antioxidant capacity was tested through the EOs’ ability to scavenge free radicals by means of the DPPH, ABTS, and FRAP assays. Antibacterial and anti-inflammatory effects were examined by the agar disc diffusion method and the lipoxygenase (LOX) inhibition test, respectively. Furthermore, the EOs’ ability to inhibit the invasion of sporozoites of Eimeria tenella (Wisconsin strain) along with any toxic effects were assayed in Madin−Darby bovine kidney (MDBK) cells. The antioxidant activity of the EOs was observed in descending order: oregano > thyme > sage. The antimicrobial effects of thyme and oregano were equivalent and higher than that of sage, while the anti-inflammatory effect of thyme was higher compared to both sage and oregano. The intracellular invasion of sporozoites was evaluated by the detection of E. tenella DNA by qPCR from cell monolayers harvested at 2 and 24 h post-infection. Parasite invasion was inhibited by the addition of oregano essential oil at the concentration of 100 μg/mL by 83% or 93% after 2 or 24 h, respectively, and was higher compared to the addition of thyme and sage, which had similar effects, but at a less intensive level. The cytotoxic assessment of all three essential oils revealed that they had no effect on MDBK cells compared to dimethyl sulfoxide (DMSO), used as the control substance. The supplementation of oregano, thyme, and sage essential oils had a potent antioxidant, anti-inflammatory, antimicrobial, and anticoccidial in vitro effect that is comparable to synthetic substances or approved drugs, justifying the need for further evaluation by in vivo studies in broilers reared in the absence of antimicrobial and anticoccidial drugs or synthetic antioxidant and/or anti-inflammatory compounds.

Preparation and characterization of oregano essential oil-loaded Dioscorea zingiberensis starch film with antioxidant and antibacterial activity and its application in chicken preservation

In this study, abundant starch was separated from the industrial crop Dioscorea zingiberensis C.H. Wright (DZW), and a novel bioactive packaging film loaded with oregano essential oil (OEO) was prepared and characterized. NaClO solution worked as a bleacher to prepare uniform starch powder from DZW tubers. OEO was selected from among three essential oils of Labiatae family plants for its strongest antibacterial activity. After the addition of OEO into the starch-based film, the UV–vis shielding property and antioxidant activity were enhanced. Meanwhile, the films still have a considerable performance in transparency, mechanical strength and water vapor permeability after incorporated with OEO. Furthermore, the 3% OEO-loaded starch film exhibited the strongest antibacterial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. It effectively lowered the total viable count of fresh chicken under 4 °C preservation conditions. These results revealed that the OEO-loaded DZW starch film can exert a positive effect on maintaining the quality and extending the shelf life of fresh meat. Therefore, readily accessible DZW tubers and oregano are very promising resources for application in degradable bioactive packaging film.

Effects of oregano essential oil and nisin on the shelf life of modified atmosphere packed grass carp (Ctenopharyngodon idellus)

Effects of oregano essential oil (EO) and nisin on the shelf life and microbial community of grass carp fillets packed under modified atmosphere were investigated. The shelf life of fish samples was evaluated based on sensory attributes and spoilage indicators, including color, odor, texture, overall acceptability, total volatile basic nitrogen, and biogenic amines. The addition of oregano EO, nisin, and oregano EO combined with nisin significantly extended the shelf life of fish fillets from 16 d to 20, 20, and 28 d, respectively. In addition, changes in microbial composition of fish fillets were measured by using Illumina-MiSeq high-throughput sequencing and classical microbiological analysis. Adding oregano EO and nisin significantly inhibited the microbial growth of fish fillets, especially lactic acid bacteria which were the dominant spoilage bacteria in fish fillets. While the use of oregano EO and/or nisin did not change the dominant bacteria of fish samples, they significantly lowered total viable counts. Treating fish fillets with nisin lowered the tyramine level and increased the pH value, due to the inhibitory effect on Gram-positive bacteria. The results suggest that oregano EO combined with nisin have great potential to be used as natural antimicrobials to extend the shelf life of grass carp.

The effects of oregano essential oil on production performance and intestinal barrier function in growing Hyla rabbits

The purpose of this study was to investigate the effects of oregano essential oil on the production performance and intestinal barrier in rabbits. One hundred and ninety-two weaned Hyla rabbits (35 days old) with similar body weight (1268.5 ± 25 g) were randomly divided into four groups (24 replicates per group, two rabbits per replicate): fed a basal diet (Control group), fed a basal diet containing 0.02% oregano essential oil (LO group, the purity of oregano essential oil was 5%), fed a basal diet containing 0.04% oregano essential oil (MO group), or fed a basal diet containing 0.08% oregano essential oil (HO group). The trial included 7 days of adaptation and 23 days of testing. Although dietary addition of oregano essential oil did not affect significantly the average daily body weight and final body weight (p > .05), dietary addition of 0.08% oregano essential oil decreased significantly feed intake and diarrhoea rate of the rabbits (p < .05). When the addition of oregano essential oil in the feed reached 0.08%, the Villus high/Crypt depth value in the ileum of meat rabbits increased significantly (p < .05). Dietary addition of 0.08% oregano essential oil increased significantly the gene expression of junctional adhesion molecule 2 (JAM2) and JAM3 in jejunum (p < .05). The content of interleukin-2 (IL-2) and immunoglobulin A (SIgA) in jejunum and IL-10 and secretory immunoglobulin G (SIgG) in ileum were significantly increased after the addition of 0.08% oregano essential oil compared with the control (p < .05). In conclusion, a dietary supplement of oregano essential oil modulates immune responses and enhances the intestinal barrier. Besides, our experiment offers positive evidence in improving rabbit health of oregano essential oil instead of antibiotics. HIGHLIGHTS Oregano essential oil can improve the production performance of rabbits. Oregano essential oil improved intestinal barrier function in rabbits. Oregano essential oil can be used as a new additive in rabbit feed.

Effect of essential oils of copaiba and oregano in substitution of synthetic antioxidants in Tambaqui fish meat balls

The objective of the present experiment was to evaluate the effects of including the essential oil of copaiba and oregano as a possible replacement for synthetic butylated hydroxytoluene (BHT) additives in fish meat ball. PH, cooking loss, texture, color, sensory acceptability and chemical composition were evaluated. The addition of oregano essential oil had an effect on the color of the fish meat ball (P &lt;0.05), showing better results for a * and Hue compared to BHT, and b * and Croma compared to the control (COM). In addition, the essential oils of copaiba and oregano showed the lowest water losses by cooking and the essential oil of oregano improved the aroma of the fish meat ball (P &lt;0.05). The treatments had no effect (P&gt; 0.05) on the chemical composition of the fish meat ball. The essential oils of copaiba and oregano are promising natural antioxidants to increase the useful life of fish by-products, in addition to being a viable solution to replace the synthetic antioxidant BHT, bringing benefits to its commercialization.

Oregano essential oil addition in rice starch films and its effects on the chilled fish storage.

Active packaging produced from biodegradable polymers and essential oil could have a great value to food industries. This study aimed to evaluate the effect of the addition of oregano essential oil (OEO) on rice starch films and its application as packaging for fish fillets. Several concentrations of OEO were added to the films, the film added with 4.5% OEO showed lower permeability to water vapor 3.7gmmkPa-1m-2day-1, intermediate solubility of 24% and high tensile strength (4.4MPa) while the standard film (without the addition of OEO) presented 8.8gmmkPa-1m-2day-1, 25.8% and 2.2MPa, respectively. Packed fish fillets with the active film showed an increase in its shelf life when compared to the standard film. Packaged fish fillets in OEO films showed greater resistance (13.4N), less oxidation (1.65mg malonaldehyde/kg of sample) and less microbiological growth 107CFU/g in 6days of storage, while packaged fish fillets in standard film showed lower resistance (10.4N), higher oxidation (1.88mg malonaldehyde/kg of sample) and higher microbiological growth 108CFU/g. Thus, the active packaging developed had the capacity to increase the shelf life of a perishable product that has great interest of food industries.

Oregano ( Origanum vulgare ) essential oil as an additive in diets for Nile tilapia ( Oreochromis niloticus ) fingerlings reared in salinized water

The present study was undertaken to examine the effects of oregano essential oil on the growth performance, blood glucose levels, body composition and intestinal morphometry of Nile tilapia reared in salinized water at 10 g/L for 64 days. The experiment was set up as a completely randomized design with five treatments and four replicates, in which a control diet and four diets containing increasing concentrations of oregano essential oil (0.75, 1.5, 2.25 and 3.0 g/kg) were tested. The best results for the growth parameters were obtained with the oregano essential oil inclusion level of 0.75 g/kg, but did not differ (p > .05) from inclusion levels of 0.0, 2.25 and 3.0 g/kg. Conversely, the treatment including the oil level of 1.5 g/kg was the only one to produce significantly (p < .05) lower results. The body composition and blood glucose were not significantly affected. Intestinal morphometry analysis revealed a significant effect on villus length, which increased with the proportion of oregano essential oil added to the diet; accordingly, the inclusion level of 3.0 g/kg provided the best results for this variable. Therefore, the addition of oregano essential oil at 3.0 g/kg in the diet of Nile tilapia cultured in salinized water may act as a stimulant to intestinal villus development and, consequently, as a growth promoter.

Elaboration of an Antimicrobial, Biodegradable and Aromatic Film Against the Natural Contamination of Sliced Mozzarella Cheese

The search for foods that do not use chemical preservatives in their composition has been growing over the years, and as a result, studies on active packaging have been intensified, which has as principle, in addition to protecting, transporting and containing the food, interact with it. In this context, the present study has developed an active antimicrobial, aromatic and biodegradable packaging in order to reduce the natural contamination of sliced Mozzarella cheese, which has shelf life of five days after manipulation. For this, a film was developed containing cassava starch, a plasticizing agent, gum arabic and oregano essential oil, as an antimicrobial agent. The research used the serial dilution methodology for counting and to aid in the isolation of the product natural contamination. The diffusion methodology in Agar in PDA medium with chloramphenicol was used to identify the antimicrobial power of the polymer matrix and the Casting method for film manufacture. With the results, it was possible to identify that only the film with the addition of oregano essential oil showed fungicidal action when compared to the same film without it, forming an inhibition halo of about 25 mm against Hyphopichia burtonii yeast isolated from the product itself, when stored under conditions stipulated by the supplier (Styrofoam trays stored in conventional refrigerator).

Elaboration of an Antimicrobial, Biodegradable and Aromatic Film Against the Natural Contamination of Sliced Mozzarella Cheese

The search for foods that do not use chemical preservatives in their composition has been growing over the years, and as a result, studies on active packaging have been intensified, which has as principle, in addition to protecting, transporting and containing the food, interact with it. In this context, the present study has developed an active antimicrobial, aromatic and biodegradable packaging in order to reduce the natural contamination of sliced Mozzarella cheese, which has shelf life of five days after manipulation. For this, a film was developed containing cassava starch, a plasticizing agent, gum arabic and oregano essential oil, as an antimicrobial agent. The research used the serial dilution methodology for counting and to aid in the isolation of the product natural contamination. The diffusion methodology in Agar in PDA medium with chloramphenicol was used to identify the antimicrobial power of the polymer matrix and the Casting method for film manufacture. With the results, it was possible to identify that only the film with the addition of oregano essential oil showed fungicidal action when compared to the same film without it, forming an inhibition halo of about 25 mm against Hyphopichia burtonii yeast isolated from the product itself, when stored under conditions stipulated by the supplier (Styrofoam trays stored in conventional refrigerator).

OXIDATIVE STABILITY OF CHICKEN MEAT AFTER USE OF OREGANO ESSENTIAL OIL

The purpose of this study was to investigate the effect of oregano essential oil on the oxidation stability of chicken meat. Oregano essential oil was applied in a different way, on the one hand in a feed for broiler chickens and on the other hand on a surface of chicken thighs. The oxidative stability of the chicken meat was investigated in the same way, i.e. 30 minutes after vacuum-packed at room temperature and 6 months after vacuum-packed and storage at -18 °C. The samples of the 1st experiment consisted breast and thigh muscles and skin and of the 2nd experiment thigh muscle and skin. Broiler chickens were fed during the experimental period in the control group with commercial feed mixtures and in the experimental group with similar diets as in the control group but with the addition of 0.05% oregano essential oil. Application of oregano essential oil on surface of thighs was realized 1 ml per 60 g of meat. The impact of oregano essential oil was measured by acid value. Number of acid value 30 minutes after oregano essential oil application in control group was significant higher (6.69 g KOH g -1) than in experimental group (5.39 g KOH g -1). Results of our experiments indicate that the oregano essential oil statistically significant (p 0.05) manifested an impact on the oxidative stability of chicken meat 30 minutes its action. The results impact of oregano essential oil on chicken meat stored at -18 °C for 6 months were comparable to control group, but a tendency to improve oxidative stability was indicated. Feed addition of oregano essential oil did not show any effects on oxidative stability chicken meat.

Effect of Rumen Culture Adaptation to Origanum vulgare L. Essential Oil on Rumen Methane and Fermentation

The main objective of this study was to investigate the impact of adding oregano essential oil (OEO) to adapted and unadapted rumen cultures on methane gas (CH4) production and rumen fermentation under in vitro condition. Rumen fluid for culture fermenters was collected from a Holstein cow located in Southern Illinois University farms.The adapted and unadapted rumen cultures were obtained from continuous culture fermenters fed a control diet, or control diet plus OEO at 250 mg day-1 for 10 days. After 10 days of adaptation, the fermenter’s contents were incubated in a 24 h gas production experiment. Treatments were unadapted culture, unadapted culture plus OEO, adapted culture and adapted culture plus OEO. The OEO was added to rumen cultures at the rate of 500 mg L-1. After 24-h of incubation, total gas production decreased (p<0.03) with the addition of OEO in both cultures and total gas production tended to be lower when added to the adapted cultures. As a percentage of total gas, CH4 production decreased (p<0.05) with OEO addition only in the adapted cultures. Total VFA and acetate concentrations were lower (p<0.05) in the adapted than unadapted cultures and their concentrations decreased (p<0.05) with the addition of OEO, particularly when added to the adapted cultures. Propionate concentrations were also lower (p<0.05) in the adapted than the unadapted cultures and concentrations decreased (p<0.05) with the addition of OEO. The greater effect of OEO on CH4 production in the adapted cultures might have resulted from lower microbial fermentation activity which also might have caused a shift in microbial fermentation favoring less CH4 formation in these cultures.

Oxidative stability, affective and discriminative sensory test of high oleic and regular peanut oil with addition of oregano essential oil.

Peanut oil is widely used in food but is susceptible to oxidation. This study investigated the antioxidant stability of high oleic (HO: 78.85g/100g oleic acid) and regular (C: 43.85g/100g oleic acid) peanut oils with oregano essential oil (OEO) added as a natural antioxidant. OEO contained γ-terpinene (25.71%), carvacrol (16.73%) and terpinen-4-ol (16.17%) as the principal compounds. Thermal processing (60°C for 28days) of OEO increased the carvacrol and o-cymene contents and decreased the terpinen-4-ol, linalool and γ-terpinene levels. Thus, carvacrol was the major compound with high oxidative stability. Thermal processing of the peanut oils showed that HO peanut oil developed less oxidation than C peanut oil. OEO provided antioxidant activity, which increased as its concentration increased (at 0.02 and 0.10% p/p of OEO, the peroxide value decreased by 18 and 46%, respectively). OEO displayed 54.7% free radical scavenging activity and 9.2mg/g total phenolic content, explaining its antioxidant activity. Sensory analysis showed that OEO was detected in all samples, but consumer acceptance was greater when OEO was present (hedonic values of 7.4 and 6.8 for OEO at 0.02 and 0.10g/100g, respectively) compared to the peanut oil only control (hedonic value of 6.0).

Functionalization of Lipid-Based Nutrient Supplement with β-Cyclodextrin Inclusions of Oregano Essential Oil.

Despite its antiparasitic activities, the addition of oregano essential oil into foods is limited due to its strong flavor and volatility. In this study, we evaluated the encapsulation of oregano essential oil with β-cyclodextrin and its addition into lipid-based nutrition supplements. The results revealed that complex encapsulation efficiency was above 80%. Also, the bioactive complexes were stable under in vitro gastrointestinal conditions. Sensory evaluation of LNS with and without encapsulated essential oil showed no difference in terms of color, aroma, and taste. The functional LNS can both address nutrient insufficiency as well as parasitic infection among malnourished populations in low-resource settings.

Modeling the effect of oregano essential oil on shelf-life extension of vacuum-packed cooked sliced ham

The present study modeled the effect of oregano essential oil, as an antimicrobial agent, on the shelf-life of vacuum-packed cooked sliced ham, based on the growth of lactic acid bacteria natural microbiota under isothermal conditions. The bacterial growth in ham without oregano essential oil (control) and with 0.4% oregano essential oil (v/w) was evaluated at five different temperatures (6, 12, 15, 20 and 25°C). Baranyi and Roberts, and modified Gompertz primary models were fitted to microbial growth curves. Square Root and Exponential secondary models were fitted to μmax parameter data. The addition of oregano essential oil increased lag phase, decreased growth rates and extended shelf-life of ham for all temperatures (at 6°C extended for, at least, 30days when compared to control). Statistical indexes showed that Baranyi and Roberts, and Exponential were the primary and secondary models, respectively, that better fit to the data. Thus, oregano essential oil showed a good antimicrobial effect and extended the ham shelf-life.