Effects of Mentha longifolia L. essential oil and Lactobacillus casei on the organoleptic properties and on the growth of Staphylococcus aureus and Listeria monocytogenes during manufacturing,ripening and storage of Iranian white‐brined cheese

This research evaluated the effects of Mentha longifolia L. essential oil (EO) in concentrations 0, 50, 150 and 300 ppm and Lactobacillus casei (10⁸–10⁹ CFU/mL) on the growth of Staphylococcus aureus and Listeria monocytogenes during the manufacturing, ripening and storage of Iranian white‐brined cheese. The growth of the two pathogens was significantly reduced (P < 0.01) by both EO concentrations ≥50 ppm and probiotic and their combination in the standard manufacturing and storage process conditions of the cheese. Furthermore, the treatment containing 150 ppm of this EO combined with probiotic had a favourable inhibitory effect on the growth of two pathogenic micro‐organisms and also was the most appropriate treatment in sensory assessment. The synergistic effects of the above‐mentioned concentration level between the essential oil and probiotic were significant compared to other treatments, including essential oil and probiotic only. Thus, a lower concentration of this EO can be used when it is combined with this probiotic.     

干燥方法对欧薄荷精油化学成分及生物活性的影响

干燥方法是影响精油组成成分和品质的主要因素之一,为研究干燥方法对欧薄荷精油产率、组成成分及生物活性的影响,以阴干、晒干、40℃烘干3种不同方法对采自新疆阿克苏地区的生长期野生欧薄荷地上部分进行干燥处理.以新鲜未经干燥处理的欧薄荷为对照,水蒸气蒸馏法提取欧薄荷精油,研究了干燥方法对精油产率的影响.通过气相色谱-四极杆-飞...     

The effects of ratio of cow's milk to soymilk,probiotic strain and fruit concentrate on qualitative aspects of probiotic flavoured fermented drinks

The effects of proportion of cow's milk to soymilk (100:0, 75:25, 50:50, 25:75, 0:100), probiotic bacteria (Lactobacillus acidophilus LA‐5 or Lactobacillus casei L‐01) and natural fruit concentrates (strawberry, apricot, peach and pear) on quality characteristics of soy‐based probiotic drink were investigated. The parameters were analysed at the end of fermentation and during 21 days of storage at 5 ^°C. The highest viability was observed when the equal proportion of cow's milk and soymilk and L. casei was used (50:50‐CY). During chilled storage, the flavouring apricot had the highest stimulatory effect on the survival of L. casei in 50:50 treatment. In general, the treatment 50:50‐CY was realised as the best one overall.     

调味香料留兰香精油的研究进展

留兰香精油是一种重要的调味香料,具有清新、凉爽、香甜的气味,主要用于糖果、酒类等食品的加香。另外,也应用于化妆品、药品等其它领域。文章综述了近年来留兰香精油的提取、提纯、化学成分及应用,并对留兰香精油的前景作了展望。     

Effects of Penicillium roqueforti and whey cheese on gross composition,microbiology and proteolysis of mould‐ripened Civil cheese during ripening

Four different types of mould‐ripened Civil cheese were manufactured. A defined (nontoxigenic) strain of a Penicillium roqueforti (SC 509) was used as the secondary starter with and without addition of the whey cheese (Lor); in parallel, secondary starter‐free counterparts were manufactured. Chemical composition, microbiology and proteolysis were studied during the ripening. The incorporation of whey cheese in the manufacture of mould‐ripened Civil cheese altered the gross composition and adversely affected proteolysis in the cheeses. The inoculated P. roqueforti moulds appeared to grow slowly on those cheeses, and little proteolysis was evident in all cheese treatments during the first 90 days of ripening. However, sharp increases in the soluble nitrogen fractions were observed in all cheeses after 90 days. Microbiological analysis showed that the microbial counts in the cheeses were at high levels at the beginning of ripening, while their counts decreased approximately 1–2 log cfu/g towards the end of ripening.     

Effects of drying methods on the quality and quantity of the essential oil of Mentha longifolia L. subsp. Capensis

The effects of various methods of drying on the content and chemical quality of the essential oil of Mentha longifolia was studied. The most prominent component in both the air-dried and sun-dried leaf oils was menthone (47.9% and 38.3%, respectively), while oven-dried leaf oil had limonene as the major compound (40.8%), whereas pulegone was the major compound from the original fresh leaf oil. Menthone and pulegone were not detected in the oven-dried leaf oil. The essential oil underwent significant chemical transformation in its monoterpenoids when the leaves were dried by the three different methods. Due to the significant reduction of the potentially harmful pulegone and menthone by oven-drying, it is suggested that this herb should be oven-dried or cooked before consumption in order to reduce toxicity.     

Composition of the essential oil of Daucus gingidium L. ssp. gingidium

The essential oils obtained from leaves and fruits of Daucus gingidium ssp. gingidium have been studied. The main constituents of the essential oil from the leaves were sabinene (26.8%), α-pinene (10.8%), germacrene D (6.9%) and limonene (5.7%). Sabinene (60.6%) was the main compound identified in the essential oil of the fruits, followed by α-pinene (12.2%) and 4-terpineol (5.4%). Furthermore, qualitative and quantitative considerations about differences with literature data on Daucus carota have been made in order to confirm the species status of D. gingidium.     

Comparison of microwave-assisted hydrodistillation withthe traditional hydrodistillation method in the extractionof essential oils from Thymus vulgaris L.

Microwave-assisted hydrodistillation (MAHD) is an advanced hydrodistillation (HD) technique utilizing a microwave oven in the extraction process. MAHD of essential oils from the aerial parts (tops) of Thymus vulgaris L. (common thyme) was studied and the results were compared with those of the conventional HD in terms of extraction time, extraction yield/efficiency, chemical composition, quality of the essential oils and cost of the operation. MAHD was superior in terms of saving energy and extraction time (75 min, compared to 4 h in HD). Scanning electron microscopy (SEM) of thyme leaves undergone HD and MAHD provided evidences as to a sudden rupture of essential oil glands with MAHD. Gas chromatography–mass spectrometry analysis of the extracted essential oils indicated that the use of microwave irradiation did not adversely influence the composition of the essential oils. MAHD was found to be a green technology.     

Effects of Zataria multiflora boiss essential oil,ultraviolet radiation and their combination on Listeria monocytogenes biofilm in a simulated industrial model

The objective of this study was to investigate the inhibitory effect of Zataria multiflora boiss essential oils (ZEOs), ultraviolet (UV) radiation and their combination against Listeria monocytogenes biofilm in a simulated industrial model (SIM). The effect of minimal inhibitory concentration (MIC) and sub‐MIC concentration of ZEOs, different contact time of UV and their combination was evaluated in a SIM on 6‐ and 12‐day‐old L. monocytogenes biofilm. In a SIM, 0.3% ZEOs were adequate to completely eliminate 6‐ and 12‐day‐old biofilm grown on stainless steel coupons. The population of viable L. monocytogenes biofilm cells under a 15‐ to 45‐min contact time of UV treatment declined significantly at 6‐ and 12‐day‐old biofilm. The combined effect of ZEO and UV showed antagonist effects. These findings indicated that in the single use, ZEO and UV revealed a suitable antilisteria biofilm activity, while combining them is not a promising method to remove listeria biofilms from stainless steel surfaces.     

Efficacy of Acorus calamus L. essential oil as a safe plant‐based antioxidant,Aflatoxin B1 suppressor and broad spectrum antimicrobial against food‐infesting fungi

The study explores the efficacy of Acorus calamus L. essential oil (EO) as a safe plant‐based broad spectrum antifungal, antiaflatoxin, antioxidant food additive. The oil completely inhibited the growth and toxin production of the toxigenic strain of Aspergillus flavus at 0.4 and 0.25 μL mL^?1, respectively. EO exhibited pronounced antifungal activity against sixteen food‐infesting fungal species at 0.5 μL mL^?1. The EO showed strong antioxidant efficacy (IC₅₀ 1.06 μL mL^?1) and nonphytotoxic nature on germination of chickpea seeds. The EO was found nonmammalian toxic showing high LD₅₀ (4877.4 μL kg^?1) for mice (oral, acute). The chemical profile of EO was determined through GC and GC–MS analysis. The findings strengthen the possibility of A. calamus EO as a plant‐based food additive in view of its favourable safety profile, antioxidant and antiaflatoxigenic efficacy and broad spectrum antimicrobial activity against food‐infesting fungi.     

Interference of Origanum vulgare L. essential oil on the growth and some physiological characteristics of Staphylococcus aureus strains isolated from foods

The aim of this study was to investigate the chemical composition of Origanum vulgare L. essential oil, the inhibitory effect of the oil on the cell viability of Staphylococcus aureus strains isolated from foods, and the influence of sub-inhibitory concentrations of the oil on some physiological attributes of these strains. GC-MS analysis showed that carvacrol (57.71%) was the most prevalent compound in the oil, followed by p-cymene (10.91%), γ-terpinene (7.18%), terpinen-4-ol (6.68%) and thymol (3.83%). The results showed that O. vulgare essential oil at 0.03, 0.6 and 0.12 μL mL⁻¹ inhibited the cell viability of Staph. aureus. At 0.12 μL mL⁻¹ the oil caused cidal effect with decrease ≥3 log cycles of the initial inoculum after 15 min of exposure. Sub-inhibitory concentrations (0.03 and 0.015 μL mL⁻¹) of the oil suppressed some physiological attributes of the Staph. aureus strains such as coagulase, lipase and salt tolerance. The oil interfered on the microbial metabolic activity in a dose-dependent manner. O. vulgare essential oil could be a novel antimicrobial with capability to suppress some physiological characteristics, in addition to inhibit the growth and survival of pathogen bacteria in foods, particularly Staph. aureus.     

Chemical composition and inhibitory effect of essential oil and organic extracts of Cestrum nocturnum L. on food-borne pathogens

In this study, we examined the chemical compositions of essential oil and tested the efficacy of oil and organic extracts of Cestrum nocturnum L. against food-borne pathogens. The chemical compositions of the oil was analysed by gas chromatography-mass spectrometry (GC-MS). Forty-seven compounds representing 93.28% of the total oil were identified. The oil [5 μL of 1:5 (v/v) dilution of oil with methanol] and organic extracts of hexane, chloroform, ethyl acetate and methanol (300 μg per disc) of C. nocturnum displayed a great potential of antibacterial activity against Staphylococcus aureus (ATCC 6538 and KCTC 1916), Listeria monocytogenes (ATCC 19166 and ATCC 15313), Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa KCTC 2004, Salmonella typhimurium KCTC 2515 and Escherichia coli ATCC 8739. Also the oil had strong detrimental effect on the viable count of the tested bacteria. The results obtained from this study may contribute to the development of new antimicrobial agents with potential applications in food industries as natural preservatives to control food-borne pathogens.     

The effect of nisin and garlic (Allium sativum L.) essential oil separately and in combination on the growth of Listeria monocytogenes

In the present study, the anti-listerial activity of the nisin and garlic (Allium sativum L.) essential oils (GO) alone and in combination was investigated at different temperatures (20 and 30 °C), pH (6.8, 5.6 and 4.8) and NaCl concentrations (0, 0.5, 2.5 and 4.5 g/100 mL). Minimum inhibitory concentrations (MICs) against Listeria monocytogenes were assessed for the nisin and essential oil. Furthermore, for combinations of the antimicrobials, the Differences in Population (DP) method were used to determine their effect. Both essential oil and nisin possessed considerable antimicrobial effects on the microorganism. The MICs for nisin and GO were 12.5 IU/mL and 100 μg/mL, respectively. Regardless of NaCl concentration and temperature, the anti-listerial activity of both GO and nisin was strongly influenced by pH. Moreover, at the same temperature, and regardless of pH value, the growth of the organism was also affected by increasing NaCl concentration. In combination, the DP was related strongly to the agent’s concentration and media pH. Meanwhile, among all combined systems, the effect of the combination (EC) of nisin with GO at 30 °C, pH 5.6 and 0 g/100 mL NaCl, showed significant anti-listerial activity (P ≤ 0.05).     

Effects of foliar fertilization and arbuscular mycorrhizal colonization on Salvia officinalis L. growth,antioxidant capacity,and essential oil composition

BACKGROUND: The effect of foliar fertilization and Glomus intraradices inoculation on the growth, qualitative and quantitative pattern of essential oil in Salvia officinalis was determined. Sage plants were grown in a glass house on a soil/sand mixture (w/w = 3:1). Agroleaf^® total, N:P:K = 20:20:20 + microelements, was used at the whole vegetative growth stage as a 0.3% solution. Inoculation with Glomus intraradices was done at the sowing stage. RESULTS: Application of foliar fertilization and/or mycorrhizal colonization improved dry biomass accumulation and increased the content of antioxidant metabolites (ascorbate and reduced glutathione). Applied treatments lowered the activities of the antioxidants enzymes catalase, ascorbate peroxidase and superoxide dismutase, while guaiacol peroxidase increased. The relative quantity of essential oil pattern was also altered as a result of the applied treatments. Combined application (FF + Gi) significantly promoted 1,8‐cineole and α‐thujone, mycorrhizal colonization enhanced bornyl acetate, 1,8‐cineole, α‐ and β‐thujones, while foliar fertilization increased bornyl acetate and camphor. The favorable effect of root colonization by Glomus intraradices was determined both on quantitative and qualitative pattern of sage essential oil. CONCLUSION: We conclude that inoculation with Glomus intraradices resulted in improved essential oil yield and quality, while combined application of foliar fertilizer and mycorrhizal fungi predominantly enhanced shoot biomass accumulation. Copyright © 2010 Society of Chemical Industry     

玳玳花精油的成分及其抗氧化活性研究

以玳玳花精油为试验材料,利用气相色谱-质谱联用技术对其进行组分分析,测定了其理化特征,采用DPPH、ABTS、羟基自由基的清除率及总抗氧化能力来评价其抗氧化活性。结果表明,玳玳花精油是一种具有玳玳花特征香气的琥珀色澄清液体,共分离出41种成分,占总成分95.80%,其中包括13种醇类化合物(59.34%),16种萜烯类化合物(22.82%),4种烷烃类化合物、3种酸、3种酯类、1种吲哚和1种酚类化合物。玳玳花精油的总抗氧化能力在4 mg/mL时超过VC;对DPPH自由基清除能力较弱,精油浓度为50 mg/mL时清除率为73.51%;对ABTS和羟基自由基清除能力较好,10mg/mL时清除率分别达到85.63%和94.87%;综上,玳玳花精油具有显著的抗氧化作用且与浓度呈正相关。     

包装对巴旦杏仁油脂氧化和抗氧化能力的影响

以经过加工的去壳巴旦杏仁为材料,研究不同包装材料对其酸价、过氧化值、TBA值、总酚含量、VE含量和DPPH自由基清除能力的影响,以期了解包装材料对巴旦杏仁贮藏过程中油脂氧化和抗氧化能力的影响.结果表明:巴旦杏仁在贮藏过程中发生油脂的氧化酸败,表现为过氧化值和酸价上升,TBA值增加;采用EVOH共挤膜包装可显著降低其贮藏过程中酸价和过氧化值的增加幅度,抑制TBA值增加,减轻脂肪的氧化酸败;并保持较高的自身抗氧化物质总酚和VE含量,减缓DPPH自由基清除能力的下降,相对较好地维持组织的抗氧化能力.     

Assessment of chemically characterised Rosmarinus officinalis L. essential oil and its major compounds as plant‐based preservative in food system based on their efficacy against food‐borne moulds and aflatoxin secretion and as antioxidant

The study explores antifungal, anti‐aflatoxigenic and antioxidant efficacy of Rosmarinus officinalis essential oil (ROEO) and its major compounds. In addition, the mode of action of ROEO and its practical efficacy as preservative have been assessed. GC‐MS analysis of ROEO identified 16 compounds; α‐pinene, 1,8‐cineole and camphor being the major compounds. The minimum concentration for inhibition of growth and aflatoxin B₁ secretion against A. flavus (LHP‐6) was found to be 1.5, >5.0, 4.0 and 3.0 μL mL^?1 and 1.25, >5.0, 3.5 and 3.0 μL mL^?1 for ROEO, α‐pinene, 1,8‐cineole and camphor, respectively. The IC₅₀ value through DPPH analysis and percentage inhibition of linoleic acid peroxidation of ROEO were 0.042 μL mL^?1 and 71.05%, respectively. The targeted site of antifungal action of ROEO was confirmed as plasma membrane through ergosterol measurement and TEM analysis. Moreover, ROEO significantly protected Piper nigrum fruits against mould infestation upto 6 months in in vivo trial.     

Analysis and the potential applications of essential oil and leaf extracts of <Emphasis Type="Italic">Silene armeria</Emphasis> L. to control food spoilage and food-borne pathogens

The aim of this study was to analyze the chemical composition of essential oil isolated from the floral parts of Silene armeria L. by hydrodistillation and to test the efficacy of essential oil and the various leaf extracts against a diverse range of microorganisms comprising food spoilage and food-borne pathogenic bacteria. The chemical composition of essential oil was analyzed by the GC–MS. It was determined that 28 compounds, which represented 89.03% of total oil, were present in the oil. The oil contained mainly methylamine (21.48%), β-butene (17.97%), α-butene (46.40%), coumaran (0.22%), eugenol (0.21%), α-humulene (0.07%), farnesol (0.05%) and linalool (0.12%). The essential oil (5 μl/ml, corresponding to 1,000 ppm/disc) and various leaf extracts of methanol, ethyl acetate, chloroform and hexane (7.5 μl/ml, corresponding to 1,500 ppm/disc) exhibited promising antibacterial effect against Bacillus subtilis ATCC6633, Listeria monocytogenes ATCC19166, Staphylococcus aureus KCTC1916, S. aureus ATCC6538, Pseudomonas aeruginosa KCTC2004, Salmonella typhimurium KCTC2515, Salmonella enteritidis KCTC2021, Escherichia coli O157-Human, E. coli ATCC8739, E. coli O57:H7 ATCC43888 and Enterobacter aerogenes KCTC2190. The zones of inhibition of different concentrations of essential oil and the various leaf extracts against the tested bacterial pathogens were found in the range of 10–19 and 7–13 mm, respectively, along with their respective MIC values ranging from 125 to 1,000 and 250–2,000 μg/ml. Also, the essential oil had a potential effect on the viable count of the tested bacteria. The results of this study suggest that the essential oil and leaf extracts derived from S. armeria could be used for the development of novel types of antibacterial agents to control food spoilage and food-borne pathogens.     

Inclusion interactions and molecular microcapsule of <Emphasis Type="Italic">Salvia sclarea</Emphasis> L. essential oil with β-cyclodextrin derivatives

The inclusion interactions of β-cyclodextrin (β-CD), heptakis (2,6-di-methyl)-β-CD (DM-β-CD), mono[2-O-(2-hydroxyethyl)]-β-CD (2-HE-β-CD), and mono[2-O-(2-hydro-xypropyl)]-β-CD (2-HP-β-CD) with Salvia sclarea L. essential oil (SEO) were investigated by spectrofluorimetry, and the various factors affecting the inclusion process were examined in detail. At the same time, the formation constants at different temperatures and the thermodynamic parameters (ΔH, ΔS and ΔG) were calculated. The molecular microcapsule of SEO with β-CD was prepared by the method of saturated aqueous solution, and the stability of the microcapsule was determined. The results suggest that the stoichiometry of the SEO–CDs inclusion complexes was 1:1 (molar ratio), the formation constants of CDs with SEO decreased with the increasing of temperature, and the order that the capability associated with SEO was β-CD > DM-β-CD > 2-HE-β-CD > 2-HP-β-CD. The thermodynamic measurements showed that the inclusion process was an exothermic and enthalpy-driven process accompanied with a negative entropic contribution, and Van der Waals force plays an importance role in the process. In addition, the content of SEO in the microcapsule was 0.14 g/g and its stabilization was obviously improved.