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Concept: Lemon


This work addresses the inactivation achieved with Escherichia coli O157:H7 and Listeria monocytogenes EGD-e by combined processes of high hydrostatic pressure (HHP) and essential oils (EOs) or their chemical constituents (CCs). HHP treatments (175-400MPa for 20min) were combined with 200μL/L of each EO (Citrus sinensis L., Citrus lemon L., Citrus reticulata L., Thymus algeriensis L., Eucalyptus globulus L., Rosmarinus officinalis L., Mentha pulegium L., Juniperus phoenicea L., and Cyperus longus L.) or each CC ((+)-limonene, α-pinene, β-pinene, p-cymene, thymol, carvacrol, borneol, linalool, terpinen-4-ol, 1,8-cineole, α-terpinyl acetate, camphor, and (+)-pulegone) in buffer of pH 4.0 or 7.0. The tested combinations achieved different degrees of inactivation, the most effective being (+)-limonene, carvacrol, C. reticulata L. EO, T. algeriensis L. EO and C. sinensis L. EO which were capable of inactivating about 4-5 log(10) cycles of the initial cell populations in combination with HHP, and therefore showed outstanding synergistic effects. (+)-Limonene was also capable of inactivating 5 log(10) cycles of the initial E. coli O157:H7 population in combination with HHP (300MPa for 20min) in orange and apple juices, and a direct relationship was established between the inactivation degree caused by the combined process with (+)-limonene and the occurrence of sublethal injury after the HHP treatment. This work shows the potential of EOs and CCs in the inactivation of foodborne pathogens in combined treatments with HHP, and proposes their possible use in liquid food such as fruit juices.

Concepts: Bacteria, Escherichia coli, Citrus, Escherichia coli O157:H7, Orange, Foodborne illness, Essential oil, Lemon


Leprosis is one of the most serious citrus plant diseases. Leprosis-affected plants, especially sweet orange [Citrus sinensis (L.) Osbeck], which is the most widely cultivated citrus fruit worldwide, show reduced photosynthetic capacity and severe defoliation. The aim was to evaluate the relationship between the Brevipalpus phoenicis (Geijskes) vector mite and citrus leprosis disease in Pera sweet orange plants grafted on different rootstocks. Data were analysed using numerical classification and conventional statistical analysis (ANOVA).

Concepts: Citrus, Fruit, Orange, Grapefruit, Tangerine, Lemon, Citron, Rutaceae


Melissa officinalis L. (lemon balm) is normally consumed as an infusion and presents therapeutic properties, such as sedative, carminative and antispasmodic, also being included in some pharmaceutical preparations. The phenolic profiles of different samples of lemon balm, prepared as infusions, were evaluated by HPLC-DAD-ESI/MS. The profiles were compared in order to understand the differences between cultivated, in vitro cultured and commercial (bags and granulated) samples. All the samples showed a similar phenolic profile, presenting differences only in the quantities found of each compound. Rosmarinic acid was the most abundant compound, being higher in commercial samples, especially in tea bag sample (55.68mg/g of infusion) and lower in in vitro cultured sample (15.46mg/g). Moreover, dimers, trimers and tetramers of caffeic acid were identified and quantified for the first time in lemon balm. Only one flavonoid, luteolin-3'-O-glucuronide was found in all the samples, ranging from 8.43mg/g in commercial granulate sample to 1.22mg/g in in vitro cultured sample. Overall, cultivated and in vitro cultured samples presented the lowest amounts of phenolic compounds (59.59 and 30.21mg/g, respectively); otherwise, commercial samples showed the highest contents (109.24mg/g for tea bag and 101.03mg/g for granulate sample). The present study shows that infusion of lemon balm can be a source of phenolic compounds, known for their bioactive effects.

Concepts: Tea, Phenols, Essential oil, Lemon, Rosmarinic acid, Aromatherapy, Lemon balm, Melissa


Considering that the determination of authenticity and of the geographical origin of food is a very challenging issue, in this study we studied by means of histological and histochemical analyses the famous Sicilian lemon known as ‘Interdonato Lemon of Messina PGI’. Since the protected geographical indication Interdonato lemon of Messina possesses high organoleptic properties, the composition of the hexane extract of lemon peel was determined by HRGC and HRGC-MS analyses and compared with that of lemon of different cultivars. The results obtained are informative of the oil’s quality and explain the variation of the lemon essential oil composition. Given the fundamental economic implications of any fraud, the aim of this study was to determine a fingerprint able to evaluate the authentication of the geographic origin in such way to prevent frauds in national and international markets.

Concepts: Petroleum, Citrus, Italy, Essential oil, Sicily, Lemon, Geographical indication, Sicilian language


Recently, there has been an increased interest in the effects of essential oils on athletic performances and other physiological effects. This study aimed to assess the effects of Citrus sinensis flower and Mentha spicata leaves essential oils inhalation in two different groups of athlete male students on their exercise performance and lung function.

Concepts: Poaceae, Citrus, Fruit, Plant morphology, Essential oil, Rose, Lemon


The clinical efficacy of standardized essential oils (such as Lavender officinalis), in treating anxiety disorders strongly suggests that these natural products are an important candidate source for new anxiolytic drugs. A systematic review of essential oils, their bioactive constituents, and anxiolytic-like activity is conducted. The essential oil with the best profile is Lavendula angustifolia, which has already been tested in controlled clinical trials with positive results. Citrus aurantium using different routes of administration also showed significant effects in several animal models, and was corroborated by different research groups. Other promising essential oils are Citrus sinensis and bergamot oil, which showed certain clinical anxiolytic actions; along with Achillea wilhemsii, Alpinia zerumbet, Citrus aurantium, and Spiranthera odoratissima, which, like Lavendula angustifolia, appear to exert anxiolytic-like effects without GABA/benzodiazepine activity, thus differing in their mechanisms of action from the benzodiazepines. The anxiolytic activity of 25 compounds commonly found in essential oils is also discussed.

Concepts: Pharmacology, Clinical trial, Citrus, Essential oil, Oil, Lemon, Bergamot orange, Bitter orange


The chemical composition of volatile oils from 22 genotypes of Citrus and related genera was poorly differentiated, but chemometric techniques have clarified the relationships between the 22 genotypes, and allowed us to understand their resistance to D. citri. The most convincing similarities include the synthesis of (Z)-β-ocimene and (E)-caryophyllene for all 11 genotypes of group A. Genotypes of group B are not uniformly characterized by essential oil compounds. When stimulated with odor sources of 22 genotypes in a Y-tube olfactometer D. citri preferentially entered the arm containing the volatile oils of Murraya paniculata, confirming orange jasmine as its best host. C. reticulata × C. sinensis was the least preferred genotype, and is characterized by the presence of phytol, (Z)-β-ocimene, and β-elemene, which were not found in the most preferred genotype. We speculate that these three compounds may act as a repellent, making these oils less attractive to D. citri.

Concepts: Citrus, Orange, Essential oil, Oil, Oils, Lemon, Rutaceae, Murraya paniculata


Human norovirus is a dominant cause of acute gastroenteritis around the world. Several norovirus disinfectants label citric acid as an active ingredient. In this study, we showed that norovirus virus-like particles (VLPs) treated with citrate buffer caused the particles to alter their morphology, including increased diameters associated with a new ring-like structure. We also found that epitopes on the protruding (P) domain on these particles were more readily accessible to antibodies after the citrate treatment. These results suggested that citrate had a direct effect on the norovirus particles. Using X-ray crystallography, we showed that the P domain bound citrate from lemon juice and a disinfectant containing citric acid. Importantly, citrate binds at the histo-blood group antigen binding pocket, which are attachment factors for norovirus infections. Taken together, these new findings suggested that it might be possible to treat/reduce norovirus infections with citrate, although further studies are needed.

Concepts: Immune system, Antibody, Acid, Citric acid, Diarrhea, Gastroenteritis, Norovirus, Lemon


Lemon balm (Melissa officinalis) has been used historically and contemporarily as a modulator of mood and cognitive function, with anxiolytic effects following administration of capsules, coated tablets and topical application. Following a pilot study with lemon balm extract administered as a water based drink, which confirmed absorption of rosmarinic acid effects on mood and cognitive function, we conducted two similar double-blind, placebo-controlled, crossover studies. These evaluated the mood and cognitive effects of a standardised M. officinalis preparation administered in palatable forms in a beverage and in yoghurt. In each study a cohort of healthy young adults' self-rated aspects of mood were measured before and after a multi-tasking framework (MTF) administered one hour and three hours following one of four treatments. Both active lemon balm treatments were generally associated with improvements in mood and/or cognitive performance, though there were some behavioral “costs” at other doses and these effects depended to some degree on the delivery matrix.

Concepts: Lemon, Rosmarinic acid, Lemon balm, Melissa


Oranges are an important nutritional source for human health and have immense economic value. Here we present a comprehensive analysis of the draft genome of sweet orange (Citrus sinensis). The assembled sequence covers 87.3% of the estimated orange genome, which is relatively compact, as 20% is composed of repetitive elements. We predicted 29,445 protein-coding genes, half of which are in the heterozygous state. With additional sequencing of two more citrus species and comparative analyses of seven citrus genomes, we present evidence to suggest that sweet orange originated from a backcross hybrid between pummelo and mandarin. Focused analysis on genes involved in vitamin C metabolism showed that GalUR, encoding the rate-limiting enzyme of the galacturonate pathway, is significantly upregulated in orange fruit, and the recent expansion of this gene family may provide a genomic basis. This draft genome represents a valuable resource for understanding and improving many important citrus traits in the future.

Concepts: Gene, Genetics, Citrus, Fruit, Orange, Grapefruit, Tangerine, Lemon