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A nanoliquid chromatographic method for the stereoisomer separation of some flavanone aglycones and 7-O-glycosides has been proposed employing a C18 capillary column and a chiral mobile-phase additive such as cyclodextrin. The chiral separation of eriodictyol, naringenin, and hesperitin was obtained by addition of carboxymethyl-?-cyclodextrin to the mobile phase, whereas eriocitrin, naringin, narirutin, and hesperidin diastereoisomers were resolved by using sulfobutyl ether-?-cyclodextrin. The influence of the composition of the mobile phase, the length of the capillary column, and the flow rate on the chiral recognition were investigated. At optimum conditions, baseline separation for the selected aglycones and glycosylated forms were achieved with a mobile phase consisting of 50 mM sodium acetate buffer pH 3 and 30% methanol containing 20 mM of carboxymethyl-?-cyclodextrin and 10 mM of sulfobutyl ether-?-cyclodextrin, respectively. Precision, linearity, and sensitivity of the method were tested. Limits of detection and quantification for the studied flavanone glycosides were in the range 1.3-2.5 and 7.5-12.5 µg/mL, respectively. The method was used for the determination of the diastereomeric composition of the flavanone-7-O-glycosides in Citrus juices after solid-phase extraction procedure.

Juices from nine new late-season triploid mandarins (Tania-46 (1), Tania-47 (2), Omet (3), Albir (4), Tania-48 (5), Tania-43 (6), Tania-44 (7), Coral (8), and Matiz (9), and from their parents were analyzed for mainly internal quality attributes, vitamin C, total phenolics, flavonoids, phenolic, and organic acids. Antioxidant activity was measured by three methods, the DPPH free radical-scavenging assay, ferric reducing antioxidant power (FRAP) test, and ABTS analysis. All the new hybrids exhibited high internal and nutritional quality which may be considerate rich sources of phytochemicals. Among the nine varieties, Tania-48 hybrid was shown to be the richest in vitamin C, flavanones (hesperidin, eriocitrin, and neoeriocitrin), polymethoxyflavones, and malic and succinic acids. Furthermore, the juice of this new triploid hybrid displayed high antioxidant capacity which may make it important for human diet as a source of health-promoting components. On the other hand, Tania-44, Tania-48, and Tania-43 fruit juices exhibited greater content of eriocitrin and neoeriocitrin than the others.

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of an aqueous extract of Citrus limon (L.) Osbeck (lemon extract) when used as a sensory additive in feed for all animal species. The FEEDAP Panel concluded that the additive under assessment is safe for all animal species up to the maximum proposed use levels of 1,000 mg/kg complete feed and 250 mg/kg water for drinking. No concerns for consumers were identified following the use of lemon extract up to the highest safe level in feed. The additive should be considered a skin and eye irritant, and a potential corrosive. The use of the extract in animal feed under the proposed conditions was not expected to pose a risk for the environment. Lemon extract was recognised to flavour food. Since its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.

Lemon fruits are well-known for their economic, nutrition and health values. In this study, the maturity degree, phenolic compounds and antioxidant capacity of Eureka lemon [Citrus limon (L.) Burm. f.] fruits harvested at different months of the year were investigated. We found that the fruits harvested in November outperformed others in terms of weight, total sugar and soluble solid content (SSC). The ρ-coumaric acid, ferulic acid, eriocitrin and hesperidin were the predominant phenolic compounds in lemon fruits. The highest total phenolic content (TPC, 3.49 ± 0.05 mg GAE g−1 FW), total flavonoid content (TFC, 1.46 ± 0.05 mg RE g−1 FW), sum of individual phenolic acids content (269.36 μg g−1 FW) and their antioxidant potency composite (APC) index (100.00%) were found in the pulps of April fruits. The maximum of sum of individual flavonoids content (3098.42 μg g−1 FW) exhibited in August. For the peels, the highest TFC (6.35 ± 0.24 mg RE g−1 FW) and APC (95.14%) appeared in April fruits, while the highest TPC (7.96 ± 0.17 mg GAE g−1 FW) and sum of individual flavonoids content (9003.91 μg g−1 FW) occurred in the August. However, the maximum of sum of individual phenolic acids content (769.28 μg g−1 FW) was detected in June fruits. We also found that soluble solid content (SSC) of the pulps of lemon fruits were negatively correlated with their TPC and APC. TPC also decreased with the increase in SSC of peels. Most importantly, our study indicated that the contents of phenolic compounds and antioxidant activity of lemon fruits varied significantly with their maturity degrees depending on different harvest time, and this information is essential for a better use of different lemons fruits resources.

The intake of hesperidin-rich sources, mostly found in orange juice, can decrease cardiometabolic risk, potentially linked to the gut microbial phase-II hesperetin derivatives. However, the low hesperidin solubility hampers its bioavailability and microbial metabolism, yielding a high inter-individual variability (high vs. low-producers) that prevents consistent health-related evidence. Contrarily, the human metabolism of (lemon) eriocitrin is hardly known. We hypothesize that the higher solubility of (lemon) eriocitrin vs. (orange) hesperidin might yield more bioavailable metabolites than hesperidin. A randomized-crossover human pharmacokinetic study (n = 16) compared the bioavailability and metabolism of flavanones from lemon and orange extracts and postprandial changes in oxidative, inflammatory, and metabolic markers after a high-fat-high-sugars meal. A total of 17 phase-II flavanone-derived metabolites were identified. No significant biomarker changes were observed. Plasma and urinary concentrations of all metabolites, including hesperetin metabolites, were higher after lemon extract intake. Total plasma metabolites showed significantly mean lower Tmax (6.0 ± 0.4 vs. 8.0 ± 0.5 h) and higher Cmax and AUC values after lemon extract intake. We provide new insights on hesperetin-eriodictyol interconversion and naringenin formation from hesperidin in humans. Our results suggest that regular consumption of a soluble and eco-friendly eriocitrin-rich lemon extract could provide a circulating concentration metabolites threshold to exert health benefits, even in the so-called low-producers.

Following the analysis of terpenes present in new lemon and grapefruit “IntegroPectin” pectins obtained via the hydrodynamic cavitation of industrial lemon and grapefruit processing waste, the HPLC‐MS analysis of flavonoid and other phenolic compounds reveals the presence of eriocitrin, naringin, hesperidin and kaempferol typical of the respective citrus fruits. The pectic fibers rich in rhamnogalacturonan‐I regions act as chemical sponges adsorbing and concentrating at their outer surface highly bioactive citrus flavonoids and terpenes. These findings, together with the unique molecular structure of these new whole citrus pectins, provide preliminary insight into the broad‐scope biological activity of these new biomaterials. Numerous new biomedical applications are anticipated, including likely use in the prevention and treatment of microbial infections and neurodegenerative disease., Molecular synergy in action, IntegroPectin! The pectic fibers rich in rhamnogalacturonan‐I regions of lemon and grapefruit “IntegroPectin” pectins obtained via the hydrodynamic cavitation of industrial lemon and grapefruit processing waste, adsorb and concentrate at their outer surface highly bioactive citrus flavonoids and terpenes. Flavonoid compounds include eriocitrin, naringin, hesperidin and kaempferol typical of the respective citrus fruits.

Recently, several studies have highlighted the role of Citrus flavanones in counteracting oxidative stress and inflammatory response in bowel diseases. The aim of study was to identify the most promising Citrus flavanones by a preliminary antioxidant and anti-inflammatory screening by in vitro cell-free assays, and then to mix the most powerful ones in equimolar ratio in order to investigate a potential synergistic activity. The obtained flavanones mix (FM) was then subjected to in vitro simulated digestion to evaluate the availability of the parent compounds at the intestinal level. Finally, the anti-inflammatory activity was investigated on a Caco-2 cell-based model stimulated with interleukin (IL)-1&beta, FM showed stronger antioxidant and anti-inflammatory activity with respect to the single flavanones, demonstrating the occurrence of synergistic activity. The LC-DAD-ESI-MS/MS analysis of gastric and duodenal digested FM (DFM) showed that all compounds remained unchanged at the end of digestion. As proof, a superimposable behavior was observed between FM and DFM in the anti-inflammatory assay carried out on Caco-2 cells. Indeed, it was observed that both FM and DFM decreased the IL-6, IL-8, and nitric oxide (NO) release similarly to the reference anti-inflammatory drug dexamethasone.

The present study aimed to develop a strategy involving quantitative analysis of multicomponents by single marker in combination with high-performance liquid chromatography fingerprint qualitative analysis for performing the quality control of Aurantii Fructus. The content of 12 components (eriocitrin, neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, meranzin, poncirin, naringenin, nobiletin, tangeretin, and auraptene) in samples was determined using reliable relative correction factors that were obtained using naringin as an internal reference standard. The new method demonstrated good applicability, and no significant differences were observed between the external standard method and the new method as determined by calculating standard method difference. Qualitative evaluation of samples was conducted using similarity analysis, hierarchical cluster analysis, and quality fluctuation analysis. Chromatographic fingerprint data were divided into three groups by similarity and hierarchical cluster analyses, and seven components may have a more significant impact on the quality of Aurantii Fructus in quality fluctuation analysis. Overall, the study suggests that the qualitative and quantitative analyses of multicomponents using quantitative analysis of multicomponents by single marker combined with chromatographic fingerprinting can be considered good quality criteria for performing quality control and providing technical support for the further pharmacological and pharmaceutical research of Aurantii Fructus.

Citrus fruits are known for their phytochemical constituents with antioxidant activity. Seven cultivars of citrus fruits were evaluated for ascorbic acid, total phenolics, total flavonoids and total carotenoids (expressed as β-carotene µg mL-1) as well as determining the presence of flavanones. We also assessed the reduction potential via free radical, DPPH•, of fruit juice and extracts of carotenoids and flavanones after isolation. Lemon contained the highest content of ascorbic acid (237.0±14.72 mg AA 100 mL-1) and the lowest content of total phenolics (453.8±28.27 mg gallic acid 10 mL-1). Ponkan tangerine obtained significantly the highest content of total carotenoids (7.665±1.290 mg β-carotene mL-1) and of total flavonoids (128.5±16.95 mg rutin mL-1). The EC50 was greater for 'Murcott' tangor. Of the five different types of flavanones evaluated in this study (eriocitrin, naringin, hesperidin, neohesperidin and poncirin), only hesperidin was present in all the fruits.

Changes in contents of sugars, organic acids, limonoids, phenolics contents, and antioxidant capacities of lemon slices dried at different temperatures were evaluated. Air drying (AD) promoted losses of sugars, citric acid, ascorbic acid, extractable phenolics (EPs), and non-extractable phenolics (NEPs), while it introduced an increase in limonoids. Phenolics of lemon were mainly presented in their extractable form. Hesperidin and eriocitrin were the main EPs; protocatechuic acid and poncirin were the predominant NEPs. The decrease in extractable phenolic acid, EP, and NEP content in lemon is lower at low drying temperatures, while the increase in non-extractable phenolic acid content is higher at high drying temperatures. The antioxidant capacity of EP was higher than that of NEP. Phenolics contributed to antioxidant capacities of lemon slices, and flavonoids were the main contributors among phenolics. Considering limonoids contents and the high levels of EP, NEP, and antioxidant capacities, AD at 60 °C could be an appreciate treatment for dehydrating lemon slices.

In this contribution, the influence of Pulsed Electric Fields (PEF) of different intensities (3–9 kV/cm and 0–300 μs) on the extraction of Total Phenols from lemon peel residues by pressing was investigated. According to the cellular disintegration index, the optimum treatment time for the increase in permeability was determined as 30 pulses of 30 μs. It was determined that the effect of PEF was independent of lemon residue size. The effectiveness of pressing-assisted extraction was evaluated by measuring the Total Phenol Content (TPC), the real antioxidant capacity and the concentrations of the main lemon polyphenols, the flavonones hesperidin and eriocitrin. The variables studied in the extraction were time, pressure applied and intensity of the electric fields. This study concludes that electric field intensity of 7 kV/cm increased the efficiency of polyphenol extraction by 300%, giving maximum values of 84 mg of hesperidin in 100 g FW and 176 mg of eriocitrin in 100 g FW. Thus, it was concluded that PEF provides a new methodology to improve polyphenol extraction with a non-thermal, environment-friendly technology, and this represents a method for increasing economic benefits of industrial processes.

The objective of this study was to provide more essential data about the bioactive, aromatic volatile composition and sensory properties of lemon seed oils to possibly establish new application areas of this unexplored new oil. Furthermore, cold pressing and hexane extraction were compared. Catechin, eriocitrin, rutin, naringin, naringenin, hesperidin, neohesperidin and kaempherol as flavonoids, and gallic, syringic, tr-ferulic, rosmaniric and tr-2-hydrocinnamic acids as phenolic acids were quantified in the oils. Naringin, gallic and syringic acids were significantly higher in the cold-pressed sample. Around 30 different aromatic volatiles were identified in both samples, and, for the majority, the concentrations were higher in the cold-pressed sample. It was observed that lemon seed oil is very aromatic, mostly characterized by citrus, herbal, terpenic, woody, and floral aroma descriptors. A panel evaluated the oils for sensory properties with 13 different definition terms (clarity, lemon peel, roasted, raw vegetable, grassy, bitter, astringent, waxy, nutty, fatty, spicy and throat-catching). The oil was defined as very bitter, astringent, spicy and throat-catching. In conclusion, lemon seed oil was found unsuitable for direct edible use, but might be preferable for its unique aroma and bioactive components for functional food, pharmaceutical and cosmetic applications.

Bioactive Phenols-loaded chitosan nanoparticles (PL-CNps) were developed by ionic gelation from Persian lemon (Citrus latifolia) waste (PLW) and chitosan nanoparticles. Response Surface Methodology (RSM) was used to determine the optimal Ultrasound-Assisted Extraction (UAE) conditions for the total phenolic compounds (TPC) recovery from PLW (58.13 mg GAE/g dw), evaluating the ethanol concentration, extraction time, amplitude, and solid/liquid ratio. Eight compounds expressed as mg/g dry weight (dw) were identified by ultra-performance liquid chromatography coupled photo diode array (UPLC-PDA) analysis: eriocitrin (20.71 &plusmn, 0.09), diosmin (18.59 &plusmn, 0.13), hesperidin (7.30 &plusmn, 0.04), sinapic acid (3.67 &plusmn, 0.04), catechin (2.92 &plusmn, 0.05), coumaric acid (2.86 &plusmn, 0.01), neohesperidin (1.63 &plusmn, 0.00), and naringenin (0.44 &plusmn, 0.00). The PL-CNps presented size of 232.7 nm, polydispersity index of 0.182, Z potential of &minus, 3.8 mV, and encapsulation efficiency of 81.16%. The results indicated that a synergic effect between phenolic compounds from PLW and chitosan nanoparticles was observed in antioxidant and antibacterial activity, according to Limpel&rsquo, s equation. Such results indicate that PLW in such bioprocesses shows excellent potential as substrates for the production of value-added compounds with a special application for the food industry.

So far, there is no report on the quality evaluation of lemonade available in the market. In this study, a sample preparation method was developed for the determination of flavonoid glycosides by ultra-performance liquid chromatography&ndash, mass spectrometry (UPLC-MS) based on vortex-assisted dispersive liquid-liquid microextraction. First, potential flavonoids in lemonade were scanned and identified by ultra-performance liquid chromatography&ndash, time of flight mass spectrometry (UPLC-TOF/MS). Five flavonoid glycosides were identified as eriocitrin, narirutin, hesperidin, rutin, and diosmin according to the molecular formula provided by TOF/MS and subsequent confirmation of the authentic standard. Then, an ultra-performance liquid chromatography&ndash, triple quadrupole mass spectrometry (UPLC-QqQ/MS) method was developed to determine these five flavonoid glycosides in lemonade. The results showed that the content of rutin in some lemonade was unreasonably high. We suspected that many illegal manufacturers achieved the goal of low-cost counterfeiting lemonade by adding rutin. This suggested that it was necessary for relevant departments of the state to make stricter regulations on the quality standards of lemonade beverages.

Citrus fruits are a rich source of bio-functional compounds with various and well-proven health properties. We focused our attention on an ancient Mediterranean species, Citrus lumia Risso. The aim of this work was to investigate the polyphenol content and biological activities of C. lumia albedo extract by cell-free and cell-based assays. Fifteen polyphenols were quantified by LC-DAD-FLD analysis (flavonoids 89.34% and phenolic acids 10.66%) with eriocitrin and hesperidin as major components (52.81% and 31.31%, respectively). These results were corroborated also by micromorphological observations, which showed clusters of needle-shaped crystals of hesperidin highlighted by TBO staining. C. lumia albedo extract revealed marked antioxidant and free radical scavenging properties, and a significant cytoprotective activity on t-BOOH-treated lymphocytes. Results indicate that C. lumia albedo extract could be exploited as an antioxidant source, suggesting the use of albedo, currently considered a by-product, as a valuable raw material for nutraceutical employments.

Obesity and oxidative damage are two important risk factors associated closely with metabolic syndrome. Utilization of functional food ingredients is considered as a feasible way to tackle these challenges. In the present study, eight representative species of citrus peel extracts (CPEs) were evaluated and compared for their flavonoid profiles, antioxidant activities, and pancreatic lipase (PL) inhibitory capacities and mechanisms. Results indicated that hesperidin, naringin, neohesperidin, narirutin and eriocitrin were the five major flavonoids in CPEs, among which hesperidin was the main active PL inhibitor. Moreover, hesperidin could interact with PL by hydrogen bonds and van der Waals forces, and the interaction would not obviously change the secondary structure of PL. Overall, ponkan peel extract, having the strongest overall antioxidant activity, the highest content of hesperidin and total phenolic compounds among all tested CPEs, is a promising natural ingredient to scavenge free radicals and manage obesity.

The lime industry is generating more waste due to the increasing demand of juice. In this study, extractable and non-extractable phenolics in the Gallega lime waste, dried at different temperatures were determined and their antioxidant capacities were evaluated using DPPH (2,2-diphenyl-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6/sulphonic acid) and, ORAC (oxygen radical absorbance capacity) methods. The amount of non-extractable phenolics measured in lime waste dried at 60, 90, and 120 °C were 38.4%, 39.2%, and 33.5%, respectively higher, compared to the amount of extractable phenolics. Dried lime waste is rich in extractable and non-extractable hesperidin (213.87 and 181.32 mg/g, respectively), and eriocitrin (55.22 and 97.24 mg/g, respectively) and non-extractable gallic acid (42.45 μg/g,). The antioxidant capacities of extractable and non-extractable phenolics were from highest to lowest: ABTS > ORAC > DPPH and ABTS > DPPH > ORAC, respectively. The information reported here may encourage lime industry operators to re-evaluate their by-products, extending the application of lime fruits and reducing waste.

The flavanones hesperidin, eriocitrin and eriodictyol were investigated for their prevention of the oxidative stress and systemic inflammation caused by high-fat diet in C57BL/6J mice. The mice received a standard diet (9.5% kcal from fat), high-fat diet (45% kcal from fat) or high-fat diet supplemented with hesperidin, eriocitrin or eriodictyol for a period of four weeks. Hesperidin, eriocitrin and eriodictyol increased the serum total antioxidant capacity, and restrained the elevation of interleukin-6 (IL-6), macrophage chemoattractant protein-1 (MCP-1), and C-reactive protein (hs-CRP). In addition, the liver TBARS levels and spleen mass (g per kg body weight) were lower for the flavanone-treated mice than in the unsupplemented mice. Eriocitrin and eriodictyol reduced TBARS levels in the blood serum, and hesperidin and eriodictyol also reduced fat accumulation and liver damage. The results showed that hesperidin, eriocitrin and eriodictyol had protective effects against inflammation and oxidative stress caused by high-fat diet in mice, and may therefore prevent metabolic alterations associated with the development of cardiovascular diseases in other animals.

Increasing evidence of the beneficial properties of polyphenols has led to a need for compositional data of foods and beverages to enable calculation of their dietary intake. The South African herbal tea, honeybush, produced from several Cyclopia species, has developed a global market during the past two decades. This herbal tea contributes to the dietary intake of compounds belonging to the xanthone, benzophenone, dihydrochalcone, flavanone and flavone sub-classes. The phenolic composition of C. genistoides, C. subternata, C. maculata and C. longifolia infusions at ‘cup-of-tea’ strength was determined using validated species-specific high-performance liquid chromatography with diode array detection (HPLC-DAD) methods. Major compounds present in one or more species included mangiferin, isomangiferin, vicenin-2, scolymoside, eriocitrin, hesperidin, iriflophenone-3-C-glucoside, iriflophenone-3-C-glucoside-4-O-glucoside, phloretin-3′,5′-di-C-glucoside and 3-hydroxyphloretin-3′,5′-di-C-hexoside. Phenolic content data showed large intra- and inter-species variation. Infusions of C. subternata, having the lowest levels of the xanthones, contained on average 0.3 mg mangiferin and 0.4 mg isomangiferin per 200 mL serving. Infusions of C. genistoides, having the highest levels of the xanthones, contained on average 20.4 and 7.1 mg (per serving) of mangiferin and isomangiferin, respectively. Consumption of C. genistoides infusions will also contribute the most to the dietary intake of benzophenones, with iriflophenone-3-C-glucoside-4-O-glucoside as its major benzophenone (6.4 mg per serving).

In this work, a cascade approach to obtain different valuable fractions from lemon peels waste was optimised using microwave-assisted processes. Microwave-assisted hydrodistillation (MAHD) with a Clevenger apparatus was firstly used to obtain the lemon essential oil (LEO). The remaining residue was then submitted to microwave-assisted extraction (MAE) to extract the lemon pigment (LP). A Box&ndash, Behnken design was used to evaluate the influence of ethanol concentration, temperature and time in LP extraction in terms of extraction yield and colour intensity. Optimal extraction conditions for LP were 80% (v/v) ethanol, 80 &deg, C and 50 min, with a liquid-to-solid ratio of 1:10. The obtained yields for LEO and LP were around 2 wt.% and 6 wt.%, respectively. The composition of LEO was analysed by gas chromatography with flame ionisation detection (GC-FID), and limonene (65.082 wt.%), &beta, pinene (14.517 wt.%) and &gamma, terpinene (9.743 wt.%) were mainly identified. LP was purified by using different Amberlite adsorption resins (XAD4, XAD7HP and XAD16N), showing XAD16N the best adsorption capacity. Enrichment factors of 4.3, 4.5 and 5.0 were found for eriocitrin, diosmin and hesperidin, respectively, which were detected as the main components in LP by ultra-high-performance liquid chromatography&ndash, diode array detector&ndash, tandem mass spectrometry (UPLC-DAD-MS) analysis, with final concentrations of 4.728 wt.%, 7.368 wt.% and 2.658 wt.%, respectively. Successful antimicrobial capacity against Escherichia coli and Staphylococcus aureus was obtained for LEO. The results from this work showed the potential of applying a cascading approach based on microwave-assisted processes to valorise lemon wastes, obtaining natural pigments and antimicrobials to be applied in food, cosmetic and polymer industries.

Made available in DSpace on 2018-12-11T16:51:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-04-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The aim of this study was to develop and validate an HPLC-DAD method to evaluate the phenolic compounds profile of organic and conventional Pêra-Rio orange juice. The proposed method was validated for 10 flavonoids and 6 phenolic acids. A wide linear range (0.01–223.4 μg·g− 1), good accuracy (79.5–129.2%) and precision (CV ≤ 3.8%), low limits of detection (1–22 ng·g− 1) and quantification (0.7–7.4 μg), and overall ruggedness were attained. Good recovery was achieved for all phenolic compounds after extraction and cleanup. The method was applied to organic and conventional Pêra-Rio orange juices from beginning, middle and end of the 2016 harvest. Flavones rutin, nobiletin and tangeretin, and flavanones hesperidin, narirutin and eriocitrin were identified and quantified in all organic and conventional juices. Identity was confirmed by mass spectrometry. Nineteen non-identified phenolic compounds were quantified based on DAD spectra characteristic of the chemical class: 7 cinnamic acid derivatives, 6 flavanones and 6 flavones. The phenolic compounds profile of Pêra-Rio orange juices changed during the harvest; levels increased in organic orange juices, and decreased or were about the same in conventional orange juices. Phenolic compounds levels were higher in organic (0.5–1143.7 mg·100 g− 1) than in conventional orange juices (0.5–689.7 mg·100 g− 1). PCA differentiated organic from conventional FS and NFC juices, and conventional FCOJ from conventional FS and NFC juices, thus differentiating cultivation and processing. Department of Food and Nutrition School of Pharmaceutical Science São Paulo State University UNESP Department of Food and Nutrition School of Pharmaceutical Science São Paulo State University UNESP FAPESP: 2013/10138-0 FAPESP: 2014/23303-1

Flowers of Citrus plants are used as mild sedatives and for the treatment of insomnia in traditional medicines. In Japan, tea made from the flowers of Satsuma mandarin is consumed as healthy drink. Hesperidin (1), hesperetin (2), rutin (3), quercetin (4), nicotiflorin (5), eriocitrin (6), narirutin (7), phenylethyl glucoside (8) and unshuoside A (9) were isolated from the MeOH extract of fresh flowers. Structure elucidation of these compounds was performed on the basis of NMR spectroscopic data. Among them, rutin (3), quercetin (4) and eriocitrin (6) showed potent free radical scavenging activity, whereas hesperetin (2) and quercetin (4) showed potent α-glucosidase inhibitory activity.

The complex-free kinetic method (CFKM), a novel variant of the kinetic method, was developed for direct quantification of isomeric O-diglycosyl flavonoids using electrospray ionization tandem mass spectrometry. Direct isomeric quantification of O-diglycosyl flavonoids by the developed CFKM was presented for the first time. The detailed fragmentation behaviours of these flavonoids, which are tightly related to their structures, were also proposed with the help of molecular modelling. The calibration curves enable the quantification of these isomeric pairs by the linear relationship of lnR vs. molar fractions of hesperidin and eriocitrin with good accuracy and good correlation coefficient(r2). High isomeric selectivity was achieved with Riso = 6.5349 and Riso = 3.5257 for hesperidin/neohesperidin and eriocitrin/neoeriocitrin, respectively by our developed CFKM. The CFKM represents a promising and practical mass spectrometric method for direct stereochemical analysis of flavonoid compounds as well as other multiple chiral center compounds.

Citrus aurantium L. var. amara Engl. (CAVA) was traditionally used as a digestant or expectorant in China. Crude polyphenols (CAVAP-W) extracted from blossoms of CAVA were mainly composed of eriocitrin/neoeriocitrin, eriocitrin/neoeriocitrin, rhoifolin, hesperidin, naringin, rutin, veronicastroside, neohesperidin, and hesperetin by LC-MS analysis. CAVAP-W showed significant anticomplement and anti-inflammatory effects. Due to the close relationship between anticomplement and anti-inflammatory activity, the anti-inflammatory effect was further investigated and the results showed that CAVAP-W significantly suppressed production of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and mRNA expression of inducible nitric oxide synthase (iNOS), IL-6, TNF-α, IL-1β, and cyclooxygenase-2 (COX-2) in lipopolysaccharides-stimulated RAW264.7 cells. Furthermore, CAVAP-W inhibited mitogen-activated protein kinase (MAPK) phosphorylation and NF-κB activation through suppressing nuclear translocation of nuclear factor-kappa B (NF-κB) P65, degradation and phosphorylation of IκBα, phosphorylation of IκKα/ß, c-Jun N-terminal kinase (JNK), and P38, and activation of COX-2, thereby exerting the anti-inflammatory effects.

Phenolic composition and antioxidant capacity of different fruit part including peel, pulp, juice, whole fruit and seed from five lemon cultivars (Feiminailao, Cuningmeng Limeng, Pangdelusaningmeng, Beijingningmeng) were investigated. Caffeic acid (9.31-741.4 μg/g FW) and chlorogenic acid (2.7-527.5 μg/g FW) were the dominant phenolic acid in fruit tested, Pangdelusaningmeng (PD) and Limeng peels with the highest contents, respectively. Hesperidin was the predominant flavanone (10.27-3315 μg/g FW), Cuningmeng (CN) peels with the highest level. PD peels had rich rutin, CN seeds had rich eriocitrin. Nobiletin was the main polymethoxylated flavonoids identified, PD with the highest level. CN peels contained rich tangeretin. Overall, peels and whole fruit had significantly higher level of phenolics than other fruit parts, and seeds were good source of flavonoids. PD and CN not only contained higher level of phenolic, but also presented higher antioxidant capacity than other cultivars tested, and are of great value for human nutrition.

Lemon processing generates thousands of tons of residues that can be preserved as flours by thermal treatment to obtain phenolic compounds with beneficial bioactivities. In this study, the effect of different drying temperatures (40, 50, 60, 70, 80, 90, 100 and 110 &deg, C) on the Total Phenolic Content (TPC), antioxidant and antimicrobial activities of phenolic compounds present in Citrus. lemon (L.) Burn f waste was determined. Identification and quantification of phenolic compounds were also performed by UPLC-PDA and UPLC-ESI-MS analysis. Eriocitrin (19.79&ndash, 27.29 mg g&minus, 1 DW) and hesperidin (7.63&ndash, 9.10 mg g&minus, 1 DW) were detected as the major phenolic compounds in the flours by UPLC-PDA and confirmed by UPLC-ESI-MS. Antimicrobial activity determined by Minimum Inhibitory Concentration (MIC) against Salmonella typhimurium, Escherichia coli and Staphylococcus aureus was observed. Accordingly, a stable functional flour as a source of bioactive phenolic compounds obtained from lemon residues at 50 &deg, C may be produced as a value-added product useful in various industrial sectors.

Membrane separation has brought about a significant change in the food processing industry because it could operate separation at low temperature without a reduction of nutrients and bioactive compounds. Citrus limon L. Burm. cv Femminello comune juice, an Italian IGP (Protected Geographical Indication) product, was subjected to the ultrafiltation (UF) process using a cellulose acetate membrane, with a cut-off of 100 kDa, subjected to different transmembrane pressures (TMP, 05&ndash, 1.5 bar). Untreated and ultra-filtrated (UF) juices were investigated for physicochemical parameters including pH, titratable acidity (TA), total soluble solids (TSS) and ascorbic acid content. Total phenols (TPC) and flavonoids (TFC) contents were also determined. Rutin, hesperidin, eriocitrin, and neohesperidin were selected as markers and quantified by HPLC. Antioxidant potential was investigated by using DPPH, ABTS, and FRAP tests. RACI was used to identify the sample with highest antioxidant potential. The hypoglycemic activity was examined using carbohydrates hydrolyzing enzymes assay. The application of increasing pressures across the membrane led to a reduction in TSS without causing a loss of bioactive compounds in terms of TPC and TFC. UF juice obtained with TMP of 1.5 bar (J3) showed a significant amount of eriocitrin and hesperidin with concentrations of 15.8 and 10.5 mg/100 mL, respectively. This sample showed the highest antioxidant potential and exhibited a promising &alpha, amylase and &alpha, glucosidase inhibitory activity with IC50 values of 31.1 and 35.3 mg/mL, respectively. Collectively our results support the use of cellulose acetate membrane to obtain an ultra-filtered juice with significant health potential.

Cyclopia subternata plants are traditionally used for the production of the South African herbal tea, honeybush, and recently as aqueous extracts for the food industry. A C. subternata aqueous extract and mangiferin (a major constituent) are known to have anti-diabetic properties. Variation in phenolic composition and antioxidant capacity is expected due to cultivation largely from seedlings, having implications for extract standardization and quality control. Aqueous extracts from 64 seedlings of the same age, cultivated under the same environmental conditions, were analyzed for individual compound content, total polyphenol (TP) content and total antioxidant capacity (TAC) in a number of assays. An HPLC method was developed and validated to allow quantification of xanthones (mangiferin, isomangiferin), flavanones (hesperidin, eriocitrin), a flavone (scolymoside), a benzophenone (iriflophenone-3-C-β-glucoside) and dihydrochalcones (phloretin-3',5'-di-C-β-glucoside, 3-hydroxyphloretin-3',5'-di-C-hexoside). Additional compounds were tentatively identified using mass spectrometric detection, with the presence of the 3-hydroxyphloretin-glycoside, an iriflophenone-di-O,C-hexoside, an eriodictyol-di-C-hexoside and vicenin-2 being demonstrated for the first time. Variability of the individual phenolic compound contents was generally higher than that of the TP content and TAC values. Among the phenolic compounds, scolymoside, hesperidin and iriflophenone-3-C-β-glucoside contents were the most variable. A combination of the measured parameters could be useful in product standardization by providing a basis for specifying minimum levels.

Economically motivated adulteration (EMA) of lemon juice was detected by LC-MS and principal component analysis (PCA). Twenty-two batches of freshly squeezed lemon juice were adulterated by adding an aqueous solution containing 5% citric acid and 6% sucrose to pure lemon juice to obtain 30%, 60% and 100% lemon juice samples. Their total titratable acidities, °Brix and pH values were measured, and then all the lemon juice samples were subject to LC-MS analysis. Concentrations of hesperidin and eriocitrin, major phenolic components of lemon juice, were quantified. The PCA score plots for LC-MS datasets were used to preview the classification of pure and adulterated lemon juice samples. Results showed a large inherent variability in the chemical properties among 22 batches of 100% lemon juice samples. Measurement or quantitation of one or several chemical properties (targeted detection) was not effective in detecting lemon juice adulteration. However, by using the LC-MS datasets, including both chromatographic and mass spectrometric information, 100% lemon juice samples were successfully differentiated from adulterated samples containing 30% lemon juice in the PCA score plot. LC-MS coupled with chemometric analysis can be a complement to existing methods for detecting juice adulteration.

Naturally occurring flavonoids display a plethora of different biological activities, but emerging evidence suggests that this class of compounds may also act as antidepressant agents endowed with multiple mechanisms of action in the central nervous system, increasing central neurotransmission, limiting the reabsorption of bioamines by synaptosomes, and modulating the neuroendocrine and GABAA systems. Due to their presence in foods, food-derived products, and nutraceuticals, we established their role and structure-activity relationships as reversible and competitive human monoamine oxidase (MAO) inhibitors. In addition, molecular modeling studies, which evaluated their modes of MAO inhibition, are presented. These findings could provide pivotal implications in the quest of novel drug-like compounds and for the establishment of harmful drug-dietary supplement interactions commonly reported in the therapy with antidepressant agents.

Analysis of phenolic compounds in Cyclopia spp. (honeybush) is very important because of commercial interest in the plant material as an herbal tea and in extracts for the nutraceutical and cosmeceutical markets. An existing HPLC-DAD method was adapted and proved reproducible as evidenced by good intra- and inter-day precision. The method allows the quantification of several well-known as well as unidentified phenolic compounds. Its suitability for quantification of the major phenolic compounds present in the water extracts of unfermented and fermented Cyclopia subternata, Cyclopia intermedia, Cyclopia genistoides and Cyclopia sessiliflora was evaluated. Known compounds that were identified and quantified include mangiferin (0.1–11.8 g/100 g), isomangiferin (0.1–3.2 g/100 g), eriocitrin (not detected–0.4 g/100 g), hesperidin (0.2–1.2 g/100 g) and scolymoside (not detected–1.8 g/100 g), while narirutin and luteolin were detected in most samples, but could not be quantified due to low concentrations and co-elution. An unidentified compound (traces–4.8 g hesperidin equivalents/100 g), unidentified hydroxycinnamic acid derivative (not detected–0.3 g mangiferin equivalents/100 g), unidentified flavanone (not detected–2.0 g hesperidin equivalents/100 g) and an eriodictyol-glycoside (not detected–0.5 g hesperidin equivalents/100 g) could also be quantified. Large variation was observed within a sample series of the same extract type due to the nature of the plant material. Qualitative and quantitative differences were observed between species, while “fermentation”, a high-temperature process involving non-enzymatic oxidation, decreased the content of most phenolic compounds. Results using DAD as the only detection method should be handled with care, as the tentative identification of compounds 9 and 10, based on retention time and UV–Vis spectrum, could not be confirmed using liquid chromatography–electrospray ionisation-mass spectrometry.

In order to develop a database for flavanones, the dominant flavonoid class in the genus citrus, the relevant scientific literature on flavonoids in grapefruit, lemons, and limes was searched, abstracted, documented, standardized by taxons and units (mg/100 g) and examined for quality. Values for eight flavanones (didymin, eriocitrin, hesperidin, naringin, narirutin, neoeriocitrin, neohesperidin, poncirin) are presented. Grapefruit had a total flavanone content (summed means) of 27 mg/100 g as aglycones and a distinct flavanone profile, dominated by naringin. White grapefruit varieties tended to be slightly but not significantly higher in total flavanones than pink and red varieties. For lemons, total flavanones (summed means) were 26 mg/100 g and for limes 17 mg/100 g. The flavanone profiles of both lemons and limes were dominated by hesperidin and eriocitrin.

Flavanones constitute the majority of flavonoids in citrus fruits such as sweet (Citrus sinensis) and sour oranges (C. aurantium) and their near relatives—tangerines/mandarins (C. reticulata), tangors and tangelos. The relevant chemical analytic literature was searched, abstracted, documented, standardized, examined for quality, enumerated, and summarized in a database for these citrus flavanones: hesperidin, naringin, narirutin, eriocitrin, neohesperidin, didymin, neoeriocitrin, and poncirin. Sour oranges had a distinct flavanone profile dominated by naringin and neohesperidin, and were highest in total flavanones (summed means) (48 mg/100 g aglycones). Total flavanones (summed means) in sweet oranges, tangerines, and tangors were similar (∼20 mg/100 g), and hesperidin and narirutin dominated the flavanone profiles for these three fruits. Total flavanones (summed means) in tangelos (30 mg/100) were midway between sour and sweet oranges and the tangelo flavanone profile exhibited characteristics of both species. The database provides information on several varieties of citrus and eight flavanone compounds.

Polyphenolic compounds such as eriocitrin, luteolin-7-O-rutinoside, diosmin, hesperidin, narirutin, isorhoifolin, rosmarinic and caffeic acids were identified in an aqueous extract (Ex) obtained from peppermint leaves (Menthae × piperitae folium). The content of polyphenols in Ex was as follows: eriocitrin 38%, luteolin-7-O-rutinoside 3.5%, hesperidin 2.9%, diosmin 0.8%, isorhoifolin 0.6%, narirutin 0.3%, rosmarinic acid 3.7% and caffeic acid 0.05%. The strongest antiradical activity (determined as DPPH• scavenging features) was observed for luteolin-7-O-rutinoside, eriocitrin and rosmarinic acid. Caffeic acid and hesperidin revealed a lower antiradical activity while isorhoifolin, narirutin and diosmin showed the lowest activity. The strongest anti-H2O2 activity was observed for eriocitrin, a little lower for rosmarinic acid. The rate of hydrogen peroxide scavenging activity displayed by luteolin-7-O-rutinoside and caffeic acid was lower than that of rosmarinic acids. Hesperidin appeared to be a very weak scavenger of hydrogen peroxide. Almost no anti-H2O2 activity was demonstrated for diosmin, narirutin and isorhoifolin. Among examined flavonoids, the strongest antiradical and anti-H2O2 activity was shown for compounds with two hydroxy groups bound to the Bring in ortho position in relation to each other. Replacement of one hydroxy group in the Bring with a methoxy group or removing one hydroxy group leads to decrease of antiradical and anti-H2O2 activity of flavonoids. Our results suggest that eriocitrin is a powerful peppermint antioxidant and a free radical scavenger.