Strong Bitter Taste Research Articles

Major Bitter-Tasting Compounds from the Dichloromethane Fraction of Bitter Gourd (Fruit of Momordica charantia L.) Extract and Their Precursors.

The unripe fruit of the plant Momordica charantia L., commonly known as bitter gourd or bitter melon, is a popular vegetable and medical herb in many parts of the world and is characterized by its strong bitter taste. In our endeavor to decode its bitter taste, the dichloromethane fraction of 75% methanol extract of bitter gourd was found to be intensely bitter. Combining sensory analysis-guided fractionation and newly developed comparative high-pressure liquid chromatography (HPLC) analysis-guided purification led to the isolation of five known compounds including momordicoside L (1), (23E)-3β-O-malonyl-7β,25-dihydroxycucurbita-5,23-dien-19-al (2), 3-O-β-d-allopyranosyl-7β,25-dihydroxycucurbita-5,23(E)-dien-19-al (3), momordicine IV (5), and charantoside B (6) and three new compounds 3-O-β-d-3-ketoglucopyranosly-7β,25-dihydroxycucurbita-5,23(E)-dien-19-al (4), 6'-O-malonylmomordicoside L (7), and 6'-O-malonylmomordicine IV (8) from bitter gourd. Sensory analysis revealed compounds 3-8 had strong bitter taste with their bitter taste recognition thresholds in the range between 3.6 (4) and 13.6 ppm (6) in 3% ethanol. UPLC-MS/MS quantification showed that their concentration in bitter gourd ranged from 16.5 ± 1.3 mg/kg (4) to 214.8 ± 14.0 mg/kg (6) on a dry weight basis. Calculation of the dose-over-threshold (DoT) factor showed that momordicine IV (5) and charantoside B (6) should be considered as bitter principles of bitter gourd. In addition, the study also demonstrated the ubiquity of the isomerization reaction in the side chain of cucurbitane-type triterpenoids. Many isolated compounds were the isomerized products of their natural precursors, and these precursors should be the primary bitterness contributors of fresh fruits. In addition, comparative HPLC analysis-guided purification could be a practical approach for the fast isolation of acid-labile precursors.

Ultra-high-performance liquid chromatography-mass spectrometry combined with molecular docking and molecular dynamics simulation reveals the source of bitterness in the traditional Chinese medicine formula Runchang-Tongbian.

The Runchang-Tongbian (RCTB) formula is a traditional Chinese medicine (TCM) formula consisting of four herbs, namely Cannabis Fructus (Huomaren), Rehmanniae Radix (Dihuang), Atractylodis Macrocephalae Rhizoma (Baizhu), and Aurantii Fructus (Zhiqiao). It is widely used clinically because of its beneficial effect on constipation. However, its strong bitter taste leads to poor patient compliance. The bitter components of TCM compounds are complex and numerous, and inhibiting the bitter taste of TCM has become a major clinical challenge. Here, we use ultra-high-performance liquid chromatography coupled with mass spectrometry (UPLC-MS) and high-resolution mass spectrometry to identify 59 chemical components in the TCM compound RCTB formula. Next, four bitter taste receptors, TAS2R39, TAS2R14, TAS2R7, and TAS2R5, which are tightly bound to the compounds in RCTB, were screened as molecular docking receptors using the BitterX database. The top-three-scoring receptor-small-molecule complexes for each of the four receptors were selected for molecular dynamics simulation. Finally, seven bitter components were identified, namely six flavonoids (rhoifolin, naringin, poncirin, diosmin, didymin, and narirutin) and one phenylpropanoid (purpureaside C). Thus, we proposed a new method for identifying the bitter components in TCM compounds, which provides a theoretical reference for bitter taste inhibition in TCM compounds.

Momordica charantia as a Prospective Raw Material for Health and Craft Products

Topicality of this study is determined by the prospect of expanding the assortment of health and craft products due to the use of fruits and leaves of a plant with high biological activity, namely, Momordica charantia. The aim of the article is to evaluate the prospects of using fruits and leaves of different Momordica charantia varieties in the production of health and craft materials. Research methods of studying the main quality indicators of raw materials and finished grout were standard, such as organoleptic, physicochemical and chromatographic ones. Results. The set organoleptic analysis of Momordica charantia fruits showed a strong bitter taste of all the species of this plant. This leads to a limited range of this fruit use, especially in food products with a bitter taste, such as dark chocolate, coffee, etc. All the studied varieties, large fruited ones, despite their rather big mass, have a high content of ascorbic acid, saponins and phenols. The active grout acidity of different varieties of momordica is in the range of 6.3–7.2, and the redox potential is 55–74 mW. Conclusions. The conducted research indicates that due to the presence of a high content of biologically active substances (ascorbic acid, phenols, saponins and mineral compounds), momordica is a promising raw material for the creation of health and preventive health products. The study of the large-fruited species of Momordica charantia showed the presence of the same components as in traditional momordica varieties. Thereby, it becomes possible to fully use them in culinary and food products.

Development and Characterization of New Green Propolis Extract Formulations as Promising Candidates to Substitute for Green Propolis Hydroalcoholic Extract.

The technologies used to produce the different dosage forms of propolis can selectively affect the original propolis compounds and their biological activities. The most common type of propolis extract is hydroethanolic. However, there is considerable demand for ethanol-free propolis presentations, including stable powder forms. Three propolis extract formulations were developed and investigated for chemical composition and antioxidant and antimicrobial activity: polar propolis fraction (PPF), soluble propolis dry extract (PSDE), and microencapsulated propolis extract (MPE). The different technologies used to produce the extracts affected their physical appearance, chemical profile, and biological activity. PPF was found to contain mainly caffeic and p-Coumaric acid, while PSDE and MPE showed a chemical fingerprint closer to the original green propolis hydroalcoholic extract used. MPE, a fine powder (40% propolis in gum Arabic), was readily dispersible in water, and had less intense flavor, taste, and color than PSDE. PSDE, a fine powder (80% propolis) in maltodextrin as a carrier, was perfectly water-soluble and could be used in liquid formulations; it is transparent and has a strong bitter taste. PPF, a purified solid with large amounts of caffeic and p-Coumaric acids, had the highest antioxidant and antimicrobial activity, and therefore merits further study. PSDE and MPE had antioxidant and antimicrobial properties and could be used in products tailored to specific needs.

The effect of drying, cell disruption and storage on the sensory properties of Nannochloropsis sp.

Adding microalgae into food could strongly influence the flavor of the final product which is the key factor for consumer acceptation. To assist food processors in the development of tasteful food products containing microalgae, it is necessary to understand the impact of processing and storage on the flavor of freshly harvested microalgae biomass. In this study, the effect of commonly used drying techniques (freeze-drying, spray drying and thin-layer oven drying) and cell disruption (high pressure homogenization) on the sensory quality of fresh Nannochloropsis sp. biomass was investigated. Furthermore, the impact of storage on the flavor properties of intact (non-disrupted) and disrupted Nannochloropsis paste was examined. Sensory evaluation by a trained panel indicated that the flavor of Nannochloropsis was not affected by freeze-drying. Whereas thin-layer oven drying at 60 °C resulted in a strong bitter taste and a musty odor. This odor is positively correlated with volatile organic compounds (VOCs) including Strecker aldehydes that arise from the Strecker degradation in the course of the Maillard reaction. Spray drying reduced the odor intensity and grassy odor of Nannochloropsis which could be attributed to the loss of several VOCs including esters, saturated alcohols and dimethyl sulfide. Furthermore, cell disruption of Nannochloropsis using high pressure homogenization resulted in intense grassy and fish oil odors features due to high amounts of fatty acid-derived unsaturated aldehydes, ketones and alcohols. Finally, dark storage of fresh intact and disrupted Nannochloropsis paste at ambient temperature strongly impacts the volatile profile due to the rapid formation of several VOCs, which negatively impact the palatability of the Nannochloropsis biomass. Our results provide the basis to be applied in downstream food processing of harvested Nannochloropsis biomass in order to maintain or optimize the flavor properties for specific food products.

Development of an HPLC-MS/MS Method for the Determination of Alkaloids in Lupins

Lupin alkaloids (LAs) represent a class of toxic secondary metabolites in plants, in particular in Lupinus spp.; they are produced as a defense mechanism due to their strong bitter taste and are very dangerous for human and animals. In this work, a sensitive and reliable high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analytical method for the identification and quantification of thirteen lupin alkaloids was developed and validated according to FDA guidelines. Efficient extraction and clean-up steps, carried out by solid-phase extraction, were finely tuned on the basis of the characteristics of the analytes and lupin samples, providing good selectivity with minimized matrix interference. The effectiveness of the method was proven by the satisfactory recovery values obtained for most of the analytes and a matrix effect ≤23% for all tested levels. In addition, a sensitive and reliable determination of the target compounds was obtained; LOQs were between 1 and 25 µg Kg-1, i.e., below the requested maximum levels (<200 mg Kg-1). The method was applied to evaluate the LAs profile in different batches of raw L. albus L. samples, varying in size and across farming treatments.

Anti-HIV drugs lopinavir/ritonavir activate bitter taste receptors.

Lopinavir and ritonavir (LPV/r) are the primary anti-human immunodeficiency virus (HIV) drugs recommended by the World Health Organization for treating children aged 3 years and above who are infected with the HIV. These drugs are typically available in liquid formulations to aid in dosing for children who cannot swallow tablets. However, the strong bitter taste associated with these medications can be a significant obstacle to adherence, particularly in young children, and can jeopardize the effectiveness of the treatment. Studies have shown that poor palatability can affect the survival rate of HIV-infected children. Therefore, developing more child-friendly protease inhibitor formulations, particularly those with improved taste, is critical for children with HIV. The molecular mechanism by which lopinavir and ritonavir activate bitter taste receptors, TAS2Rs, is not yet clear. In this study, we utilized a calcium mobilization assay to characterize the activation of bitter taste receptors by lopinavir and ritonavir. We discovered that lopinavir activates TAS2R1 and TAS2R13, while ritonavir activates TAS2R1, TAS2R8, TAS2R13, and TAS2R14. The development of bitter taste blockers that target these receptors with a safe profile would be highly desirable in eliminating the unpleasant bitter taste of these anti-HIV drugs.

Detection of Bitterness in Vitamins Is Mediated by the Activation of Bitter Taste Receptors.

Vitamins are known to generate bitterness, which may contribute to an off-taste or aftertaste for some nutritional supplements. This negative sensation can lead to a reduction in their consumption. Little is known about the bitter taste threshold and taste sensing system for the bitter taste detection of vitamins. To better understand the mechanisms involved in bitterness perception, we combined taste receptor functional assays and sensory analysis. In humans, bitter taste detection is mediated by 25 G-protein-coupled receptors belonging to the TAS2R family. First, we studied the bitterness of thirteen vitamins using a cellular-based functional taste receptor assay. We found four vitamins that can stimulate one or more TAS2Rs. For each positive molecule–receptor combination, we tested seven increasing concentrations to determine the half-maximal effective concentration (EC50) and the cellular bitter taste threshold. Second, we measured the bitter taste detection threshold for four vitamins that exhibit a strong bitter taste using a combination of ascending series and sensory difference tests. A combination of sensory and biological data can provide useful results that explain the perception of vitamin bitterness and its real contribution to the off-taste of nutritional supplements.

Pear polyphenol oxidase enhances theaflavins in green tea soup through the enzymatic oxidation reaction

AbstractPolyphenol oxidase (PPO) is a necessary medium for converting catechins into theaflavins in tea. This study aimed to provide an efficient and cost‐effective method for the purpose of developing a tea beverage rich in four main theaflavins (TFs) by optimizing the key factors affecting the enzymatic oxidation reaction to produce TFs. Autumn green tea (AT) soup was mixed with pear PPO crude enzyme solution and then reacted for different time at varying reaction temperatures, pH, ratios of tea soup to crude enzyme solution, and ratios of tea to water. The content of TFs in tea beverage was monitored by UPLC‐Q‐Orbitrap‐MS/MS to select the optimal process parameters to produce the maximum TFs. The TFs content after the reaction increased 968.49 times compared with that before the reaction. The results showed that the use of the enzymatic oxidation reaction of pear PPO crude enzyme solution to improve the TFs in AT soup was efficient. This method helped regulate the strong bitter and astringent taste sensation in AT, and it is unnecessary to purify the PPO enzyme source. This method is expected to be a breakthrough to use AT to produce high TFs tea beverages in a cost‐effective way with high value.

Total Asymmetric Synthesis and Stereochemical Confirmation of (+)- and (-)-Lyoniresinol and Its Deuterated Analogues.

Lyoniresinol and its derivatives are lignans which have been isolated from a plethora of plant species. In addition to exhibiting a range of interesting biological activities including anticancer, anti-inflammatory, antimicrobial, and others, these compounds have also been discovered in wines and spirits and shown to have gustatory effects in these alcoholic matrices. (+)-Lyoniresinol 1 is reported to impart a strong bitter taste while its enantiomer (-)-lyoniresnol 2 is tasteless. The first total asymmetric synthesis of both natural enantiomers (+)-1 and (-)-2 and their deuterated analogues (D4)-(+)-3 and (D4)-(-)-4 has been achieved, confirming the structure and stereochemistry of the natural products. The synthesized compounds can be utilized as internal standards in stable isotope dilution analysis for improving and optimizing the existing lyoniresinol quantitation methods in the future.

Formulation and Evaluation of Orodispersible Tablets Containing Taste Masked Mirabegron Resinate

The objective of present work was to develop taste masked orodispersible tablets of mirabegron. Mirabegron is beta 3 adrenoceptor agonist used to treat overactive bladder. Overactive bladder (OAB) is defined as a symptom syndrome showing feeling of urgency to urinate, typically accompanied by frequent daytime and nocturnal urination, in the absence of proven infection or other obvious pathology. Over active bladders are generally common in geriatrics. Moreover, this drug has a very strong bitter taste. Frequent dosing requires frequent water intake, which further aggregates the condition of over active bladder and bitter taste of drug affects patient compliance. Hence a need arises to mask the bitter taste for development of an ODT which does not require consuming water with every dosage. In this work, the bitter taste of mirabegron was masked by forming a complex with an ion exchange resin tulsion 344. The drug resin complexation process was optimized for resin activation, drug: resin ratio, soaking time and stirring time. In –vitro release studies revealed complete drug elution from the complex within 10 minutes in pH 1.2 buffer. The taste-masked complex was then formulated into palatable orodispersible tablets using a direct compression approach by use of superdisintegrants to achieve a rapid disintegration. The tablets were evaluated for weight variation, hardness, friability, drug content, wetting time, In- vivo disintegration time and in-vitro dissolution time.

In vitro and in vivo evaluation of taste-masked orodispersible tablets of fluoxetine hydrochloride for the treatment of depression

Aim Fluoxetine (FLX) has become the first-line drug in the pharmacotherapy of patients with depression. However, it has a strong unpleasant bitter taste, leading to the failure to complete the therapy. In this study, FLX is formulated into orodispersible tablets (ODTs) characterized by a fast release with an acceptable taste. Method FLX ODTs were prepared by the complexation of FLX with β-cyclodextrin (β-CD) for taste-masking, using different super disintegrants, namely crospovidone (CP), croscarmellose sodium (Ccs), sodium starch glycolate (SSG), and indion. The FLX powder blend is estimated for pre-and post-compression parameters. The selected tablet formulations based upon drug release at 40 s with acceptable release patterns are investigated for accelerated stability testing and comparative in vivo study with a marketed product. Results It was found that all FLX-powder blends have good flow properties; all the prepared tablets complied with the pharmacopeial requirements for the unity of content, weight, friability, and hardness. Moreover, all the tablets obtained acceptable taste after complexation with β-CD. The order of release of the drug, regarding super disintegrants used, was as in the following descending order: CP > Ccs > SSG > indion. Accelerated stability study of selected formulation F2 and F6 showed that; there were no considerable changes in physical properties, drug content, and percentage drug release. Furthermore, also the in vivo study proved the effectiveness of FLX ODTs as an antidepressant. Conclusion The results obtained showed a promising potential of the prepared FLX ODTs for treating depression effectively.

Comprehensive identification of non-volatile bitter-tasting compounds in Zanthoxylum bungeanum Maxim. by untargeted metabolomics combined with sensory-guided fractionation technique

Zanthoxylum Bungeanum Maxim. is an important seasoning in Chinese cooking, but its bitter taste limits its use by some consumers. In this study, metabolomic analysis based on ultra-high-performance liquid chromatograph–tandem mass spectrometry (UPLC–MS) was used to screen out a vast number of potential non-volatile bitter compounds in Z. bungeanum. Results showed that there were 37 potential bitter compounds in Z. bungeanum, and possible mechanisms underlying its bitter taste were provided. Further, instrumental analyses combined with sensory evaluation were used to identify the key bitter compounds in Gou jiao, a wild variant of Z. Bungeanum with a strong bitter taste. Totally 15 key bitter compounds were identified, most of which have a low bitterness recognition threshold. This study is the first comprehensive identification of non-volatile bitter compounds in Z. bungeanum and provides a basis for future investigations into mitigating bitterness and uncovering how the interaction between different bitter compounds affects taste.

Encapsulation of Momordica Charantia Linn. (bitter gourd) juice by spray dying technique

Momordica Charantia Linn. (Bitter gourd) is a cucurbit, mainly known for its medicinal properties commonly used for its anti-diabetic properties, due to presence of saponins, flavonoids, phenolic and its antioxidant activity. Despite of so many medicinal properties and health benefits, bitter gourd is still treated as an underutilized fruit due to its strong bitter taste. Bitter taste of the bitter gourd can be masked by the means of encapsulation of bitter taste. Hence in the present study, the encapsulation of bitter gourd extract was done by spray drying method to mask the bitter taste. Spray drying process parameters i.e. inlet air temperature, in-feed concentration and maltodextrin to gum acacia ratio in encapsulation material was optimized to get maximum masking of bitter taste of bitter gourd. A solution of 5% (w/v) turmeric powder treatment for 2 h was found to be best pretreatment method for de-bittering of bitter gourd. D-optimal, response surface design optimization of spray drying conditions provided the optimum results at inlet air temperature of 138 °C, in feed concentration of 26% and maltodextrin to gum acacia ratio of 54/46 with process yield of 65.99%, TPC retention of 83.68%, FRAP retention of 86.40%, TSC retention of 86.41%, microencapsulation efficiency of 81.92% and sensory overall acceptability of 7.97.

English

Warbugia ugandensis is among the ten most utilized medicinal plants in East Africa. Stem-bark and leaves are used as remedies for malaria, stomachache, coughs and several skin diseases. Consequently, the plant is endangered because of uncontrolled harvest from the wild and lack of domestication. There is therefore fear of poor quality commercialized products due to lack of quality control mechanisms. The objective of this study was to investigate features of diagnostic value that could be used to confirm its authenticity and purity. Samples in the study were obtained from six different geographical locations in Kenya by random purposive sampling. Macroscopic and microscopic studies of the leaf and stem-bark were done based on a modified method from the American herbal pharmacopoeia. The study revealed over five macroscopic and organoleptic characteristics for W. ugandensis leaf and stem-bark including strong aromatic odor and bitter peppery taste. Major microscopic characteristics of the leaf included anomocytic stoma, oil glands and trichomes. Microscopy of stem-bark revealed scaly outgrowths and parenchyma cells in addition to clusters of simple starch granules. Macroscopic and microscopic features of diagnostic value identified can be used to evaluate the quality of W. ugandensis herbal materials especially for confirmation of purity and authenticity. Key words: Microscopic, macroscopic, Quality, Warbugia ugandensis, herbal.

Denatonium as a bitter taste receptor agonist damages jejunal epithelial cells of yellow-feathered chickens via inducing apoptosis

The sense of bitter taste is critical for chickens to acquire and select feeds. It is important to understand the roles and mechanisms of bitter taste transduction in chickens. Denatonium is extensively used as a bitter taste receptor agonist to activate bitter taste receptors in recent studies. The objective of this study was to investigate the physiological effects and the potential molecular mechanisms of dietary exposure to a strong bitter taste receptor agonist on the jejunal epithelial cells of yellow-feathered chickens. A total of 240 yellow-feathered chickens were divided into four treatments receiving a normal diet (Control), a low-dose denatonium treatment (Control + 5 mg/kg denatonium), a middle-dose denatonium treatment (Control + 20 mg/kg denatonium) and a high-dose denatonium treatment (Control + 100 mg/kg denatonium) for 56 days, respectively. The results showed that dietary denatonium reduced (P < 0.05) the growth performance of chickens. High-dose denatonium damaged the morphology of the jejunal epithelium and decreased (P < 0.05) the activities of Ca2+-ATPase, sucrase and maltase after 56 days of exposure. Meanwhile, high-dose denatonium increased (P < 0.05) mRNA expressions of bitter taste receptors, which resulted in enhanced apoptosis in jejunal epithelial cells after 56 days of exposure. Furthermore, middle-dose and high-dose denatonium exhibited increased (P < 0.05) mRNA level of claudin 2 and decreased (P < 0.05) mRNA level of occludin after 28 days of exposure. Only high-dose denatonium decreased (P < 0.05) mRNA level of occludin after 56 days of exposure. In conclusion, denatonium manifested deleterious effects on the jejunum of chickens in a dose–effect manner via damaging the morphology of the jejunal epithelium, and inducing apoptosis associated with bitter taste receptors. Our data suggest that bitter-tasting feed additives may have side effects on the growth and development of intestines in chickens.

Orphan Formulations in Pediatric Schistosomiasis Treatment: Development and Characterization of Praziquantel Nanoparticle-Loaded Powders for Reconstitution.

Praziquantel is a broad spectrum antihelmintic agent and represents the drug of choice for the treatment of schistosomiasis. However, its low aqueous solubility and strong bitter taste highly affect the bioavailability and compliance in pediatric patients. Thus, the purpose of this study was to develop a dry nanosuspension, by a combination of high-pressure homogenization and spray drying, intended for redispersion in a pleasant taste vehicle for extemporaneous use. Three formulations, varying stabilizers to drug ratio, were developed and characterized in terms of particle size distribution, crystallinity, morphology, in vitro dissolution, and sedimentation-redispersibility behavior. A significant reduction in particle size was achieved after the high-pressure homogenization process, and the nanoparticles were further microencapsulated by spray drying technique. The redispersed dried powders exhibited a conserved particle size distribution (in the nanometric range) and certain crystallinity extent, with satisfactory redispersion ability. Besides, the enhancement of the dissolution performance obtained after comminution was conserved, even after drying and redispersion of the extemporaneous powdered formulation. In conclusion, the developed nanoparticle-loaded powders comprise an interesting tool for the administration of praziquantel to preschool-age children.

Denatonium Benzoate-Induces Oxidative Stress in the Heart and Kidney of Chinese Fast Yellow Chickens by Regulating Apoptosis, Autophagy, Antioxidative Activities and Bitter Taste Receptor Gene Expressions.

Simple SummaryDenatonium benzoate is a strong bitter taste receptor agonist, extensively used for its activation of different cell pathways. Taste signals have been associated to food recognition and avoidance, and bitter taste provokes an aversive reaction and is assumed to protect chickens from consuming poisons and harmful toxic substances. The results of the study revealed that dietary supplementation with medium and high doses of denatonium benzoate damaged the epithelial cells of the heart and kidneys by inducing apoptosis and autophagy and reduced the growth of chickens, respectively. However, mRNA expressions of bitter taste receptors, downstream signaling effector genes, apoptosis-, autophagy- and antioxidant-related genes were higher on day 7, while these expressions were subsequently decreased on day-28 in the heart and kidney of Chinese Fast Yellow chickens in a dose-response manner.The sense of taste which tells us which prospective foods are nutritious, poisonous and harmful is essential for the life of the organisms. Denatonium benzoate (DB) is a bitter taste agonist known for its activation of bitter taste receptors in different cells. The aim of the current study was to investigate the mRNA expressions of bitter taste, downstream signaling effectors, apoptosis-, autophagy- and antioxidant-related genes and effector signaling pathways in the heart/kidney of chickens after DB dietary exposure. We randomly assigned 240, 1-day-old Chinese Fast Yellow chicks into four groups with five replicates of 12 chicks and studied them for 28 consecutive days. The dietary treatments consisted of basal diet and feed containing DB (5, 20 and 100 mg/kg). The results revealed that dietary DB impaired (p < 0.05) the growth performance of the chickens. Haemotoxylin and eosin staining and TUNEL assays confirmed that medium and high doses of DB damaged the epithelial cells of heart/kidney and induced apoptosis and autophagy. Remarkably, the results of RT-PCR and qRT-PCR indicated that different doses of DB gradually increased (p < 0.05) mRNA expressions of bitter taste, signaling effectors, apoptosis-, autophagy- and antioxidant- related genes on day 7 in a dose-response manner, while, these expressions were decreased (p < 0.05) subsequently by day-28 but exceptional higher (P < 0.05) expressions were observed in the high-dose DB groups of chickens. In conclusion, DB exerts adverse effects on the heart/kidney of chickens in a dose-response manner via damaging the epithelium of the heart/kidney by inducing apoptosis, autophagy associated with bitter taste and effector gene expressions. Correlation analyses for apoptosis/autophagy showed agonistic relationships. Our data provide a novel perspective for understanding the interaction of bitter taste, apoptosis, autophagy and antioxidative genes with bitter taste strong activators in the heart/kidney of chicken. These insights might help the feed industries and pave the way toward innovative directions in chicken husbandry.

Separation of praziquantel enantiomers using simulated moving bed chromatographic unit with performance designed for semipreparative applications.

Praziquantel (PZQ) composes a regular medicine available in a tablet form to fight schistosomiasis and just half of its mass is composed by the active principle (L-PZQ), the other half, D-PZQ, is frequently associated to a strong bitter taste. Moreover, optically pure L-PZQ derivatives could be used in studies about adult and juvenile worms' resistance. Nowadays, these studies use racemic PZQ (rac-PZQ) as starting point. The D-PZQ, which would be discarded, could be racemized, coming back as feed concentration in the process. The present work aims to get L-PZQ and D-PZQ with high optical purities (more than 97%) and productivity (more than 253gkgads -1 day-1 ) towards semipreparative scale for researches involving L-PZQ, L-PZQ derivatives, and D-PZQ racemization. In order to achieve this goal, a built-in-house simulated moving bed chromatographic unit with the cellulose tris (3-chloro-4-methylphenylcarbamate) (Chiralcel OZ) as chiral stationary phase (CSP) was used to investigate different scenarios of separation according to a well-known design method called triangle theory. In all scenarios investigated, at least one of the outlet streams presented high optically purity for one of the enantiomers. Comparison with literature showed superior performance of our unit even at racemic mixture concentrations that were 10 times lower than the racemic concentrations found in literature.

Progress in the development of garden asparagus resistant toAsparagus virus1 (AV-1)

A genetically determined resistance to the Asparagus virus 1 was identified within the Mediterranean wild relative Asparagus amarus. Field experiments under climatic conditions in Germany showed for A. amarus a relative low yield potential (~20%) compared with various cultivars of A. officinalis. Analyses of volatile organic compounds revealed a number of significant differences. Furthermore, the wild relative is hexaploid (2n=6x=60), expresses a strong bitter taste and is frost tolerant up to -15°C. A backcross programme was started for introgression the AV-1 resistance from the wild relative into the genome of garden asparagus. Interspecific hybrids were obtained by reciprocal crosses between A. amarus and tetraploid A. officinalis via embryo rescue approach. Four F1 progenies were cloned in vitro and transplanted in the field. Two progenies showed resistance to AV-1, while two progenies were susceptible.