Why is yam bitter

What we call "yams" here in America are, in fact, sweet potatoes. Yams are not sweet potatoes. Similar but still 2 different things. Yams are indigenous to the Carribean and the African and Asian continents. In the Southern states, they may call the sweet potato a yam, but they are not. And to add to the confusion, the cooked, canned sweet potatoes are also not yams, even though it says so on the can label.

Wow that's so interesting that you were able to find a variety of yams. I'm sure there was nothing wrong with the potato you ate but I probably would have reacted the same way, especially if the taste is so similar to a white potato. But I would try to not have any fears, they wouldn't import and then sell something that was poisonous in an American grocery store would they?

Actually, not even sure if you are in America so that might not be true if you are in some other country. If you are still interested in trying out these varieties then you may want to ask someone else who is buying them. I can't tell you how many times someone has approached me at the grocery store and has said "excuse me, what do you do with THAT? AMF root colonization, however, was higher in yam than in sorghum vs.

After 8 months of trap culturing, the mycorrhizal yam had a higher tuber biomass than the nonmycorrhizal controls. The AMF actually colonizing D. Multiple phylotaxa were detected that corresponded with the spore morphotypes observed.

It is, therefore, likely that the legacy of indigenous AMF from the natural savanna plays a crucial role for yam. Bitter -responsive brainstem neurons: characteristics and functions. The sensation that humans describe as " bitter " is evoked by a large group of chemically diverse ligands. Bitter stimuli are avoided by a range of species and elicit reflex rejection, behaviors considered adaptations to the toxicity of many of these compounds.

We review novel evidence for neurons that are narrowly tuned to bitter ligands at the initial stages of central processing. These "B-best" neurons in the nucleus of the solitary tract NST and parabrachial nucleus PBN respond to multiple types of bitter stimuli and exhibit average responses to bitter tastants that are times larger than to moderate concentrations of compounds representing other qualities.

However, in the PBN B-best units are appreciably activated by intense salt and acid. Neurons broadly sensitive to salts and acids "AN" neurons also responded to bitter stimuli. This sensitivity appeared restricted to stronger intensities of ionic bitters , as cycloheximide remained ineffective across concentrations.

In addition to chemosensitive profile, B-best neurons were also distinctive with regard to their posterior receptive fields, long latencies, slow firing rates and projection status. Compared to B-best NST cells, those in the PBN received increased convergence from anterior and posterior receptive fields and responded to a greater number of bitter stimuli.

We conclude that B-best neurons likely contribute to pathways underlying gaping, aversive hedonic quality and taste coding. The differential responsiveness of B-best and AN neurons to ionic and nonionic bitter ligands also suggests a potential substrate for discrimination within this quality. Optimized aqueous extraction of saponins from bitter melon for production of a saponin-enriched bitter melon powder. Bitter melon, Momordica charantia L. Cucurbitaceae , aqueous extracts are proposed to have health-promoting properties due to their content of saponins and their antioxidant activity.

However, the optimal conditions for the aqueous extraction of saponins from bitter melon and the effects of spray drying have not been established. Therefore, this study aimed to optimize the aqueous extraction of the saponins from bitter melon, using response surface methodology, prepare a powder using spray drying, and compare the powder's physical properties, components, and antioxidant capacity with aqueous and ethanol freeze-dried bitter melon powders and a commercial powder.

For many of its physical properties, components, and antioxidant capacity, the aqueous spray-dried powder was comparable to the aqueous and ethanol freeze-dried bitter melon powders and the commercial powder.

The optimal conditions for the aqueous extraction of saponins from bitter melon followed by spray drying gave a high quality powder in terms of saponins and antioxidant activity. This study highlights that bitter melon is a rich source of saponin compounds and their associated antioxidant activities, which may provide health benefits. The findings of the current study will help with the development of extraction and drying technologies for the preparation of a saponin-enriched powdered extract from bitter melon.

The powdered extract may have potential as a nutraceutical supplement or as a value-added ingredient for incorporation into functional foods.

Research progress of the bitter taste receptor genes in primates. Among the five basic tastes umami, sweet, bitter , salty and sour , the perception of bitterness is believed to protect animals from digesting toxic and harmful substances, thus it is vital for animal survival. The taste of bitterness is triggered by the interaction between bitter substances and bitter taste receptors, which are encoded by Tas2rs. The gene numbers vary largely across species to meet different demands. So far, several ligands of bitter receptors have been identified in primates.

They also discovered that the selective pressure of certain bitter taste receptor genes vary across taxa, genes or even different functional regions of the gene. In this review, we summarize the research progress of bitter taste receptor genes in primates by introducing the functional diversity of bitter receptors, the specific interaction between bitter taste receptors and ligands, the relationship between the evolutionary pattern of bitter taste receptors and diets, and the adaptive evolution of bitter taste receptor genes.

We aim to provide a reference for further research on bitter receptor genes in primates. Bitter and sweet tasting molecules: It's complicated. This oppositional relationship is complicated by the fact that some molecules are simultaneously bitter and sweet.

In some cases, a small chemical modification, or a chirality switch, flips the taste from sweet to bitter. Here we characterize the chemical space of bitter and sweet molecules: the majority of bitter compounds show higher hydrophobicity compared to sweet compounds, while sweet molecules have a wider range of sizes. Importantly, recent evidence indicates that TAS1Rs and TAS2Rs are not limited to the oral cavity; moreover, some bitterants are pharmacologically promiscuous, with the hERG potassium channel, cytochrome P enzymes, and carbonic anhydrases as common off-targets.

Further focus on polypharmacology may unravel new physiological roles for tastant molecules. Bitterness prediction in-silico: A step towards better drugs. Bitter taste is innately aversive and thought to protect against consuming poisons. Bitter taste receptors Tas2Rs are G-protein coupled receptors, expressed both orally and extra-orally and proposed as novel targets for several indications, including asthma.

Many clinical drugs elicit bitter taste, suggesting the possibility of drugs re-purposing. On the other hand, the bitter taste of medicine presents a major compliance problem for pediatric drugs. Thus, efficient tools for predicting, measuring and masking bitterness of active pharmaceutical ingredients APIs are required by the pharmaceutical industry. Here we highlight the Bitter DB database of bitter compounds and survey the main computational approaches to prediction of bitter taste based on compound's chemical structure.

Current in silico bitterness prediction methods provide encouraging results, can be constantly improved using growing experimental data, and present a reliable and efficient addition to the APIs development toolbox. Bitterness in Almonds1[C][OA. Bitterness in almond Prunus dulcis is determined by the content of the cyanogenic diglucoside amygdalin.

The ability to synthesize and degrade prunasin and amygdalin in the almond kernel was studied throughout the growth season using four different genotypes for bitterness. Liquid chromatography-mass spectrometry analyses showed a specific developmentally dependent accumulation of prunasin in the tegument of the bitter genotype. The prunasin level decreased concomitant with the initiation of amygdalin accumulation in the cotyledons of the bitter genotype.

By administration of radiolabeled phenylalanine, the tegument was identified as a specific site of synthesis of prunasin in all four genotypes. The prunasin turnover may offer a buffer supply of ammonia, aspartic acid, and asparagine enabling the plants to balance the supply of nitrogen to the developing cotyledons. Complete genome sequence of a divergent strain of Japanese yam mosaic virus from China.

Its genomic sequence of nucleotides encodes a polyprotein of amino acids. Its organization was virtually identi Effects of drying processes on starch-related physicochemical properties, bioactive components and antioxidant properties of yam flours.

The effects of five different drying processes, air drying AD , sulphur fumigation drying SFD , hot air drying HAD , freeze drying FD and microwave drying MWD for yams in terms of starch-related properties and antioxidant activity were studied.

The bioactive components and the reducing power of the dried yams , were lower than those of fresh yam. When five dried samples were compared by principal component analysis, the HAD and SFD samples were observed to have the highest comprehensive principal component values. Bitterness and antibacterial activities of constituents from Evodia rutaecarpa.

Bitter herbs are important in Traditional Chinese Medicine and the Electronic Tongue e-Tongue is an instrument that can be trained to evaluate bitterness of bitter herbs and their constituents. The aim of this research was to evaluate bitterness of limonoids and alkaloids from Evodia rutaecarpa to demonstrate that they are main bitter material basic of E. Nine compounds, including limonoids, indoloquinazoline alkaloids and quinolone alkaloids, were isolated, identified and analyzed by the e-Tongue.

Additionally, the antibacterial activities of the nine compounds were evaluated against E. All the nine compounds had bitter taste and antibacterial activities to some extent. Among them, limonoids, which were the bitterest compounds, had greater antibacterial activities than alkaloids. And there is a positive correlation between bitter taste and antibacterial activities. It was confirmed in our study that limonoids, indoloquinazoline alkaloids and quinolone alkaloids are main bitter material basic of E.

In addition, the e-Tongue technique is a suitable new method to measure bitter degree in herbs. Textural and sensory properties of trifoliate yam Dioscorea dumetorum flour and stiff dough 'amala'.

The use of trifoliate yam Dioscorea dumetorum flour for stiff dough 'amala' production is one of the ways to curb under-utilization of the tuber. The study evaluates the textural and sensory properties of trifoliate yam flour and stiff dough. The sliced yam were soaked in water for 12 h, dried and milled into flour. Pasting viscosities, functional properties, brown index and sensory attributes of the flour and stiff dough were analyzed.

Peak, holding strength and final viscosities ranged from White raw flour had higher viscosity than the yellow flours. The swelling index, water absorption capacity and bulk density ranged from 1. Blanching method employed improved the swelling index and water absorption capacity of flour. The brown index values of flour and stiff dough ranged from 6. Sensory evaluation revealed significant differences in the colour, odour and general acceptability of the product when compared with the stiff dough from white yam.

Rapid and specific detection of Yam mosaic virus by reverse-transcription recombinase polymerase amplification. Yam mosaic virus YMV; genus Potyvirus is considered to cause the most economically important viral disease of yams Dioscorea spp. Yams are a vegetatively propagated crop and the use of virus-free planting material forms an essential component of disease control. Current serological and PCR-based diagnostic methods for YMV are time consuming involving a succession of target detection steps.

In this study, a novel assay for specific YMV detection is described that is based on isothermal reverse transcription-recombinase polymerase amplification RT-exoRPA. These features make the RT-exoRPA assay a promising candidate for adapting into a field test format to be used by yam breeding programmes or certification laboratories. The bitter pill: clinical drugs that activate the human bitter taste receptor TAS2R Bitter taste receptors TAS2Rs mediate aversive response to toxic food, which is often bitter.

These G-protein-coupled receptors are also expressed in extraoral tissues, and emerge as novel targets for therapeutic indications such as asthma and infection. Our goal was to identify ligands of the broadly tuned TAS2R14 among clinical drugs. Molecular properties of known human bitter taste receptor TAS2R14 agonists were incorporated into pharmacophore- and shape-based models and used to computationally predict additional ligands. Despite immense chemical diversity of known TAS2R14 ligands, novel ligands and previously unknown polypharmacology of drugs were unraveled by in vitro screening of computational predictions.

This enables rational repurposing of traditional and standard drugs for bitter taste signaling modulation for therapeutic indications. Increasing evidence indicates the occurrence of cognitive impairment in astronauts under spaceflight compound conditions, but the underlying mechanisms and countermeasures need to be explored.

In this study, we found that learning and memory abilities were significantly reduced in rats under a simulated long-duration spaceflight environment SLSE , which includes microgravity, isolation confinement, noises, and altered circadian rhythms.

Dammarane sapogenins DS , alkaline hydrolyzed products of ginsenosides, can enhance cognition function by regulating brain neurotransmitter levels and inhibiting SLSE-induced neuronal injury.

These findings defined the characteristics of SLSE-induced cognitive decline and the mechanisms by which DS improves it. The results provide an effective candidate for improving cognitive function in spaceflight missions. The effect of Taro Colocasia esculenta L. The results showed that the addition ratio of taro and lesser yam flour affected to the physical characteristics of frozen wheygurt. The addition of lesser yam flour increased total soluble solids until the addition ratio of due to the higher ash content of lesser yam 2.

Addition ratio of taro and lesser yam flour do not have a significant effect on the viscosity of the frozen wheygurt, due to both starch have similar setback viscosity. Lesser yam setback viscosity was Setback viscosity showed a high tendency of retrogradation. The addition ratio of taro and lesser yam flour have a significant effect to the overrun of frozen wheygurt.

Addition ratio of taro and lesser yam flour have a significant effect to melting rate of frozen wheygurt. This result was caused by higher peak viscosity of taro starch compared to lesser yam , thus produced thicker gel than lesser yam. This lead increased water contents in the mixtures entrapped and slows down water mobility, hence melting rate would decrease.

Antifungal activity of n-tributyltin acetate against some common yam rot fungi. The antifungal activity of n-tributyltin acetate TBTA was examined in relation to combating yam rot disease. TBTA exhibited a significant effect in vitro and in vivo on four yam rot fungal isolates tested. However, the in vitro toxicity of TBTA was drastically reduced when 2. Bitter Gourd: Botany, Horticulture, Breeding.

Bitter gourd fruits are a good source of carbohydrates, proteins, vitamins, and minerals and have the highest nutritive value among cucurbits. Moreover, the crude protein content This book chapter focuses on the Bitter -sweet processing in larval Drosophila.

However, the behavioral significance of such a potential for combinatorial coding is little understood. Using larval Drosophila as a study case, we find that the preference towards fructose is inhibited when assayed in the background of the bitter tastant quinine.

When testing the influence of quinine on the preference to other, equally preferred sweet tastants, we find that these sweet tastants differ in their susceptibility to be inhibited by quinine.

Such stimulus specificity argues that the inhibitory effect of quinine is not due to general effects on locomotion or nausea. In turn, not all bitter tastants have the same potency to inhibit sweet preference; notably, their inhibitory potency is not determined by the strength of the avoidance of them.

Likewise, equally avoided concentrations of sodium chloride differ in their potency to inhibit sugar preference. Furthermore, Gr33a-Gal4-positive neurons, while being necessary for bitter avoidance, are dispensable for inhibition of the sweet pathway. Thus, interactions across taste modalities are behaviorally significant and, as we discuss, arguably diverse in mechanism.

These results suggest that the coding of tastants and the organization of gustatory behavior may be more combinatorial than is generally acknowledged. Published by Oxford University Press. For permissions, please e-mail: journals. Bitterness values for traditional tonic plants of southern Africa. Bitterness values have been determined for southern African plant species that are traditionally used as tonics imbizas or 'musa-pelo to alleviate the symptoms of stress and a variety of ailments related to the digestive system.

To measure and present, for the first time, the bitterness values of 15 of the best-known and most widely used tonic plants in southern Africa in order to find a rationale for their traditional use in improving appetite and treating digestive ailments. Most of the plants were found to be very bitter , with bitterness values comparable to those reported for internationally well-known bitter tonics such as Artemisia absynthium L.

The relatively high bitterness values obtained for all of the plants indicate that their alleged value in improving digestion and appetite may at least be partly ascribed to the bitter tonic amarum effect, i. It may be interesting to examine the chemical compounds responsible for the bitter taste, as well as the possible links between bitterness and the anecdotal anti-stress properties ascribed to these species.

Kolombia, Yao A. The root-knot nematodes RKN , Meloidogyne spp. With the aim to establish the diversity of RKN species affecting yam tubers, for control and resistance screening purposes, surveys were conducted in the main yam producing areas of Nigeria. Results of both identification methods revealed the same species, confirming their accuracy for the identification of these tropical RKN species.

In addition to M. This finding extends the list of yam pests and calls for caution when developing practices for yam pest management. Summary The extent of diversity among bitter -sensing neurons is a fundamental issue in the field of taste.

Data are limited and conflicting as to whether bitter neurons are broadly tuned and uniform, resulting in indiscriminate avoidance of bitter stimuli, or diverse, allowing a more discerning evaluation of food sources. We provide a systematic analysis of how bitter taste is encoded by the major taste organ of the Drosophila head, the labellum. Each of 16 bitter compounds is tested physiologically against all 31 bitter neurons, revealing responses that are diverse in magnitude and dynamics.

Four functional classes of bitter neurons are defined. Four corresponding classes are defined through expression analysis of all 68 Gr taste receptors. A receptor-to-neuron-to-tastant map is constructed. Misexpression of one receptor confers bitter responses as predicted by the map.

These results reveal a degree of complexity that greatly expands the capacity of the system to encode bitter taste. Yam anthracnose caused by Colletotrichum gloeosporioides C. In the present study, we evaluated the culture filtrate extract CFE of azalomycin-producing Streptomyces malaysiensis strain MJM for the control of yam anthracnose.

MJM showed strong antagonistic activity against C. Furthermore, a greenhouse study was conducted to evaluate the CFE from MJM as a fungicide for the control of yam anthracnose.

Analysis of the yam tubers from the CFE-treated and non-treated groups showed that tubers from the CFE-treated plants were larger than that of non-treated plants, which produced abnormal smaller tubers typical of anthracnose.

This study demonstrated the utility of the CFE from S. In order to reduce calories in foods and beverages, the food industry routinely uses non-nutritive sweeteners. Unfortunately, many are synthetically derived, and many consumers have a strong preference for natural sweeteners, irrespective of the safety data on synthetic non-nutritive sweeteners. Additionally, many non-nutritive sweeteners elicit aversive side tastes such as bitter and metallic in addition to sweetness. Here we examined bitterness and sweetness perception of natural and synthetic non-nutritive sweeteners.

For comparison, we also present sweet and bitter ratings of AceK collected in the original experiment for the same participants. At similar sweetness levels, aspartame elicited less bitterness than RebD, which was significantly less bitter than RebA. The bitterness of RebA and RebD showed wide variability across individuals, and bitterness ratings for these compounds were correlated.

The influence of chemical methods acid modification on elephant foot yam flour to improve physical and chemical quality on processed food. This study was aimed at improving the physicochemical quality of elephant foot yam flour in Gunungpati, Semarang by acid modification.

The flour of the experimental result discussed in this study was expected to become a reference for the manufacturers of elephant foot yam flour and its processed food in Gunungpati. This study modified the elephant foot yam flour using acid modification method. The physical and chemical quality of each elephant foot yam flour of the experimental result sample were assessed using proximate analysis.

Chemical test was conducted after elephant foot yam was acid modification to determine changes in the quality flour: test levels of protein, fat, crude fiber content, moisture content, ash content and starch content. The masking of bitterness is considered important because many pharmaceutical compounds have a bitter taste. The bitterness -masking effect of powdered roasted soybeans PRS was investigated using a bitter taste sensor.

PRS was revealed to significantly suppress the bitterness of quinine hydrochloride and denatonium benzoate. Furthermore, the bitterness -masking mechanism of PRS extracts was evaluated using dynamic light scattering. These results showed that the extracted suspension consisted of particles that were several hundreds of nanometers in size.

Analysis of the PRS extracts by nuclear magnetic resonance spectroscopy indicated that denatonium benzoate was entrapped in the PRS extracts.

Thus, PRS may be useful as a bitterness -masking agent in orally administered pharmaceuticals. Genome sequencing of the staple food crop white Guinea yam enables the development of a molecular marker for sex determination. Root and tuber crops are a major food source in tropical Africa. Among these crops are several species in the monocotyledonous genus Dioscorea collectively known as yam , a staple tuber crop that contributes enormously to the subsistence and socio-cultural lives of millions of people, principally in West and Central Africa.

Yam cultivation is constrained by several factors, and yam can be considered a neglected "orphan" crop that would benefit from crop improvement efforts.

However, the lack of genetic and genomic tools has impeded the improvement of this staple crop. To accelerate marker-assisted breeding of yam , we performed genome analysis of white Guinea yam Dioscorea rotundata and assembled a Mb genome, In total, we predicted 26, genes.

Phylogenetic analyses with conserved genes revealed that Dioscorea is a unique lineage of monocotyledons distinct from the Poales rice , Arecales palm , and Zingiberales banana. The entire Dioscorea genus is characterized by the occurrence of separate male and female plants dioecy , a feature that has limited efficient yam breeding.

We further delineated the W locus and used it to develop a molecular marker for sex identification of Guinea yam plants at the seedling stage. Guinea yam belongs to a unique and highly differentiated clade of monocotyledons. The genome analyses and sex-linked marker development performed in this study should greatly accelerate marker-assisted breeding of Guinea yam. In addition, our QTL-seq approach can be utilized in genetic studies of other outcrossing crops and organisms with highly heterozygous genomes.

Study of the proximate and mineral composition of different Nigerian yam chips, flakes and flours. Yam Dioscorea spp is an essential tuber crop for hundreds of millions of people in many African, Asian and South American countries. Considering in particular Southwest Nigeria, chips, flakes and flours are amongst the most common shelf-stable traditionally-processed yam products.

This paper reports a systematic study on the proximate moisture, protein, carbohydrate, fibre, fat, ash and gross energy and mineral composition of these three food commodities sold in Nigerian markets. Food Chem — Bradbury JH The chemical composition of tropical root crops. J Ethanopharmacol 51— Exp Neurol 40— Article PubMed Google Scholar. Trop Agric Trin — J Am Soc Hortic Sci — Plant Foods Hum Nutr 33— Anthony C The wild yams: A review. Wissenschaftliche Verlagsgesellschaft mbH, Stuttgart, pp J Agric Food Chem — Tetrahedron Lett — Contact Dermat 9: — Chem Pharm Bull — J Agric Food Chem 67— Directory of Germplasm Collections.

Singh SC Some wild plants of food value in Nepal. Journal of Tribhuwan Univ 4: 50— Phytochemistry — The toxic alkaloid, dioscorine and histamine an allergen were not detected in these tubers, whereas cyanogens as HCN equivalent content were found ranging from 3. Our results revealed that Nepali wild yam tubers are not toxic varieties, as they do not contain either toxic dioscorine or histamine and cyanogens contents were satisfactorily below the safety limits.

The inflammation and occasional toxicity observed could possibly be due to the presence of high level of oxalate in these tubers.