Wild Yam Research Articles

Molecular and agro-morphological evaluations of interspecific hybridisation in two wild yams (Dioscorea spp.) for genetic improvement

Molecular and agro-morphological evaluations of interspecific hybridisation in two wild yams (Dioscorea spp.) for genetic improvement

Food taboos among indigenous pregnant women of Khagrachari District, Bangladesh.

This study aimed to explore food taboos among indigenous pregnant women in Bangladesh. A mixed-method study was conducted among the Tripura, Chakma, and Marma communities in Khagrachari district of Bangladesh. To identify the list of existing tabooed foods, six focus group discussions were conducted with 36 women aged 15 years and above. For the quantitative part, 75 indigenous pregnant women were interviewed face-to-face to identify the commonly avoided food items during their current pregnancy. All the interviews were conducted in the participant's native language. A total of 64 different items were identified as tabooed food during pregnancy. Among the current pregnant, 46.6% were adhering to food taboos. The most commonly avoided fruits were pineapple (33.3%) and papaya (20.0%). For vegetables, organic sweet potato (4.0%) and pumpkin (2.6%) were the most common. For animal products, 8.0% of participants avoided fish of any kind, and 2.6% restricted duck meat. Cold food (4.0%) was the most avoided beverages and snacks. Betel leaf and nut (2.6%) were also in the list of tabooed food. Distinct locally grown Ghut Ghutte, Chinese yam, and wild yam were also refrained. The health and well-being of the baby were the main concerns behind the food taboos. There is a high prevalence of food taboo practices among the indigenous pregnant women of Bangladesh. Tailored intervention programs to address misunderstandings, dispel myths, and encourage healthier food choices during pregnancy among the indigenous communities of Bangladesh can be beneficial for both pregnant and babies.

GENETIC VARIABILITY AND MULTI-TRAIT SELECTION FOR SUPERIOR TRAITS IN WILD YAM HYBRIDS

The interspecific breeding of yams (Dioscorea spp.) for superior traits is hindered by the dioecious nature of their flowers and low flowering frequency, despite the potential of wild yams to improve related cultivated varieties. However, the genetic variability of these wild yam species has yet to be fully explored. This study investigated the genetic variability and heritability estimates for multi-trait selection of hybrids derived from crosses between two wild yam species, Dioscorea abyssinica and Dioscorea praehensilis. Field experiment was conducted on 65 hybrids using a partially replicated block design. With standard descriptors, data were collected on phenotypic traits, including stem length, internode, plant vigour, tuber length, tuber weight, tuber width, tuber thorniness, and tuber surface cracks. Heritability, genetic advance and variance components were estimated to quantify the genetic contribution to trait variability. Analysis of variance identified significant differences (p=0.00) among hybrids and high genetic variability was observed in phenotypic traits assessed, with tuber weight showing the highest genotypic (104%) and phenotypic (127%) variances. Heritability estimates suggested strong selection potential for stem length (74%), tuber weight (67%) and tuber hairiness (65%), while tuber shape (7%) and tuber width (9%) showed low genetic potential. Multi-trait Genotype Ideotype Distance Index (MGIDI) analysis further identified 8 high-performing wild yam hybrid accessions (TDabp2101010, TDabp2101013, TDabp2101030, TDabp2101042, TDabp2101046, TDabp2101050, TDabp2101052, and TDabp2101055). These findings demonstrate the potential of wild yam hybrids for trait introgression, thereby paving way for the development of new yam cultivars and providing valuable insights for yam improvement programs.

Indigenous Knowledge on Edible Wild Yams (Kumbu) in the Mount Cameroon Region: Towards Domestication for Enhanced Food Security

Growing food insecurity can in part be attributed to a lack of diversity in arable crops, with most African countries now focused on the production of a few “green revolution crops”. Indigenous knowledge of traditional food types could hold the key to the genetic diversification of crop production systems. Wild yams are indigenous crops that have been relegated to the background. This study aimed to assess the state of knowledge in, and cultivation of, wild yams collectively called “Kumbu” by the Bakweris of the Mount Cameroon Region. Following reconnaissance surveys, semi-structured questionnaires were administered to 583 interviewees across 41 villages in this region. Data were analysed in the SPSS version 21 statistical package with significance at α = 0.05 where necessary. Results showed that the study population was fairly balanced in terms of gender (SD = 0.534), with males representing 56.8% of the sample. A majority of the interviewees (53.3%) were married, and most had received at least primary education (85.2%). Most (61.6%) of the interviewees do not cultivate Kumbu due to a lack of available seeds (69.3%) and a preference for other yams (30.7%). Of those who cultivate Kumbu (38.4% of the interviewees), a majority (89.6%) have less than five stands of Kumbu. The different names (10) and types (13) of Kumbu could represent linguistic polymorphism, requiring further studies for proper identification. A majority (68.1%) of the interviewees had no idea of the differences between Kumbu types. Agronomic practices, pests, and disease management reported for Kumbu are similar to those of other mainstream yam types. We conclude that the state of knowledge on Kumbu in the Mt Cameroon Region is limited and on the decline. Bringing Kumbu production to the mainstream requires research on molecular taxonomy, propagation techniques, and agronomic practices for better yields.

Gall midges of wild yam (Dioscorea: Dioscoreaceae) in Japan, with integrative descriptions of two new species

Gall midges of wild yam (Dioscorea: Dioscoreaceae) in Japan, with integrative descriptions of two new species

Diosgenin-Loaded Silver Nanoparticles Mitigate B[a]P-Induced Lung Fibrosis Through Modulation of Oxidative Stress and Inflammatory Pathways.

Lung fibrosis, characterized by the thickening and scarring of lung tissue, is a serious condition often triggered by environmental toxins like Benzo[a]pyrene (B[a]P). Diosgenin, a natural steroidal sapogenin found in plants such as fenugreek and wild yam, has shown potential to protect against lung damage due to its anti-inflammatory and antioxidant properties. However, its clinical application is limited by poor solubility and bioavailability. The current investigation aims at developing diosgenin-loaded silver nanoparticles (DioAgNPs) to enhance their delivery and efficacy. This study investigates the preparation, characterization, and protective effects of Dio-AgNPs against B[a]P-induced lung fibrosis in mice. Acute toxicity studies in mice were conducted to determine the lethal dose (LD50) of DioAgNPs. Sub-lethal doses (1/50 and 1/20 LD50) were selected for subsequent experiments. Mice were exposed to B[a]P to induce lung fibrosis. Dio-AgNPs were administered to assess their protective effects. Biochemical assays measured levels of total cholesterol (TC), triglycerides (TG), malondialdehyde (MDA), nuclear factor kappa B (NF-κB), interleukin-6 (IL-6), matrix metalloproteinase-2 (MMP2), and matrix metalloproteinase-12 (MMP12). Additionally, high-density lipoprotein cholesterol (HDL-C), glutathione (GSH), catalase (CAT), and glutathione peroxidase (GPx) levels were evaluated. Quantitative PCR (qPCR) was used to analyze the expression levels of lung signal transducer and activator of transcription 3 (STAT3), transforming growth factor- β1(TGF-β1), and Sirtuin 1 genes. Insilico molecular docking studies were performed to evaluate the binding affinity of diosgenin with SIRT1, STAT3, and TGF-β1 proteins, with binding energies (ΔG) calculated to predict interaction strength. The synthesized Dio-AgNPs exhibited a mean diameter of 51.60±1.54 nm, a zeta potential of -19.5 mV, and encapsulation efficiency of 84.98%, confirming their stability through spectral analysis. In B[a]P-exposed mice, there was a significant elevation in TC, TG, MDA, NF-κB, IL-6, MMP2, and MMP12 levels, alongside a reduction in HDL-C, GSH, CAT, and glutathione peroxidase (GPx) levels. Additionally, lung STAT3 and TGF-β1 gene expression was upregulated, while SIRT1 gene expression was downregulated. Administration of Dio-AgNPs to B[a]P-treated mice resulted in a significant reduction in TC, TG, and HDL-C levels, improvement in lung MDA, NF-κB, IL-6, MMP2, and MMP12 levels, downregulation of lung STAT3 and TGF-β1, and upregulation of SIRT1 gene expression. In-silico molecular docking studies demonstrated strong binding affinities of diosgenin with SIRT1, STAT3, and TGF-β1 proteins, with binding energies (ΔG) of -9.7, -9.6, - 10.1, and -9.7 kcal/mol, respectively. This study innovatively enhances the delivery and efficacy of diosgenin by developing diosgenin-loaded silver nanoparticles (Dio-AgNPs), addressing its solubility and bioavailability challenges. Dio-AgNPs demonstrated significant protective effects against B[a]P-induced lung fibrosis in mice, reducing oxidative stress and inflammation while modulating key genes like STAT3, TGF-β1, and SIRT1. Molecular docking studies confirmed strong binding affinities, underscoring the therapeutic potential of Dio-AgNPs. This research marks a significant advancement in nanomedicine and respiratory therapy, offering a promising approach to managing lung fibrosis and related conditions.

Utility Assessment of Isolated Starch and Extract from Thai Yam (Dioscorea hispida Dennst.) for Cosmetic via In Vitro and In Vivo Studies.

In Thailand, wild yam, or Dioscorea hispida Dennst., is a starchy crop that is usually underutilized in industry. The purpose of this study was to isolate the starch and extract the phytochemical from D. hispida and use them in cosmetics. Starch was used instead of talcum, which can cause pulmonary talcosis in dusting powder formulas (DP 1-5). GC-MS was used to identify the bioactive components present in the ethanolic extract of D. hispida. The main compounds were identified as 9,12-octadecadienoic acid (Z,Z)- (6.51%), stigmasta-5,22-dien-3-ol, (3.beta.,22E)- (6.41%), linoleic acid ethyl ester (5.72%), (Z,Z)-9,12-octadeca-dienoic acid, 2,3-dihydroxy-propyl (3.89%), and campesterol (3.40%). Then, the extract was used as an ingredient in facial sleeping mask gel formulas (SM 1-SM 5). Stability tests, physical characteristics, enzyme inhibitions, and sensitization dermal toxicity tests were used to evaluate the DP and SM formulations. The results showed that the fresh tubers of D. hispida showed a 12.5% w/w starch content. The findings demonstrated that starch powder had a restricted size distribution, ranging from 2 to 4 μm, and a smooth surface that was polygonal. Following stability testing, the color, odor, size, and flowability of all DP formulations did not significantly differ. The SEM investigation revealed that DP particles were homogenous. For the sensitization dermal toxicity test, DP denoted no erythema or skin irritation in the guinea pigs. After stability testing, the colors of the SM formulas were deeper, and their viscosity slightly increased. The pH did not significantly change. After the stability test, SM formulas that contained Glycyrrhiza glabra and D. hispida extracts exhibited stable tyrosinase and elastase inhibitory activities, respectively. In the sensitization dermal toxicity test, guinea pigs showed skin irritation at level 2 (not severe) from SM, indicating that redness developed. All of these findings indicate that D. hispida is a plant that has potential for use in the cosmetics industry. Furthermore, D. hispida starch can be made into a beauty dusting powder, and more research should be conducted to develop an effective remedy for patients or those with skin problems.

Comparative plastomic analysis of cultivated Dioscorea polystachya and its close relatives provides insights on the inter- and intraspecific phylogenies and potential wild origins of domestication

BackgroundDioscorea polystachya and its closely related species are original plants of the tuber crop “yam”, which had been intensively use for medicinal and food purposes and widely cultivated in northern China and its surrounding areas with a long history. Many cultivars of these species are often confused with one another because of similar tuber morphology, however, conventional DNA barcoding faces practical limitations restricting the method to effectively identify closely related species. In addition, phylogenetic relationships among various cultivar groups of Chinese yam (D. polystachya) remains unclear. To solve these problems, genomic DNAs of 15 Dioscorea samples were sequenced to assemble and annotate chloroplast genomes, which were used for analyzing their structural characteristics and identifying phylogenetic relationships at the inter- and intraspecific levels.ResultsThe size of chloroplast genomes of the tested samples is about 153 kb, and 79 protein-coding genes, 29 tRNA genes, and 4 rRNA genes are annotated. Phylogenetic analysis showed that D. polystachya were sister to Dioscorea japonica, and for Huaishan yams, Dioscorea persimilis did not cluster with Dioscorea alata and Dioscorea fordii. Four cultivar groups of Chinese yam were determined, namely Tiegun group, Anping group, Foshou group and Taihang complex group. Among these cultivar groups, Foshou and Taihang complex are clustered with different wild yams, respectively. Amino acid preferences are similar at the inter- and intraspecific levels, while synonymous codon usage reflects distinct patterns in the majority of cultivars of D. polystachya. There are distinct SSR variations among species, as well as four cultivar groups. Collinearity and SNP analyses show that nucleotide hypervariable regions among Dioscorea species are mainly concentrated in trnK–atpA, rps16–trnQ, atpA–atpH, rpoB–psbD, atpH–atpI, trnV–ndhC in the LSC region, and ccsA–ndhF in the SSC region, while intraspecific variation of Chinese yam is enriched in the intergenic spacers of rpoB–psbC, ndhD–ndhF, and trnQ-trnS, as well as the gene ycf1.ConclusionPhylogenetic analysis supports that Huaishan yams are not of monophyletic origin and the cultivated Chinese yam has at least two wild origins of domestication, which is consistent with the historical records of these wild yams from Mt. Dabie and Mt. Taihang. The identification efficiency of the newly developed barcodes for cultivar groups based on chloroplast genome SNP screening is significantly better than those of conventional barcodes. This approach to generate viable candidate markers based on the comparison from interspecific and intraspecific hypervariable regions of chloroplast genomes can be applied to conduct phylogenetic relationships of more important crop species and their close relatives, which are difficult to identify, as well as their wild origins of domestication.

Nutritional Potential and Antioxidant Activity of Dioscorea spp. Tubers from Mtwara Rural District, Tanzania

The wild yam Dioscorea hirtiflora subsp. orientalis, native to the Mtwara rural district in Tanzania, remains underutilized despite its considerable nutritional and health benefits. This study aimed to assess the nutritional composition and antioxidant properties of its tubers. Standard AOAC procedures were employed to analyze dried tuber samples, while antioxidants and antioxidant capacity were evaluated. The tuber was found to have carbohydrates content ranging from 21.02% to 23.57%, crude protein from 1.0% to 1.5%, crude lipids between 0.46% and 0.68%, and crude fiber from 11.26% to 13.52%, with an energy value of 97.26 to 101.1 Kcal/100 g. Vitamin C content varied from 18.9 to 26.4 mg/100 g, beta-carotene from 4.15 to 17.8 µg/g, and lycopene from 6.89 to 9.10 µg/g. Methanol extracts revealed total phenolic content ranging from 60.28 to 122.51 mg GAE/g and flavonoids ranging from 599 to 1240.4 mg RUE/g, with notable DPPH radical scavenging activity, demonstrated an EC50 of 0.04 mg/mL for brown tuber extract and 0.09 mg/mL for white tuber extract. These findings suggest that D. hirtiflora is a rich source of vital nutrients and antioxidants, with potential to enhance local diets and serve as a basis for developing antioxidant-rich supplements or functional foods. Future research should focus on refining extraction techniques and exploring the health applications of this valuable tuber. Wild Yam (Dioscorea orientalis); Nutritional Composition; Phenolic; Flavonoid Content; Antioxidant Activity

Effects of Okinawan wild yam and its component diosgenin on glucose and lipid metabolism in type 2 diabetes model KK-Ay mice

Effects of Okinawan wild yam and its component diosgenin on glucose and lipid metabolism in type 2 diabetes model KK-Ay mice

Effects of mode of reproduction on genetic polymorphism and divergence in wild yams (Dioscoreaceae: Dioscorea)

Effects of mode of reproduction on genetic polymorphism and divergence in wild yams (Dioscoreaceae: Dioscorea)

Himalayan Dioscorea villosa: A Comprehensive Analysis

Himalayan Dioscorea villosa, a species of wild yam indigenous to the Himalayan region, has garnered attention for its diverse phytochemical composition and traditional medicinal uses. This comprehensive analysis explores the botanical, phytochemical, pharmacological, and ethnobotanical aspects of Himalayan Dioscorea villosa. The review synthesizes existing literature to provide insights into its taxonomical classification, morphological characteristics, and distribution patterns in the Himalayan ecosystem. It delves into the phytochemical profile of Dioscorea villosa, highlighting the presence of bioactive compounds such as diosgenin, flavonoids, alkaloids, and saponins. Moreover, the review examines the traditional uses of Himalayan Dioscorea villosa in folk medicine, shedding light on its purported therapeutic properties in treating various ailments. Furthermore, this analysis critically evaluates pharmacological studies elucidating the anti- inflammatory, antioxidant, antimicrobial, anticancer, and hormone-modulating activities of Dioscorea villosa extracts and isolated compounds. The pharmacokinetics and toxicological aspects of Himalayan Dioscorea villosa are also discussed, emphasizing the need for further research to ascertain its safety profile and dosage recommendations. Additionally, cultivation practices and conservation strategies for sustaining wild yam populations in the Himalayan region are addressed.

Pseudomonas fortuita sp. nov., isolated from the endosphere of a wild yam

A Gram-negative, strictly aerobic bacterial strain was isolated from asymptomatic leaf tissue of a wild yam plant. Optimal growth was observed at 28 °C and pH 7, and catalase and oxidase activities were detected. Polyphasic taxonomic and comparative genomics revealed that strain LMG 33091T represents a novel species of Pseudomonas. The nearest phylogenetic neighbours of strain LMG 33091T were Pseudomonas putida NBRC 14164T (with 99.79 % 16S rRNA sequence identity), Pseudomonas alkylphenolica KL28T (99.28 %) and Pseudomonas asplenii (99.07 %) ATCC 23835T. MALDI-TOF MS analysis yielded distinct profiles for strain LMG 33091T and the nearest phylogenetic neighbours. Average nucleotide identity analyses between the whole genome sequence of strain LMG 33091T and of the type strains of its nearest-neighbour taxa yielded values below the species delineation threshold and thus confirmed that the strain represented a novel Pseudomonas species, for which we propose the name Pseudomonas fortuita sp. nov., with strain LMG 33091T (=GMI12077T= CFBP 9143T) as the type strain.

The association between Dioscorea sansibarensis and Orrella dioscoreae as a model for hereditary leaf symbiosis.

Hereditary, or vertically-transmitted, symbioses affect a large number of animal species and some plants. The precise mechanisms underlying transmission of functions of these associations are often difficult to describe, due to the difficulty in separating the symbiotic partners. This is especially the case for plant-bacteria hereditary symbioses, which lack experimentally tractable model systems. Here, we demonstrate the potential of the leaf symbiosis between the wild yam Dioscorea sansibarensis and the bacterium Orrella dioscoreae (O. dioscoreae) as a model system for hereditary symbiosis. O. dioscoreae is easy to grow and genetically manipulate, which is unusual for hereditary symbionts. These properties allowed us to design an effective antimicrobial treatment to rid plants of bacteria and generate whole aposymbiotic plants, which can later be re-inoculated with bacterial cultures. Aposymbiotic plants did not differ morphologically from symbiotic plants and the leaf forerunner tip containing the symbiotic glands formed normally even in the absence of bacteria, but microscopic differences between symbiotic and aposymbiotic glands highlight the influence of bacteria on the development of trichomes and secretion of mucilage. This is to our knowledge the first leaf symbiosis where both host and symbiont can be grown separately and where the symbiont can be genetically altered and reintroduced to the host.

The association between Dioscorea sansibarensis and Orrella dioscoreae as a model for hereditary leaf symbiosis

Hereditary, or vertically-transmitted, symbioses affect a large number of animal species and some plants. The precise mechanisms underlying transmission of functions of these associations are often difficult to describe, due to the difficulty in separating the symbiotic partners. This is especially the case for plant-bacteria hereditary symbioses, which lack experimentally tractable model systems. Here, we demonstrate the potential of the leaf symbiosis between the wild yam Dioscorea sansibarensis and the bacterium Orrella dioscoreae (O. dioscoreae) as a model system for hereditary symbiosis. O. dioscoreae is easy to grow and genetically manipulate, which is unusual for hereditary symbionts. These properties allowed us to design an effective antimicrobial treatment to rid plants of bacteria and generate whole aposymbiotic plants, which can later be re-inoculated with bacterial cultures. Aposymbiotic plants did not differ morphologically from symbiotic plants and the leaf forerunner tip containing the symbiotic glands formed normally even in the absence of bacteria, but microscopic differences between symbiotic and aposymbiotic glands highlight the influence of bacteria on the development of trichomes and secretion of mucilage. This is to our knowledge the first leaf symbiosis where both host and symbiont can be grown separately and where the symbiont can be genetically altered and reintroduced to the host.

Climate-Adapted Circular Poultry Production: Salt-Treated Wild Yam Tubers as Sustainable Supplementary Feed Ingredients Via Osmosis-Based Detoxification

Wild yams have tremendous potential as nutritious food and feed sources. However, anti-nutritional factors like oxalates and phenolics limit their utilization. This study evaluated salt-assisted osmosis for detoxification and nutritional improvement of wild yam tubers and assessed their application as a feed ingredient for native chickens. Wild yam tubers were treated with 10%, 20%, and 30% salt solutions to induce osmosis-based leaching of water-soluble toxins. Proximate analyses confirmed nutrient retention post-treatment. Four isonitrogenous experimental chicken feeds were formulated with varying proportions of standard commercial diet and salt-treated wild yam meal. Ninety-six 5-week-old native chicks were randomly allocated to the diets for 8 weeks to assess growth performance, intake, meat quality, and physiological parameters. Toxin levels decreased up to 50% with a 30% salt solution while beneficial nutrients were preserved. The inclusion of treated yam meal did not adversely affect growth rate, though higher salt levels reduced feed palatability. Carcass traits remained unaffected although minor organ weight and serum biomarker changes indicated physiological stress. Salt-assisted osmosis the demonstrates potential for efficient detoxification to promote better utilization of under-explored nutritious crops like wild yam as sustainable, alternative feed sources without compromising nutritional adequacy. Further optimization to prevent anti-nutrient reaccumulation and physiological imbalance is recommended before scalability for food/feed security.

Nutritional value, anti-nutrient and amino acid profile of raw and processed wild aerial yam (Dioscorea bulbifera) meal

The study evaluated the effect of different processing methods (boiling, toasting and soaking) on the nutrient and of wild aerial yam (Dioscorea bulbifera). One kilogram of raw wild Dioscorea bulbifera (RWDB) was boiled for 30 minutes at 100?C, another one kg was soaked for 24 hours. Toasting of another one kg of Dioscorea bulbifera tubers were carried out for 30 minutes. The raw and processed tubers were dried, milled and chemically analysed for proximate compositions, phytochemical components, minerals and amino acid content. Mean dry matter, crude protein, lipid, fibre, ash and carbohyd-rate contents of boiled wild Dioscorea bulbifera meal were 10.86%, 89.14%, 11.63%, 32.28%, 4.10%, 3.61% and 66.53% respectively. There were significant differences (p<0.05) in all parameters for all the processing methods. RWDB meals was a good source of Calcium (0.27%), Phosphorus (0.38%), Magnesium (0.29%), Potassium (0.75%), Sodium (0.25%), Iron (56.78%), Copper (9.91%), Zinc (52.87%), Manganese (17.51%) and Cobalt (0.52%). Increase in contents of macro and micro minerals were observed during toasting and these were significantly (p<0.05) superior to raw and other processing methods. Values obtained for soaked WDB meal were significantly lower (p<0.05) in all the phytochemical substances (tannin 0.0012, oxalate 1940, flavonoid 0.002) determined, while boiled WDB meal had the least HCN. Boiling process improved the amino acid profile of WDB meal, and there were significant differences (p<0.05) in all its parameters. Boiling compared to other methods appeared to be the best in terms of nutrient content, anti-nutritional factors and amino acid profile, therefore stands as the preferred method for preparing WDB as a livestock feed ingredient

Wild edible yams from Madagascar: New insights into nutritional composition support their use for food security and conservation.

Yams (Dioscorea species) are an important food resource in Madagascar, where both cultivated winged yam (D. alata) and wild edible yams are consumed. However, there is limited knowledge on the nutrient composition of wild edible yams in Madagascar, and on how they compare with the cultivated winged yam. Therefore, in this study, nine wild edible yam species, one with two subspecies from Madagascar (D. bako, D. buckleyana, D. irodensis, D. maciba, D. orangeana, D. pteropoda, D. sambiranensis subsp. bardotiae and subsp. sambiranensis, D. seriflora, and Dioscorea species Ovy valiha), were analyzed for their nutrient composition, compared with cultivated D. alata. They include 6/6 of the most favored wild edible yam species in Madagascar. New nutrient composition data (protein, carbohydrate/starch, energy, lipid, β-carotene, and minerals) are presented for these nine wild edible yam species. The results show that they contain comparable levels of lipids and starch to D. alata, but none are better sources of protein than D. alata. The results show that D. irodensis contains a significantly higher β-carotene content when compared to all other edible yams analyzed, and that D. buckleyana, D. irodensis, and D. sambiranensis subsp. bardotiae have a higher calcium content than cultivated D. alata, while all nine wild edible yam species analyzed contain a higher iron content, compared to cultivated D. alata. The nutrient composition data presented could provide new incentives to conserve wild edible yams and inform on strategies to select Dioscorea species for sustainable cultivation and use, providing opportunities to enhance future food security in Madagascar.

Blending neglected and underutilised wild yam tubers from forest to functional food

Blending neglected and underutilised wild yam tubers from forest to functional food

Physicochemical Properties of Wild Yam (Dioscorea villosa) Starch.

Native starch extracted from wild yam (Dioscorea villosa) was evaluated for its intrinsic physicochemical properties. From the results, essential metals such as K, Ca, P, and Fe were detected along with some nonessential heavy metals below the WHO permissible limits. Bulk density was 0.13-0.63 g/mL. The water absorption capacity, oil absorption capacity, swelling power, and solubility of the starch were pH-responsive. Thermal profiles showed onset temperature, To (59.21 °C), peak temperature, Tp (60.22 °C), endset temperature, Tc (63.12 °C), gelatinization enthalpy, ΔHgel (0.54 J/g), temperature range of gelatinization, R (3.91 °C), and peak height index, PHI (1.87 J/g °C). Exhibiting a crystallite size of 0.03 nm, absorption peaks of 15.3119°, 24.4120°, and 18.4170°, corresponding to interplanar d-spacings of 3.7500 Ǻ, 5.14000 Ǻ, and 4.954610 Ǻ, were obtained. Evidence of C-H at 1338.1 cm-1, C-O at 640.0 cm-1, C-H stretch at 2829.7 cm-1, and a strong and broad O-H group at 3291.2 cm-1 were obtained. The starch granules had low particle sizes, were homogeneous, and were aggregates of irregular shapes. At a lower pH (2-4), the wild yam starch studied could be a potential absorbent material in the production of disposable diapers and female napkins and as biodegradable films due to its high hydrophobicity at a high pH (8-12).