Total Oxalate Research Articles

Effect of crop maturity stages and lactic acid fermentation on nutrient absorption properties, and bioaccessibility of Fe, Zn and Ca in Spinacia oleracea L

This study explores the variability in nutritional composition of spinach at different maturity stages and assesses the effects of fermentation on reducing oxalates and enhancing minerals bioaccessibility. Spinach harvested at the age of 4th to 6th weeks was processed as raw, blanched, and fermented to develop freeze-dried powders. The growth stages of spinach from the 4th to the 6th week showed a significant (p < 0.05) increase in crude fiber (12.1 – 16.1 g/100 g), protein (6.6 – 12.1 g/100 g), inorganic residues (9.7 – 12.3 g/100 g), total carbohydrates (75.0 – 65.4 g/100 g), Fe (150 – 297 mg/kg), Ca (147 – 236 mg/kg), vitamin C (96 – 111 mg/100 g), and total oxalates (1.46 – 2.35 g/100 g) on a dry weight basis (d.w.). The lowest levels of oxalates were recorded in 4 week-old raw, blanched and fermented spinach, i.e., 1.46, 1.07 and 1.01 g/100 g d.w., respectively. The bioaccessibility of Fe, Zn, and Ca were the lowest in 6th week old spinach, while fermentation with Lactiplantibacillus plantarum v299® improved the bioaccessibility of Fe, Zn and Ca from 19.6 % to 26.7 %, from 32.4 % to 41.6 %, and, from 19 % to 33.9 %, respectively. In conclusion, the findings showed that blanching in combination with lactic acid fermentation in spinach was effective in reducing antinutrients, specifically oxalates, and increasing mineral bioaccessibility.

Fermenting kale (Brassica oleracea L.) enhances its functional food properties by increasing accessibility of key phytochemicals and reducing antinutritional factors.

The properties of kale as a functional food are well established. We sought to determine how fermentation further enhances these properties. We tested different fermentation conditions: (i) spontaneous fermentation with naturally occurring bacteria, (ii) spontaneous fermentation with 2% salt, (iii) Lactococcus lactis, (iv) Lactobacillus acidophilus, (v) mixture of L. lactis and L. acidophilus, (vi) mixture of L. lactis, L. acidophilus, and Clostridium butyricum. We quantified selected bioactive components using high-performance liquid chromatography (HPLC) and antinutritional factors using a gravimetric method and spectrophotometry. We then determined (i) the antioxidant capacity of the vegetable, (ii) anti-inflammation capacity, and (iii) the surface microbiota composition by 16S sequencing. All fermentation methods imparted some benefits. However, fermentation with mixed culture of L. lactis and L. acidophilus was most effective in increasing polyphenols and sulforaphane accessibility, increasing antioxidant activity, and reducing antinutritional factors. Specifically, fermentation with L. lactis and L. acidophilus increased total polyphenols from 8.5 to 10.7 mgGAE/g (milligrams of gallium acid equivalent per gram) and sulforaphane from 960.8 to 1777 μg/g (microgram per gram) but decreased the antinutritional factors oxalate and tannin. Total oxalate was reduced by 49%, while tannin was reduced by 55%-65%. The antioxidant capacity was enhanced but not the anti-inflammation potential. Both unfermented and fermented kale protected equally against lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages and prevented increases in inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 messenger RNA (IL-6 mRNA) expression by 84.3%, 62%, 68%, and 85.5%, respectively. Unfermented and naturally fermented kale had high proportions of sulfur reducing Desulfubrio and Proteobacteria usually associated with inflammation. Fermenting with L. lactis and/or L. acidophilus changed the bacterial proportions, reducing the Proteobacteria while increasing the genera Lactobacilli and Lactococcus. In summary, fermentation enhances the well-known beneficial impacts of kale. Fermentation with mixed cultures of L. lactis and L. acidophilus imparts higher benefits compared to the single cultures or fermentation with native bacteria present in the vegetable.

Multiomics Assessment of the Gut Microbiome in Rare Hyperoxaluric Conditions

IntroductionHyperoxaluria is a risk factor for kidney stone formation and chronic kidney disease progression. The microbiome is an important protective factor against oxalate accumulation through its oxalate-degrading enzyme activity. In this cross-sectional study, we leverage multi-omics to characterize the microbial community of participants with primary and enteric hyperoxaluria, as well as idiopathic calcium oxalate kidney stone (CKS) formers, focusing on the relationship between oxalate degrading functions of the microbiome. MethodsPatients diagnosed with Type I Primary Hyperoxaluria (PH), Enteric Hyperoxaluria (EH), and CKS were screened for inclusion in the study. Participants completed a food frequency questionnaire recording their dietary oxalate content while fecal oxalate levels were ascertained. DNA and RNA were extracted from stool samples and sequenced. Metagenomic and metatranscriptomic data were processed through our bioinformatics pipelines, and microbiome diversity, differential abundance, and networks were subject to statistical analysis in relationship with oxalate levels. Results38 subjects were recruited, including 13 healthy participants, 12 patients with recurrent CKS, 8 with PH, and 5 with EH. Urinary and fecal oxalate were significantly higher in the PH and the EH population compared to healthy controls. At the community level, alpha- and beta-diversity indices were similar across all populations. The respective contributions of single bacterial species to the total oxalate degradative potential were similar in healthy and PH subjects. Metatranscriptomic-based network analysis identified the most interactive bacterial network in PH patients. EH patients had a decreased abundance of multiple major oxalate degraders. ConclusionThe composition and inferred activity of oxalate-degrading microbiota were differentially associated with host clinical conditions. Identifying these changes improves our understanding of the relationships between dietary constituents, microbiota, and oxalate homeostasis, and suggests new therapeutic approaches protecting against hyperoxaluria.

Nutritional evaluation of Colocasia esculenta (L.) Schott leaves and corms from KwaZulu-Natal, South Africa

Green leafy vegetables (GLVs) are good sources of vital nutrients for human health sustenance. In this study, the nutrient compositions of Colocasia esculenta L. (Schott) leaves and corms from both Southern and Northern locations of KwaZulu-Natal province were investigated. Total, soluble, and insoluble oxalates and soil minerals were analysed to establish nutrient-plant organ correlations. Substantial variations were observed in nutrient contents among plant parts and locations. Young leaves in both locations showed higher phosphorus content and the northern location had the highest potassium levels in both young and mature leaves. Zinc and copper contents of leaf tissues were relatively low, ranging from 1.9 to 4.7 mg/100 g and 0.48–1.46 mg/100 g FW, respectively, whereas manganese (2–64 mg/100 g FW) and iron (13 – 88 mg/100 g FW) showed higher variability. While oxalate levels showed minimal location effects, corms had more than double the total oxalate content (35–39 g/100 g FW) of leaf tissues. Despite variations in mineral profile, Colocasia esculenta leaves can serve as a valuable source of essential micronutrients to address micronutrient needs in vulnerable communities.

Assessment of oxalates and phytic acid contents in Asian green leafy vegetables: Dietary recommendations

Increased vegetable consumption is one of the recommended dietary interventions for optimal health but there is a lack of documentation about their anti-nutrients content, such as oxalates and phytic acid, which can modulate other health risks such as mineral deficiencies and urinary stone formation. The objective of this study was to evaluate the oxalates and phytic acid content of 26 green leafy vegetables (GLV) indigenous to and commonly consumed in Asia to expand existing nutritional information on food sources. The total oxalate contents ranged from 6 ± 0.2 mg/100 g fresh weight (FW) (iceberg lettuce) to 557 ± 47 mg/100 g FW (spinach), while the soluble oxalate contents ranged from 2 ± 0.3 mg/100 g FW (iceberg lettuce) to 501 ± 36 mg/100 g FW (turmeric leaves). The phytic content of the GLV ranged from 6 ± 2 mg/100 g FW (celery) to 111 ± 16 mg/100 g FW (moringa leaves). Overall, the anti-nutrients data have provided an increased understanding of these Asian GLV which will be important for nutritional and healthcare professionals to improve the dietary regime of the population. Data will also allow general consumers to make informed choices on how best these GLV can contribute to optimal health.

Physicochemical Analysis of Taro (Colocasia esculenta (L.) Schott) Accessions

Taro is an important staple meal for rural people in resource-poor nations in sub-Saharan Africa countries. This study looked at the proximate, mineral, and anti-nutrient content of whole taro corm. Understanding the extent and distribution of genetic diversity in taro is critical for creating conservation and enhancement initiatives. The aim of the study was to assess nutritional diversity and construct a taro pre-breeding population for high dry matter and low oxalate levels. One hundred and eighty eight taro accessions were procured and planted in alpha lattice design in 2019 at Ebonyi State University's teaching and experimental fields. The corms were picked from each accession, washed, and shipped to Nigeria's National Root Crop Research Institute Biochemistry Laboratory. The corms were freeze-dried, crushed, and analyzed for physiochemical parameters using the standard techniques of analysis provided by the Association of standard Analytical Chemists. Significant differences were observed among the taro populations in dry matter content at 22.53 %, ash at 2.46 %, crude lipid at 0.60 %, fibre at 1.74 %, crude protein at 7.79 %, carbohydrates at 9.97 %, and energy at 76.48 Kcal. Potassium content was at 638.91 mg/100 g, sodium at 28.39 mg/100g, calcium at 35.18 mg/100g, phosphorus at 117.61 mg/100g, iron at 7.78 mg/100g, zinc at 2.84 mg/100g, and manganese at 2.03 mg/100g. The soluble, insoluble, and total oxalate concentration was at 74.18 mg/100g, 218.76 mg/100 g, and 291.63 mg/100 g, respectively. A hierarchical cluster analysis of taro accessions revealed three distinct groupings, with cluster three distinguished by high dry matter content and an intermediate oxalate level. The findings revealed the existence of a considerable differential in nutritional content among the taro populations analyzed. Taro is divers in its dry matter and anti-nutrient content. Clustering the accessions according to their merit would aid breeders in sorting genotypes for eating quality metrics like high dry matter and low oxalate levels. These results, needs further work for reliability.

#4328 CHK-336, A FIRST-IN-CLASS ORALLY ADMINISTERED LDH INHIBITOR: SAFETY, PK AND TARGET ENGAGEMENT IN A FIRST-IN-HUMAN PHASE 1 HEALTHY VOLUNTEER STUDY

Abstract Background and Aims CHK-336 is a first-in-class, orally bioavailable, liver-targeted small molecule lactate dehydrogenase (LDH) inhibitor for the treatment of primary hyperoxalurias and other kidney stone disorders caused by oxalate overproduction. The primary objectives of this first-in-human (FIH) study were characterization of the safety and pharmacokinetics (PK) of CHK-336 following single and repeat doses in healthy volunteers (HVs). Exploratory objectives were demonstration of proof of mechanism in HVs based on inhibition of hepatic oxalate production using a stable-label 13C2-glycolate tracer for hepatic LDH target engagement and characterization of the exposure-response relationship. Method This Phase 1, placebo-controlled (6:2 randomization within a cohort), dose escalation study explored single ascending (SAD, 15-500 mg) and multiple ascending (MAD, 30 mg and planned up to 500 mg QD, 14 consecutive days) doses. A total of 104 subjects will be enrolled in this study. A stable-label 13C2-glycolate tracer was administered orally at baseline and following CHK-336 administration to evaluate the inhibition of LDH-mediated production of [13C2]-oxalate by CHK-336, as a measure of hepatic LDH target engagement in HVs. Food-effect was evaluated following a single dose after a standard high fat meal. CHK-336 concentrations were determined in plasma and urine by a validated LC-MS/MS assay. Total oxalate and 13C2-oxalate were determined in urine by validated GC/MS assays. Results CHK-336 was generally well tolerated following single doses from 15 – 500 mg, with no dose-related trends in total adverse events (AEs) or types of AEs. There were no serious AEs, or severe treatment-related AEs (TRAEs). Treatment-emergent AEs were observed in 10 of 56 (17.9%) subjects, 7 (12.5%) of whom experienced TRAEs; all TRAEs were mild or moderate in severity. CHK-336 PK profiles were characterized with a median tmax of 6 hrs following absorption in fasted-state followed by bi-exponential decline and a terminal half-life of 18 ± 8 hrs. Dose-proportional increases in exposure AUC were observed from 15 up to 500 mg. Cmax increase was greater than dose-proportional at ≥60 mg with a concomitant decrease in median tmax from 6hr to 2hr. A high fat meal decreased CHK-336 AUC0-72h by 32% (AUC0-72h) and Cmax by 55%. Renal elimination of unchanged CHK-336 was quantitatively minor (&amp;lt;1% of administered dose). A direct effect inhibitory Imax-IC50 model adequately described the relationship between CHK-336 plasma concentrations and urinary 13C2-oxalate (% of control). Robust target engagement was demonstrated with an exposure-related reduction in urinary 13C2-oxalate from 15 – 60 mg, with maximum inhibition achieved at CHK-336 doses ≥60 mg. Conclusion CHK-336 is a first-in-class, orally administered, liver-targeted LDH inhibitor that was generally well-tolerated following single doses from 15 – 500 mg, with dose proportional increases in AUC exposure. Hepatic oxalate production was robustly reduced by CHK-336, as measured by urinary 13C2-oxalate, thus achieving proof of mechanism in HVs.

Assessment of ethnobotanical uses, household, and regional genetic diversity of aroid species grown in northeastern India.

Aroids are an important group of indigenous tuber crops, grown widely for their leaves, petioles, stolons, corms, and cormels. A total of 53 genotypes were evaluated for their genetic diversity in northeastern region of India. At household level, a total of 16 landraces of Aroids were recorded having different ethnobotanical uses. Based on the population study under Jhum/Shifting farming, landrace Rengama was dominant in area with 47% of the total population followed by Tamachongkham and Tasakrek. However, Pugarkusu and Chigi occupied 33.0 and 24.0% of the population, respectively under backyard farming, and were considered as major landraces. Tamachongkham, high in acridity and total oxalate content (0.82%), was used for cooking with meat, while Tasakrek was used as a baby food due to high total sugar (>3.0%), low in acridity, and total oxalate content (<0.12%). The Simpson's diversity index of the backyards was higher (0.80) as compared to Jhum field (0.63). The genotypes showed wider variability in growth and yield attributes like; plant height (89.4-206.1 cm), number of side shoots (1.84-5.92), corm weight (38.0-683.3 g), cormel weight (14.0-348.3 g), yield (0.24-1.83 kg plant-1). Similarly, wide variations were also observed for quality traits like total sugar (1.93-4.94%); starch (15.32-32.49%), total oxalate (0.10-0.82%), and dry matter (16.75-27.08%) content. Except for total oxalate, all the growth and yield attributes have shown high heritability and moderate to high genetic advance. Molecular analysis (33 polymorphic SSR markers) detected a total of 136 alleles, ranged 3 to 8 alleles per marker. The observed heterozygosity (0.24) was less than expected heterozygosity (0.69). The group-wise maximum genetic divergence was observed between Colocasia fallax (cv. Chigi) to C. esculenta var. aquatilis (cv. Tharsing); C. fallax (cv. Chigi) to C. gigantea (cv. Ganima) and C. gigantea (cv. Ganima) to Xanthosoma spp., while it was least between eddo and dasheen. The findings indicated, a wider diversity and distinct ethnobotanical uses of Aroid landraces at the house hold levels, which should be conserved and popularized to ensure nutritional security.

Quantitative Determination of Oxalic and Phytic Acids of Lippia Multiflora Moldenke (Verbenaceae) Leaves and In Silico Study of Their Interaction with Haemoglobin S and 2,3-DPG-Mutase

The aim of this study is to measure oxalic and phytic acids from the leaves of Lippia multiflora and to evaluate their anti-sickle cell activity in silico. The histological characterization of the leaves of L. multiflora was performed by optical micrography. Theseanti-nutritional factors oxalic acid and phytic acid were determined by the standard method. Discovery Studio, ChemDraw and Autodock Vina software were used in molecular modeling. The pharmacokinetic and toxicological profile was evaluated using the bioinformatics descriptor SWISSADME. Histological analysis shows that fibres, sclerites and suber fragments are characteristic tissues of L. multiflora leaves. These leaves contain oxalic acid (insoluble oxalates: 51.457±27.653 mg/100 g DM; total oxalates: 59.483±0.704 mg/100 g MS; calcium oxalates: 0.216±0.0021 mg/100 g MS) and phytic acid (18.400±5.062 mg/100 g MS). Oxalic acid interacts more effectively with 2,3-diphospgoglycerate mutase (ΔG=-5.30±0.03 kcal/mol) while phytic acid interacts more strongly with deoxyhemoglobin S (ΔG=-9.30±0.01 kcal/mol) in silico. Phytic acid interacts with deoxyhemoglobin S by two hydrogen bonds (Arginine 31 and Lysine 120) while oxalic acid forms five hydrogen bonds with 2,3-DPG mutase (Arginine 10, Asparagine 17; Arginine 62; Histidine 188 and Glycine 189). The pharmacopharmacokinetic profile shows that these compounds do not inhibit cytochrome P450 complex enzymes and are not toxic. Both compounds represent added value for L. multiflora in the symptomatic treatment of sickle cell disease. In addition to attenuating hypersideremia, they can inhibit erythrocyte sickle formation via interaction with both protein receptors.

Nutritional Composition, Antinutrient Contents, and Polyphenol Compounds of Selected Underutilized and Some Commonly Consumed Vegetables in East Wollega, West Ethiopia

In Ethiopia, some plants (Ethiopia kale, Swiss chard, and celery) remain underutilized for human consumption, as information on their nutritional potential remains limited. As a result, the purpose of this study was to determine the proximate, mineral, antinutrient, and phytochemical content of Ethiopia kale (Brassica carinata), Swiss chard (Beta vulgaris), carrot (Daucus carota), tomato (Lycopersicon esculentum), and cabbage (Brassica oleracea) using standard analytical methods. The moisture, crude protein, crude fiber, crude fat, total ash, total carbohydrate, and energy contents were found to be 6.44–16.62%, 6.76–33.64%, 9.19–54.86%, 0.50–4.00%, 1.00–2.75%, 7.28–68.73%, and 141.06–333.28 kcal/100 g, respectively. Ethiopia's kale had a high protein content, while celery had a high fat and fiber content. The calcium, magnesium, iron, phosphorous, potassium, zinc, and sodium content (mg/100 gdb) ranged between 8.00 and 306.00, 8.10–11.83, 0.64–4.85, 11.34–63.00, 2.83–810.00, 0.15–41.65, and 1.50–443.80 mg/100 g, respectively. Swiss chard contained magnesium, potassium, and sodium, whereas celery was high in calcium and iron. The total oxalate, condensed tannin, and phytate (mg/100 gdb) ranged as follows: 0.88–4.92, 138.27–892.19, and 69.14–265.99, respectively. Ethiopia’s kale recorded a comparatively low amount of tannin and phytate. High mineral bioavailability, such as calcium, iron, and zinc, was obtained in Ethiopia kale. The results also showed that Ethiopia's kale contained a good amount of total phenolic and flavonoid content. The findings indicated that Ethiopia kale was a significant source of protein, had low antinutrient content with high mineral bioavailability, and had the potential to formulate nutrient-rich infant and young child foods using staple cereals and pulse grains.

A STUDY ON QUANTITATIVE ESTIMATION OF ANTI-NUTRITIONAL FACTORS OF SYZYGIUM JAMBOS FRUIT AND ITS SEED

Syzygium jambos (L.) Alston is an evergreen tree that belongs to the Myrtaceae family. It is commonly found in the South-East region of Asia. The fruit of this plant is known as “Rose apple”, “Malabar plum” and “Golap-jam” in West Bengal (India). This fruit and its seed have beenObjective: used in Ayurveda from ancient times. Although it is not very popular as fruit among people. This study was carried out to identify the anti- nutritional factors (oxalate, phytate, alkaloids, tannin and saponins) present in the fruit and its seed. The total oxalate, phytate, alkaloid,Results: tannin and saponin content of Syzygium jambos fruit was found to be 4.54 mg/100g, 5.68 mg/100g, 3.53 mg/100g, 32.43mg/100g, 386.49mg/100g respectively. The total oxalate, phytate, alkaloid, tannin and saponin content of Syzygium jambos seed was found to be 9.87 mg/100g, 7.34 mg/100g, 5.38 mg/100g, 168.29 mg/100g, 528.55 mg/100g respectively. A comparative study of anti-nutritional factors has beenConclusion: done among 3 fruits (Jackfruit, Mango, Syzygium jambos) and their respective seeds. The results show that Syzygium jambos (fruit &amp; seed) has less quantity of antinutritional factors than commonly consumed fruits (Jackfruit &amp; Mango) and their seeds. So, it may be concluded that Syzygium jambos fruit and its seed may be safe to include in the daily diet. These may not lead to any adverse health effects. Moreover, S.jambos fruit and its seed may be benecial to meet daily dietary requirements for maintaining a good nutritional status for humans.

Do the Invasive Earthworms Amynthas agrestis (Oligochaeta: Megascolecidae) and Lumbricus rubellus (Oligochaeta: Lumbricidae) Stimulate Oxalate-Based Browser Defenses in Jack-in-the-Pulpit (Arisaema triphyllum) by Their Presence or Their Soil Biogeochemical Activity?

The introduction of invasive earthworms initiates physical and chemical alterations in previously earthworm-free forest soils, which triggers an ecological cascade. The most apparent step is the shift in the herbaceous plant community composition. However, some species, such as Arisaema triphyllum (jack-in-the-pulpit), persist where earthworms are present. It has been hypothesized that A. triphyllum produces insoluble oxalate, an herbivory deterrent, in the presence of earthworms. This study aimed to distinguish between the effects of earthworm-induced changes in soils and the physical presence of earthworms on oxalate production. As such, a two-way factorial greenhouse trial was conducted using uninvaded soils to test this hypothesis for two invasive earthworm species (Amynthas agrestis and Lumbricus rubellus). The sequential extraction of oxalates in A. triphyllum corms was performed with absolute ethanol, deionized water, acetic acid and HCl, representing fractions of decreasing solubility. Earthworm presence increased water-soluble (p = 0.002) and total oxalate (p = 0.022) significantly, but only marginally significantly for HCl-soluble oxalate (p = 0.065). The corms of plants grown in soils previously exposed to the two species did not differ in oxalate production when earthworms were not present. However, the data suggest that earthworms affect corm oxalate concentrations and that the sequence of invasion matters for oxalate production by A. triphyllum.

Nutritional Potential of Pulp Powders of Safou (Dacryodes edulis var Edulis): Effects of Cooking Treatments

Aims: The objective of this study is to determine the physicochemical characteristics, functional properties, antioxidant and anti-nutrient activities of pulp powders of Safou (Dacryodes edulis var edulis) according to cooking methods in order to promote their consumption for food security.&#x0D; Study Design: Biochemical and technological studies.&#x0D; Place and Duration of Study: Laboratory of Biocatalysis and Bioprocessing, Abidjan, Côte d’Ivoire.&#x0D; Methodology: Three different Safou powders were prepared (PSS, PSV and PSEB). PSS (Safou pulp was not cooked before drying); PSV (Safou pulp was steamed before drying) and PSEB (Safou pulp was cooked in hot water before drying). The determination of the physicochemical characteristics concerned rates of dry matter, ashes, proteins, lipids, carbohydrates and energy value. The determination of the functional properties concerned water and oil capacity, water solubility index, bulk density, porosity, wettability, foaming capacity, hydrophilic-lipophilic ratio, swelling, solubility, foam stability and dispersibility. The determination of antioxidant and anti-nutrient activities concerned total polyphenols, tannins, DPPH, iron reducing power, total oxalates and phytates.&#x0D; Results: Uncooked Safou pulp powders (PSS) are good sources of protein, ash, lipid and polyphenols. Cooking improved carbohydrate and energy values and the functional properties and lowered the anti-nutritional factors of Safou pulp powders.&#x0D; Conclusion: The different cooking methods applied to the Safou pulp had an influence on the contents of nutrients. The powder of Safou cooked in boiling water (PSEB) showed the best functional properties and lowered the anti-nutrient factors. It could be recommended for the enrichment of local infant flours.

The effect of the boiling process on the Oxalic acid content of some vegetables in the Syrian local market

Oxalic acid HOOC-COOH (OA) is the first in the homologous series of dicarboxylic acids. It is one of the most common acids present in vegetable world1, it is one of the abundant organic compound acts as an anti-nutrient present in most vegetables in various quantities. It is found as salts of insoluble complexes with divalent cations, minerals and trace elements. Oxalates react with calcium to precipitate calcium oxalate and accumulation of oxalates in the body prevents the absorption and utilization of calcium; which in turn causes calcium imbalance, rickets and osteomalacia. In the present study oxalate content of various vegetables commonly available in local market of Syria were determined and effect of boiling on oxalate content of selected vegetable were investigated. Most of the samples analyzed were contained more than 100mg/100g on dry weigh basis. The higher value of total oxalate content was found in Parsley (1466.82 mg/100g); spinach and Cabbage contain (478.7, 191.08 mg/100g). Boiling has shown reduction in total oxalate content and least reduction was obtained in Parsely leaves (28.33%) and highest reduction was obtained from Spinach (40.00%)

Evaluation of Enzymatic and Chemical Treatments to Produce Oxalate Depleted Starch from a Novel Variety of Colocasia esculenta Grown in Joida, India

AbstractThis research aimed to study granular and molecular structures, physicochemical, and functional properties of the starch extracted from a novel, dasheen type of taro conserved, and cultivated by several generations of Kunabi tribes of Joida, Karnataka, India. Further, an enzymatic (oxalate oxidase) and chemical (phosphoric acid) treatment processes are evaluated for reducing total oxalate content in the starch extracted from the taro flour. The total oxalate content of the taro flour is found to be 2344 mg 100 g−1, and the starch yield is about 45% in all the methods. The oxalate oxidase (OxO) and phosphoric acid treatment reduced the total oxalate content by 98.37% and 98.03%, respectively. The residual oxalate content in the resultant starch is within the threshold limit (71 mg 100 g−1). The study of characteristic properties of enzyme‐treated (ET), phosphoric acid‐treated (PT), and native starch (NT) revealed minor changes in ET and PT compared to NT.

Antioxidants Capacity, Phenolic and Oxalate Content from Two Varieties of Solanum melongena at Different Maturity Stages

Aims: To investigate the antioxidant activities, total phenolic and oxalate contents in two varieties of eggplant (Solanum melongena) (terung telunjuk (TT) and terung rapuh (TR)) at different maturity stages.&#x0D; Study design: Each sample was extracted three times (n=3) for the antioxidant activities, total phenolic and oxalates content. All the data were analysed by using ANOVA and Tukey Pairwise tests.&#x0D; Place and duration of study: Malaysian Agricultural Research and Development Institute (MARDI), between December 2019 and October 2020.&#x0D; Methodology: Two varieties of eggplant (TT and TR) were cultivated and the samples were tagged and the fruits were harvested according to their maturity stages (stage 1 – stage 4). Samples were freeze dried and extracted to evaluate the antioxidant activities as well as the total phenolic and oxalate contents.&#x0D; Results: Total phenolic contents (TPC) in TR were lower from stage 1 to stage 3 but high at over mature stage (stage 4) meanwhile TPC in TT increased upon maturity. The DPPH assay from the fruit extracts of TT in all maturity stages showed a stronger antioxidant activity as compared to TR, in which fruit of TT from stage 3 was double in antioxidant activity as compared to TR. The FRAP assay of both eggplants showed extracts of TT having a higher ferric reduction power in all stages as compared to TR. Meanwhile, both eggplant varieties showed different total, soluble and insoluble oxalate contents in all maturity indices. TT had the highest total oxalate content at stage 1 as compared to TR while the soluble oxalate content increased in TR in all maturity stages. The highest percentage of soluble oxalate content was observed in TR at stage 4 with 95.5%. Conclusion: Phytochemical findings from these eggplant varieties showed their potentials to improve livelihood and public health. More comprehensive studies on the bioactive compounds, structural elucidation and pharmacological evaluation are to be conducted to understand the possible effects of these phytochemical results.

Transformation of crystalline and short-range order minerals in a long-term (47 years) rice-rice cropping system

The effect of long-term fertilizer and manure applications on short-range order (SRO) and crystalline mineral transformation was studied in a 47-year puddled rice-rice cropping system experiment in Odisha, India. The relationship of SRO minerals with phosphorus and potassium fixation capacity and soil carbon fractions was also evaluated. Soils from different treatment combinations of farmyard manure (FYM), nitrogen (N), phosphorus (P) and potassium (K) were separated in two ways: (i) removal of binding materials (ii) non-removal of binding materials (ultrasonic vibration), followed by fractionation of the contents into silt and clay. All crystalline minerals, SRO minerals, P and K fixation were measured in silt and clay. The X-ray diffractograms of clays (<2 μm) were recorded in Philips Diffractometer (model PW 1710). Selective dissolutions of SRO minerals were carried out by extraction with sodium hydroxide, acid ammonium oxalate, dithionite-citrate-bicarbonate and sodium pyrophosphate. The results showed that the soils were composed of kaolin (49.6–54.4%), mica (32.7–39.0%) and smectite (10.6–17.0%). The clay-size mica loses its crystallinity and becomes finer after the addition of fertilizers and manure during intensive rice cultivation. The content of amorphous ferri-aluminosilicate varied from 8.0 to 16.23 g 100 g−1 in clay and 1.49–3.38 g 100 g−1 in silt. The plots treated with NP + FYM had the highest total oxalate extractable oxide in both clay and silt. Application of FYM increased ferrihydrite in both clay and silt. Potassium fixation was higher in plots skipped with the long-term application of K. Formation of SRO minerals was positively affected by nutrient stress caused by the omission of one or more nutrients. SRO minerals in the rice soil did not have a major effect on the fixation of K and P; rather, it is controlled by the fertilizer and FYM application. However, carbon fractions had a significant positive correlation with SRO minerals.

Oxalate-rich foods

The intake of large amounts of the antinutrient oxalate can induce hyperoxaluria, an important risk factor for the development of calcium oxalate stones. The soluble and total oxalate concentrations of plants of the Fabaceae, Convolvulaceae, and Malvaceae families were determined using an HPLC-enzyme-reactor method. Sweet potato is a species of the Convolvulaceae, Fabaceae includes beans, lentils, peas, licorice and blue fenugreek, whereas okra and cocoa are species of the Malvaceae family. Total oxalate content was highest in licorice root (Glycyrrhiza glabra; 3569 mg/100 g), an important medicinal herb and sweetener in candies, blue fenugreek (Trigonella coerulea; 1246 mg/100 g) and white beans (Phaseolus vulgaris L.; 548 mg/100 g), plants of the Fabaceae family. Total oxalate content amounted to 496 mg/100 g in sweet potato (Ipomoea batatas), 619 mg/100 g in cocoa powder (Theobroma cacao) and 317 mg/100 g in okra (Abdelmoschus esculentus), the most important agricultural crops of the Convolvulaceae and Malvaceae, respectively. The findings suggested that most foods of these plant families contain high to excessively high oxalate concentrations. The consumption of these oxalate-rich plants can negatively impact calcium oxalate stone formation.

Variation in oxalate content among corm parts, harvest time, and cultivars of taro (Colocasia esculenta (L.) Schott)

Taro (Colocasia esculenta L. Schott) is considered a dietary staple food crop for millions of people throughout tropical and subtropical regions. Depending on the cultivar, taro may contain oxalic acid deposited in plant tissues as calcium oxalate crystals, causing a very unpleasant burning sensation in the mouth. In the present study, oxalate content was quantified in four different parts of the taro corm, as well as variation in dry matter, Ca, and the oxalate content of corms harvested at different developmental stages, from 5 months after planting (MAP) to 13 MAP. The results revealed that the level of oxalates varies according to corm part and cultivar. The cultivars with the lowest and highest water-soluble and total oxalate content in the central part, which is critical for human nutrition, were VU268 (87 and 134 mg 100 g−1 DW) and VU384 (182 and 230 mg 100 g−1 DW, respectively). Water-soluble oxalates accumulate mainly in the central and lower parts, while insoluble oxalates are concentrated in the marginal part of the corm. Their content can be almost halved by removing a 1 cm thick marginal layer (peeling). The oxalate/Ca molar ratio ranged from 0.78 in the upper to 1.31 in the central part, suggesting that the bioavailability of Ca in corms could be low. The dry matter content and Ca, insoluble and total oxalate levels vary according to the harvest time. The lowest total oxalate content was determined at 8 MAP (the usual time for taro harvest), while water-soluble oxalates increased with growing period. The proper assessment of corm maturity before harvest is, therefore, a critical step in controlling corm quality. Taro breeding programs aimed at reducing corm acridity need to take into consideration these results when designing protocols for optimum nutritional quality improvement of new cultivars.

Effect of ensiling duration on nutritional composition and oxalate content in dwarf Napier grass silage

Napier grass (Pennisetum purpureum) is a common forage plant that is usually given to ruminant animals. Besides moderate nutritive values, this grass also contains anti-nutrients such as oxalate. Dietary soluble oxalate can combine with blood calcium (Ca) or magnesium (Mg) and form insoluble crystals, which can give negative effects on animal health. This study was conducted to assess the effects of ensiling durations on fermentation characteristics, nutritional composition and oxalate content of dwarf Napier grass silage. Plants were cultivated under standard level of fertiliser application, harvested at 45 days of plant maturity, and then chopped into 2-3 cm manually. Chopped grasses were mixed with 5% molasses (w/w), and filled in plastic bags, compressed and kept it in air-tight conditions in room temperature at five different ensiling durations (0, 15, 30, 60 and 90 days). Three replicates were made for each of the treatment durations. The fermentation characteristics, chemical composition and oxalate content, were evaluated. Silage at 30 day fermentation showed the highest lactic acid (10.02%) and NH3-N (1.79%) contents, while silage at 90 d fermentation showed the lowest lactic acid (3.47%) and NH3-N (1.50%) contents. The initial pH value (pH 5.01) and dry matter content (22.8%) declined to pH 4.36 and 20.2% at the end of 90 d ensiling period. Ensiling significantly improved the crude protein, ether extract and ash contents of Napier grass silage. The soluble, insoluble and total oxalate contents in silage decreased as ensiling durations increased. Ensiling also significantly improved the sodium contents of Napier grass silage, while no consistent trend was observed on Ca, Mg and potassium contents. The results suggest that at least 30 days of ensiling duration can be recommended for Napier grass silage to get the optimum nutrients and oxalate content.