Total Oxalate Contents Research Articles

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.

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.

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.

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.

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.

Oxalate and silica contents of seven varieties of Napier grass (Pennisetum purpureum)

Oxalate and silica are considered antinutrients. Large quantities of oxalate and silica in plants can interfere with the uptake of essential minerals in ruminants. Therefore, the aim of this study was to compare the total silica and oxalate contents of seven varieties of Napier grass to find out which is best for cultivation. Taiwan, Zanzibar, Pakchong, Purple, Kobe, Indian, and Dwarf Napier grass were grown in a completely randomized design with three replications to determine their soluble oxalate, total oxalate, and silica contents. Plants were harvested at two months of plant maturity. Whole plant of the Dwarf Napier grass contained significantly higher soluble oxalate content than tall varieties. Total oxalate content in whole plant differed significantly among varieties. Dwarf showed the highest total oxalate content (3.23% dry matter (DM)) followed by Kobe (2.61%), Zanzibar (2.60%), Purple (2.44%), Taiwan (2.43%), Indian (2.15%), and Pakchong (1.95%). Regardless of variety, leaf tissue contained significantly higher soluble oxalate and total oxalate than stem tissue. There were no differences in silica content among them. In conclusion, the tall varieties could produce lower levels of soluble oxalate than the Dwarf variety, whereas silica content might not vary among them.Keywords: botanical fractions, mineral bioavailability, ruminant

Determination of Oxalates in Corms of Selected Taro (Colocasia esculenta) Varieties in Malaysia Using Ultra High-Performance Liquid Chromatography

Aims: To determine the oxalate contents in different varieties of taro (Colocasia esculenta) collected in Peninsular Malaysia.&#x0D; Study Design: Ultra High-Performance Liquid Chromatography (UHPLC) with UV detector (Diode Array Detection, (DAD)) was used to determine the total and soluble oxalate contents in different varieties of taro corms. Meanwhile, the insoluble oxalate content (calcium oxalate) was estimated from the subtraction of soluble oxalate content from total oxalate content.&#x0D; Place and Duration of Study: Malaysian Agriculture Research and Development Institute (MARDI Headquarters), Persiaran MARDI-UPM, 43400 Serdang, Selangor, Malaysia between December 2018 to December 2019.&#x0D; Methodology: 9 different varieties of taro were collected from different locations in Peninsular Malaysia. All the samples were analysed for their oxalate contents. Extractions were carried out to determine the total oxalate and soluble oxalate contents. All the samples were analysed using UHPLC. The generated data of oxalate contents were analysed using Analysis of Variance (ANOVA).&#x0D; Results: There is a significant difference (P &lt;.05) between the oxalate content in the examined varieties with respect to the amount of total, soluble and insoluble oxalate contents. The putih variety has significantly the highest amount of total oxalate content with 218.8 ± 28.2 mg/100 g DW (dry weight) followed by the udang variety with 184.2 ± 24.7 mg/100 g DW and the wangi variety with 178.3 ± 5.1 mg/100 g DW. Tapak badak variety has the lowest total oxalate content with 70.5 ± 20.1 mg/100 g DW. Result showed that wangi variety has significantly the highest soluble oxalate content with 135.1 ± 4.8 mg/100 g DW followed by udang with 100.9 ± 49.8 mg/100 g DW. The lowest soluble oxalate content was found in tapak badak with 17.7 ± 2.9 mg/100 g DW.&#x0D; Conclusion: Despite many factors contributing to the difference in oxalate content between varieties, this study would help researchers or policy makers to suggest potential taros for commercial cultivation.

Infuence of chemically synthesized copper nanoparticles and cupric ions on oxalate oxidation system in germinating Sorghum grain

We have earlier reported the effects of chemically synthesized copper nanoparticles (CuNPs) on oxalate oxidase (OxOx) activity, extracted from the shoot tissue of germinating grain sorghum i.e. in vitro. Here, we tried to study this effect in vivo and compare it with those of Cu2+. We describe herein, characterization of CuNPs and their effects on oxalate oxidation system i.e. OxOx activity, total oxalate and H2O2 content in vivo i.e. in shoot tissues/leaves of germinating grain Sorghum (Sorghum vulgare L). To achieve it, grain sorghum seeds were grown up to 10 days in laboratory, irrigated with Hoagland’s solution containing either CuNPs (1.0 ppm) or Cu2+ (1.0 ppm) after 4 days of germination. Control were irrigated with Hoagland solution only. The shoot/leaves of the seedling plants were harvested at 4, 6, 8 and 10 day of germination and analysed quantitatively for OxOx activity, soluble protein, H2O2 and total oxalate. The growth of the Sorghum seedling plants supplemented with CuNPs and Cu2+ was decreased significantly (P <0.1) at all growth stages compared to control. This inhibitory effect of CuNPs was higher than Cu2+. CuNPs decreased the activity of OxOx but Cu2+ had no effect at day 10. Both CuNPs and Cu2+ decreased the specific activity of OxOx and H2O2 content but increased total oxalate content at day 10. The decrease in H2O2 content in both CuNPs and Cu2+ supplemented shoot tissues with concomitant increase in oxalate content confirmed the decreased activity of OxOx in CuNPs and Cu2+ supplemented seedling plants.

Estimation of Oxalate Content of Bottle Gourd Leaves

Bottle gourd leaves are widely used as animal feed in India. Consumption among the human beings, especially in low income group people are also found. But many of the leafy vegetables contain oxalate which may have hindering effect on the absorption of some important minerals like Calcium, Iron etc in human body. In this present study total oxalate content of bottle gourd leaves ( Lagenaria siceraria ) has been estimated by permanganate titration method. The result shows that the oxalate content of bottle gourd leaves ( Lagenaria siceraria ) is 49.086mg/100gm. The oxalate contents of some of the common leafy vegetable are also compared to the bottle gourd leaves ( Lagenaria siceraria ). From this study it may be concluded that oxalate content of bottle gourd leaves is much lower than that of other leafy vegetables.

Oxalate Contents of Raw, Boiled, Wok-Fried and Pesto and Juice Made from Fat Hen (Chenopodium album) Leaves.

The total, soluble, and insoluble oxalate contents of fresh and wok-fried fat hen (Chenopodium album) leaves were extracted and measured using High pressure liquid chromatography. The total oxalate content of the raw leaves was 1112.4 mg/100 g dry matter (DM), and the levels were significantly reduced by boiling (682.8 mg/100 g DM) or cooking the leaves in a wok (883.6 mg/100 g DM). The percentages of soluble oxalate contents in the total oxalates of the raw and boiled leaves were similar (mean 75%), while the proportion of soluble oxalate content in the wok-fried leaves was reduced to 53.4% of the total, giving a significant increase in the insoluble oxalate content of the wok-fried leaves. The percentage of insoluble calcium in the total calcium was significantly reduced (p < 0.05) when the leaves were boiled, but the insoluble oxalate content significantly increased (67.2%) in the wok-fried leaves when compared to the content of the original raw leaves. Processing the cooked leaves into pesto or extracting the juice gave final products that contained significantly reduced total and soluble oxalate contents. The addition of calcium chloride to the juice caused a very small reduction in the soluble oxalate content in the juice.

Oxalate content of raw, wok-fried, and juice made from bitter gourd fruits.

The total, soluble, and insoluble oxalate contents of fresh and wok‐fried bitter gourd (Momordica charantia) fruits were extracted and measured using HPLC chromatography. Frozen bitter gourds were imported from Vietnam, and two cultivars characteristic of bitter gourd fruits grown in India and Malaysia were grown locally in the North Island of New Zealand. The mean total oxalate contents of ripe fruits from Vietnam, India, and Malaysia were 85.90 ± 8.60 mg/100 g wet matter (WM), while the mean total oxalates fell to 88.06 ± 0.95 mg/100 g FM when the fruits were wok‐fried. The mean soluble oxalate content of the total oxalate was 54.42% of the ripe fruits and 58.14% of the wok‐fried fruits. The three cultivars of bitter gourds were processed into juice by the addition of standard ingredients and then processed through a screw press to remove excess fiber. The final juices had an overall mean value of 27.11 mg of total oxalates/100 g WM; the mean soluble oxalate content was 85.5% of the total, which was much higher than that measured in the cooked gourds (mean 70.7%).

Optimization of Purslane Plant Using Cooking and Pickling Processes for Reducing Oxalate Conten

Purslane (Portulaca oleracea) is an edible plant rich in benefcial nutrients. Therefore, this study aimed to determine the chemical composition, minerals, fatty acid analysis, phenolic compounds and radical scavenging activity of purslane plant. In addition, the effect of cooking of purslane at different temperatures (60, 80 and 100 °C), for various durations (5, 10, 15 and 20 minute), and pickling for various durations (3, 6 and 9 days) on oxalate content. Sensory evaluation of quality characteristics and fatty acids analysis of biscuits fortified by purslane powder after reducing oxalate content were carried out. Protein, fat, ash and fiber contents of purslane were 5.64, 5.30, 23.42 and 16.03 %, respectively on dry matter basis. The highest concentration mineral was K (4694.0 mg/100g), while the lowest concentration mineral was Zn (0.93 mg/100g). Total phenolic and radical scavenging activity of purslane were 193.22 mg/100g gallic acid equivalent and 87.29 %, respectively. Purslane contains high percentage of unsaturated fatty acids, especially linolenic acid (40.4 % of total fatty acids). On the other hand, the soluble fraction of total oxalate content of purslane cooked for 20 minutes at 60, 80 and 100 °C were 34.65, 19.84 and 15.84 %, respectively. While, the soluble fraction of total oxalate content of purslane pickled for 0, 3, 6 and 9 days were 47.80, 36.23, 25.60 and 14.39 %, respectively. Fortification of biscuits using purslane powder after treatments led to improvement of the quality characteristics of product. Portulaca oleracea could be used as a good source of minerals, antioxidants and omega-3 especially for functional food and nutraceutical applications.

A Novel Enzymatic Process to Produce Oxalate Depleted Starch From Taro

A novel process comprising treatment of Taro (Colocasia esculenta (L.) Schott) tuber flour with oxalate oxidase enzyme is developed to deplete the oxalate content. Oxalate oxidase enzyme produced by an endophyte, Ochrobactrum intermedium CL6 is employed to treat taro tuber flour. The treatment followed by extraction of starch results in a 97% reduction in total oxalate content. Further, several physicochemical properties such as paste clarity, swelling power, solubility, amylose content, granule size of starch produced out of enzyme treatment are studied and compared with properties of taro starch produced without enzyme treatment. The study reveals that enzyme treatment does not bring appreciable changes in the studied parameters. The taro starch produced by enzyme treatment shows very low paste clarity (9.38%), high swelling power (15.32 g/g), very low solubility (21.66%), and low amylose content (7.52%) at 100 °C compared to potato and sweet‐potato starches. X‐ray diffraction data reveal that taro starch possesses an A‐crystalline form, unlike the B‐crystalline form found in potato and sweet potato starch. To the best of the authors knowledge, for the first time, the use of oxalate oxidase to produce oxalate depleted taro starch is reported. One of the interesting food industry applications of oxalate‐depleted taro starch, among many other uses could be for baby food formulation because of its small granule size.

Rates of Ligand Exchange around the Bis-Oxalato Complex [NpO2 (C2 O4 )2 ]3- Measured by Using Multinuclear NMR Spectroscopy under Neutral to Semi-Alkaline Conditions.

The kinetics of ligand exchange between the free oxalate ion, C2 O4 2- , and the bis-oxalato NpV complex, [NpO2 (C2 O4 )2 ]3- , in aqueous solution are reported by using 13 C and 17 O NMR spectroscopy methods. Rates of exchange were measured in the pH regime of 6.5-9.0, at which speciation is shown to be suitably simple. Because the neptunium(V) complex is paramagnetic, the rates of ligand exchange were estimated by following the width of the 13 C and 17 O signals assigned to the free oxalate ion in solution and by applying the Swift-Connick method for measuring rates of exchange. A set of experiments were conducted in which pH and total oxalate concentration were varied, and the linear dependence of the rate on these parameters was demonstrated. Variable-temperature NMR spectroscopy was also performed to measure activation parameters of complexation. At pH<8.0, ΔH≠ =16.9 ±4.9 kJ mol-1 and ΔS≠ =-116.3 ±17.1 kJ mol-1 K-1 , whereas at pH>8.0 there is almost no dependence on temperature, which is interpreted to indicate that hydrolysis is coupled to ligand exchange under these conditions.