Article

Assessment of oxalate absorption from almonds and black beans with and without the use ofan extrinsic label

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Abstract

Oxalate bioavailability is an important determinant of whether the consumption of a particular food is a high risk in individuals predisposed to kidney stones. We estimated and compared oxalate absorption from a high oxalate containing legume (black beans) and a high oxalate containing nut (almonds). We also compared an isotope method using extrinsically labeled oxalate and an oxalate load method to assess oxalate absorption. Six male and 5 female subjects participated in the 4 oxalate load tests, namely almonds, almonds with 20 mg C2-oxalic acid, black beans and black beans with 20 mg C2-oxalic acid. Each treatment provided a total of 120 mg oxalate, after which timed urine samples were collected for the analysis of oxalate, calcium and creatinine. Average oxalate absorption from the 2 almond treatments (5.9%) using the oxalate load method was significantly higher than that from the 2 black bean treatments (1.8%) during the 24-hour post-oxalate load collection period. In contrast, C2-oxalic acid absorption from the almond (7.9%) and black bean (8.6%) treatments did not significantly differ. The higher oxalate absorption from almonds than from black beans suggests that the relative amount of soluble and insoluble oxalate in food has an important role in the determination of oxalate absorption. Since extrinsically provided C2-oxalate and oxalate naturally occurring in the high oxalate test foods appeared to be differentially absorbed, the data do not support the use of extrinsically labeled oxalate to assess food oxalate absorption.

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... The anti-nutritional composition of the aerial part of Lablab purpureus is presented in table 4. Six (6) factors which include tannins, saponins, oxalates, phytates, cyanogenic glycosides and free phenolics were quantitatively determined. (Chai and Liebman, 2004). In addition, Chai and Liebman (2004) reported that higher value of tannins in feeds interferes with protein absorption and digestive enzymes. ...
... (Chai and Liebman, 2004). In addition, Chai and Liebman (2004) reported that higher value of tannins in feeds interferes with protein absorption and digestive enzymes. From the results obtained in this study, the concentrations of oxalates, tannins and phytates in the aerial part of Lablab purpureus are low to cause any health risk in both human and animals. ...
Article
This study evaluates the nutritional and anti-nutritional potentials of the aerial part of Lablab purpureus as it relates to its use in Animal nutrition. The preliminary phytochemical test of the plant revealed the presence of bioactive secondary metabolites; glycosides, saponins, flavonoids, tannins, steroids, alkaloids, coumarins, phenols, carbohydrates and terpenoids in the crude extract. Results from the study revealed significant mineral composition in Lablab purpureus. Atomic Absorption Spectroscopic (AAS) technique was employed in the elemental analysis. Substantial amounts of Ca, Na, K and Mg were found, while Cu, Fe, P, Mn and Zn were present in trace amounts. Proximate analysis revealed the ash and fat contents to be 5.6 % and 4.2 % respectively. The protein level, total Carbohydrate and Fibre contents were determined to be 25.4 %, 46.93 % and 7.5 % respectively. The presence of anti-nutritional secondary metabolites; tannins, saponins, oxalates, phytates, cyanogenic glycosides and free phenolics were quantitatively determined to be 0.50 %, 3.8 %, 0.70 %, 2.2 %, 1.2 % and 2.1 % respectively. The results of the phytochemical constituents, proximate composition, anti-nutritional factors and mineral composition of the aerial part of Lablab purpureus in this study demonstrates high nutrients content with potentials to meet the nutritional requirements in monogastric diets.Keywords: Anti-nutritional composition, Lablab Purpureus, Mineral composition, Proximate analysis
... Because oxalate has a detrimental effect on the availability of minerals, it is a concern. An excessively high oxalate diet has been linked to kidney stones and may raise the risk of renal calcium absorption (Chai and Liebman, 2004). ...
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... Oxalate is a concern because of its negative effect on mineral availability. High oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones [25]. Oxalate recorded in this study was 3460.00mg/100g ( Table 3). ...
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Proximate analysis and phytochemical screening of fluted pumpkin (Telfairia occidentalis) pod was investigated using standard analytical methods. Results of the proximate analysis showed moisture (43.18±0.59%), Ash (6.26±0.59%), crude fibre (15.43±0.01%), lipid (7.43±0.01%), crude protein (10.73±0.20%) and carbohydrate (16.97±0.21%); while phytochemical screening gave tannins (6.41±0.95%), saponins (0.83±0.01%), alkaloids (0.66±0.01%), flavonoids (1.48±0.01%), cardiac glycosides (9.37±0.02%), oxalate (3460.00±0.01mg/100g), phytate (0.65±0.02%) and phenol (0.63±0.00%). It can be concluded that pumpkin pod waste has high moisture, fibre and tannins with low phytate, phenol and oxalate contents.
... High concentration of phytochemicals beyond permissible range can be deleterious to the body of animals. According to Chai and Liebman (2004), high oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones. However, all values were within the tolerable level recorded for rabbits by Omokore and Alagbe (2019). ...
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This study was conducted to evaluate the effects of Trichilia monadelpha stem bark extract on the fatty acid composition of rabbit’s thigh meat. A total of 40, 6-7 weeks New Zealand white × Chinchilla crossbred rabbits with an average weight of 490 ± 4.40 were randomly divided to 4 groups with 5 replications consisting of 2 animals each in a completely randomized design. Rabbits in treatment 1 (T1) was fed basal diet with no Trichilia monadelpha stem bark extract (TMSB), T2, T3 and T4 were fed basal diet with 3mL, 6mL and 9mL TMSB per rabbit/day. Phytochemical analysis of TMSB revealed the presence of tannins (10.95 mg/g), alkaloids (9.22 mg/g), saponins (4.75 mg/g), oxalates (3.10 mg/g), flavonoids (15.88 mg/g), phenols (18.46 mg/g), terpenoids (8.62 mg/g), glycosides (7.11 mg/g) and 2-diphenyl 1-piccrlhydrazyhydrate (430.8 mg/g). Concentrations of vitamins identified in the extract are; vitamin A (2.190 mg/100g), vitamin B1 (0.567 mg/100g), vitamin B2 (0.301 mg/100g), vitamin B3 (0.227 mg/100g), vitamin B9 (0.080 mg/100g), vitamin B12 (0.209 mg/100g) and vitamin C (5.680 mg/100g). Composition of saturated fatty acid (TSFA) decrease with a significant increase in monosaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) (P˂0.05) across the treatments. It was found that TMSB significantly (P˂0.05) influenced the concentration of total unsaturated fatty acid (TSFA). Therefore, it can be concluded that TMSB is capable of modulating the fatty acid and improving the quality of meat from rabbit without causing any deleterious effect on the performance of the animal.
... Oxalate is a concern because of its negative effect on mineral availability. High oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones [18]. Processing was reported to improve the digestibility of the protein by destroying the protease inhibitor and opening the protein structure through denaturation and can also cause a decrease in protein digestibility via the non-enzymatic browning reaction and thermal cross-linking [2]. ...
... From this reported, soaking influences the reduction of anti-nutritional factors present in food. Higher value of oxalate in human diet can increase the risk of renal calcium absorption and source of kidney stones (Chai and Liebman, 2004). The values obtained in this present study is slightly higher than 0.45-1. ...
... No significant difference (P<0.05) in oxalate levels was found between the fruits studied. Higher value of oxalate in human diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones (Chai and Liebman, 2004). Higher value of tannin in foods interferes with protein absorption and digestive enzymes. ...
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The knowledge of nutritional composition of fruits is very essential as it increases their utilization by humans. The aim of the study was to determine the phytochemical factors, anti-nutritional and mineral composition of mango, orange, pawpaw, and watermelon. Phytochemical factors were analysed using Association of Official Analytical Chemists (AOAC) methods. Anti-nutrients factors were analysed using standard analytical methods. Minerals compositions were determined using Atomic Absorption spectroscopy (AAS). Phytochemical screening showed that saponin, alkaloid, tannin, cardiac glycoside and phenol were present in the fruits analysed. The result of the anti-nutritional studies showed the following for mango, orange, pawpaw and watermelon respectively; oxalate: 1.54, 1.54, 1.46 and 1.61mg/g, saponin: 40, 45.86, 39.20, and 32.13mg/g, alkaloid: 0.64, 5.46, 27.26, and 3.15mg/g, tannin: 0.17, 0.13, 0.79, and 0.43mg/g, hydrogen cyanide: 0.61, 0.26, 0.09, and 0.30mg/g, phyatate: 0.37, 0.40, 0.51, and 0.40mg/g. The result of mineral composition observed were calcium 96.8, 267.59, 143.59 and 181.49mg/g, zinc 1.1, 0.48, 1.26 and 1.95mg/g, iron 9.85, 5.94, 7.00, and 15.81mg/g manganese 0.87, 0.33, 0.26 and 0.42mg/g. Mineral analyses shows higher concentration of calcium in the fruits pulps(mango, orange, pawpaw and watermelon). The data reported shows that the various fruit used for the analysis have significant amount of anti-nutrient, Phytochemicals and minerals in them. The low level of anti-nutrients may enhance mineral availability in biological systems.
... Oxalate is a concern because of its negative effect on mineral availability. High oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones (Chai and Liebman, 2004). The average result of the vitamins composition in Parquetina nigrescens leaf extract (Table 3) reveals that vitamin A composition was 2.27mg, vitamin B content which are Vitamin B1 (270.25mg), ...
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The increasing clamour for organic animal production necessitated the investigation on the potential of Parquetina nigrescens leaf extract in livestock production. The extract of the leaves of Parquetina nigrescens was evaluated for the proximate, phytochemical, minerals and vitamins compositions. The fresh leaves of Parquetina nigrescens were harvested around 6:00hrs and 6:30hrs, thereafter, they were washed. 20g of the fresh leaves harvested were blended with 100ml of water using a blender. The blending was done for about 5 minutes after which the blended samples were well filtered using standard filter papers (Whatman paper No. 1). The filtrates were then used for chemical analysis. Proximate analysis indicated that the leaf extracts had high concentration of moisture (7.80%), crude fibre (9.38%), crude protein (8.40 %), ether extract (9.38%), and ash (6.90%). Mineral and vitamin analysis showed that Parquetina nigrescens leaf extract contained macro minerals (%) such as Na (0.36), Ca (29.96), P (6.88), K (23.21), Mg (4.05), micro minerals such as Si (23.71 ppm), Al (4.34%), Fe (3.59%), Ti (2.11ppm), Mn (1.46 ppm) and Cl (0.33%) and high content of vitamins A (2.27 mg/100g), B1 (270.25 mg/100g), B2 (850.26 mg/100g), B3 (325.20 mg/100g), C (16.20 mg/100g) and E (0.015 mg/100g) respectively. Phytochemical evaluation revealed that Parquetina nigrescens leaf extract have high contents of alkaloids (8.27 mg/100g), flavonoids (2.25 mg/100g), glycosides (0.06 mg/100g), saponin (5.20 mg/100g), steroids (0.20 mg/100g), phenols (0.86 mg/100g), terpenoids (0.52 mg/100g), tannin (6.30 mg/100g) and anthraquinones (1.55 mg/100g). The results showed that Parquetina nigrescens leaf extract are of high nutritional quality due to high crude protein, vitamins and mineral contents especially calcium and potassium with the resultant phytochemicals attributes that could serve as feed additives in monogastric animal production.
... In the literature, it was reported that oxalates reduce the availability of essentials nutrients [50]. Diet high in oxalate has been reported to increase the risk of development of kidney stone [51]. The oxalate to calcium (Oxalates/Ca) ratio of the biofortified beans varied from 2.10x10 -3 to 8.40x10 -4 (Table 4). ...
... The body easily uses it because of its insolubility [47]. It is highly toxic at higher concentrations but non-toxic when the concentration is a minimal amount [48]. The tannin values from Table 5 showed a progressive rise as more acha and African yam bean flour were added. ...
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The consumption of bakery products, the vast majority of which are from cereal flours, is increasing rapidly. Cereal proteins, on the other hand, lack essential amino acids and must be supplemented with legumes to ensure a balanced nutrient intake. The study aims to evaluate the nutritional composition of biscuits made from the blend of wheat, acha and African yam bean flours. Different proportions of flour blends were obtained using D-optimal mixture of design of Response Surface Methodology. The flour produced from this blend was analyzed for proximate composition, functional properties, pasting properties, mineral content and anti-nutritional factors. The biscuit produced from the resulting flour was analyzed for physical characteristics and sensory attributes. The results obtained showed that the proximate composition of the flour blend varied from 7.26-9.05 %, 7.94-8.20.12%, 6.01-7.85%, 1.05-2.16%, 1.43-2.14%, 60.38-74.64% for moisture, protein, fat, crude fibre, ash and carbohydrate respectively. The functional properties of flour ranged from 0.76 to 0.84 g/ml for bulk density, 76.50 to 84.50% for water absorption capacity, 72.00 to 82.50%, for oil absorption capacity, 1.94 to 2.63g/g for swelling capacity and 2.00 to 6.00 % for solubility index. The pasting properties of the flour varied from 2049.00- 2333.00, 1217.50-1461.50, 1134.50-1238.00 for peak velocity, trough velocity and break down velocity, respectively. The mineral composition of the flour ranged from 1.70-2.13 mg/l, 2.12-2.22 mg/l, 19.63-24.63 mg/l, 0.40-0.58 mg/l, 3.25-4.96 mg/l for calcium, sodium, magnesium, iron and potassium, respectively. The anti-nutrient content of the flour blend ranged from 0.36 to 0.44 g/kg, 0.014 to 0.14 g/kg, and 0.40 to 0.54 g/kg for phytate, oxalate, and tannin content, respectively. The physical attributes of the biscuits ranged from 13.00-17.00 g, 56.00-60.33 mm, 5.76- 6.83 mm, 8.69-10.57 for weight, diameter, thickness, and spread ratio, respectively. The sensory evaluation results of the biscuits revealed that all the biscuit samples received high ratings for all the sensory attributes evaluated. Considerable increases in crude protein, ash, and crude fibre contents observed in the flour blend are indications that biscuits made from this blend could help reduce protein-energy malnutrition.
... For example, it was lower than 20.97 mg/100 g reported for brebra seeds (Andualem & Gessesse, 2014). Consumption of plants with high oxalate content may produce acute metabolic calcium deficiency (hypocalcemia) because it interferes with the absorption of calcium and other divalent minerals by forming insoluble salts and its presence in food has been implicated in causing mouth irritation and kidney stones (Chai & Liebman, 2004;Mohammed et al., 2014). ...
Article
The nutritional, anti-nutritional contents of calabash gourd (Lagenaria siceraria) seed flour and some nutritional values of its oil were evaluated using standard analytical methods. The proximate analysis ranged from 3.9 (ash) – 46.2% (fat). Phosphorous (554 mg/100 g) was found to be the most abundant mineral in the seed flour. Anti-nutrients recorded for the seed flour were 10.2% (saponin), 0.794 (cyanide), 1.31 (tannin), 10.3 (oxalate) and 19.3 mg/100 g (Phytate). The amino acids composition of the seed flour ranged from 0.746 (methionine) – 18.6 g/100 g cp (glutamic acid). The total PUFA and the total SFA contents of the seed oil were 63.6% and 20.6% respectively. The total phospholipid content of the seed oil was 987 mg/100 g while the total sterol value was 257 mg/100 g. The seeds of calabash gourd could be utilized as an alternative source of stable vegetable oil, mineral elements and protein for culinary and industrial applications.
... Study had shown that oxalates in large amounts bind with calcium forming calcium oxalate, which is insoluble and not absorbed by the body [54]. Oxalates are considered poisonous at high concentration, but harmless when present in small amounts [55]. Highest oxalate contents were found in sample B and F 0.11% while the lowest value 0.05% was in sample D. There was no significant difference in the phytate contents of the flour samples. ...
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The study examined the chemical and functional properties of composite flours based on maize, Bambara groundnut, and mango for possible use as complementary food. Flours were prepared from yellow maize variety, Bambara groundnut and mango pulp and blended in the ratios 100/0/0, 90/5/5, 85/10/5, 75/20/5, 70/25/5 and 65/30/5 labelled as samples A, B, C, D, E and F respectively. Standard methods were used to evaluate the composite flours and the control for functional properties, and chemical properties. Analysis showed an increase in the moisture content, proteins (19.28% in sample A to 23.81 %
... In the literature, it was reported that oxalates reduces the availability of essentials nutrients [40]. Diet high in oxalate has been reported to increase the risk of development of kidney stone [41]. ...
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Among legumes, common bean plays significant role in the diet of Cameroonians. It is a good source of protein, fiber and micronutrients. However, bean contains substantial amount of antinutrients, which limit their utilization. This work evaluates the effect of different processing methods on the macronutrients, micronutrients and antinutrients contents in two bean cultivars (Phaseolus vulgaris L.). A survey was done in the city of Yaounde on the different processes applied on the cultivar before cooking. From the results of the survey, beans treatment were divided into six groups: raw, boiled, boiled with sodium bicarbonate, boiled with Echinops giganteus bark powder, soaked and boiled, soaked with sodium bicarbonate and boiled. The processed samples were analyzed for proximate and antinutrients composition using AOAC methods and minerals by atomic absorption spectrophotometry. The raw seed served as the control. The results of this study have shown that processing led to an increase significantly (p<0.05) in protein contents. The higher rate of protein were observed for soaked and boiled (25.82%) and boiled (24.23%) respectively for white and red bean. The fiber contents of soaked with sodium bicarbonate and boiled white bean were higher (8.39%) compare to fiber content values recorded for red bean cultivars samples. Fat contents are significantly (p<0.05) lower with all samples after processing. The carbohydrate content of the boiled with Echinops giganteus bark powder of red bean was the highest (59.26%) followed by boiled with sodium bicarbonate red bean 58.61%. Boiled with Echinops giganteus bark powder white bean cultivar had higher iron, zinc, potassium and magnesium while boiled red and white bean cultivar had higher copper levels. Soaked and boiled white bean cultivar had higher calcium while boiled with sodium bicarbonate red bean had higher sodium levels. Processing improved significantly (p<0.05) the nutritional value of the beans by reducing the antinutrient contents. Soaking with sodium bicarbonate and boiling were found to have the highest level of reduction effect on the tannin, oxalate and saponin particularly in the white bean cultivar. Red and white bean cultivars could be used as a food formulation material for infants and young children to prevent protein energy malnutrition.
... Oat bran has been found to be rich in both soluble and insoluble oxalates (Israr, Frazier, & Gordon, 2013). Soluble forms of oxalate including oxalic acid and sodium/potassium oxalate are better absorbed in the intestine than insoluble forms such as calcium/magnesium oxalate (Chai & Liebman, 2004). Low calcium intake can result in the increase of both intestinal absorption and urinary excretion of oxalate (von Unruh, Voss, Sauerbruch, & Hesse, 2004). ...
Article
Oats are a rich source of a soluble fibre, beta-glucan, phenolic compounds, as well as functional lipid and protein components that could potentially aid in preventing and managing hypertension. Processing techniques commonly used to manufacture oat based foods have been shown to improve its physiological efficacy. Hypertension is a common condition that is a risk factor for cardiovascular disease, a primary cause of mortality worldwide. Though exercise and pharmacological interventions are often used in the management of hypertension, diet is an incredibly important factor. One preclinical study and a handful of clinical studies have shown that oat components/products are effective in lowering blood pressure. However, research in this area is limited and more studies are needed to elucidate the anti-hypertensive potential of oats.
... RDI of magnesium is around 0.4 g per day for an adult, whereas the dried CQ stem is having 0.8 g of magnesium per 100 grams. This is a substantial quantity while equating with magnesium-rich black beans and other diet sources (Weiwen & Michael, 2004). All these elements have direct or indirect impacts on bone health. ...
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This study aimed to prepare the fortified rice/flour with Cissus quadrangularis (CQ) stem powder to eliminate nutritional deficiency and improve bone health. Mineral analysis by atomic absorption spectroscopy revealed that the CQ stem has adequate quantities of calcium, magnesium, and a moderate amount of phosphorous to meet the Recommended Dietary Allowance (RDA). Thus, the rice and flour were fortified with freeze-dried CQ stem powder to improve its nutraceutical contents. The fortification was done using standard vacuum impregnation and blending process. Furthermore, the recuperative activity of prepared fortified rice (CQFR) and flour (CQFF) was tested in chemically induced osteoporosis and osteoarthritis animal models. The efficiency of CQ fortified diet against these complications was confirmed by hematology, radiology, and histopathological analysis. The rat groups fed with CQFF/CQFR diet showed significant improvement from calcium deficiency and its allied physiological damage. Thus, this study confirms that the CQ fortified rice would provide recovery from skeletal complications associated with calcium deficiency through fixing both homeostasis and bio-accessibility of the calcium. Practical applications Micronutrient and mineral deficiency is relatively higher in the regions where rice/rice products are consumed as a staple diet. Dietary intake of calcium and some essential minerals have major influences on bone and joint health. Cissus quadrangularis (CQ) is a familiar herb, conventionally used in India to fix broken bones and strengthen the skeletal system. The Atomic absorption spectroscopy data from this study showed that the CQ stem holds a high amount of calcium and other essential minerals to promote skeletal health. Preparation of fortified rice and flour with CQ stem would be a beneficial source of the essential minerals/ bioactive principles to promote and sustain skeletal health in the underprivileged population. These study data substantiated the practical application of producing the CQ fortified nutraceutical staple diet, especially to the people who are afflicted with morbid skeletal complications.
... 4,5 These cases explain why most research on high-oxalate food crops has focused on the amount of soluble oxalate that they contain. [6][7][8][9] Spinach belongs to the Chenopodiaceae family, with a domestic species (Spinacia oleracea L.) and two well-known wild species (S. turkestanica and S. tetrandra) worldwide. 10 Previous studies have discussed the main origins of the spinach, which is commonly cultivated in Central Asia, particularly in Iran. ...
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BACKGROUND Oxalic acid is a common antinutrient in the human diet, found in large quantities in spinach. However, spinach is highly regarded by vegetable producers because of its nutritional content and economic value. One of the primary purposes of spinach‐breeding programs is to improve the nutritional value of spinach by adjusting oxalate accumulation. Knowledge of the biosynthetic patterns of oxalic acid, and its different forms, is important for a better understanding of this process. RESULTS We found three biosynthetic patterns of accumulation and concentration of oxalates. Two of them are related to the maximum type and one is related to the minimum type. We also developed a general model of variations in these compounds in the genotypes that were studied. CONCLUSION This study introduced a unique type of spinach with high oxalate accumulation, which could be particularly suitable for consumption. This had the highest ratio of insoluble oxalate to soluble oxalate. It also accumulated more ascorbic acid (AA) than other types. Our findings in this study also indicate a small role for AA as a precursor to oxalate production in spinach, possibly confirming the significant role of glyoxylate as the most critical precursor in this plant. © 2021 Society of Chemical Industry.
... The concentration of oxalate found in the seed is 0.017 mg/100g which is not high to pose any health risk. Oxalate forms a complex with calcium, thereby making it unavailable when fed into animals, and so high oxalate diets can increase the risk of renal calcium absorption and has been implicated as a source of kidney stone (Osagie and Eka, 1998;Chai and Liebman, 2004). The concentration of nitrate in the seed is 0.255 mg/100 g. ...
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The proximate, minerals constituents and anti-nutritional factors of Hura crepitans seeds were evaluated. The results of the proximate analysis showed that 3.13%, 4.00%, 7.83%, 33.17%, 17.30%, 8.17%, 29.53% were the percentage composition of moisture, ash, crude lipid, crude protein, fibre and carbohydrate respectively. The calorific value was obtained to be 485.85±7.22 kJ/kg. The anti-nutritional analysis showed that phytate had the highest concentration of 20.28±0.90 while oxalate has the lowest concentration of 0.017±0.15 mg/100g dry weight respectively. The mineral analysis of Hura crepitans seed also indicates that K has the highest value of 238.33 mg/100g dry weight while Cd with a value 0.71±0.01 mg/100g dry weight has the least. The result shows that the H. crepitans seeds if properly utilized can serve as good source of minerals.Keywords: Anti-nutritional, Hura crepitans, Proximate, Mineral, Nutritional
... The study had shown that oxalates in large amounts bind with calcium forming calcium oxalate, which is insoluble and not absorbed by the body (Taiwo et al., 2017). Oxalates are considered poisonous at high concentration, but harmless when present in small amounts (Chai and Liebman, 2004). The phytate content varied from 5.27 to 5.57 mg/100 g also increased as the addition of African yam bean and acha flour increased. ...
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In this study, the suitability of wheat, acha and African yam bean composite flour in the development of cookies was investigated. Wheat, acha and African yam bean were blended into various proportions of flour mixes and used to produce cookies. The flour mixes were analyzed for the proximate, minerals composition, functional properties and anti-nutrients, while the cookies were evaluated for its sensory and physical properties. The proximate composition of the flours varied from 7.85-9.71%, 12.34-14.01%, 1.15- 1.86%, 1.21-1.49%, 1.65-1.92% and 70.01-76.11% for moisture, protein, fat, crude fiber, ash and carbohydrate content of the flour, respectively. The mineral content ranged from 10.11-13.12 mg/100 g, 52.65-61.76 mg/100 g, 130.71-211.76 mg/100 g, 111.97-130.84 mg/100 g and 14.81-20.43 mg/100 g for calcium, magnesium, potassium, phosphorus and sodium, respectively. The functional properties ranged from 0.76-0.80 g/cm3 ; 86.65- 188.11 g/g; 94.30-197.23 g/g; 569.23-699.54%; 5.68-6.44%; 61.50-125.50 sec, 73.75- 75.25% for bulk density, water absorption capacity, oil absorption capacity, swelling capacity, solubility, wettability and dispersiblity respectively. The anti-nutritional properties ranged from 37.67 to 46.73 mg/100 g, 5.27 to 5.57 mg/100 g and 32.91 to 35.10 mg/100 g for oxalate, phytate and tannin, respectively. The physical properties values ranged from 6.11-8.20 mm, 38.46-39.30 mm, 37.83-38.23 mm, 4.79-5.85, 5.35-7.49 g and 1.72-1.90 kg for thickness, diameter, height, spread ratio, weight and break strength respectively. Cookies from composite flours were not significantly (p>0.05) different from the control in overall acceptability. This shows the possibility of producing nutritious cookies with desirable organoleptic qualities from wheat, acha and African yam bean flour.
... However, these values were higher than (0.45 mg/g) obtained for sample F. Ojo and Akande (2013) reported that soaking influences the reduction of anti-nutritional factors present in food. Higher value of oxalate in human diet can increase the risk of renal calcium absorption and source of kidney stones (Chai & Liebman, 2004). The values obtained in the present study were higher than the average mean value of oxalates (0.42 mg/g) recorded by Polycarp, Afoakwa, Budu, and Otoo (2012) but were still within the toxicity limit of 2-5 g/day for humans as regards to oxalates and phytates (Awolu, Omoba, Olawoye, & Dairo, 2017). ...
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Sweet cassava and guinea corn were processed into flour using two different drying methods (sun and oven) to produce unfer-mented enriched fufu. Experimental design from which ten blends were selected for analyzes, sample F (100% traditional processed fufu) and sample C (commercial market sample-semolina) were used as control. In-vitro starch digestibility, gly-cemic index/load, antioxidant potential, and sensory attributes were evaluated, analyzed and mean were separated using Duncan New Multiple Range (DNMR) test at p ≤ 0.05. In-vitro starch digestibility of the experimental samples were significantly (p ≤ 0.05) higher than 8.91% obtained for sample F in both sun-and oven-dried samples. Results of the estimated glycemic index/load of the experimental samples showed that enriched fufu can be classified as low glycemic foods and are significantly (p ≤ 0.05) higher than sample F (55%) and glucose (100%). The samples also had better ability to scavenge free radicals against DPPH and ABTS. ARTICLE HISTORY
... Oxalate which has a negative effect on mineral availability was observed in reduced quantity in the extract. Diets high in oxalate increase the risk of renal calcium absorption and oxalate has been indicated as a source of kidney stones (Chai and Lieman, 2004). There was decrease in the total phenolic (2.08mg/g) and flavonoid (2.60%) contents of the watermelon peel compared to the amount of alkaloids and saponin. ...
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The present study was undertaken to investigate the phytochemicals present in the ethanolic extract of watermelon peel (Citrullus lonatus, family Cucurbilaceae). Watermelon which was obtained from Eke-Awka market, Anambra state, Nigeria was analyzed quantitatively and qualitatively for the presence of phytochemicals such as tannins, flavonoids, alkaloids, saponin, terpenoids, and phenols using standard chemical methods. The qualitative results obtained showed that, phenol, terpernoid, saponin, proteins, flavonoid and alkaloid were present. Phenol, flavonoid, saponin, alkaloids and oxalate contents of watermelon peel extract were quantified and results showed the following: phenol (2.08mg/g), flavonoid (2.60%), saponin (6.20%), alkaloid (4.40%) and oxalate 0.43mg/100g. The results obtained from this study indicate that the peels will be of medicinal importance which suggest the possibility of utilizing the peels as functional foods or herbal drug to prevent or manage some critical diseases of man.
... Oxalate which has a negative effect on mineral availability was observed in reduced quantity in the extract. Diets high in oxalate increase the risk of renal calcium absorption and oxalate has been indicated as a source of kidney stones (Chai and Lieman, 2004). There was decrease in the total phenolic (2.08mg/g) and flavonoid (2.60%) contents of the watermelon peel compared to the amount of alkaloids and saponin. ...
... Além de garantir uma boa porção do grupo de leguminosas, o consumo de feijão contribui ainda mais para o aumento de potássio, fibras e proteínas vegetais na dieta. Por outro lado, também pode fornecer uma grande quantidade de oxalato 13,30 . Embora Ferraro et al. 31 não encontraram um risco aumentado para a formação de cálculos por proteína vegetal; é importante enfatizar que a quantidade de ingestão proteica do grupo Lit na presente série foi mais do que duas vezes acima da recomendação do IOM para ingestão total de proteína de 0,8 g/kg/dia. ...
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Recent epidemiological studies have shown that dietary patterns may have a more persistent impact on the risk of stone formation than single nutrients of the diet. Dietary Approaches to Stop Hypertension (DASH), a low-sodium and fruits/vegetables-rich diet, has been associated with a lower risk of nephrolithiasis, due to altered urinary biochemistry. This observational study aimed to investigate whether the dietary pattern of stone formers (SF) resembled a DASH-diet and its influence on urinary lithogenic parameters. Anthropometric data, fasting serum sample, 24-h urine samples, and a 3-day food intake record under an unrestricted diet were obtained from 222 SF and compared with 136 non-SF subjects (controls). The DASH-diet food portions were determined from the food records whereas intakes of sodium chloride (NaCl) and protein (protein equivalent of nitrogen appearance, PNA) were estimated from 24-hr urinary sodium and urea. A dietary profile close to a DASH-diet was not observed in any of the groups. NaCl intake and PNA were significantly higher in SF versus non-SF (12.0 ± 5.2 v.s. 10.1 ± 3.4 g/day, p = 0.01 and 1.8 ± 0.1 v.s. 1.4 ± 0.1 g/kg/day, p = 0.03). SF exhibited a positive correlation of NaCl intake and PNA with urinary calcium, oxalate and uric acid, and of PNA with urinary sodium. SF consumed more vegetables and legumes, but less fruits and low-fat dairy items than non-SF. The present series presented a dietary profile characterized by low calcium and high salt and protein contents, not reflecting an ideal DASH-style diet pattern.
... Absorption of dietary oxalate is highly variable between individuals as well as its contribution to the urinary oxalate excreted [40] and the food oxalate content can vary due to different methods of cooking and agricultural conditions, such as soil and water nutrients [48]. Furthermore, bioavailability of oxalate in foods is highly variable [49] so that the increment in oxaluria may be Nutrients 2020, 12, 1442 4 of 15 greater even after consumption of foods containing a smaller oxalate content but in a more soluble form [50]. Oxalate absorption from almonds has been reported to be six-fold higher than from black beans [51]. Moreover, intestinal oxalate absorption is known to be critically dependent on the amount of daily calcium intake [47,52,53], increasing from around 3% with high calcium intakes to as much as 17% under conditions of a very low intake [52], which can be the case among bariatric patients. ...
Article
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Bariatric surgery (BS) is one of the most common and efficient surgical procedures for sustained weight loss but is associated with long-term complications such as nutritional deficiencies, biliary lithiasis, disturbances in bone and mineral metabolism and an increased risk of nephrolithiasis, attributed to urinary metabolic changes resultant from low urinary volume, hypocitraturia and hyperoxaluria. The underlying mechanisms responsible for hyperoxaluria, the most common among all metabolic disturbances, may comprise increased intestinal oxalate absorption consequent to decreased calcium intake or increased dietary oxalate, changes in the gut microbiota, fat malabsorption and altered intestinal oxalate transport. In the current review, the authors present a mechanistic overview of changes found after BS and propose dietary recommendations to prevent the risk of urinary stone formation, focusing on the role of dietary oxalate, calcium, citrate, potassium, protein, fat, sodium, probiotics, vitamins D, C, B6 and the consumption of fluids.
... Oxalate is a concern because of its negative effect on mineral availability. High oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones (Chai and Liebman, 2004). Bello et al;(2008) reported an oxalate content of 0.093g/100g for parkia fruit. ...
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The effects of boiling and fermentation on the anti-nutritive values of locust beans were investigated. The anti-nutritional screening was carried out on the hull, raw seed, boiled seed and the fermented locust beans. Some samples were taken to the laboratory to determine the anti-nutritive values before boiling, the boiled and fermented samples were also tested. The results showed the presence of the anti-nutrients except for cyanide which was negative after fermentation. The anti-nutritional values of the hull of the locust beans has Tannin of (0.46 mg/100g), Phytate (1.98 mg/100g), Oxalate (0.98 mg/100g), Cyanide (0.12 mg/100g), Trypsin inhibitor (0.53 mg/100g), Flavonoid (36.12%), Alkaloid (21.12%). The result showed that the boiling and fermentation processes reduced the Tannin (0.31 mg/100g), Phytate (1.68 mg/100g), Oxalate (0.64 mg/100g), Cyanide (0.08 mg/100g), Trypsin inhibitor (0.37 mg/100g), Flavonoid (23.14%), Alkaloid (13.12%) of raw seeds to Tannin (0.14 mg/100g), Phytate (1.12 mg/100g), Oxalate (0.26 mg/100g), Cyanide (Nil), Trypsin inhibitor (0.26 mg/100g), Flavonoid (11.12%) and Alkaloid (8.78%) of fermented seeds (iru) respectively. The analysis of variance of the results were carried out which showed that there is no significant different in the anti-nutritive values of the raw seed, boiled and fermented locust beans. Therefore, it was recommended that boiling and fermentation reduce the anti-nutritive values of locust beans in the same proportion.
... The problem with phytic acid in foods is that it can bind some essential minerals nutrient in the digestive tract and can result in mineral deficiencies. High oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones [10]. ...
Article
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Plant mineral elements play a special role in the maintenance of good health. Nigeria is rich in natural wealth and there is an ample scope to explore mineral constituents from the plant kingdom. Teak is an exotic tree in Nigeria but easily grows on almost all soil types in the country. This research aimed at comparatively investigating the macro nutrient status of both withered brown leaf and green leaf of teak from Onigambari plantation. The result of the analysis shows that Green T. grandis leaves contains Sodium 0.488/48.8%,Calcium 0.162/16.2%, Magnesium 0.034/3.4%, Potassium 0.065/6.5% and phosphorus 0.0006/0.06% respectively while the withered brown leaves contains Sodium 0.488/48.8%, Calcium 0.174/17.4%, Magnesium 0.034/3.4%, Potassium 0.046/4.6% and phosphorus 0.005/0.5% respectively. Also the trace elements contents of Green T. grandis leaves contains Iron 0.41/41%, Copper 0.067/6.7%, Manganese 0.010/1%, Zinc 0.005/0.5%, Lead 0.004/0.4%, Chromium 0.002/0.2%, Cadmium 0.00002/0.002% respectively. While the Withered brown T. grandis contains Iron 0.53/53%, Copper 0.064/6.4%, Manganese 0.014/1.4%, Zinc 0.006/0.6%, Lead 0.003/0.3%, Chromium 0.003/0.3%, Cadmium 0.0001/0.01% respectively. The result of this analysis shows that withered T. grandis leaves is a good source of iron, however both Green and withered T. grandis leaves are good sources of Na, Ca, Fe and Cu. The result also shows that both samples are non toxic due to the low amount of lead. World Scientific News 128(2) (2019) 426-432-427
... Controversy encompasses the issue of whether black tea consumption raises urinary oxalate crystals or not. A number of researches [31][32][33] had supported the idea that soluble oxalate is absorbed more significantly than insoluble oxalate. Therefore, it has been proposed that black tea had a notable amount of soluble oxalates and could increase the risk of oxalate stone production due to an increase in the discharge of urinary oxalate [34] . ...
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Background: Oxalate is a frequent component in foods from plant origin. Extraordinary concentrations of oxalate in urine leads to several renal pathological disorders. Green tea and black tea have several beneficial effects attributed to their polyphenols which act as metal chelators and scavengers of free radicals. Aim: The present study aimed to clarify the possible ameliorating impact of black and green tea on renal tissue damage caused by oxalate. Material and Methods: Thirty male mice were divided into six groups: Group I (control) ,Group II were injected with sodium oxalate, group IIIwere fed with black tea extract and group IV were fed with black tea extract and injected with sodium oxalate, group V were fed with green tea extract and group VI were fed with green tea extract and injected with sodium oxalate. The black or green tea extracts were given orally for 10 days (2ml/100g/day). Sodium oxalate (100 mg/kg) were injected as a single intraperitoneal dose at the11th day and animals sacrificed 12 h later. At the end of experiment, blood samples and kidney specimenswere obtained from all groups. Serum urea and creatinine analysis were done. The renal tissue sections were stained with H&E and PAS stains and examined. Immunohistochemical investigation for iNOS and NF-κB and morphometric analysis were also implemented. Results:Microscopically, the examined kidneys in oxalate group revealed degenerated and necrotic tubular cells ,tubular dilatation, protein casts and translucent oxalate crystals and interrupted tubular brush border and basal laminae. Furthermore, serum urea and creatinine were elevated and iNOS and NF-κB immunoreaction were highly positive. The aforementioned changes were reversed in group IVand VI. Conclusion: Black and green tea extracts could protect against oxalate-induced nephrotoxicity due to their antioxidant characters.
... The soluble oxalate (water soluble) exists in plants as crystals of sodium, potassium and ammonium salts (Holloway et al., 1989). The amount of soluble oxalate is important in food because its bioavailability is more than insoluble oxalate (Chai and Liebman, 2004). The soluble oxalate content of elephant foot yam paste ranged between 7.20-12.75 ...
... Food analysts are greatly concerned about oxalate due to its adverse effect on the availability of minerals. Food having high level of oxalate can result in kidney stones as its high levels tantamount to increased absorption of calcium in the kidneys (Chai and Liebman, 2004). The levels of oxalate in S. stenocarpa seeds were higher than 0.23 to 1. 10 g/100 g (Bello et al., 2008) and 0.4% (Amoo and Agunbiade, 2010) found in certain Nigerian fruits and full seed flour of Pterygota macrocarpa. ...
... The levels of the antinutrient in the flour samples was below the estimated threshold limit of this antinutrient and would pose no threat to the health of consumers [43]. Studies have shown that high level of oxalates increases calcium absorption in the kidney [44], because high oxalate level in food has been implicated as the cause of kidney stones. Therefore, consumers of the fortified flours, should have low risk of adverse health effect due to oxalate toxicity. ...
... The reduction in blood glucose levels caused by phenolic compounds have been attributed to actions such as reduction in the absorption of nutrients (e.g catechins which inhibits intestinal glucose absorption) [38], reduction in food intake [39], induction of β cell regeneration [40] and a direct action on adipose cells that enhances insulin activity [41]. Studies show that oxalate in large amount bind with calcium forming oxalate which is insoluble and not absorbed by the body [42] and they are considered as poisonous at high concentration but harmless when present in small amount [43]. Phytate content of the raw samples were very high while both blanching amd fermentation reduced the value. ...
Article
In this study, defatted soybean cake, Moringa oleifera leaves and wonderful kola combination were used to raise the nutritional value and scavenging properties of maize-based formulated diets. After blanching and fermentation process, maize (popcorn), moringa leaves, wonderful kola seeds, defatted soybean cake were milled into flour and blended to obtain six samples (R1, R2, B1, B2, F1, F2). Samples were analyzed for antinutrients, phytochemicals, scavenging properties and glycemic index using standard methods. Both processing methods reduced antinutrient levels; particularly for phytic acid. Of the methods used, fermentation is the most effective in increasing the protein content of the formulated diets, it also had the highest scavenging ability and the lowest glycemic index. For DPPH (1,1 diphenyl-2-picryhydrazyl) assay, R1, B1, F1 had high scavenging abilities with F1 having the highest. Albino rats fed with 1 g of sample F1 showed a great decrease in blood glucose level below 5 mmol/l when compared with other samples and reference sample (glucose). This shows the importance of a healthy diet and the effectiveness of Moringa oleifera leaves in the prevention and management of diabetes.
... Oxalate is a concern because it has undesirable effects on mineral availability. Diets rich in oxalates can increase the risk of renal calcium absorption which is linked to the formation of kidney stones (Chai et al., 2004). The level of saponins in the fruits ranged from 0.06 ± 0.03 mg/g DW in E. operculata to 0.17 ± 0.03 mg/g DW in O. alismoides. ...
Article
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Background: Wild fruits have traditionally been important food sources for rural population which are known to contain many biologically active compounds that can help in the prevention of several diseases. Objective: To investigate the anti-bacterial property and anti-nutritional contents of Grewia sapida Roxb. ex DC., Ottelia alismoides (L.) Pers., Aporosa dioica (Roxb.) Muell.-Arg., Antidesma bunius (L.) Spreng., and Eugenia operculata Roxb. fruits obtained in Assam, India. Methods: The methanolic extracts of five wild fruits were studied for anti-bacterial activities against two strains of gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and two strains of gram-negative bacteria (Escherichia coli and Proteus vulgaris) using the disc diffusion method. The anti-nutritional contents such as oxalate, phytate, tannins, saponins, and alkaloid were also assessed following the reported procedures. Results and Conclusion: All the fruit extracts exhibited different degrees of anti-bacterial activities. E. operculata, A. dioica, and O. alismoides extracts were the most effective extracts, which showed strong anti-bacterial activities against the studied bacteria. The five wild fruits showed varied concentrations of anti-nutritional factors and very high levels of anti-nutritional compounds were not observed.
... The reduction in the oxalate value is due to the substitution of unripe plantain and pumpkin seed flour to yellow yam. High oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones [37]. Tannins content ranged from 4.39-10.53 ...
... The concentration of oxalate found in the seed is 0.017 mg/100g which is not high to pose any health risk. Oxalate forms a complex with calcium, thereby making it unavailable when fed into animals, and so high oxalate diets can increase the risk of renal calcium absorption and has been implicated as a source of kidney stone (Osagie and Eka, 1998;Chai and Liebman, 2004). The concentration of nitrate in the seed is 0.255 mg/100 g. ...
Article
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The proximate, minerals constituents and anti evaluated. The results of the proximate analysis showed that 3.13%, 4.00%, 7.83%, 33.17%, 17.30%, 8.17%, 29.53% were the percentage composition of moisture, ash, crude lipid, crude protein, fibre and carbohydrate respectively. The kJ/kg. The anti-nutritional analysis showed that phytate had the highest concentration of 20.28±0.90 while oxalate has the lowest concentration of 0.017±0.15 mg/100g dry weight respectively. The mineral analysis of Hura cr of 238.33 mg/100g dry weight while Cd with a value 0.71±0.01 mg/100g dry weight has the least. The result shows that the H. crepitans minerals.
... Interestingly, the impact of dietary oxalate on urinary oxalate excretion and development of kidney stones appears to be small [33,34], while the degree of enteric oxalate absorption seems to be more critical [35]. The latter is determined by different factors, including a significant intra-and inter-individual variability, and depends on the bioavailability of oxalate that can be affected by dietary intake of calcium or magnesium [35,36]. In a randomized controlled trial by Borghi et al., a diet low in sodium and animal protein reduced stone recurrence rates after 5 years compared with a low calcium diet in male recurrent kidney stone formers with idiopathic hypercalciuria [12]. ...
Article
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Background: Kidney stone disease is common in industrialized countries. Recently, it has attracted growing attention, because of its significant association with adverse renal outcomes, including end stage renal disease. Calcium-containing kidney stones are frequent with high recurrence rates. While hypercalciuria is a well-known risk factor, restricted intake of animal protein and sodium, combined with normal dietary calcium, has been shown to be more effective in stone prevention compared with a low-calcium diet. Notably, the average sodium intake in Switzerland is twice as high as the WHO recommendation, while the intake of milk and dairy products is low. Methods: We retrospectively analyzed Swiss recurrent kidney stone formers (rKSF) to test the impact of a low-sodium in combination with a low-calcium diet on the urinary risk profile. In patients with recurrent calcium oxalate containing stones, we investigated both, the consequence of a low-sodium diet on urinary volume and calcium excretion, and the influence of a low-sodium low-calcium diet on urinary oxalate excretion. Results: Of the 169 patients with CaOx stones, 49 presented with hypercalciuria at baseline. The diet resulted in a highly significant reduction in 24-h urinary sodium and calcium excretion: from 201 ± 89 at baseline to 128 ± 88 mmol/d for sodium (p < 0.0001), and from 5.67 ± 3.01 to 4.06 ± 2.46 mmol/d (p < 0.0001) for calcium, respectively. Urine volume remained unchanged. Notably, no increase in oxalate excretion occurred on the restricted diet (0.39 ± 0.26 vs 0.39 ± 0.19 mmol/d, p = 0.277). Calculated Psf (probability of stone formation) values were only predictive for the risk of calcium phosphate stones. Conclusion: A diet low in sodium and calcium in recurrent calcium oxalate stone formers resulted in a significant reduction of urinary calcium excretion, but no change in urine volume. In this population with apparently low intake of dairy products, calcium restriction does not necessarily result in increased urinary oxalate excretion. However, based on previous studies, we recommend a normal dietary calcium intake to avoid a potential increase in urinary oxalate excretion and unfavorable effects on bone metabolism in hypercalciuric KSFs.
... Saponin has the highest value while oxalate has the least value. Higher value of oxalate in human diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones (Chai and Liebman [12]). Higher value of tannin in foods interferes with protein absorption and digestive enzymes. ...
... Oxalate form complexes with minerals such as calcium thus interfering with the absorption of this mineral. Diet high in oxalate has been reported to increase the risk of development of kidney stone [47]. Oxalate content in the baked and cooked lima beans samples were 10.10 and 9.15mg/kg respectively. ...
Article
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Malnutrition such as protein and iron deficiencies is still prevalent in developing countries such as Nigeria 1. This is because most of the staple foods consumed are carbohydrate based. Legumes are known to be a good and cheap source of protein. However some legumes, though available, are under-utilized. Lima bean is one of the grain legumes that are under-utilized in Nigeria. This is because lima beans are not popularly known 2 and also the seeds are hard to cook 3. It belongs to the family Fabaceae in the genus Phaseollus. Lima beans are usually cultivated for their edible seeds. Lima beans like other legumes are important source of protein, carbohydrate and dietary fibres but low in fat. It also contains thiamin, riboflavin, niacin and vitamin B6 which are co enzymes for protein, carbohydrate and fat metabolism 4. Like other legumes, lima beans contain some anti-nutrients including trypsin inhibitors, phytic acid, haematoglutinns, oxalate, tannins and cyanide which interfere with absorption and utilization of important minerals such as calcium, iron, zinc and magnesium 5. These anti-nutrients reduce protein digestibility and the nutritive value of foods 6. However these anti-nutrients can be reduced through different processing methods 7, 8. In Nigeria, Lima beans are traditionally consumed as cooked beans either as sole or in combination with cereals such as rice or tuber such as yam. Utilization of lima beans this way started to reduce due to its hard seed coat which makes the beans to take too long to cook. There is therefore the need to find alternative ways of utilizing this legume which is of nutritional and health benefits. Some authors have started work on utilizing lima beans to produce daddawa 8, 9, 10 and lima bean flour 11. Baked beans could be tested as another way for lima bean utilization. Baked beans are oven cooked by baking the beans in tomato sauce. The tomato sauce in which baked beans are cooked and served is rich in lycopene. Lycopene is free radicals fighting antioxidant 12. Free radicals are known to cause damage in the body systems causing different diseases. The development of value-added bean-based products such as baked beans will assist the food industry, fast-food restaurants, and domestic consumers. Baked beans are nutritious, rich in protein (including the important amino acid lysine). Baked beans contain energy giving low glycaemic index carbohydrates. They are also very good source of dietary fibre which help to reduce constipation and bad cholesterol in the body 13, 14, 15. It is also a very good source of B vitamins (vitamin B6, niacin and folate). Consumption of baked lima beans will improve the nutritional status of the consumers. Baked beans are international food, hence development of baked beans from lima beans in the country will provide dietary diversity and will also serve as an international product for boosting the country’s economy. Utilization of lima bean in this way will also enhance its cultivation and production need thus improving the livelihood of farmers and food processors
... Study had shown that oxalates in large amounts bind with calcium forming calcium oxalate, which is insoluble and not absorbed by the body [35]. Oxalates are considered poisonous at high concentration, but harmless when present in small amounts [36]. Tannin had been implicated to form insoluble complexes with proteins thereby reducing digestibility and utilization of food proteins, interference with the absorption of Iron and inhibition of trypsin, chymotrypsin, amylase and lipase [37,38]. ...
... The concentration of oxalate (0.021 mg/100 g) recorded in this study is similar to 0.023 mg/100 g reported by [17]. High oxalate concentration in a diet increases the risk of renal calcium absorption [20]. The level of oxalate in the seed meal is not high to pose any health threat to the animals. ...
... Oxalate is a concern because of its negative effect on mineral availability. High oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones [13]. ...
Article
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The phytochemical and vitamin analysis of the crude peel extracts of Citrus sinensis and Vitis vinifera was determined. The phytochemical and vitamin contents were determined using standard biochemical methods. The results of phytochemical studies showed C. sinensis peels had high levels of Saponins, alkaloids and tannins with low levels of oxalate and phenol while V. vinifera had high levels of alkaloids, phenol, tannins and oxalate with saponin low. Analysis vitamins showed that the C. sinensis has highest level of vitamin C (136.67 ± 4.16) and B9 (26.67 ± 0.58), moderate level of vitamin A (4.10 ± 0.06) with low contents of vitamin B2 (0.11 ± 0.01) while V. vinifera had highest amounts of Vitamin A (210.12 ± 0.01) and B9 (63.25 ± 0.21), moderate amounts of C (4.16 ± 0.00 and E (1.16 ± 0.00) with trace amounts of B1, B2 and B5 (0.07 ± 0.00). The findings therefore, suggest that there is an indication that C. sinensis and V. vinifera peels contains important phytochemicals and vitamin compounds that may be linked to its beneficial effects on health.
... The oxalate value is higher than 1.06mg/100g reported for B.coricea seeds (Amaechi, 2009) and 0.159mg/100g reported for Pennsetum purpureum (Okaraonye and Ikewuchi, 2009) but lower than (58.81mg/100g) reported for seeds of Solanum nigrum (Akubugwo et al., 2007) and 109.00mg/100g reported for Gnetum africanum seeds (Ekpo,2007).Oxalate is of concern because of its negative effect on mineral availability. High oxalate diet can increase the risk of renal calcium absorption and has been implicated as a source of kidney stones (Chai and Liebman, 2004). The level of oxalate in the fruit may not play important role in its nutritive value. ...
Article
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Quantitative phytochemical test shows that the pulp contains 3.45% saponin, 57.01%`flavonoids, 7.12% tannin, 0.0001% alkaloids, 0.0001% glycosides, 0.0003% resins, 0.0002% terpenoids, 0.0001% steroids and 0.0003% cyanogenic glycosides.Antinutrient analyses of the pulp show 5.67% oxalate, 0.03% phytates and 0.02% hemagglutanin. Amino acid analyses shows that S.dulcificum pulp contains 8.055% tryptophan, 1.35% phenylalanine, 0.7% isoleucine, 0.5% tyrosine, 1.05% methionine, 0.4% proline, 0.69% valine, 1.1% threonine, 0.4% histidine, 0.5% alanine, 1.02% glutamine, 1.6% glutamic acid, 0.7% glycine, 0.3% serine, 1% arginine, 0.1% aspartic acid, 1.23% asparagine, 0.6% lysine and 0.6% leucine.
... Tannins are known to inhibit the activities of digestive enzymes and nutritional effects of tannin are mainly related to their interaction with protein. Tannin protein complexes are insoluble and the protein digestibility is decreased Carnovale et al, (1991), Chai and Liebman, (2004). The values reported for tannin was low when compared with 0.992mg/100g reported for raw bread fruit Fagbemi et al, (2005). ...
Article
Wild fruits play a vital role in the diets and economic well-being of tribal communities of Uttarakhand, India. Despite their significance, there is limited information on some of the wild Ficus species such as Ficus drupacea, Ficus rumphii, Ficus semicordata, Ficus subincisa and Ficus hispida. This research aimed to analyse the nutritional potential, anti-nutritional compositions, mineral composition, antioxidant and finally the phytochemical properties of Ficus fruits to ascertain their medicinal and nutritional significance. The proximate analysis results of all the five wild Ficus species displayed varying percentages of protein, moisture, fat, ash, crude fibre, carbohydrates. Ficus species exhibited superior nutritional and mineral parameters along with a significant amount of vitamin C. Additionally, these fruits significantly showed lower levels of anti-nutritional and good amount of antioxidant parameters. Thus, adequate consumption of these wild Ficus fruits could potentially contribute to human nutritional needs and may serve as sources for dietary enhancements.
Chapter
The nutritional consequences of short bowel depend on the site and extent of resection, the presence or absence of colon in continuity, the integrity and degree of adaptation within the remaining bowel as well as underlying disease. Understanding the anatomical and physiological changes facilitates the provision of individualised dietary advice to optimise absorption, reduce stoma/stool losses and minimise complications. Balance studies show that short bowel patients develop an adaptive hyperphagia that supports an increased oral energy and protein intake to compensate for malabsorption and that the optimal dietary composition to promote absorption depends on the presence or absence of colon. Jejunum-colon patients benefit from a diet that is high in carbohydrate with fibre to tolerance, moderate in long-chain triglycerides with partial substitution of medium-chain triglycerides to increase energy absorption as required and low in oxalate to reduce the risk of renal stones. Jejunostomy patients should take a high fat diet with added salt and restrict hypotonic fluids with substitution of oral rehydration solution. Nutritional outcomes are improved by intensive education with individualised verbal and written advice, to help patients to understand how their bowel function has changed, the importance of hyperphagia and rationale for dietary advice, appropriate food choices, restriction of hypotonic fluids and substitution of oral rehydration solution. The dietary regimen should be tailored to the patient’s preferences and lifestyle and regularly reviewed and adjusted in response to intestinal adaptation or changes in their condition to aid compliance. Optimal nutritional care is best supported by a multidisciplinary team where there is close liaison between doctors, nurses, dietitians and pharmacists. Dietitians play a key role in assessing the patient’s nutritional status and requirements, providing diet and fluid advice that is appropriate to their anatomy, treatment goal and lifestyle, monitoring the impact of dietary changes on intestinal function and quality of life and coordinating the relative nutritional contributions from diet, oral nutrient supplements, enteral or parenteral support.
Chapter
Nutrition intervention in the form of formulation of nutritionally adequate, but low cost, complementary foods from locally available crops is a veritable means of tackling malnutrition problem in Nigeria. This study evaluated the nutrient composition, functional and sensory attributes of composite flour prepared from biofortified cassava, soybean and pigeonpea, for optimal formulation of a complementary food. Design Expert software was employed in the formulation and optimisation of the composite flour. The proximate, total carotenoids, anti-nutrient and mineral composition, as well as the functional and sensory properties of the composite flour were determined using standard laboratory methods. Data were analyzed using the analysis of variance, with significance accepted at P < 0.05. The protein and iron contents, which increased as the quantity of legumes increased in the blend, varied from 12.33 to 25.73 g/100 g and 1.19 to 3.11 mg/kg, respectively. The carbohydrate and total carotenoid contents of the blends increased as the level of biofortified cassava flour increased in the blends. All the cooked gruels prepared from the composite flours were found acceptable by the nursing mothers. In conclusion, a complementary food has been optimally formulated from the composite flour of 65.81% biofortified cassava, 10% pigeonpea and 24.19% soybean.
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Introduction: Calcium oxalate supersaturation is regularly exceeded in the plasma of patients with end-stage renal disease (ESRD). Previous reports have indicated that hemodialfiltration (HDF) lowers elevated plasma oxalate (POx) concentrations more effectively compared with hemodialysis (HD). We reevaluate the therapeutic strategy for optimized POx reduction with advanced dialysis equipment and provide data on the effect of extended treatment time on dialytic oxalate kinetics. Methods: Fourteen patients with ESRD who underwent HDF 3 times a week for 4 to 4.5 hours (regular HDF; n ¼ 8) or 7 to 7.5 hours (extended HDF; n ¼ 6) were changed to HD for 2 weeks and then back to HDF for another 2 weeks. POx was measured at baseline, pre-, mid-, and postdialysis, and 2 hours after completion of the treatment session. Results: Baseline POx for all patients averaged 28.0 � 7.0 mmol/l. Intradialytic POx reduction was approximately 90% and was not significantly different between groups or treatment modes [F(1) ¼ 0.63; P ¼ 0.44]. Mean postdialysis POx concentrations were 3.3 � 1.8 mmol/l. A rebound of 2.1 � 1.9 mmol/l was observed within 2 hours after dialysis. After receiving 2 weeks of the respective treatment, predialysis POx concentrations on HD did not differ significantly from those on HDF [F(1) ¼ 0.21; P ¼ 0.66]. Extended treatment time did not provide any added benefit [F(1) ¼ 0.76; P ¼ 0.40]. Discussion: In contrast to earlier observations, our data did not support a benefit of HDF over HD for POx reduction. With new technologies evolving, our results emphasized the need to carefully reevaluate and update traditional therapeutic regimens for optimized uremic toxin removal, including those used for oxalate.
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This research work was carried out to evaluate the physicochemical properties of Elekute enriched with African oil bean seed. Elekute (a maize-based snack in West Africa) was substituted with oil bean seed in the ratio 90:10, 80:20, 70:30 and 60:40 with 100% Elekute as control. Results revealed higher protein content with increased substitution (highest was 23.14% in 60:40). Mineral composition as well as the phytic acid, oxalate and tannins in the samples also increased with higher substitution level. There was significant difference among the samples in bulk density, water absorption capacity, oil absorption capacity, emulsion capacity and stability and foaming capacity but no significant difference in gelation capacity. Enrichment of Elekute snack by incorporating African oil bean seed improved the nutritional quality of this maize-based snack with high level of acceptance from the taste panelist.
Article
Purpose To synthesise and evaluate the properties of a novel smart material consisting of a metal-free organic black pigment with a unique chromophore for bifunctional applications in optoelectronics. Design/methodology/approach A robust and highly efficient organic reaction, namely, a double [2 + 2] cycloaddition, was deployed to transform a rod-like structure for charge-transfer applications to a strongly-conjugated light-absorbing molecule for both optical and electronic applications. Findings The synthesis and characterisation of an air-stable metal-free black pigment is reported which contains an unconventional donor-acceptor panchromatic chromophore with an absorption window spanning 600 nm; the compound was synthetically converted from an organic semiconducting molecular rod and retains strong charge-transfer properties. The chromophore is comprised of tetracyanoquinodimethane (TCNQ) adduct either side of a dithienothiophenyl (DTT) core, capped with hexyl thiophenes that ensures solubility in common organic solvents. Its propensity to form excellent thin-films on different substrates such as glass and paper, with a total opacity in organic solvent, gives it the potential for wide-ranging applications in organic optoelectronics. Research limitations/implications The synthetic chemistry and fundamental properties are investigated in the present study, with more detailed treatments and analysis to be soon developed. One leading smart material is presented, with further derivatives under investigation. Practical implications The work presented shows the possibility of converting structures from one application to another with relative ease, but retain properties for both, using well-known and facile conditions. Originality/value The structures are novel, and an enhanced air-stable organic panchromatic chromophore is reported for processing in common organic solvents.
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Full-text available
This research work was carried out to evaluate the physicochemical properties of Elekute enriched with African oil bean seed. Elekute (a maize-based snack in West Africa) was substituted with oil bean seed in the ratio 90:10, 80:20, 70:30 and 60:40 with 100% Elekute as control. Results revealed higher protein content with increased substitution (highest was 23.14% in 60:40). Mineral composition as well as the phytic acid, oxalate and tannins in the samples also increased with higher substitution level. There was significant difference among the samples in bulk density, water absorption capacity, oil absorption capacity, emulsion capacity and stability and foaming capacity but no significant difference in gelation capacity. Enrichment of Elekute snack by incorporating African oil bean seed improved the nutritional quality of this maize-based snack with high level of acceptance from the taste panelist.
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Eight healthy adults with no prior history of kidney stones participated in eight oxalate (Ox) load tests, seven foods, and an Ox solution control. After correction for endogenous Ox synthesis, increases in urinary Ox excretion during the 8 hours after eating one meal of the two soybean lines and five soyfoods tested ranged from 19.6 ± 23.3 to 124 ± 156 mmol (1.7 ± 2.1 to 10.9 ± 13.8 mg). Thus, frequent consumption of soybeans and soy products (TVP, soynuts, soy beverage, and tofu) may be a risk factor for CaOx kidney stone formation in susceptible individuals, such as those with a prior history of Ca stones, high normal urinary Ox concentrations, or intestinal disease.
Article
An experimental model that allowed differentiation between endogenously and exogenously derived urinary oxalate was used to assess the effect of different forms and doses of ingested calcium on oxalate absorption and excretion. In replication 1 (R-1), subjects participated in three oxalate load (OL) tests: baseline (OL alone), calcium carbonate (OL with concomitant calcium carbonate ingestion), and calcium citrate malate (CCM) (OL with concomitant CCM ingestion). The calcium salts each provided 300 mg elemental Ca. OLs consisted of 180 mg unlabeled and 18 mg 1,2[13C2]oxalic acid. In R-2, subjects participated in four OL tests: baseline (OL alone) and OLs administered concomitantly with 100, 200, or 300 mg Ca. Timed urine samples after the OL were collected at 2-h intervals for the initial 6 h and samples were pooled into 9-h aliquots for the remaining 18 h of the 24-h period. In R-1, 24-h mean exogenous oxalate decreased (P < 0.05) after the OL from 36.2 mg (baseline) to 16.1 mg (after calcium carbonate) and to 14.3 mg (after CCM) whereas endogenous oxalate remained relatively constant. Mean 24-h oxalate absorption decreased significantly from that at the time of the baseline treatment (18.3%) after both calcium carbonate (8.1%) and CCM (7.2%) treatments. In R-2, mean 24-h oxalate absorption was significantly lower after 200 (5.9%) and 300 (7.6%) mg Ca than after 100 mg Ca (9.1%) and the OL alone (11.3%). Concomitant meal ingestion significantly decreased oxalate absorption in the absence of dietary calcium but not in association with the 300-mg Ca treatment. The overall data provide definitive evidence that dietary calcium can reduce oxalate absorption and excretion. Calcium carbonate and CCM were equally effective in this regard and a minimum of 200 mg elemental Ca maximized this effect in conjunction with an oxalic acid intake of 198 mg.
Article
Oxalate bioavailability from sugar beet fibre (40 g), spinach (25 g) and a solution of sodium oxalate (182 mg) was tested in nine women using a triplicated 3 x 3 Latin square arrangement. Each test substance provided 120 mg oxalic acid. Throughout the study the volunteers consumed a control diet and the test substances were administered at breakfast on specified days. After an initial 2-day control period, oxalate was administered in three test periods that consisted of one test day followed by one control day. Urine collected during 24-hr periods was analysed daily for oxalate. Oxalate excretion did not differ among the five control days and was not increased significantly following the ingestion of sugar beet fibre by the volunteers. Oxalate excretion was greater (P less than 0.0001) for the mean of the spinach and sodium oxalate solution diets than for the mean of the sugar beet fibre and control diets. Oxalate bioavailability from sugar beet fibre was 0.7% compared with bioavailabilities of 4.5 and 6.2% for spinach and oxalate solutions, respectively. The low bioavailability of oxalate from sugar beet fibre may be attributable to its high ratio of minerals (calcium and magnesium) to oxalate, its complex fibre matrix or the loss of the soluble oxalate during processing of sugar beets.
Article
With typical, moderate levels of oxalate consumption, about one half of urinary oxalate derives from the diet in healthy people without gastrointestinal disease. Thus far, nine foods have been shown to increase urinary oxalate. These foods are spinach, rhubarb, beets, chocolate, nuts, tea, wheat bran, strawberries, and soy foods, which should be limited in the diets of patients susceptible to kidney stone formation. In addition, including more calcium-rich foods with meals can reduce urinary oxalate excretion as dietary calcium appears to bind oxalate in the gut lumen reducing its absorption. Thus, evidence suggests that limiting dietary intake of high oxalate foods and increasing calcium intake with meals may reduce urinary oxalate and may decrease renal stone formation.
Article
Oca (Oxalis tuberosa Mol.) or New Zealand yam, in common with other members of this genus, contains oxalate, an antinutritive factor. Twelve South American and two New Zealand cultivars of oca were analyzed for total and soluble oxalate contents of the tubers. The range of total oxalate levels was 92-221 mg/100 g of fresh weight. Levels of soluble and total oxalate extracted from the tubers were not significantly different, suggesting that no calcium oxalate is formed in the tubers. The oxalate concentrations obtained in this study for oca suggest that previously reported values are too low and that oca is a moderately high oxalate-containing food. This is the first report of a tuber crop containing moderate to high levels of soluble oxalates in the tubers and no insoluble oxalates.
Article
We extended the study of oxalate bioavailability by testing 7 additional food items: brewed tea, tea with milk, turnip greens, okra, peanuts and almonds. Nine normal subjects ingested a large serving of each of these items. The bioavailable oxalate was calculated from the increment in urinary oxalate during 8 hours after ingestion and bioavailability was determined as the percentage of total oxalate content in a given food item represented by bioavailable oxalate. Brewed tea and tea with milk, with a high oxalate content, had a low bioavailable oxalate level (1.17 and 0.44 mg. per load) because of the low oxalate availability (bioavailability of 0.08 and 0.03%). Turnip greens, with a satisfactory oxalate bioavailability (5.8%), had a negligible effect on urinary oxalate excretion, since oxalate content was relatively low (12 mg. per load). Okra, with a moderate oxalate content (264 mg. per load) had a negligible bioavailable oxalate (0.28 mg. per load). Only peanuts and almonds provided a moderate increase in oxalate excretion (3 to 5 mg. per load) due to the modest oxalate content (116 and 131 mg. per load) and oxalate bioavailability (3.8 and 2.8%). Thus, the ability of various oxalate-rich foods to augment urinary oxalate excretion depends not only on oxalate content but on the bioavailability.
Article
This article reviews the mechanisms involved in the synthesis, absorption, excretion and transport of oxalic acid, and the factors controlling these processes in man. The clinical syndromes associated with hyperoxaluria and recurrent calcium oxalate stone disease are reviewed, including new studies that raise the possibility of a generalized oxalate transport abnormality in some patients with renal stone disease. The important role of oxalate in the determination of calcium oxalate solubility in patients with calcium oxalate stone disease is emphasized and future directions for research in the prevention of recurrent calcium oxalate stone disease are discussed.
Article
The ability of 7 "oxalate-rich" foods to enhance urinary oxalate excretion was measured in 8 normal volunteers. The analyzed value for oxalate was high for spinach (1,236 mg.), moderate for chocolate (126 mg.) and tea (66 mg.), and for low vegetable juice, cranberry juice, pecans, and orange juice (2 to 26 mg.). The urinary oxalate increased by 29.3 mg. during eight hours after ingestion of spinach. However, it rose by less than 4.2 mg. from consumption of other food items. The bioavailable oxalate (per cent of total appearing in urine) was much less from food items of high or moderate oxalate content (spinach and chocolate) than from standard solutions of sodium oxalate (2.4 to 2.6 versus 6.5 to 7.3 per cent). Thus, only spinach among food items tested was capable of causing hyperoxaluria in normal subjects.
Article
The hypothesis that mild hyperoxaluria is more important than hypercalciuria in the pathogenesis of urolithiasis is re-examined in the light of new evidence. Small increments in urinary oxalate in the normal to high-normal range are much more critical than similar rises in urinary calcium for increasing the relative supersaturation of urine with respect to calcium oxalate, the oxalate/calcium ratio in urine, the total volume of calcium oxalate crystals excreted, the proportion of abnormally large crystals and aggregates of calcium oxalate and the severity of the disorder as defined by the recurrence rate of stone-formation. Data from the Arabian Peninsula, where the prevalence of calcium-containing stones is considerably higher than in the West, have shown that this occurs in spite of the almost complete absence of hypercalciuria. On the other hand, there is a strong association between stone-formation and the occurrence of mild hyperoxaluria. The life-time expectancy of stone-formation in men from various countries is strongly correlated with the average daily excretion of oxalate in the urine of the normal men in these countries. This relationship extends to include patients with enteric and hereditary hyperoxaluria. There is no such relationship, however, between the life-time expectancy of stones and urinary calcium excretion in the same populations. Studies on the regulation of urinary oxalate indicate that it is largely controlled by the quantity of "free" dietary oxalate available for absorption in the lower intestine. This can be calculated from the intakes of calcium and oxalate and the urinary excretion of calcium.
Article
Dietary oxalate is currently believed to make only a minor contribution (< 20%) to urinary oxalate excretion. A recent prospective study of stone disease suggested that dietary oxalate may be a significant risk factor. This observation led us to re-evaluate the contribution of dietary oxalate to urinary oxalate excretion. Previous studies have been hampered by inaccurate food composition tables for oxalate and inadequate methods for studying intestinal oxalate absorption. This evidence as well as factors that modify oxalate absorption are reviewed. New approaches to measure food oxalate and intestinal oxalate absorption have been examined. Capillary electrophoresis appears to be well suited for the analysis of the oxalate content of food. Two individuals consumed an oxalate-free formula diet for 7 days. This diet decreased urinary oxalate excretion by an average of 67% (18.6 mg per 24 hours) compared to oxalate excretion on self-selected diets. The absence of detectable oxalate in feces by day 6 of the diet suggested that the intestinal absorption was minimal. However, an effect of the formula diet on endogenous oxalate synthesis cannot be excluded. Restoring oxalate to the formula diet increased urinary oxalate excretion and illustrates that this experimental protocol may be well-suited for studying oxalate absorption and factors that modify it. Our results suggest that the intestinal absorption of dietary oxalate makes a substantial contribution to urinary oxalate excretion and that this absorption can be modified by decreasing oxalate intake or increasing the intakes of calcium, magnesium, and fiber.
Article
An experimental model that allowed differentiation between endogenously and exogenously derived urinary oxalate was used to assess the effect of different forms and doses of ingested calcium on oxalate absorption and excretion. In replication 1 (R-1), subjects participated in three oxalate load (OL) tests: baseline (OL alone), calcium carbonate (OL with concomitant calcium carbonate ingestion), and calcium citrate malate (CCM) (OL with concomitant CCM ingestion). The calcium salts each provided 300 mg elemental Ca. OLs consisted of 180 mg unlabeled and 18 mg 1,2[13C2]oxalic acid. In R-2, subjects participated in four OL tests: baseline (OL alone) and OLs administered concomitantly with 100, 200, or 300 mg Ca. Timed urine samples after the OL were collected at 2-h intervals for the initial 6 h and samples were pooled into 9-h aliquots for the remaining 18 h of the 24-h period. In R-1, 24-h mean exogenous oxalate decreased (P < 0.05) after the OL from 36.2 mg (baseline) to 16.1 mg (after calcium carbonate) and to 14.3 mg (after CCM) whereas endogenous oxalate remained relatively constant. Mean 24-h oxalate absorption decreased significantly from that at the time of the baseline treatment (18.3%) after both calcium carbonate (8.1%) and CCM (7.2%) treatments. In R-2, mean 24-h oxalate absorption was significantly lower after 200 (5.9%) and 300 (7.6%) mg Ca than after 100 mg Ca (9.1%) and the OL alone (11.3%). Concomitant meal ingestion significantly decreased oxalate absorption in the absence of dietary calcium but not in association with the 300-mg Ca treatment. The overall data provide definitive evidence that dietary calcium can reduce oxalate absorption and excretion. Calcium carbonate and CCM were equally effective in this regard and a minimum of 200 mg elemental Ca maximized this effect in conjunction with an oxalic acid intake of 198 mg.
Article
Urinary oxalate is a primary determinant of the level of calcium oxalate saturation and the formation of calcium oxalate crystals, a key event in kidney stone formation. The primary objective of this study was to compare the effects of calcium carbonate and magnesium oxide on oxalate absorption. An experimental model was used that allowed differentiation between endogenously and oxalate load-derived urinary oxalate. Twenty-four healthy subjects (10 males, 14 females) participated in three oxalate load (OL) tests: control (OL alone), calcium carbonate (OL with concomitant calcium carbonate ingestion), and magnesium oxide (OL with concomitant magnesium oxide ingestion). Oxalate loads consisted of 180 mg. unlabeled and 18 mg. 1,2[13C2] oxalic acid. Timed urine samples were collected after the OL for analysis of oxalate, calcium, magnesium, and creatinine. Both the calcium carbonate and magnesium oxide treatments were associated with significantly lower load-derived oxalate levels at all time points within the initial 24-hour post-oxalate ingestion period compared with levels observed for the control treatment. There were no treatment effects on endogenous oxalate levels. The efficiency of oxalate absorption for the calcium carbonate (5.1%) and magnesium oxide (7.6%) treatments was significantly lower than that for the control treatment (13.5%). The results suggested that magnesium was nearly as effective as calcium in reducing oxalate absorption and urinary excretion. Higher levels of urinary oxalate, calcium, and magnesium in males appeared to be largely a function of body size since gender differences either disappeared or were reversed when a correction was made for urinary creatinine excretion.
Article
It is believed that soluble oxalate has higher bioavailability than insoluble oxalate. Oca (Oxalis tuberosa) is moderately high in oxalate and contains oxalate in soluble form only. We estimated the bioavailability of oxalate in oca based on the urinary excretion of oxalate after oxalate loading with oca to estimate the bioavailability of oxalate in oca. We also clarified whether bioavailability differs in various oxalate loads from the same food source and studied the effect of an additional calcium source on the bioavailability of oxalate from oca. Four men and 4 women ingested 50, 100 and 150 gm. oca as well as 100 gm. oca with 100 gm. sour cream. Oxalate was measured in a 6-hour urine sample from each volunteer. The mean bioavailability of oxalate from oca plus or minus standard deviation was 1.44% +/- 1.31% during the 6-hour period after intake. There was no significant difference in oxalate bioavailability among oxalate intake levels in this study, although oca consumption with sour cream significantly decreased the uptake of oxalate (p <0.01). The variation in bioavailability among individuals was high in our study. The bioavailability of oxalate in oca appears to be similar to that in spinach. However, bioavailability varies among individuals and depends on other constituents of a combined meal.
Article
To compare urinary oxalate excretion after the oral administration of oxalic acid, disodium oxalate, or calcium oxalate in rats. Male Wistar rats were divided into four groups of six rats each and were intravenously hydrated with normal saline, and then were administered normal saline (control group), 10 mg of oxalic acid, equimolar disodium oxalate, or equimolar calcium oxalate via a gastrostomy. Urine specimens were collected just before administration and at hourly intervals up to 5 h afterwards. The urinary oxalate, calcium, magnesium and phosphorus levels were measured. Urinary oxalate excretion peaked at 1-2 h after administration of oxalic acid or equimolar disodium oxalate, while administration of calcium oxalate only caused a small increase of urinary oxalate excretion. Cumulative urinary oxalate excretion during 5 h was 1.69 +/- 0.10 mg (mean +/- SD; 17%), 1.43 +/- 0.13 mg (13%), and 0.22 +/- 0.03 mg (2%) after the administration of oxalic acid, disodium oxalate, and calcium oxalate, respectively. Urinary calcium excretion showed a decrease in the oxalic acid and disodium oxalate groups, while urinary magnesium or phosphorus excretion did not change significantly. The upper gastrointestinal tract seems to be the major site of oxalic acid absorption and only free oxalate is absorbed irrespective of whether it is the sodium salt or not. After binding to calcium in the gut, oxalic acid absorption seems to be inhibited in the presence of calcium and this means that calcium oxalate is poorly absorbed (at least in the upper gastrointestinal tract).
Article
Hyperoxaluria is a prominent risk factor for calcium oxalate urinary stones. Oxalate in urine is synthesized in the body or absorbed from food in the gastrointestinal tract. The amount of oxalate absorbed by patients with calcium oxalate stones may vary from a few percent to 50% of the dietary intake. Reference values for oxalate absorption measured under a standardized diet have never been attained in sufficient numbers from healthy individuals. Therefore, to our knowledge we collected for the first time the values required to interpret test results in patients with recurrent urinary stones. A total of 120 healthy volunteers, including 60 females and 60 males, received an identical standard diet on 2 consecutive days. On the morning of day 2 a capsule containing 0.37 mmol. sodium [13C2]oxalate (not radioactive) was ingested with water. Urinary oxalate was measured by gas chromatography-mass spectrometry. Absorption at a fixed 800 mg. daily Ca input is expressed as a percent of the labeled oxalate dose. For the standardized [13C2]oxalate absorption test the reference range in 95% of the 120 volunteers was 2.2% to 18.5% (mean +/- SD 7.9% +/- 4.0%). The repeatability of the standardized test was determined in 26 of the 120 volunteers by repeating the test twice. The mean intra-individual SD was 3.39% +/- 1.68%. We assessed reference values of intestinal oxalate absorption using a standardized diet. Interindividual and intra-individual variance was high.
Article
Leafy vegetables such as spinach (Spinacia oleracea) are known to contain moderate amounts of soluble and insoluble oxalates. Frozen commercially available spinach in New Zealand contains 736.6+/-20.4 mg/100g wet matter (WM) soluble oxalate and 220.1+/-96.5mg/100g WM insoluble oxalate. The frozen spinach contained 90mg total calcium/100g WM, 76.7%of this calcium was unavailable as it was bound to oxalate as insoluble oxalate. The oxalate/calcium (mEq) ratio of the frozen spinach was 4.73. When frozen convenience food is grilled there is no opportunity for the soluble oxalates to be leached out into the cooking water and discarded. Soluble oxalates, when consumed, have the ability to bind to calcium in the spinach and any calcium in foods consumed with the spinach, reducing the absorption of soluble oxalate. In this experiment 10 volunteers ingested 100g grilled spinach alone or with 100g additions of cottage cheese, sour cream and sour cream with Calci-Trim milk (180 g) and finally, with 20g olive oil. The availability of oxalate in the spinach was determined by measuring the oxalate output in the urine over a 6-hour and 24-hour period after intake of the test meal. The mean bioavailability of soluble oxalate in the grilled spinach was 0.75+/-0.48% over a 6-hour period after intake and was 1.93+/-0.85% measured over a 24-hour period. Addition of sour cream and Calci-Trim milk reduced the availability of the oxalate in the spinach significantly (P<0.05) in both the 6-hour and 24-hour collection periods.
Intrinsic and extrinsic labelling of inorganic nutrients in food studies In: Stable Isotopes in Human Nutritionoxalate absorption test
  • S J Fairweather-Tait
  • T E Fox
  • Oxalate Absorption From Almonds And Black
  • Beans
Fairweather-Tait, S. J. and Fox, T. E.: Intrinsic and extrinsic labelling of inorganic nutrients in food studies. In: Stable Isotopes in Human Nutrition. Edited by F. Mellon and B. Sandstrom. London: Academic Press, pp. 15–21, 1996 C 2 ]oxalate absorption test. J Urol, 169: 687, 2003 OXALATE ABSORPTION FROM ALMONDS AND BLACK BEANS
Intrinsic and extrinsic labelling of inorganic nutrients in food studies
  • Fairweather-Tait
Reference range for gastrointestinal oxalate absorption measured with a standardized [13C2]oxalate absorption test
  • von Unruh