Characterisation of the leaf meals,protein concentrates and residues from some tropical leguminous plants

Leaf meals (LMs) from freshly harvested leaves of butterfly pea (Centrosema pubescens), devil bean (Mucuna pruriens), flamboyant flower (Delonix regia), Bauhinia tomentosa, coast wattle (Acacia auriculiformis), quick stick (Glyricidia sepium) and ipil‐ipil (Leucaena leucocephala) were analysed for their nutrient and anti‐nutritional content. Then, leaf protein concentrates (LPCs) were produced from the leaves by fractionation and characterised along with the fibrous residues. On average, the LM contained 181 g kg^?1 dry matter (DM) CP (range: 100–280 g kg^?1 DM), 139 g kg^?1 DM crude fibre (range: 77–230 g kg^?1 DM) and 133 g kg^?1 DM ether extract (range: 86–165 g kg^?1 DM) while the gross energy averaged 17.0 MJ kg^?1. On average, leaf protein fractionation enhanced the CP, ether extract and the gross energy in the LPC by 39.5%, 33.5% and 22.0%, respectively, while the crude fibre of the LMs was reduced by 41%, on average, in the LPCs. Fractionation reduced the mineral content of the leaves generally. The mean phytin content varied from 0.36 g kg^?1 in LPCs to 0.86 g kg^?1 in leaf meal, while the mean phytin‐P content varied from 0.10 g kg^?1 in LPCs to 0.24 g kg^?1 in leaf meal. The total phenol levels in the LMs were reduced by 33.7% in the LPCs, on average. These results suggest that, while the LPCs from these plants could be used as protein supplements in non‐ruminant feeds in regions where there is an acute shortage of plant protein, the LMs or LPC fibrous residues could be fed to ruminant animals. Copyright © 2006 Society of Chemical Industry     

Soil selenium treatments to ameliorate selenium deficiency in herbage

Sodium selenite, sodium selenate, and sodium selenate in a pill formulation were applied to three soils known to produce Se-deficient herbage ( < 100 μg Se kg^?1 dry matter (DM)). The ability of the salts, applied in spring 1985, to ameliorate Se deficiency was followed over 3 years by taking four harvests each year. Selenate treatment at 10 g Se ha^?1 and selenate prill treatment at 20 g Se ha^?1 produced herbage with Se levels (geometric means) of between 0.57-0.86 and 1.79-1992 mg kg^?1 DM respectively in the first spring harvest after treatment. Selenite was less potent and selenite at 100 g Se ha^?1 produced a response in herbage closely similar to that of selenate at 10 g Se ha^?1. Even at 300 g Se ha^?1 the selenite treatment produced herbage with only 1.00-1.36 mg Se kg^?1 DM at the first harvest. Application of selenate in the prill form at 60 g Se ha^?1 produced herbage potentially toxic to grazing animals with 4.81-4.94 mg Se kg^?1 DM. The addition of fertiliser N to Se-treated plots increased total Se uptake at the first harvest by a factor of 4 and had a small effect on Se concentration. The Se concentration levels in herbage from Se-treated plots declined exponentially (t_1/2 = 21-43 days). On one soil derived from Lower Old Red Sandstone and lava, selenite at 300 g Se ha^?1 gave herbage with Se contents significantly above background (P < 0.05) in all harvests over 3 years.     

Mineral contents of some aromatic plants,their growth soils and infusions

BACKGROUND: In this study, 18 kinds of medicinal plants were collected together with their soils from different regions of Turkey and their macro‐ and micro‐element and heavy metal contents were determined by inductively coupled plasma atomic emission spectrometry (ICP‐AES). In soils, pH, electrical conductivity, carbonate (lime), organic matter, texture, P, K, Ca, Mg, Fe, Cu, Mn, Zn and B were analysed. In plants and extracts, P, K, Ca, Mg, Fe, Cu, Mn, Zn, B, Na, Al, Li, Pb, Ni, Cd, Co and Cr contents were determined. Also, correlations between soil and plant and between plant and extract were established. RESULTS: Element concentrations ranged between 0.11 and 5160 µg g^?1 in soil samples, between 0.14 and 54400 µg g^?1 in plant samples and between 0.039 and 22033 µg g^?1 in extract samples. While sage was rich in Fe (981.3 µg g^?1), basil was abundant in P (9.8 mg g^?1), K (54.4 mg g^?1), Ca (22.6 mg g^?1), Mg (3.1 mg g^?1) and Zn (46.05 µg g^?1) and mint was rich in Li (23.50 µg g^?1). Moreover, while high levels of P (4100.9 µg g^?1), K (22033 µg g^?1) and Mg (529.15 µg g^?1) were found in basil extract, Ca (5979.3 µg g^?1) was present at high concentration in marjoram leaf extract. Also, Fe (4.25 µg g^?1) and Zn (17.51 µg g^?1) were detected at high levels in lime flower and mint extracts respectively. CONCLUSION: It was concluded that aromatic plants are important sources of nutrients and essential elements. Copyright © 2007 Society of Chemical Industry     

The potential of sunflower as a crop for ensilage

The chemical composition and nutritive value of sunflower, cv. Armavirec, was examined at 12 stages of growth. Maximum yield of dry matter (18.2 t ha^?1) occurred at the dough seed stage. Ether extract showed a five-fold increase with the development of the seed. This increase was reflected in the gross energy value which was maximal at 19.1 MJ kg^?1 dry matter at the dough seed stage. In-vitro organic matter digestibility was highest at the onset of flowering when the estimated metabolisable energy value was 10.5 MJ kg^?1 dry matter. Throughout the sampling period the calcium to phosphorus ratios varied from 3.9-5.9:1, an imbalance which would have to be redressed on diets based largely on sunflowers. Fresh and wilted sunflowers were successfully ensiled at the flowering stage, without the use of additives. pH values of the resulting silages were 3.86 and 4.01. The silages were each fed to six cross-bred wethers and voluntary dry matter intakes were 23.9 and 26.5 g kgW^?1 for the fresh and wilted silages respectively. For the fresh silage, intakes of digestible organic matter and digestible nitrogen were 612 and 13.6 g day^?1 compared with 684 and 16.7 g day^?1 for the wilted silage. Nitrogen retention increased with increase in silage dry matter. The optimum time of cutting for yield of nutrients is at the milky ripe stage. The composition of the crop at this stage should facilitate a satisfactory preservation by ensiling. The crop provides a high yield of dry matter over about 10 weeks in late summer and could provide a valuable standby forage crop for grass in dry areas.     

Evaluation of acrylamide and selected parameters in some Turkish coffee brands from the Turkish market

The purpose of this study was to measure acrylamide (AA) levels and selected parameters of different traditional Turkish coffees. AA, 5-hydroxymethylfurfural (HMF), total reducing sugar, protein, pH, moisture, dry matter (DM) as well as ash, caffeine and soluble solids content (SSC) in DM, L*, a*, b* colour parameters of coffee samples were determined and the correlation between AA level and these parameters were investigated. A total of 36 coffee samples (20 Turkish, 8 Dibek and 8 Terebinth coffee) from the Turkish market were examined. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated for the detection and quantitation of AA in coffee samples. The calibration curve was linear (R² ≥ 0.999) over the range of 30–1000 μg kg^?1. The limit of detection (LOD) and limit of quantification (LOQ) were found as 4.6 μg kg^?1 and 15.5 μg kg^?1, respectively. The amounts of AA in analysed coffee samples were in the range 31.1 ± 0.6 to 323.4 ± 5.4 µg kg^?1. The highest mean AA levels were found in Terebinth coffees (240.3 μg kg^?1) followed by Turkish coffees (204.3 µg kg^?1) and then Dibek coffees (78.6 µg kg^?1). No tested Turkish coffee samples had an AA concentration above the indicative value (450 µg kg^?1) for roast coffee recommended by the European Commission (EC) in 2011. In addition, a strong positive correlation was found between HMF values and AA amounts of selected coffee types.     

Characterisation of musk lime (Citrusmicrocarpa) seed oil

BACKGROUND: The seeds of musk lime (Citrus microcarpa) represent a substantial waste product of small‐scale citrus‐processing factories, as they constitute about 100.0 ± 3.2 g kg^?1 of the whole fruit and contain a considerable amount of crude fat (338.0 ± 11.3 g kg^?1). Thus the aim of the present study was to determine the physicochemical properties of this fat with a view to potential applications. RESULTS: The iodine and saponification values and unsaponifiable matter and free fatty acid contents of the freshly extracted oil were 118.0 g I₂ per 100 g oil, 192.6 mg KOH g^?1 oil, 22 mg g^?1 oil and 18 mg oleic acid g^?1 oil respectively. The oil had a Lovibond colour index of 33.1 Y + 1.1 B. Its fatty acid profile indicated that 73.6% of the fatty acids present were unsaturated. Linoleic (L, 31.8%), oleic (O, 29.6%) and palmitic (P, 21.4%) acids were the predominant fatty acids, existing mainly as the triacylglycerols POL (18.9%), PLL (13.7%) and OLL (11.9%). The melting and cooling points of the oil were 10.7 and ? 45.2 °C respectively. Electronic nose qualitative analysis of the oil showed the presence of volatile (aroma) compounds, although the concentrations of the more volatile compounds were lower than those present in the seeds. CONCLUSION: Musk lime seeds are a rich source of oil, which is unusual in having linoleic, oleic and palmitic acids dominating the fatty acid composition. This property should make the oil both relatively stable to thermal oxidation owing to the combined presence of oleic and palmitic acids (61.0%) and highly nutritive owing to its high concentration of unsaturated fatty acids (73.6%). Copyright © 2007 Society of Chemical Industry     

Biodegradation of Jatropha curcas phorbol esters in soil

BACKGROUND: Jatropha curcas seed cake is generated as a by‐product during biodiesel production. Seed cake containing toxic phorbol esters (PEs) is currently used as a fertiliser and thus it is of eco‐toxicological concern. In the present study the fate of PEs in soil was studied. RESULTS: Two approaches for the incorporation of PEs in soil were used. In the first, silica was bound to PEs, and in the second, seedcake was used. At day 0, the concentration of PEs in soil was 2.6 and 0.37 mg g^?1 for approach 1 and 2 respectively. PEs from silica bound PEs were completely degraded after 19, 12, 12 days (at 130 g kg^?1 moisture) and after 17, 9, 9 days (at 230 g kg^?1 moisture) at room temperature, 32 °C and 42 °C respectively. Similarly at these temperatures PEs from seed cake were degraded after 21, 17 and 17 days (at 130 g kg^?1 moisture) and after 23, 17, and 15 days (at 230 g kg^?1 moisture). Increase in temperature and moisture increased rate of PEs degradation. Using the snail (Physa fontinalis) bioassay, mortality by PE‐amended soil extracts decreased with the decrease in PE concentration in soil. CONCLUSION: Jatropha PEs are biodegradable. The degraded products are innocuous. Copyright © 2010 Society of Chemical Industry     

Ruminal nitrogen metabolism and the passage of amino acids to the duodenum in sheep receiving diets containing hay and concentrates in various proportions

Three sheep fitted with rumen cannulas and three sheep fitted with duodenal re-entrant cannulas in addition to rumen cannulas were given, in successive periods, 700 g d^?1 of five diets consisting of chopped hay and a concentrate mixture of rolled barley and flaked maize (50:50) in the ratios of 1:0, 5:2, 3:4, 1:6, and 0:1. For bacteria isolated from the rumen of sheep fitted with rumen cannulas only, there were no significant differences in either the content of nitrogen in their dry matter or in the amino acid composition, but the content of α-?-diaminopimelic acid varied significantly (P < 0.05) between diets, mean values ranging from 39 to 50 kg^?1 nitrogen. As the proportion of concentrate in the diet increased, the intake of nitrogen was progressively reduced from 11.9 to 9.8 g d^?1 and this was accompanied by an increase in the amount of organic matter apparently digested in the rumen, from 296 to 402 g d^?1. But there were no significant differences between diets in either the ruminal concentration of ammonia-nitrogen (mean values varied from 78 to 96 mg litre^?1) or in the duodenal passage of total nitrogen, which ranged from 12.1 to 14.7 g d^?1 with a peak value for the 5:2 diet. Rates of synthesis of bacterial protein in the rumen were 186, 228, 124 and 94 g crude protein per kg organic matter apparently digested in the rumen for the 1:0, 5:2, 3:4, 1:6 and 0:1 diets respectively, the rates for the 1:6 and 0:1 diets being significantly (P < 0.05) lower than those for the other diets. The 0:1 diet was associated with a low proportion, 0.5, of bacterial protein in the duodenal crude protein and it is suggested that with this diet, protozoal protein made an appreciable contribution to the crude protein passing from the rumen.     

Quantitative analysis of styrene monomer in foods. A limited East Australian Survey

The levels of styrene monomer in foods packaged in polystyrene containers were determined by a headspace gas chromatography (g.c.) method and two reversed phase high-performance liquid chromatography (h.p.l.c.) methods. A total of 146 samples were analysed from Victoria and New South Wales which included yoghurt, cream, cheese, dessert, ice cream, egg white, onion dip and margarine. The highest level of styrene found was 0.1 mg kg^?1 in yoghurt. About 85% of all yoghurt samples were found to have values less than 0.05 mg kg^?1. The lowest values of styrene obtained were for margarine samples, of which more than 90% contained less than 0.010 mg kg^?1. The estimated limits of detection of the h.p.l.c. methods for all products except margarine were 0.005 mg kg^?1. The h.p.l.c. detection limit for margarine and the g.c. method for yoghurt were estimated to be 0.01 mg kg^?1.     

Cassava leaves as animal feed: Potential and limitations

The nutrient composition and potential productivity of cassava (Manihot esculenta Crantz) leaves are examined, and their usefulness as a protein supplement in animal nutrition in the tropics is reviewed. On average, meal prepared from cassava leaves contains (on a dry matter basis) 210 g kg^?1 crude protein, 250 g kg^?1 acid detergent fibre, 85 g kg^?1 ash, 14.5 g kg^?1 calcium and 4.5 g kg^?1 phosphorus. Cassava leaf protein is well balanced, except for a deficiency of sulphur-containing amino acids. The presence of hydrocyanic acid and tannins is considered, but a leaf meal with low levels of these anti-nutritional factors may be prepared using simple processing techniques. The most immediate prospects for the use of cassava leaf products are in the following areas: (i) low level inclusion of leaf meal in feed formulations for monogastric animals, and (ii) fresh forage as a protein supplement to low-quality roughages in ruminant feeding. Relevant future research needs are also identified.     

Kigelia africana seed: proximate,mineral, vitamin E,fibre, amino acid and fatty acid composition

Research reports on the ethnomedical and pharmacological potential of Kigelia africana extracts. In this study, the nutritional potential of K. africana seed and seed oil was evaluated by chemical analyses. Organic matter and ash constituted 915.23 ± 7.98 g kg^?1 DM and 49.05 ± 4.55 g kg^?1 DM of the seed mass, respectively. Oil constituted 492.2 g kg^?1 DM of the seed mass with oleic acid, linoleic acid and α‐linolenic acid constituting 17.6%, 12.9% and 54.3%, respectively, of the seed oil. Vitamin E concentration was 0.94 ± 0.25 μg g^?1. Crude protein was 357.35 ± 3.39 g kg^?1 DM. Arginine (6.14 ± 0.31 g per 100 g) as the most abundant amino acid and hydroxyproline (0.11 ± 0.06 g per 100 g) the least. Phosphorus (1123.2 mg per 100 g) and calcium (56.1 mg per 100 g) were, respectively, the most and least abundant minerals. Gross energy was 29.6 ± 0.06 MJ kg^?1. Kigelia africana seeds could be exploited as nutrient‐dense dietary supplement rich in protein, oleic acid and essential fatty acids.     

Analyses of tomato peel and seed byproducts and their use as a source of carotenoids

Commercial tomato canning yields two different byproducts. One is the material that results from peeling tomatoes, while the other results from removing the seeds. The peel byproduct contained 100.8 g protein, 256.4 g ash and 299.4 g acid detergent fiber kg^?1. Ash content was high because the peel byproduct contained 83.8 g kg^?1 sodium as a result of using a sodium hydroxide solution to peel the tomatoes. The seed byproduct contained 202.3 g protein, 51.8 g ash, and 537.9 g acid detergent fiber kg^?1. An amino acid analysis of seeds indicated that approximately 60% of the protein results from amino acids. Both byproducts were analyzed for carotenoid content. The lycopene content of peel byproduct was 734 µg g^?1 of dry material. Significant amounts of lutein, β‐carotene, and cis‐β‐carotene were also present. Seed byproduct contained 130 µg lycopene kg^?1 of dry matter. The content of other carotenoids was approximately half of that present in the peels. Peel and seed byproducts were included at 75 g kg^?1 in hen diets to determine the transfer of carotenoids to the yolk. When fed at this concentration, the lycopene content of dry egg yolk was approximately 0.9 µg g^?1. Approximately 0.1% of the lycopene in peel byproduct and approximately 0.7% of the lycopene in the seed byproduct was transferred from the feed to the yolk. Lycopene appears more similar to carotene than to oxycarotenoids in its transfer to the yolk. Copyright © 2005 Society of Chemical Industry     

Oil recovery and lecithin production using water degumming sludge of crude soybean oils

BACKGROUND: Wet gums produced during aqueous degumming of crude soybean oils are currently processed to produce lecithin or added to meals to increase their nutritive value for animal feed. Oils occluded in these gums are generally not recovered or processed. In this work, three methods to recover occluded oil and obtain lecithin from wet gums were assayed: direct extraction of oil with cold acetone (Method I), extraction after water elimination under vacuum (Method II) and by solvent partition with hexane/ethanol (Method III). RESULTS: Higher oil yields (up to 588 g kg^?1 of occluded oil) were obtained when water was eliminated before extraction (Methods II and III). No significant differences were observed in lecithin yields between three methods (720–807 g kg^?1 of dried gums). Recovered oils had acidity = 16.7–21.7 g kg^?1 as oleic acid, TOTOX (total oxidation) values ≤ 8.82, unsaponifiable matter = 9.0–12.1 g kg^?1, and Phosphorus = 87–330 mg kg^?1. Lecithins obtained by Methods I, II and III hexane phase had the same purity level (610–691 g of total measured phospholipids kg^?1). CONCLUSIONS: The occluded oil in soybean wet gums can be recovered, with quality and stability indexes compatible with their reinsertion in the productive process, by water elimination and extraction with acetone. Lecithins can be obtained with different phospholipid composition and diverse application fields. Copyright © 2008 Society of Chemical Industry     

Total mercury in milled rice and brown rice from China and health risk evaluation

Total mercury (THg) levels in 440 pairs of milled rice samples and brown rice samples from 15 major rice grain-producing provinces of China were measured and the associated health risk via rice consumption for different age categories of Chinese population was also assessed. THg contents were measured by a direct mercury analyser and the limit of detection (LOD) was 1.5 μg kg^?1. The THg levels for milled rice samples and brown rice samples varied from non-detected to 17.8 μg kg^?1 and 1.5 to 25.4 μg kg^?1, respectively, with a mean level of 3.4 μg kg^?1 and 4.9 μg kg^?1, respectively. The THg levels in all milled and brown rice samples were generally low, except three brown rice samples having concentrations above the legally set value for cereals (20 μg kg^?1 Hg). THg intakes for different age categories were estimated according to THg content and corresponding rice consumption and the associated health risk was evaluated by the corresponding provisional tolerable weekly intake (PTWI) for THg (5.0 μg kg^?1 bw week^?1), which was established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The 50th percentile of the THg intakes via milled rice and brown rice consumption for different age categories was in the range 0.09–0.19 μg kg^?1 bw week^?1 and 0.14–0.27 μg kg^?1 bw week^?1, respectively, well below the PTWI, suggesting that the associated health risk is relatively low. However, the 99.9th percentile of the THg intakes for 2–4-year-old children amounted up to 20.6% of the PTWI (milled rice) and 29.5% of the PTWI (brown rice), which deserves attention.     

Physicochemical,functional and structural characterization of fibre from defatted Rosa rubiginosa and Gevuina avellana seeds

The composition, functional properties and structural features of the fiber from Rosa rubiginosa defatted seeds and from Gevuina avellana defatted and partially deproteinized seeds were evaluated. The effect of phosphate salts and temperature during the extraction of fibres and the influence of two drying technologies on the distribution of soluble and insoluble dietary fibre were assessed. The extraction of protein and monosaccharides was favoured by increasing temperature in the range studied. Water and oil absorption capacities higher than 10 g g^?1 were observed for soluble and insoluble fibres from Gevuina avellana and for the soluble ones from Rosa rubiginosa. The insoluble fibre product from Rosa and Gevuina contained 650–810 g kg^?1 and 390–440 g kg^?1 neutral detergent fibre respectively. The protein content in the insoluble fibre varied in the range 100–150 g kg^?1 and 120–260 g kg^?1 and in the soluble fibre between 200–550 g kg^?1 and 180–370 g kg^?1 for Rosa and Gevuina respectively. Copyright © 2004 Society of Chemical Industry     

A study of the need for fibre by the growing New Zealand white rabbit

New Zealand White rabbits, aged between 5 and 8 weeks, were offered diets based on oatmeal together with up to 500 g kg^?1 of ground oat husk, or 500 g kg^?1 of ground barley straw or 400 g of a purified cellulose. The rabbits gained about 40 g liveweight per day when fed a well-balanced control diet (in which oatmeal, grassmeal, corn oil and fishmeal were the main constituents) and, apart from one occasion, there was no significant reduction in this rate of gain even when the diets offered contained up to 500 g kg^?1 of these fibre sources. Food consumption increased from 80 g day^?1 to 115 g day^?1 as the acid detergent fibre concentration in the diet increased from 39 to 270 g kg^?1. Digestible and metabolisable energy contents of the diets fell as the fibre concentration rose but the rabbits were able to adjust their intakes and maintain their daily metabolisable energy intakes constant at about 1100 kJ. The proportion of fat in the body dry matter fell as the fibre concentration in the diet was raised. A minimum dietary fibre content of 100 g kg^?1 as measured by the acid detergent fibre or crude fibre techniques is suggested for optimum healthy growth.     

Monitoring of seed composition of prickly pear (Opuntia ficus‐indica L) fruits during maturation period

Prickly pear fruit seeds were subjected to a range of chemical analyses during their 15 week maturation period. Seeds contained on average 71.5 g kg^?1 dry matter, 61.9 g kg^?1 crude oil, 9.4 g kg^?1 protein, 507.4 g kg^?1 crude fibre, 12.3 g kg^?1 ash and 409.0 g kg^?1 carbohydrate. The fatty acid composition of prickly pear seed oil consisted of 1.3–1.9 g kg^?1 myristic (14:0), 132.1–156.0 g kg^?1 palmitic (16:0), 14.4–18.5 g kg^?1 palmitoleic (16:1), 33.1–47.9 g kg^?1 stearic (18:0), 210.5–256.0 g kg^?1 oleic (18:1), 522.5–577.6 g kg^?1 linoleic (18:2), 2.9–9.7 g kg^?1 linolenic (18:3), 4.2–6.6 g kg^?1 arachidic (20:0) and 2.1–3.0 g kg^?1 behenic (22:0) acids, which is comparable with that of corn oil. No statistical difference in seed weight ratio was determined during the maturation period, whereas changes in the saturated fatty acids of the seed oil were observed. From this study it can be concluded that the seeds of prickly pear are suitable as animal feed. Copyright © 2003 Society of Chemical Industry     

Analytical composition and rumen degradability of isogenic and transgenic corn varieties

Two different corn cultivars were compared with their genetically modified counterparts containing the gene coding for the Cry1A(b) protein of Bacillus thuringiensis (Bt). There were no analytical differences between the conventional and transgenic genotype kernels, whereas stovers from Bt⁺ plants had higher sugar (148.3 g kg^?1 versus 115.9 g kg^?1; P < 0.01) and lower NDF (592.7 g kg^?1 versus 631.5 g kg^?1; P < 0.05) contents than Bt^? maize. A comparison of the amino acid profiles showed higher phenylalanine content in kernels from the Bt⁺ plants (49.1 g kg^?1 vs 47.8 g kg^?1; P < 0.05) which was, however, not reflected in the protein content. The initial dry matter rumen degradability of the isogenic kernels was higher than that of Bt⁺ varieties (569.5 g kg^?1 vs 543.7 g kg^?1; P < 0.05), whereas the lower fibre content increased the dry matter (548.6 g kg^?1 vs 526.6 g kg^?1; P < 0.01) and protein (695.6 g kg^?1 vs 647.9 g kg^?1; P < 0.01) degradability after 24 h of incubation in stovers from Bt⁺ plants. The NDF degradability was higher in Bt^? corn varieties because of the higher proportion of hemicellulose in the total fibre. Copyright © 2003 Society of Chemical Industry     

Chemical composition and toxic trace element composition of some Nigerian edible wild mushrooms

Two essential amino acids (methionine and tryptophan); anti‐nutritional factors (tannin and trypsin inhibitor) and toxic elements (Pb, Cd, Ni, As, Hg and Cr) were determined spectrophotometrically from five edible wild mushrooms. The tryptophan content was between 1.00 and 1.82 g (100 g)^?1 but methionine was low at 0.26–1.38 g (100 g)^?1. Tannin content was high (30.3–40.0 mg g^?1) but trypsin inhibitor was low (22.0–39.5 TIU g^?1). Trace elements analysis reviled Pb (0.34–5.06 mg kg^?1) to be the highest of all the trace elements. Cd was (0.06–1.70 mg kg^?1), Ni (0.26–2.08 mg kg^?1), As (0.17–0.92 mg kg^?1), Hg (0.01–0.05 mg kg^?1) and Cr (0.04–0.22 mg kg^?1). These mushrooms are nutritious but must be well processed to eliminate or at least reduce the levels of tannin and Pb to improve their nutritional values.     

The apparent digestibility of alkali-treated willow (Salix aquatica var. gigantia) when fed to sheep

Dried, ground willow (Salix aquatica) treated with 33 g sodium hydroxide kg^?1 (7.5M solution) was fed to sheep in pelleted diets containing 0, 100, 200, 300, 400 g treated willow kg^?1. Apparent digestibility coefficients of dietary dry matter, organic matter and energy declined linearly with increasing content of treated willow. Extrapolation of these relationships gave estimated apparent digestibility values for treated willow of 0.42 and 0.40 for dry matter (DM) and gross energy respectively. The apparent digestibility of acid-detergent fibre was shown to be 0.36. The metabolisable energy content of the treated willow was calculated to be 5.7 MJ kg^?1 DM. The high copper content (579 mg kg^?1) of the treated willow did not appear to have any deleterious effects on the animals during this short-term experiment as shown by the normal liver copper concentrations in the sheep at the end of the experiment.