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1.
BACKGROUND: The oil content and fatty acid composition of the mature seeds of Acacia species collected from natural habitat of the northwest zone of the Indian subcontinent (Rajasthan) were analyzed in order to determine their potential for human or animal consumption. RESULTS: Oil content varied between 40 and 102 g kg?1. The highest oil content was obtained in Acacia bivenosa DC. (102 g kg?1) among the nine Acacia species. The fatty acid composition showed higher levels of unsaturated fatty acids, especially linoleic acid (~757.7 g kg?1 in A. bivenosa), oleic acid (~525.0 g kg?1 in A. nubica) and dominant saturated fatty acids were found to be 192.5 g kg?1 palmitic acid and 275.6 g kg?1 stearic acid in A. leucophloea and A. nubica respectively. Seed oils of Acacia species can thus be classified in the linoleic–oleic acid group. Significant variations were observed in oil content and fatty acid composition of Acacia species. CONCLUSION: The present study revealed that the seed oil of Acacia species could be a new source of high linoleic–oleic acid‐rich edible oil and its full potential should be exploited. The use of oil from Acacia seed is of potential economic benefit to the poor native population of the areas where it is cultivated. The fatty acid composition of Acacia seed oils is very similar to that reported for commercially available edible vegetable oils like soybean, mustard, sunflower, groundnut and olive. Hence the seed oil of Acacia species could be a new source of edible vegetable oil after toxicological studies. Copyright © 2012 Society of Chemical Industry  相似文献   

2.
Some nutritional and anti-nutritional characteristics of mucuna (Mucuna utilis (Wight) Burck) bean seeds were studied. The mature seeds contained 264 g crude protein, 63 g crude fibre, 41 g crude fat, 37 g ash and 595 g carbohydrates kg?1 DM. The essential amino acid profile compared well with the FAO/WHO scoring pattern except for a deficiency of sulphur-containing amino acids. Mineral composition was similar to those reported for most tropical grain legumes. Raw mucuna seed samples contained moderately high levels of anti-tryptic activity (2170 trypsin units inhibited g?1 DM), but this was completely destroyed by cooking. The other anti-nutritional factors (phytate, cyanide and tannins) are probably of little nutritional significance provided that the beans are properly processed. The in-vitro protein digestibility of raw and cooked beans were 71·5 and 80·3 %, respectively. In view of the high L-DOPA contents reported in some mucuna cultivars, overconsumption of mucuna beans should be viewed with some caution until suitable processing methods are developed.  相似文献   

3.
The hulls and cotyledons from three Western Australian cultivars (Gungurru, Yorrel and Danja) of Lupinus angustifolius, all of low alkaloid content, were analysed separately for their carbohydrate content and composition. Only minor differences in composition between these three cultivars were observed. More notably, the cotyledons of all the cultivars contained levels of non-starch polysaccharides (NSP), ranging from 290 to 310 g kg?1 dry weight considerably higher than had been measured previously in cultivars of this species. Galactose, arabinose and uronic acid residues accounted for approximately 67%, 13% and 10%, respectively, of the cotyledon NSP. Although only a small proportion of the cotyledon NSP is soluble, a much larger proportion could be extracted with hot EDTA treatment. The oligosaccharide content of the cotyledons ranged from 74 to 80 g kg?1 dry weight. Cotyledons had very low contents of cellulose, lignin and starch. Hulls consisted predominantly of NSP, with values ranging from 856 to 891 g kg?1 dry weight. Glucose, xylose, uronic acids and arabinose were the principal sugar residues present reflecting the compositions of the major constituent polysaccharides, cellulose, hemicelluloses and pectins. Only low levels of lignin were measured in hulls. Cotyledon NSP and hulls from these cultivars may have considerable value as sources of dietary fibre in the human diet.  相似文献   

4.
BACKGROUND: Grain legumes are under‐exploited as possible sources of phytase for the poultry industry. The current study was conducted to assess the effect of germination on phytase activities, phytate and total phosphorus content in samples of Nigerian‐grown grain legumes. The legumes screened were African yambean (AYB, Sphenostylis stenocarpa), lima bean (Phaseolus lunatus), pigeon pea (Cajanus cajan), cowpea (Vigna unguiculata) and groundnut (Arachis hypogea). RESULTS: Phytase activity was low in AYB, lima bean and pigeon pea but high in cowpea and groundnut. Phytate content ranged between 3.01 g kg?1 and 8.95 g kg?1 while total phosphorus content ranged between 2.63 g kg?1 and 5.93 g kg?1. The grain legumes with higher phytase activity recorded the lowest phytate and phosphorus content. During germination there was an initial 4‐fold to 35‐fold increase in phytase activity after 6–7 days of germination followed by a decrease until 10 days (P < 0.05). The increase in phytase activity during germination was accompanied by a significant reduction in phytate (P < 0.05) and a small but significant increase in total phosphorus. CONCLUSION: The increase in phytase activity and the accompanying decrease in phytate content could have a positive implication for the nutrition of poultry and ruminants and for the environment. Copyright © 2010 Society of Chemical Industry  相似文献   

5.
A greenhouse experiment was conducted to investigate the nutritional quality of solution‐cultured rice. Five rice cultivars, different in grain amylose content and protein content, were grown under 10, 40 and 80 mg l?1 nitrogen levels during the period of July 2003 to October 2003. In comparison to their original seeds, the solution‐cultured rice Oryza sativa L grain had strikingly higher protein content across all the cultivars and nitrogen levels, and remarkably lower amylose content in the waxy and low amylose cultivars, which might be due to the sufficiently stable nitrogen supply and well‐controlled temperature and humidity. The highest grain protein content was 163.6 g kg?1 in this experiment, which is the highest reported rice grain protein content. The residual nitrogen concentration was greater than 12.39 g kg?1 in the roots, 8.95 g kg?1 in the stems, and 21.97 g kg?1 in the flag leaves across all the cultivars and nitrogen treatments at harvesting. The rice grain had a narrow range of grain carbon content and hydrogen content. The average grain carbon and hydrogen contents for all the rice samples were 42.95 ± 0.15 (n = 60) and 6.81 ± 0.04 g kg?1 (n = 60), respectively. The solution cultured rice grain was characterized with lower carbon–nitrogen mole ratio and lower hydrogen–nitrogen mole ratio, which could be mainly attributed to the increased protein content. The response of plant nitrogen, grain protein and amylose concentration to the supplemental nitrogen level varied with the cultivars. The results in this study suggested that solution culture technology could improve the production potential of rice. Copyright © 2005 Society of Chemical Industry  相似文献   

6.
The chemical composition of the grain of a number of wild grasses used as food in times of famine in western Sudan are reported and compared with those of the local staple cereals. Species investigated were Cenchrus hiflorus (haskaneet). Dactyloctenium aegyptium (korecb). Echinochloa colona (difra) and Oryza punctata (ruz el wadi). The grain of all species except C biflorus had protein contents in the range 110-140 g kg?1, broadly similar to those of the local staple cereals. The grain of C biflours possessed a particularly high protein content of 210 g kg?1. The nutritional quality of the proteins as measured by their chemical scores ranged from 20 for C biflorus to 65 for O punctata compared with scores of 36 and 58 for the local sorghum var Kurgi and millet respectively. Lysine was the limiting amino acid in all cases. Whilst the composition of the protein of sorghum var Kurgi was typical of sorghum generally, that of var Karamaka was unusual in possessing lysine levels of 3.4 g (16 g N)1, double that normally present in sorghum and raising the chemical score of the protein to 62. The ash content of the famine food cereals was high, attaining 113 g kg1 in C biflorus. All grains were good sources of zinc and D aegyptium. O punctata and E colonum additionally contained comparatively high levels of iron. Remarkably for a cereal D aegyptium was also very rich in calcium, containing over 10 g kg1, and possessed high concentrations of manganese. Carbohydrate content of the famine food grains varied from 617 g kg1 for C biflorus to 748 g kg1 for O punctata, values comparable to the local staple cereals. The proportion of starch in this fraction ranged from 650 g kg1 in D aegyptium to 940 g kg1 in O punctata. Seed oils of all species were predominantly unsaturated containing mainly oleic and linoleic acids.  相似文献   

7.
BACKGROUND: Quinoa is a good source of protein and can be used as a nutritional ingredient in food products. This study analyses how much growing region and/or seasonal climate might affect grain yield and nutritional quality of quinoa seeds. RESULTS: Seeds of ten quinoa cultivars from the Andean highlands (Bolivia/Argentina site) and Argentinean Northwest (Encalilla site) were analysed for seed yield, protein content and amino acid composition. Grain yields of five cultivars growing at Encalilla were higher, and four were lower, compared with data from the Bolivia/Argentina site. Protein contents ranged from 91.5 to 155.3 and from 96.2 to 154.6 g kg?1 dry mass for Encalilla and Bolivia/Argentina seeds respectively, while essential amino acid concentrations ranged from 179.9 to 357.2 and from 233.7 to 374.5 g kg?1 protein respectively. Significant positive correlations were found between the content of essential amino acids and protein percentage. CONCLUSION: It appears that there are clear variations in seed yield, total protein content and amino acid composition among cultivars from the two sites. Essential amino acid composition was more affected than grain yield and protein level. The study revealed that both environmental and climatic factors influence the nutritional composition of quinoa cultivars growing in different agroecological regions. Copyright © 2011 Society of Chemical Industry  相似文献   

8.
Physical characteristics of pods and seeds, proximate composition, different protein fractionation, SDS‐PAGE analysis of proteins, amino acid composition, starch content, fatty acid profiles and various antimetabolic substances of Gila bean (Entada phaseoloides Merrill) were studied. The pod length and the number of seeds per pod ranged from 55 to 90 cm and from 5 to 11 respectively. The kernel comprised 66.1% of the seed weight (18.41 ± 1.14 g). The seed kernels contained 256.7 g kg?1 crude protein, 108.1 g kg?1 lipid, 27.3 g kg?1 ash and a high content of carbohydrate (585.7 g kg?1). The levels of potassium, phosphorus, zinc and iron were similar to those in conventional pulses. Among the different protein fractions of seed kernels, albumins constituted the major storage proteins (69.7%). The kernel proteins were rich in essential amino acids, particularly sulphur‐containing amino acids, and their values appeared to be higher than the FAO/WHO (1990) reference protein for a 2–5‐year‐old growing child and soybean, and comparable to hen egg. Seed kernel lipids contained high levels of unsaturated fatty acids, oleic and linoleic acids, which accounted for 83% of the total fatty acid recovered. The kernel exhibited high trypsin and chymotrypsin inhibitor activities (96.65 mg TI g?1 and 30.02 CIU mg?1 sample respectively) in addition to containing phenolics, phytic acid, lectins and oligosaccharides. Another major toxic constituent was identified as a group of triterpenoid saponins (3.21%), which had high haemolytic activity (HeU) against cattle erythrocytes and caused high mortality in fish. The in vitro digestibility of the kernel protein was low (67%). © 2001 Society of Chemical Industry  相似文献   

9.
BACKGROUND: The stage of fruit ripeness at the time of harvest determines the final quality of ripe fruit. In this study, changes in the chemical composition of seed kernels from the oleaginous gourd Lagenaria siceraria (Molina) Standl. during maturation were evaluated to determine the best time to harvest the berries. Two cultivars (round and oval berry) were studied at three maturation stages (30 and 50 days after fruit set (DAFS) and complete plant whiteness (CPW)). RESULTS: Seed kernels were rich in oil (527.2–544.6 g kg−1), protein (402.8–403.3 g kg−1), minerals and energy. Maturation influenced the chemical compounds of the two cultivars differently. Best quantities of these components were reached at 50 DAFS. However, protein bioavailability was better at 30 DAFS and CPW in the round and oval berry cultivars respectively. Lagenaria siceraria oils were of good quality, containing an abundance of essential fatty acids (647.2–667.0 g kg−1). CONCLUSION: Both cultivars of L. siceraria should be harvested at 50 DAFS owing to the good nutritional properties of their seeds and oils. However, to obtain best‐quality proteins, round and oval berry cultivars should be harvested at 30 DAFS and CPW respectively. The results of this study will be useful in reducing the production time of fruits and improving the nutritional quality of their seeds. Copyright © 2011 Society of Chemical Industry  相似文献   

10.
The foliage of 61 accessionso f amaranthus comparising both the grain and vegetable types referable to 10 species were evaluated for carotenoid, protein, nitrate, odxalate and moisture contents (fresh weight). Carotenoid varied from 90 to 200 mg kg?1 in vegetable types and from 60 to 200 mg kg?1 in the leaves of grain types. Variation for leaf protein was found to be 14-30, 15-43 g kg?1; nitrate 1.8.-8.8, 4.1-9.2 g kg?1; oxalate 5.1-19.2, 3-16.5 g kg?1; and moisture 780-860, 750-840 g kg?1 in vegetable and grain types, respectively. Analysis of the amino acid composition of leaf protein of some high carotenoid lines revealed a well balanced composition with high lysine (40-56 g kg?1). variation of all the five parameters (carotenoid, protein, nitrate, oxalate and moisture) with respect tot he leaf position in vegetable type (4- and 8-week-old plants) and with respect to age (- to 4-month-old plants) in grain types was also studied.  相似文献   

11.
Colombia has a biodiversity centre of diploid potatoes located at south of the country. This study evaluated the amounts of potassium (K), calcium (Ca), iron (Fe) and zinc (Zn) in a biodiversity panel of potato tubers, constituting native cultivars, accessions of the Working Collection of Potato Breeding Program at the Universidad Nacional de Colombia (CCC) and commercial cultivars. The highest quantity of minerals found were as follows: 34 333 ± 4509 mg K kg−1 potato dry weight (DW; CCC112), 1965 ± 898 mg Ca kg−1 potato DW (CCC23), 87.5 ± 8.8 mg Fe kg−1 potato DW (CCC116) and 60.7 ± 5.1 mg Zn kg−1 potato DW (CCC31). As compared to those in commercial cultivars, the currently evaluated tubers had an increase of 1.4, 12.5, 3.5 and 3.6-fold in K, Ca, Fe and Zn. These genotypes can be used in the future breeding programmes to enhance specific mineral contents in tubers.  相似文献   

12.
BACKGROUND: Today, few known plant species provide both an essential oil (EO) and a vegetable oil (VO). Seed and husk of two Aframomum species were investigated and compared in terms of EO, fatty acids, tocopherols, and tocotrienols. RESULTS: EO yield reaches 15.3 g kg−1 in the seeds and 3.2 g kg−1 in the husks, while VO yield is 180.0 g kg−1 in the seeds and 25.0 g kg−1 in the husks. β‐Pinene, 1,8‐cineol, α‐selinene, terpine‐4‐ol, linalool, myrtenal and β‐caryophyllene are the major compounds of seed and husk EO. Fatty acid analysis of two Aframomum species shows that oleic, linoleic, and palmitic acids were the major compounds of VO. Total sterol contents reached 4.3 g kg−1 in seed VO and 8.5 g kg−1 in husk VO. An appreciable amount of tocopherols (0.52 g kg−1) was found in seed VO. CONCLUSION: The seed and husk oil of A. stipulatum and A. giganteum fruits are rich sources of many bioactive constituents such as fatty acids, sterols, tocopherols and tocotrienols. These tropical wild fruits can be considered as new Aroma Tincto Oleo Crops (ATOC) resources that contain both EOs and VOs. Copyright © 2012 Society of Chemical Industry  相似文献   

13.
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  相似文献   

14.
Due to limited data-describing abilities of mushrooms to accumulate platinum group elements (PGEs) and rare-earth elements (REEs), the aim of this study was to determine, by inductively coupled plasma optical emission spectrometry followed by microwave-assisted sample digestion by nitric acid, the content of these elements in 20 mushroom species (10 above ground and 10 growing on wood), mostly edible, collected near a busy trunk road. The highest content of PGEs in above-ground mushroom species was observed in Lepista gilva and Suillus bovinus fruit bodies (0.38 ± 0.05 and 0.37 ± 0.03 mg kg?1 DW, respectively), while in mushrooms growing on wood, the highest content was observed in Pleurotus ostreatus (0.35 ± 0.04 mg kg?1 DW). The mean content of PGEs for both these groups was 0.23 ± 0.08 and 0.26 ± 0.07 mg kg?1 DW, respectively. The highest content of REEs in Suillus luteus and Tricholoma equestra was 5.03 ± 0.50 and 2.18 ± 0.56 mg kg?1 DW, respectively, but within mushrooms growing on wood in Ganoderma applanatum fruiting bodies it was 4.19 ± 0.78 mg kg?1 DW. Mean contents of REEs were 1.39 ± 1.21 and 1.61 ± 0.97 mg kg?1 DW in above-ground species and species growing on wood, respectively. Generally, the group of mushroom species growing on wood was capable of slightly higher accumulation of both REEs and PGEs. No limits have been established for both the groups until now.  相似文献   

15.
BACKGROUND: Beans are rich and inexpensive sources of proteins and carbohydrates around the world, but particularly in developing countries. However, many legume varieties are still underutilized. In this study, physical characteristics of the seeds of three Phaseolus lunatus cultivars were characterized. Also, the chemical composition and starch digestibility in the cooked beans were assessed. RESULTS: ‘Comba floja’ variety exhibited the highest thousand‐kernel weight whereas the lowest was found in ‘comba violenta’. This agrees with seed dimensions: ‘comba floja’ had the Longest seeds (16.36 mm) and ‘comba violenta’ the shortest ones (13.98 mm). All samples exhibited high protein content, but levels in ‘comba blanca’ variety (216 g kg?1) were lower than the in other two cultivars. Total starch (370–380 g kg?1) and potentially available starch content (330–340 g kg?1) were similar in the three varieties. Resistant starch level in the cooked seeds ranged between 38 and 45 g kg?1. Low enzymatic hydrolysis indices (HI) were recorded (30.2–35%), indicating a low digestion rate for Phaseolus lunatus starch. HI‐based predicted glycemic indices ranged between 34% and 39%, which suggests a ‘slow carbohydrate’ feature for this legume. CONCLUSION: Phaseolus lunatus beans appear to be a good source of protein and slow‐release carbohydrates with potential benefits for human health. Copyright © 2007 Society of Chemical Industry  相似文献   

16.
BACKGROUND: The aim of this study was to evaluate the intake of selenium, total and inorganic arsenic and the bioaccessibility of arsenic in diets of Mexican schoolchildren using an in vitro method. RESULTS: Total and inorganic arsenic concentrations in the diets ranged from 0.05 to 1.15 mg kg?1 dry weight (DW) and from 0.023 to 0.088 mg kg?1 DW respectively, while selenium levels were between 0.08 and 0.20 mg kg?1 DW. Daily intake of total and inorganic arsenic ranged from 0.15 to 10.49 µg day?1 kg?1 body weight (BW) and from 0.06 to 1.11 µg day?1 kg?1 BW respectively, while that of selenium varied from 0.29 to 2.63 µg day?1 kg?1 BW. Bioaccessibility of total and inorganic arsenic ranged from 4 to 97% (mean 44 ± 21.5%) and from 33 to 97% (mean 71 ± 22.5%) respectively. CONCLUSION: Inorganic arsenic levels in the diets were low. Therefore there appears to be a low risk of adverse effects resulting from excess inorganic arsenic intake from these diets. Copyright © 2011 Society of Chemical Industry  相似文献   

17.
The composition of common buckwheat (Fagopyrum esculentum Moench) seed milling fractions depends upon the relative abundance of various seed tissues in each. Fancy (light) flour contains mainly central endosperm, while the bran milling fraction has seed coat and some embryo tissues. Phytate, found in protein bodies of embryo and aleurone cells, is the major storage form of phosphorus, potassium, magnesium and some microelements in seeds. Phytic acid (35–38 g kg?1) and minerals are concentrated in bran, a milling fraction with high concentrations of phytate‐rich tissues. Polyphenolics, including condensed tannins (proanthocyanidins), are also concentrated in bran (11–15 g kg?1). Rutin is concentrated in the hull of common buckwheat (0.8–4.4 g kg?1). Rutin concentration is low (0.2–0.3 g kg?1) in groats of common buckwheat but higher (0.7–0.8 g kg?1) in bran containing hull fragments. Rutin is 300‐fold more concentrated (81 g kg?1) in groats of tartary buckwheat (Fagopyrum tataricum (L) Gaertn) than in groats of common buckwheat. Only small amounts of quercetin were detected. Bran is a concentrated source of phytic acid and tannins, a consideration in consumption of large amounts of buckwheat bran for nutritional or medicinal purposes. © 2001 Society of Chemical Industry  相似文献   

18.
The chemical composition of the seed shell of the apricot (Prunus armeniaca) were investigated. Acid and neutral detergent fibres (ADF and NDF) and their fractions—hemicellulose, cellulose and lignin—were determined. The NDF content was about 920 g kg?1 DM. The concentrations of oils, soluble sugars, pectins, polyphenolic compounds, proteins and mineral elements were also determined. None of these fractions was present at levels higher than 25 g kg?1 DM. Essential amino acids comprised 38-41% of the total amino acids. Potassium (2.44 g kg?1) was the most abundant element, followed by calcium (1.15 g kg?1). Some possible applications for apricot seed shell are considered.  相似文献   

19.
Five castrated male Iberian pigs (100 ± 2 kg mean live body weight) fitted with T‐shaped ileal cannulas were used to determine ileal digestibility of legume seed meals. The diets were based on defatted soybean (256 g kg?1), lupin (451 g kg?1) or chickpea (731 g kg?1) seed meals and contained similar amounts of digestible energy (14.2–15.1 kJ g?1) and protein (107 g kg?1). Only myristic acid (C14:0) ileal apparent digestibility was higher (p < 0.05) in lupin than in chickpea meal. Ileal apparent digestibility of unsaturated fatty acids (FA) (710–920 g kg?1) was higher (p < 0.05) than that of saturated (480–710 g kg?1) FA for both seed meals. Ileal digestibility of chickpea starch was 850 g kg?1. Ileal digestibility of oligosaccharides (sucrose, raffinose, stachyose, verbascose and ciceritol) in lupin (820 g kg?1) and chickpea (690 g kg?1) was higher (p < 0.05) than that of defatted soybean (510 g kg?1). However, total amounts of oligosaccharides digested were higher (p < 0.05) for lupin and chickpea meals (29.6 and 24.6 g kg?1 feed respectively) than for soybean (15.2 g kg?1 feed). Among individual non‐starch polysaccharide (NSP) sugars, ileal digestibility values for rhamnose and xylose in lupins were higher (p < 0.05) than those for soybean or chickpea. Ileal digestibility of lupin meal NSP (650 g kg?1) was higher (p < 0.05) than those of soybean (560 g kg?1) or chickpea (430 g kg?1). Up to the terminal ileum, higher (p < 0.05) amounts of lupin total NSP (94.1 g kg?1) than for soybean (24.3 g kg?1) or chickpea (27.1 g kg?1) were digested. Lactate, acetate and isobutyrate concentrations were higher (p < 0.05) in ileal contents of pigs fed lupin and chickpea seed meals compared with soybean‐fed animals. It is concluded that higher lactate and short chain fatty acids concentrations in ileal contents of pigs fed lupin or chickpea seed meals compared with soybean are likely to be the result of higher total amounts of lupin NSP and/or lupin and chickpea oligosaccharides digested up to the terminal ileum. This might have a protective effect on Iberian pig's intestinal physiology. Both lupin and chickpea meals are likely to constitute a valuable alternative to defatted soybean in Iberian pig feeding. Copyright © 2005 Society of Chemical Industry  相似文献   

20.

BACKGROUND

Since available arable land is limited and nitrogen fertilizers pollute the environment, cropping systems ought to be developed that do not rely on them. Here we investigate the rapidly growing, N2‐fixing Azolla/Nostoc symbiosis for its potential productivity and chemical composition to determine its potential as protein feed.

RESULTS

In a small production system, cultures of Azolla pinnata and Azolla filiculoides were continuously harvested for over 100 days, yielding an average productivity of 90.0–97.2 kg dry weight (DW) ha?1 d?1. Under ambient CO2 levels, N2 fixation by the fern's cyanobacterial symbionts accounted for all nitrogen in the biomass. Proteins made up 176–208 g kg?1 DW (4.9 × total nitrogen), depending on species and CO2 treatment, and contained more essential amino acids than protein from soybean. Elevated atmospheric CO2 concentrations (800 ppm) significantly boosted biomass production by 36–47%, without decreasing protein content. Choice of species and CO2 concentrations further affected the biomass content of lipids (79–100 g kg?1 DW) and (poly)phenols (21–69 g kg?1 DW).

CONCLUSIONS

By continuous harvesting, high protein yields can be obtained from Azolla cultures, without the need for nitrogen fertilization. High levels of (poly)phenols likely contribute to limitations in the inclusion rate of Azolla in animal diets and need further investigation. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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