In vitro protein digestibility and mineral availability of green beans (Phaseolus vulgarisL) as influenced by variety and pod size

Three varieties of green beans (Cleo, Strike and Sentry) were harvested and sorted into four fractions according to pod size (diameter <7 mm; 7–8·5 mm; 8·6–10 mm and >10 mm). Ash content and dietary fibre increased significantly as pod size increased mainly in Cleo and Strike beans. Strike showed the highest fibre content (378·0 g kg⁻¹) but the lowest carbohydrate (364·6 g kg⁻¹) and ash (68·4 g kg⁻¹) values. Mean values for Fe and Mg content were higher in Cleo beans (70·9 and 27·1 mg kg⁻¹, respectively), Zn, Cu and Mg were higher in Strike beans (48·7 mg kg⁻¹, 22·4 mg kg⁻¹ and 3·15 g kg⁻¹, respectively) while Na and Ca values were maximum in Sentry (459·1 mg kg⁻¹ and 7·11 g kg⁻¹, respectively). Trypsin inhibitor was negatively related to in vitro protein digestibility but no relationship was found between this last parameter and phytic acid content. This antinutrient, together with dietary fibre, and a negative influence on in vitro mineral dialysability of green beans. © 1998 SCI     

Sugar Beet Grown Using Nutrient Film Technique: Yield and Nutritional Quality

Sugar beet (Beta vulgaris L cv Great Western Sugar) was grown using the nutrient film technique with a half-strength modified Hoagland nutrient solution to determine its biomass yield and nutritional quality. After 6 months, storage root and foliage weights per plant were 493·1 g and 551·0 g, respectively. Sucrose content in the fresh storage root was 118·4 g kg⁻¹ but was less than 10 g kg⁻¹ in the fresh leaves and petioles. Some nutrients in the leaves and petioles were analysed to evaluate their potential as a leafy vegetable. Fresh leaf protein, total dietary fibre, mineral (Ca, Mg, Zn, Fe and K), vitamin (carotene, ascorbic acid and thiamine) and oxalic acid concentrations were similar to those of consumer-accepted green vegetables.     

The effect of pod and seed positions on the physical and cooking properties of faba beans (Vicia faba)

The effect of pod location on plant (lower, middle and upper regions) and seed position inside the pods (nodular, middle and terminal) on certain characteristics of dry and stewed faba beans were studied. The weight, volume, relative density, seed coat (%), hydration and swelling coefficients were determined for dry seeds. Hydration and swelling coefficients, fractured beans (%), penetrometer readings and scores of colour, granulation and softness (by taste panel) were evaluated for stewed beans. The weight, volume, relative density, pH, and total and soluble solids content of the stewed liquor were also measured. Analysis of variance showed that the weight and volume of 1000 dry seeds were significantly (P<0.001) affected by pod location and seed position. Higher values were obtained for lower pods and terminal and middle seeds. Seeds from upper pods had the highest percentage of seed coat. Pod location showed a significant effect on the weight, volume, pH, soluble and insoluble solids of stewed liquor. No significant effect was found for pod location or seed positions on the characteristics of stewed beans, except the hydration coefficient which was significantly affected by pod location.     

Broad bean and pea by‐products as sources of fibre‐rich ingredients: potential antioxidant activity measured in vitro

BACKGROUND By‐products generated during the processing of plant food can be considered a promising source of dietary fibre as a functional compound. The dietary fibre composition, soluble sugars and antioxidant activity of the extractable polyphenols of pea and broad bean by‐products have been analysed in this study. RESULTS: Total dietary fibre using AOAC methods plus hydrolysis (broad bean pod: 337.3 g kg^?1; pea pod: 472.6 g kg^?1) is higher (P < 0.05) in both by‐products than with the Englyst method (broad bean pod: 309.7 g kg^?1; pea pod: 434.6 g kg^?1). The main monomers are uronic acids, glucose, arabinose and galactose in broad bean pods. However, pea pods are very rich in glucose and xylose. The soluble sugars analysed by high‐performance liquid chromatography in both by‐products have glucose as the most important component, followed by sucrose and fructose. The ferric reducing antioxidant power (broad bean pod: 406.4 µmol Trolox equivalents g^?1; pea pod: 25.9 µmol Trolox equivalents g^?1) and scavenging effect on 2,2‐diphenyl‐1‐picrylhydrazyl radical (EC₅₀ of broad bean pod: 0.4 mg mL^?1; EC₅₀ of pea pod: 16.0 mg mL^?1) were also measured. CONCLUSIONS: Broad bean and pea by‐products are very rich in dietary fibre, particularly insoluble dietary fibre and their extractable polyphenols demonstrate antioxidant activity. Therefore they might be regarded as functional ingredients. Copyright © 2011 Society of Chemical Industry     

Physico-Chemical Properties of Immature Pods of Japanese Soybean Cultivars

Twelve Japanese cultivars and JS335, the most popular soybean cultivar in India, were grown in the field. Days to arrival of R6 stage (when pods are still green, immature, and tight with fully developed immature green seeds) of these cultivars were recorded. Pods picked at this stage were evaluated for pod yield per plant, pod characteristics (width, presence of hairs) fresh green seed weight and percent moisture content. Fresh green seeds were analyzed for compositional traits viz. protein content, trypsin inhibitor lipoxygenase isozymes, oil content, and polyunsaturated fatty acids (essential fatty acids). Japanese cultivars showed higher fresh green seed weight and pod yield than JS335. On a fresh weight basis, Japanese cultivars exhibited lower protein content but higher oil content than JS335. Most of the Japanese cultivars showed lower trypsin inhibitor content and a varying level of lipoxygenase-I, as well as lipoxygenase-II + III when compared to JS335. Total polyunsaturated fatty acids content in JS335 was higher than some of the Japanese cultivars. The number of pods per plant showed a positive correlation (r = 0.863, p < 0.001) with pod yield per plant. Some of the Japanese cultivars offer great potential for consumption at the green pod stage or as a source for desirable traits.     

Effect of post-harvest treatments on the occurrence of ochratoxin A in raw cocoa beans

Cocoa beans are the principal raw material for chocolate manufacture. Moulds have an important place in the change in the quality of cocoa beans due to their role in the production of free fatty acids and mycotoxins, namely ochratoxin A (OTA). This study investigated the impact of the key post-harvest treatments, namely the fermentation and drying methods on OTA contamination of raw cocoa beans. Analytical methods for OTA detection were based on solid–liquid extraction, clean-up using an immunoaffinity column, and identification by reversed-phase HPLC with fluorescence detection. Of a total of 104 randomly selected cocoa samples analysed, 32% had OTA contents above 2 µg kg^–1. Cocoa sourced from pods in a bad state of health had a maximum OTA content of 39.2 µg kg^–1, while that obtained from healthy pods recorded 11.2 µg kg^–1. The production of OTA in cocoa beans increased according to the pod-opening delay and reached 39.2 µg kg^–1 after an opening delay of 7 days after harvest, while 6.1 and 11.2 µg kg^–1 were observed when pods were opened after 0 and 4 days. OTA production also seemed to depend considerably to the cocoa fermentation materials. When using plastic boxes for bean fermentation, the OTA production was enhanced and reached an average OTA content of about 4.9 µg kg^–1, while the raw cocoa treated in banana leaves and wooden boxes recorded 1.6 and 2.2 µg kg^–1 on average respectively. In parallel, the OTA production was not really influenced by either the mixing or the duration of the fermentation or the drying materials.     

Exocrine Pancreatic Secretions in Young Pigs Fed Diets Containing Faba Beans (Vicia faba) and Peas (Pisum sativum): Nitrogen,Protein and Enzyme Secretions

Two experiments were carried out to investigate the effect of feeding diets containing faba beans and peas on pancreatic secretions in young pigs fitted with a pancreatic pouch re-entrant cannula. In Experiment 1, eight barrows, with an average initial weight of 8·5 kg, were fed one of two maize starch-based diets formulated to contain 200 g crude protein (CP) kg⁻¹ according to a completely randomised design. In one of the diets, soya bean meal was the sole protein source; in the other diet, soya bean meal and faba beans (cv Fibro; dark-flowering) each supplied 50% of the dietary CP. In Experiment 2, five barrows, with an average initial weight of 18·1 kg, were fed one of two diets according to a two-period change-over design. The diets were formulated to contain 150 g CP kg⁻¹ with peas (cv Ascona or cv Radley) as the sole protein source. In both experiments, the experimental periods consisted of 8 days: 6 days adaptation followed by a 2 day collection of pancreatic juice. The soya bean meal diet and the faba bean diet contained 0.04 and 0.21% tannins (catechin equivalents), respectively. The trypsin inhibitor activities of the Ascona and Radley pea diets were 0·76 and 3·24 mg of trypsin inhibited per gram, respectively. In both experiments, diet did not affect ( P> 0·05) the pancreatic secretions of nitrogen, protein, amylase, lipase and chymotrypsin. In Experiment 1, specific trypsin activity was higher ( P< 0·05) in pancreatic juice from pigs fed the diet containing soya bean meal and faba beans (53700 units litre⁻¹) than for those fed the soya bean meal diet (41200 units litre⁻¹). However, there was no effect ( P> 0·05) when trypsin activity was expressed as total activity (units 24 h⁻¹). It is concluded that the inclu-sion of faba beans and peas in diets for young pigs has only minor effects on exocrine pancreatic secretions.     

Amino acid composition and In Vitro digestibility of some Egyptian foods made from faba bean (Vicia faba L)

Faba beans were cooked to prepare four different dishes—Medammis, Falafel, Bissara and Nabet Soup—that are widely consumed in many Middle Eastern Countries, especially in Egypt. Amino acid composition and in vitro digestibility were determined and compared to raw beans. Severe heat-processing markedly decreased some essential amino acids, especially phenylalanine, cystine, methionine and tryptophan. Protein scores were 38·1, 21·2, 39·3, 33·7 and 42·4 for raw faba beans, Medammis, Falafel, Bissara and Nabet Soup, respectively. Cooking resulted in an appreciable increase in the in vitro digestibility which amounted to 98·4% for Nabet Soup, being close to that of casein (99·6%). The in vitro digestibility values were 75·9%, 92·7%, 85·0% and 97·2% for raw beans, Medammis, Falafel and Bissara, respectively.     

Effect of two pre-treatments on phenolic acid yield in three forage species

A direct comparison of two pre-treatments was undertaken to test their effect on the recovery of phenolic acids (PA) from three forage species. Samples of lucerne (Medicago sativa L), reed canarygrass (Phalaris arundinacea L), and switchgrass (Panicum virgatum L) were refluxed with 95% ethanol (EtOH) or neutral detergent solution (NDS). Subsequently, the resulting ethanol insoluble residue (EIR) and neutral detergent fibre (NDF) were treated with 1 M NaOH, and the extract was assayed for concentrations of p-coumaric acid (PCA) and ferulic acid (FA). In lucerne, the concentration of PCA was 9 times greater in the EIR than in the NDF (0·90 vs 0·11 mg g^?1 dry matter, DM), and the FA concentration was 27 times greater in forage treated with EtOH than with NDS (1·89 vs 0·07 mg g^?1 DM). In reed canarygrass (RCG), the concentrations of PCA and FA were slightly though significantly higher when the forage was pre-treated with EtOH. No significant differences in PA yield were detected between pre-treatments in switchgrass (SG). Extraction of EIR with hot EDTA (0·025 M , pH = 6·8) removed 80 to 90% of the total PA in EIR in lucerne but less than 5% of the PCA and FA in the grasses. These results indicate that almost all the PA in lucerne, in direct contrast to the grasses, are present in a fraction of the plant that is soluble in NDS. The relatively high PA concentration in the NDS soluble fraction suggests that the structure and composition of the fraction to which PA is esterified influence the degree to which PA affects digestibility.     

Simultaneous Determination of Alkaloids in Green Coffee Beans from Ethiopia: Chemometric Evaluation of Geographical Origin

The alkaloid compositions of 99 green coffee (Coffea arabica L.) bean samples comprising eight varieties (Harar, Jimma, Kaffa, Wollega, Sidama, Yirgachefe, Benishangul and Finoteselam) from the major production regions of Ethiopia were investigated. High performance liquid chromatography was applied for the simultaneous determination of four coffee alkaloids in the aqueous extracts of the beans. The limits of detection for the method were established as 13 mg kg^?1 for trigonelline, 7 mg kg^?1 for theobromine, 8.5 mg kg^?1 for caffeine and 4 mg kg^?1 for theophylline in the dry coffee beans. Theophylline was not detected in any of the samples. The determined concentrations (% w/w dry coffee beans) ranged from 0.98 to 1.32 % for trigonelline, 0.0048 to 0.0094 % for theobromine and 0.87 to 1.38 % for caffeine. The concentrations of the alkaloids varied significantly, depending on the geographical origin of the beans. Theobromine was not detected in coffee beans from the East (Harar coffees), and its absence in samples can be used to ascertain whether the coffee originates from this region. Coffee beans from the Northwest were characterized by higher concentrations of caffeine. Application of linear discriminant analysis provided 75 % correct classification of samples into the respective production regions, with a 74 % prediction success rate. The moderate classification efficiency obtained when using alkaloid data demonstrates the potential of using this class of compounds in discriminant models for determination of the geographical origin of green coffee beans from Ethiopia.     

花生主要农艺性状的相关性及聚类分析

应用DPS统计软件对18个花生品系的主要农艺性状的考种数据进行变异性、相关性和聚类分析。结果表明,主茎高、总分枝数、结果枝数、单株荚果数变异系数较大。主茎高与侧枝长、百果重与百仁重均呈极显著正相关;单株荚果产量与主茎高、侧枝长、总分枝数、结果枝数、单株果数、百果重、百仁重均呈正相关,与出米率呈负相关。18个花生品系因参与聚类的性状组合不同而聚类结果各异,综合性状的聚类在D＾2=5.91水平下分为4大类,其中第一类（1号和13号品系）和第四类（8、11、18）表现良好,值得推广种植。     

Interactions between plants in intercropped maize and common bean

BACKGROUND: Intercropping maize (Zea mays L.) with common bean (Phaseolus vulgaris L.) can give silage yields that are as high as with monocropped maize, but with more crude protein. Interactions between maize and common bean intercropped in the UK were assessed at a range of plant densities (maize 100 000, 75 000 and 50 000 plants ha^?1 and beans at a fixed density of 50 000 plants ha^?1). RESULTS: In monoculture, maize yield per plant increased as planting density decreased from 100 000 to 50 000 plants ha^?1. At a density of 50 000 maize plants ha^?1, both dry weight yield per plant and shoot N concentrations of maize were greater when intercropped with 50 000 Type III (bush‐type) bean plants ha^?1 than in monoculture (196.4 g plant^?1 and 167.0 g plant^?1; 21.6 g N kg^?1 dry mass and 17.4 g N kg^?1 dry mass, respectively), but intercropping Type IV (climbing) beans at this density combination had no effects on either maize plant weight or shoot N concentration. Invariably, however, the beans grown at 50 000 plants ha^?1 were adversely affected by competition with maize at all densities. Weight per plant of both Type III (bush‐type) and Type IV (climbing) beans grown in competition with 50 000 maize plants ha^?1 was only about half that of when grown alone. Intercropping gave increased mycorrhizal colonization of both species, especially in unfertilized plots, and gave a higher shoot N concentration in the maize. The beans had more nodules in the intercrop than in the monocrop. CONCLUSIONS: Intercropping maize with Type III common bean at 50 000 plants of each species ha^?1 increases yield per maize plant above that of monoculture maize at 50 000 plants ha^?1, despite plant density being doubled. This increase is brought about by increased maize shoot N concentration. Mycorrhizal infection of both species, and bean plant nodulation, are stimulated, and N moves from the beans to the maize. Copyright © 2008 Society of Chemical Industry     

Impact of industrial treatments on ochratoxin A content in artificially contaminated cocoa beans

Ochratoxin A (OTA) is a mycotoxin mainly produced by mould species of the genera Aspergillus and Penicillium, which grow on a variety of agricultural products. OTA-contaminated foodstuffs pose a major health hazard to consumers, including human and animal. In Côte d’Ivoire, numerous studies are being carried out to find the best way of preventing OTA contamination of cocoa raw material. The objectives of this investigation were to assess the impact of industrial treatment on OTA content in cocoa-derived products. Samples of cocoa pods were prepared under specific conditions promoting fungal proliferation on cocoa beans before processing. The beans underwent the usual industrial treatments – roasting, shelling, crushing, pressing and additive addition – and samples were taken at each stage. OTA was extracted with a methanol/3% sodium hydrogen carbonate solution and purified using an immunoaffinity column prior to HPLC analysis with fluorescence detection. OTA was detected in artificially contaminated cocoa beans at levels ranging from 3.4 to 44.7 µg kg^?1 with a mean value of 22.9 ± 3.6 µg kg^?1. OTA was mainly concentrated in the shell (93%). Roasting, shelling and additive addition significantly decreased levels of OTA by 24–40, 76 and 52%, respectively, with an overall reduction of ～91%. These results indicate that industrial processing of cocoa has a real impact on the reduction of OTA in final cocoa products.     

Investigations on the trypsin inhibitor,hemagglutinin, phytic and tannic acid contents of cowpea Vigna unguiculata

Ten cultivated varieties of mature dry beans Vigna unguiculata were analysed for trypsin inhibitor (TI) and hemagglutinating activities, phytic acid, phytic acid-phosphorus and tannic acid. The respective concentrations were: 19·6–28·2 TUI mg^?1 protein,¹ 33·5–98·9 HU mg^?1 protein,² 280–331 mg 100 g^?1, 131–200 mg 100 g^?1 and 0·42–0·78 g 100 g^?1 dry weight. Phytic acid-phosphorus as a percentage of total phosphorus was highest in Farv-13 (49·9) and lowest in Samaru local (29·8). Considerable variability in hemagglutinating activity was evident among the different varieties as indicated by the high percentage co-efficient of variation. Some of these differences may be genetic and may provide an opportunity for the genetic development of cowpea strains with superior protein quality, low in hemagglutinin content.     

Accumulation of Calcium in Bean Cultivars Differing in Seed Size

Accumulation of Ca, Mg and K, the principal cations in dry bean (Phaseolus vulgaris L) seed, was studied under field and greenhouse conditions. ‘Cran-09’, a cranberry bean and ‘Norstar’, a navy bean, were grown to maturity under greenhouse conditions. ‘Cran-09’ had a seed weight of 605 mg, a seed Ca concentration of 1·2 g kg^-1 and a Ca harvest index of 0·032. The corresponding three parameters in ‘Norstar’ were a seed weight of 161 mg, a seed Ca concentration of 2·2 g kg^-1 and a Ca harvest index of 0·064. The difference in seed Ca concentration was not due to increased absorption of Ca by ‘Norstar’, but rather was due to a larger proportion of Ca in plant tops being diverted to the seed component. The larger seed Ca concentration in ‘Norstar’ was compensated to some extent by a smaller seed K concentration. In contrast to Ca, cultivar had relatively little effect on harvest indices for Mg, K, N and P. The average seed Ca concentration in six navy bean cultivars grown under field conditions was 90% more than that of three kidney and three cranberry bean cultivars. © 1997 SCI.     

Correlation between Pod Shape Traits and Its Fiber Quality of Wild Calotropis Gigantea

Seed fiber in the Calotropis gigantea (C. gigantea) pods is the most valuable component and can be developed into textile material. Cultivating high-yield and high-quality seed fibers for C. gigantea is one of the critical preconditions for its textile industrialization. In this paper, pods picked from wild C. gigantea plants were used as the experimental materials. The fiber length distribution of the pods was studied. The pod characters (pod shape, single pod weight, fiber weight per pod and seed number per pod, etc.) and the crucial quality characteristics of seed fibers (length, diameter and strength) were tested. The correlations between them were analyzed. The results show that the fiber lengths at the tip, the petiole and the middle part of the pods are significantly different: the fibers from the two sides of the middle part are the longest and more uniform. The pod shape is closely correlated with the fiber length, fineness and strength: longer pods have longer fiber length, smaller length variation and larger fiber diameter, and the percentage of low strength fiber (single fiber strength <1.2 cN) is significantly lower compared to smaller pods. Cultivating C. gigantea with large size and heavy pods will improve the seed fiber yield and the fiber quality.     

Rapid separation of soft drinks ingredients using high performance liquid chromatography

A method is described which uses high performance liquid chromatography in the reverse phase mode to separate amaranth, quinoline yellow, quinine sulphate, sunset yellow, caffeine, aspartame, saccharin, vanillin, sorbic acid, benzoic acid and green S in 4 min in samples of soft drinks. The final separation was achieved using 17·5% acetonitrile, 12·5% methanol, 70% buffer (0·85% v/v sulphuric acid and 17·5% mm potassium dihydrogen orthophosphate in water with the pH adjusted to 1·8), with a flow rate of 1·35 ml/min through a 100 mm × 4·6 mm column containing 3 μm Spherisorb octylsilane. The octylsilane material is fully capped with monolayer coverage and a carbon loading of 6% w/w, pore diameter of 8 nm and a surface area of 220 m²/g. This material was used in preference to the more widely used octadecylsilane as it provides shorter analysis time and allows for the use of more polar eluting solvents. Detection was at 220 nm, 0·1 AUFSD with an injection of 5 μl samples using a rotary injection valve. The standard solution concentration was 100 mg litre⁻¹ for aspartame; 20 mg litre⁻¹ for quinine sulphate, caffeine, vanillin, sorbic acid and benzoic acid and 5 mg litre⁻¹ for amaranth, quinoline yellow, sunset yellow, green S, tartrazine, indigo carmine and carmoisine.     

Changes of Mineral Concentrations in Serra Cheese during Ripening and Throughout the Cheesemaking Season

Seasonal changes of the ash content and mineral concentrations in Serra cheese were studied over a typical 35-day ripening period. Statistically significant differences (at the 5% level) exist between the ash content and the concentrations of Na, K, Ca, P, Mg and Zn in cheeses during ripening. The highest concentrations of Na was obtained in cheese ripened for 7 days, whereas the concentrations of K, Ca, P, Ng and Zn decreased significantly during ripening. For 35-day-old cheeses, concentrations of Na, K and Cu were lowest and concentration of P was highest for cheeses manufactured in May. The concentration of Ca was lowest for cheeses manufactured in February. On average, the most concentrated minerals (in g kg^-1 of total solids, TS) in 35-day-old Serra cheese were Na (18·56), Ca (9·70) and P (7·92) and, at a lower level, K (1·70) and Mg (0·96). Only trace levels (in mg kg_TS^-1) of Zn (94·33), Cu (2·26) and Mn (1·25) were detected. A high mineral nutrition quality was thus ascribed to 35-day-old Serra cheese based on the average nutritional densities: 4·8 for Ca, 4·0 for P, 1·1 for Mg, 3·4 for Na, 2·4 for Zn, 0·4 for Cu, 0·2 for Mn and 0·2 for K. © 1997 SCI     

Protein supplementation of broad beans with sesame

Feeding experiments with weanling rats indicated that the protein of broad beans (Vicia faba var. major) and sesame (Sesamum indicum) are mutually supplementary. A standard diet in which 75% of the protein was provided by broad beans and 25% by sesame had a protein efficiency ratio (PER) of 2·36 compared to a casein PER adjusted to 2·50. A similar diet in which broad beans and sesame contributed equal amounts of protein had a PER of 2·41. The PER of broad beans was 0·99 and that of sesame 1·55.     

Quantitative analysis of the isoflavone content and biological growth of soybean (Glycine max L.) at elevated temperature,CO2 level and N application

Effects of ambient and elevated CO₂ levels (360 and 650 µmol mol^?1 respectively), ambient and high (5 °C above ambient) temperatures and their interactions with N application on soybean (Glycine max L.) were studied in 2001. Overall, total isoflavones in whole soybean seeds were highest (1383.0 µg g^?1) in the elevated CO₂ (AE) treatment without N application and lowest (414.1 µg g^?1) in the elevated temperature (EA) treatment with N application. Malonylgenistin (449.2 µg g^?1) and malonyldaidzin (435.9 µg g^?1) concentrations in the AE treatment without N application were highest among the 12 individual isoflavones, while aglycon and acetyl conjugates showed lower concentrations (below 10 µg g^?1) than glucoside and malonyl conjugates in all treatments. Overall, N application had no effect on total isoflavone concentration, while both temperature and CO₂ level had a higher effect on increasing isoflavones, including aglycon and acetyl conjugates (P = 0.001). In the biological growth analysis, total dry weight was highest (100.9 g) in the elevated temperature and CO₂ (EE) treatment with N application, while leaf area was more affected by CO₂ than by temperature and increased with N application. There were larger numbers of pods (99) and seeds (176) per plant in the EE treatment with N application, and generally the AE treatment showed a greater increase in 100‐seed weight (g per 100 seeds) and in pods and seeds per plant than other treatments. Overall, total dry weight was highly affected (P = 0.001) by three main factors, temperature, CO₂ and N application, but the interactions temperature × N and temperature × CO₂× N did not affect total dry weight. Also, total dry weight tended to increase with increasing numbers of pods (r² = 0.93***) and seeds (r² = 0.93***) and larger leaf area (r² = 0.85***). In addition, numbers of pods and seeds were significantly affected (P = 0.01–0.001) by temperature, CO₂ and temperature × CO₂. Generally, elevated CO₂ and temperature did not affect N, P and K concentrations in the seeds but did decrease the concentrations of Ca and Mg, which were increased in the AE treatment. Among the nutrients, Ca and Mg were highly correlated with temperature and CO₂ level. N concentration in the seeds increased with applied N and in particular showed a high increase with elevated temperature and ambient CO₂ (EA treatment). The variation in isoflavones was correlated with temperature (r² = ?0.70**) and CO₂ (r² = 0.67**), while N application was not correlated with isoflavone concentration. Also, Ca (r² = ?0.85***) and Mg (r² = ?0.57*) in the seeds were correlated with variation in isoflavones. This indicated that isoflavones were in higher concentrations under conditions of low temperature and increasing CO₂, which also resulted in low Ca and Mg concentrations in the seeds. The results of this study suggest that the long‐term adaptation of the soybean to growth at elevated CO₂ level and high temperature might potentially increase its isoflavone content, growth and yield. Copyright © 2005 Society of Chemical Industry