Underutilized sources of dietary fiber: A review

Interest in the fiber content of foods has decreased in recent years as concerns about fat intake have increased. Fiber, however, remains an important component of the diet. Soluble dietary fiber, including pectic substances and hydrocolloids, is found naturally in foods such as fruits, vegetables, legumes and oat bran. Insoluble fiber, including cellulose and hemicellulose, is found in foods such as whole grains. Fiber supplementation has been used to enhance the fiber content of a variety of foods ranging from cereal-based products to meats, imitation cheeses and sauces. Products used to enhance fiber content of foods have traditionally come from cereals such as wheat, corn and oats. There are a variety of other products, however, such as fruits, vegetables, legumes and less commonly used cereals such as barley, which are potential sources of dietary fiber supplements. This article reviews research on some of these underutilized sources of dietary fiber.     

三种野豌豆属牧草种子萌发期抗旱性的研究

以毛叶苕子、箭筈豌豆及光叶苕子种子为材料,用不同浓度（0、5%、10%、15%、20%）的聚乙二醇（PEG-6000）模拟干旱进行发芽试验。对供试牧草种子的生物学特性及干旱胁迫下种子萌发期的相对发芽势、相对发芽率、相对发芽指数、相对活力指数、相对芽长、抗旱指数等指标进行研究,并采用隶属函数法对三种牧草种子萌发期的抗旱性进行综合评价。结果表明：（1）箭筈豌豆种子吸水率大于光叶苕子、毛叶苕子种子,光叶苕子种子含水量、种子活力大于其他两种牧草种子。（2）随着PEG浓度的升高,三种牧草种子相对发芽势、相对发芽率、相对发芽指数、相对活力指数与抗旱指数总体呈下降趋势。（3）5% PEG能促进毛叶苕子种子的萌发。（4）三种牧草的抗旱性强弱顺序为箭筈豌豆>光叶苕子>毛叶苕子。     

利用禾草隔离技术防控鼢鼠危害豆科人工草地的研究

豆科牧草来源匮乏始终是制约高寒牧区畜牧业发展的短板之一。除了天然草地资源本身的限制以外,豆科牧草人工草地的建植也存在诸多限制因素,其中一个重要的限制因素就是鼢鼠(Myospalax)危害。研究表明,鼢鼠对豆科等轴根系植物具有强烈的采食偏向性,而对禾本科等须根系植物则表现为相对冷淡。据此,本研究采用在豆科草地外围种植禾本科草隔离带的方式,从草种选择、隔离带宽度、种植方式等技术环节对此种方法的有效性和技术要点进行了探索。结果表明:禾草隔离技术是防控豆科人工草地鼢鼠危害的有效方法,平均可减少危害量82.4%以上;一年生禾草的隔离效果明显优于多年生禾草(P0.01),短期多年生禾草明显优于长期多年生禾草(P0.01);隔离带宽度应控制在3~5m之间;豆科草地建植当年以一年生、短期多年生和长期多年生混播隔离带效果最佳。     

Impact of microwave heating on hemagglutinins,trypsin inhibitors and protein quality of selected legume seeds

Selected legume seeds (dry and soaked) including faba beans, peas, chickpeas, soybeans, lentils and common beans containing 8 and 25% moisture, respectively, were subjected to microwave heating, and to a conventional cooking method to determine the heating effect on toxic compounds and protein quality. Trypsin inhibitors, hemagglutinins and available lysine were analyzed, and laboratory rats were used to determine digestibility and protein efficiency ratio (PER). Results indicated that microwaving destroyed trypsin inhibitors to a similar degree to that observed in beans cooked using the conventional method without affecting PER for raw seeds with low antinutrients content (faba beans, peas, chickpeas and lentils). Microwave-heated soaked soybeans had a higher amount of destroyed trypsin inhibitors, along with a higher PER, compared with microwave-heated dry soybeans. Microwave heating of common beans failed to destroy hemagglutinins and trypsin inhibitors, and consequently their digestibility and PER values were poor. Finally it was concluded that microwave heating constitutes an adequate method for destroying hemagglutinins and trypsin inhibitors without affecting protein quality of most legume seeds, except for common beans that despite of this process retained the antinutritional substances.     

The intercropping common bean with maize improves the rhizobial efficiency,resource use and grain yield under low phosphorus availability

In order to better understand how mixed crop cultures mitigate stressful conditions, this study aims to highlight the beneficial effect of the intercropping legume-cereal in enhancing soil phosphorus (P) availability for plant growth and productivity in a P-deficient soil of a northern Algerian agroecosystem. To address this question, common bean (Phaseolus vulgaris L. cv. El Djadida) and maize (Zea mays L. cv. Filou), were grown as sole- and inter-crops in two experimental sites; S1 (P-deficient) and S2 (P-sufficient) during two growing seasons (2011 and 2012). Growth, nodulation and grain yield were assessed and correlated with the rhizosphere soil P availability. Results showed that P availability significantly increased in the rhizosphere of both species, especially in intercropping under the P-deficient soil conditions. This increase was associated with high efficiency in use of the rhizobial symbiosis (high correlation between plant biomass and nodulation), plant growth and resource (nitrogen (N) and P) use efficiency as indicated by higher land equivalent ratio (LER > 1) and N nutrition index (for maize) in intercropping over sole cropping treatments. Moreover, the rhizosphere P availability and nodule biomass were positively correlated (r² = 0.71, p < 0.01 and r² = 0.62, p < 0.01) in the intercropped common bean grown in the P-deficient soil during 2011 and 2012. The increased P availability presumably improved biomass and grain yield in intercropping, though it mainly enhanced grain yield in intercropped maize. Our findings suggest that modification in the intercropped common bean rhizosphere-induced parameters facilitated P uptake, plant biomass and grain yield for the intercropped maize under P-deficiency conditions.     

Field evaluation of lentil cultivars inoculated with Rhizobium leguminosarum bv. viciae strains for nitrogen fixation using nitrogen-15 isotope dilution

 A ¹⁵N isotope dilution technique was applied to quantify the extent of N₂ fixation in lentil (Lens culinaris Medik.) cultivars as influenced by Rhizobium leguminosarum bv. viciae strains in a field experiment in Pakistan. The experiment was conducted on a soil with a very small indigenous rhizobial population and where N was a limiting factor for crop production. Significant variations in number of nodules, dry weight of nodules, biomass yield, grain yield, total N yield, proportion of plant N derived from N₂ fixation (P_fix) and amount of N derived from the atmosphere (N_dfa) were observed among combined treatments of four rhizobial strains and six lentil varieties. In a field previously labelled with ¹⁵N, to which a basal dose of 75 kg P₂O₅ ha^–1 was applied as single super phosphate, N_dfa ranged from 15 to 24 kg N ha^–1 when calculated according to rhizobial strain and from 4 to 38 kg N ha^–1 when calculated according to lentil variety. Lc 26 was the most effective strain and fixed 243% more N than the indigenous population in the uninoculated control. In treatments with the lentil variety PL-406, N_dfa was 38 kg N ha^–1, which was 850% higher than with the lentil variety Precoz/F6-20-1×M-85. Generally, the varieties with greater P_fix produced a higher dry matter yield. Received: 26 May 1999     

Fallow residue management effects on upland rice in three agroecological zones of West Africa

Improving fallow quality in upland rice-fallow rotations in West Africa through the site-specific use of leguminous cover crops has been shown to sustain the productivity of such systems. We studied the effects of a range of residue management practices (removal, burning, mulching and incorporation) on fallow biomass and N accumulation, on weed biomass and yield response of upland rice and on changes in soil physical and chemical characteristics in 2-year field trials conducted in three agroecological zones of Côte d'Ivoire. Across fallow management treatments and agroecological zones, rice yields were on average 20–30% higher in legume than in natural fallow plots. Weed biomass was highest in the savanna zone and lowest in the bimodal forest and tended to be less following a legume fallow. Regardless of the type of fallow vegetation and agroecological zone, biomass removal resulted in the lowest rice yields that varied from 0.5?t ha^–1 in the derived savanna zone to 1.5?t ha^–1 in the Guinea savanna zone. Burning of the fallow vegetation significantly increased yield over residue removal in the derived savanna (0.27?t ha^–1, P<0.05) and bimodal forest zones (0.27?t ha^–1, P<0.01), but not in the Guinea savanna. In both savanna environments, residue incorporation was superior to the farmers' practice of residue removal and rice yield increases were related to amounts of fallow N returned to the soil (r²=0.803, P<0.01). In the forest zone, the farmers' practice of residue burning produced the highest yield (1.43?t ha-1 in the case of legumes) and resulted in the lowest weed biomass (0.02?t ha^–1). Regardless of the site, improving the quality of the fallow or of its management had no significant effects on either soil physical or soil chemical characteristics after two fallow cycles. We conclude that incorporation of legume residues is a desirable practice for rice-based fallow rotation systems in savanna environments. No promising residue management alternatives to slash-and-burn were apparent for the forest zone. Determining the possible effects on soil productivity will require longer-term experiments.     

Phytosterol,Squalene, Tocopherol Content and Fatty Acid Profile of Selected Seeds,Grains, and Legumes

The unsaponifiable lipid fraction of plant-based foods is a potential source of bioactive components such as phytosterols, squalene, and tocopherols. The objective of the present study was to determine the levels of phytosterols, and squalene, as well as tocopherols (α and β + γ) in selected grains, seeds, and legumes. The method comprised acid hydrolysis and lipid extraction followed by alkaline saponification, prior to analysis by HPLC. In addition, the fatty acid profile of the foods was determined via total lipid extraction, fatty acid derivitisation and GC analysis. In general, β-sitosterol was the most prevalent phytosterol, ranging in concentration from 24.9 mg/100 g in pumpkin seed to 191.4 mg/100 g in peas. Squalene identified in all foods examined in this study, was particularly abundant in pumpkin seed (89.0 mg/100 g). The sum of α- and β+ γ-tocopherols ranged from 0.1 mg/100 g in rye to 15.9 mg/100 g in pumpkin seeds. Total oil content ranged from 0.9% (w/w) in butter beans to 42.3% (w/w) in pumpkin seed and the type of fat, in all foods examined, was predominantly unsaturated. In conclusion, seeds, grains, and legumes are a rich natural source of phytosterols. Additionally, they contain noticeable amounts of squalene and tocopherols, and in general, their fatty acid profile is favorable.     

水分胁迫下豆科牧草的生理生化变化

试验在温室条件下,分别于5月、8月采用盆栽控水研究了3种豆科牧草(5个品种)在水分胁迫下的一些生理生化变化,包括叶片相对含水量、细胞膜透性、游离脯氨酸、可溶性糖和SOD酶活性的变化。结果表明:紫花苜蓿Eureka和Defi两个品种在供试牧草中是最抗旱的,且前者更强;百脉根和白三叶两个品种(Huia和Revendel)因鉴定时期不同而有所差异,5月份白三叶两个品种强于百脉根,而8月份随着百脉根生长速度的加快,其抗旱性强于白三叶品种。其中Huia的抗旱性要强于Revendel。     

The long-term effect of legumes as forecrops on the productivity of rotation winter triticale–winter rape with nitrogen fertilisation

ABSTRACT

The aim of the study was to determine the long-term effect of legumes as forecrops on the productivity of rotation with nitrogen fertilisation. The rotation included: legumes + spring barley, winter triticale and winter rape. The study was conducted as a two-factorial field experiment with four replications. The present study showed that legumes, as forecrops, increased the yield of WT cultivated in the second year of rotation. The seed yield of WR cultivated in the third year of rotation significantly increased after all legume forecrops, with the exception of PEA. Yielding of these crops depended also on nitrogen fertilisation. In the case of WT doses 120 kg N ha^?1 and 180 kg N ha^?1 there was an increased yield compared with control independent of forecrop, but there were no significant differences between doses 120 and 180 kg N ha^?1. The conclusion is that we do not need to use dose 180 kg N ha^?1 for WT cultivated directly after legumes. In the cultivation of WR in the third year of rotation there is no need to use a dose of nitrogen 180 kg N ha^?1 if the fore-fore-crops were indeterminate cultivars of BL or YL.