Nutrients and antinutritional factors in faba beans as affected by processing

 The influence on the nutrients content (soluble sugars, starch, dietary fibre and calcium) and antinutritional factors (α-galactosides and phytic acid) of faba beans (Vicia faba, L. major) of soaking in different solutions (distilled water, citric acid, and sodium bicarbonate solutions), cooking the presoaked seeds, dry-heating and germination have been studied. Soaking brought about a decrease in starch, sucrose, fructose, α-galactoside, dietary fibre and calcium content. Glucose was detected in soaked faba beans and soaking did not modify the phytic acid content. Cooking the presoaked faba beans produced a slight decrease in starch, and caused a general drop in α-galactosides, dietary fibre, calcium and phytic acid, with the exception of seeds presoaked in sodium bicarbonate in which cooking did not cause any appreciable changes in comparison with the unprocessed faba beans. Germination caused a sharp reduction in α-galactoside and phytic acid content after 6 days, whilst starch and dietary fibre decreased slightly. Calcium, however, enjoyed a slight increment during germination which was related to the decrease in the content of hemicellulose and phytic acid. Dry-heating caused a noticeable reduction in all the nutrients and antinutritional factors investigated. Of all the treatments studied, germination appears to be the best processing method to obtain nutritive faba bean flour, since it caused a minor decrease in starch content (15% loss), the largest α-galactoside and phytic acid removal (94% and 45%, respectively) and provided an appreciable amount of dietary fibre. Received: 21 December 1997 / Revised version: 19 February 1998     

Comparison of selected food characteristics of three cultivars of bean Phaseolus vulgaris

Three bean ( Phaseolus vulgaris ) cultivars were selected to study some of the physical properties of the seeds, hydration capacity, cooking time, phytic acid content, digestibility, colour changes as a function of soaking and cooking, and sensory properties. These cultivars were bayocel, canario 101 and flor de mayo. The water uptake was much lower for the cultivar with larger seeds. Some slight losses of phytic acid were found due to the cooking treatment; cooking improved the protein digestibility. The cultivar flor de mayo exhibited the most desirable sensory attributes.     

PHYSICAL AND COOKING PROPERTIES OF MICRONIZED LENTILS

The potential for reducing the cooking time of lentils by micronization was studied. The effect of infrared heat and initial seed moisture on the internal temperature of lentil seeds was monitored up to the stage of seed browning. The seed physical properties, water uptake by seeds, cooking time and starch properties were determined. The cooking time was shortened from 30 min for the control seeds to 15 min for lentils adjusted to 25.8% wb moisture content and micronized for 55s to 18.0% wb moisture. Micronization was effective in gelatinizing and solubilizing 45 to 65% of the starch in the lentil seed, depending on the initial seed moisture content.     

Effects of hardshell character on cooking time of common beans grown in the semiarid highlands of Mexico

The present study was undertaken to develop a protocol to screen bean germplasm for the hardshell character, evaluate the effect of hardshell on cooking time and study the relationship between hardshell and other seed characteristics in bean genotypes grown in the semiarid highlands of Mexico. Between 50 and 75% of the variation in cooking time of recently harvested beans was explained by differences in the degree of water absorption after soaking for 18 h. Seed coat brightness was negatively correlated with water absorption and increased cooking time in two of the three populations evaluated. The difference in cooking time and water absorption between scarified (hilum perforated) and unscarified seed of different genotypes would indicate that the hardshell characteristic plays a major role in extending the cooking time of beans. This study indicates that when seeds have an initial moisture content of 90 g kg^?1 seed or less, the hardshell problem is easily detected after soaking for 18 h, while the problem is rarely detected when initial seed moisture levels are 120 g kg^?1 or higher. Selection against the hardshell characteristic could be practised in bean germplasm using this information as part of a protocol to shorten the cooking time of beans grown in the Mexican highlands.     

Effect of soaking and heat processing on the levels of antinutrients and digestible proteins in seeds of Vigna aconitifolia and Vigna sinensis

The effect of soaking, cooking and autoclaving on the levels of total free phenolics, tannins, phytic acid and in vitro protein digestibility (IVPD) were studied in Vigna aconitifolia and Vigna sinensis. Though soaking significantly reduced the content of tannins alone in V. aconitifolia, both total free phenolics and tannins were markedly reduced in V. sinensis. Greater loss of total free phenolics as well as tannins occurred under autoclaving compared to soaking and cooking in both the legumes investigated. In V. aconitifolia, soaking in distilled water for 6 h and cooking for 30 min reduced the phytic acid content by up to 43%. Maximum reduction in the level of phytic acid (36%) was observed under distilled water soaking compared to cooking and autoclaving in V. sinensis. Limited loss in content of phytic acid was noticed under autoclaving compared to soaking and cooking in both the pulses studied. In vitro protein digestibility (IVPD) of V. aconitifolia and V. sinensis was enhanced to 12.5 and 14.8%, respectively, under autoclaving. Of all the processing methods, autoclaving seemed to be the most efficient for reduction in content of the antinutrients, except phytic acid, and improving IVPD in both the pulses.     

Influence of Soaking and Cooking upon the Softening and Eating Quality of Black Beans (Phaseolus vulgaris)

Soaking and cooking treatments: were evaluated to establish the relationship of various regimes to the development of cooked bean texture and flavor of black beans (Phaseolus vulgaris L.). A salt combination soaking solution was most effective in promoting bean softening during cooking, compared to no soaking or a distilled water soak. A high correlation was observed between objective and sensory texture scores. An Instron puncture force of.150g (0.14 cm probe, 5 cm/min) accurately defined the “eating-soft” limit of texture acceptability.     

Phenolic composition,antioxidant capacity and inhibitory effects on α-glucosidase and lipase of immature faba bean seeds

Immature faba bean seeds of five varieties were investigated for changes in phenolic composition, antioxidant capacity and inhibitory effects on α-glucosidase and lipase at three edible stages (S1, S2 and S3). Phenolics and antioxidant capacity in seed coats were significantly higher than those in cotyledons, and the highest was found of FD18 at stage S3. While phenolic content in cotyledons decreased steadily with the harvest time delayed. Eight phenolic compounds were confirmed with epicatechin and catechin prominent and their levels showed a great variability depending on varieties, maturation stages and plant parts of faba bean seeds. Unexpectedly, the inhibitory effects of purified phenolics on α-glucosidase were even stronger than that of the positive control acarbose, and the inhibitory effects on lipase in the cotyledons declined gradually from stage S1 to S3. Significant positive correlations between phenolics from seed coats and antioxidant capacity, and phenolics from cotyledons and the enzyme inhibitory effects were observed. Overall, the immature faba bean seed, especially its seed coat, has great potential as a functional food.     

Nutritional quality of legume seeds as affected by some physical treatments 2. Antinutritional factors

Raw and treated cowpea, pea and kidney bean seeds were investigated for their content of antinutritional factors including tannins, phytic acid, trypsin inhibitors and oligosaccharides. Treatments applied included water soaking, boiling, roasting, microwave cooking, autoclaving, fermentation and micronization. Kidney bean contained the highest antinutrient content among all investigated seeds. The least tannins and phytic acid contents were recorded in Canadian cowpea while Canadian pea showed the lowest TIA. All treatments conducted caused significant decreases in tannins, phytic acid, TIA and oligosaccharides as compared to the raw seeds. Boiling caused the highest reduction in tannins followed by autoclaving and microwave cooking. Autoclaving and fermentation were the most effective in reducing phytic acid content. Heat treatments (boiling, roasting, microwave cooking and autoclaving) brought a total removal of trypsin inhibitors of all samples. Furthermore, autoclaving caused the highest reduction in oligosaccharides followed by fermentation while the least reductions were caused by either roasting or micronization with no significant difference between these two treatments.     

Effect of processing on water absorption and softening kinetics in chickpea (Cicer arietinumL) seeds

The processing effect on the physical properties of chickpea seeds (kabuli type cv Athenas) is reported. Soaking of chickpea seeds in different solutions (distilled water, 0·5% NaHCO₃ and 0·5% CaCl₂) is characterised by a rapid water absorption followed by a decrease in the hydration rate to saturation point. An improvement in chickpea softening rate and water absorption during cooking, with previous 12 h soaking in 0·5% NaHCO₃, was observed. The presence of Ca²⁺ ions delayed the softening process in chickpea seeds. Physicochemical changes associated to the soaking and cooking process necessary for reducing cooking time are discussed. The texturometer method was estimated as a suitable objective method for the evaluation of the cooking degree in chickpea seeds. © 1998 Society of Chemical Industry     

Effect of soaking, germination, autoclaving and cooking on chemical and biological value of guar compared with faba bean

Raw, soaked, germinated, autoclaved and cooked both of guar and faba bean were chemically and biologically evaluated. Crude protein, crude fiber and ash contents of guar and faba bean decreased as a result of all treatments with the exception of protein content in both germinated guar and faba bean. A slight decrease in lipid content was noticed during germination, while there were no changes in lipids after soaking, autoclaving and cooking. Protein content of guar was higher than of faba bean, and showed higher values for all amino acids than faba bean protein except for lysine and tryptophan. Germination caused a slight increase in total essential amino acids, while soaking caused a slight decrease in both of guar and faba bean. There was a slight decrease in the mineral contents by the heat processes with the exception of Mg and Mn for guar and Na, Mn for faba bean due to the cooking process. Germinated guar and faba bean showed noticeable decrease in Na, K, Cu, Mn and Mg and a slight increase in Fe and Zn than the raw materials. Germination was more effective in reducing phytic acid than heat treatment, and therefore it improves the nutritional quality of both guar and faba bean. Protein efficiency ratio (PER), true digestibility (DT) and biological value (BV) were estimated in all treatments under study using rat bioassay procedures. Data revealed pronounced improvements of the nutritive value as a result of all processes under study especially germination being the most effective.     

Effect of Processing on Certain Antinutrients in Seeds of Şeker Variety (P. vulgaris L.) Grown in Turkey

Abstract

The effects of different cooking/autoclaving methods were investigated on sucrose, raffinose, stachyose, phytic acid, and tannins content of ?eker bean seeds (Phaseolus vulgaris). All these oligosaccharides and antinutrients decreased under various cooking/autoclaving treatments. Among the different cooking/ autoclaving treatments, 18 h sodium bicarbonate solution soaking followed by autoclaving procedures were the most effective for removing oligosaccharides (65–72%), phytic acid (51%), and tannins (100%). These conditions could be recommended to remove undesirable sugar contents and antinutrients of the ?eker bean used for culinary purposes.     

超声和碳酸氢钠处理对绿豆浸泡特性的影响

为了改善绿豆的质地特性,提高其浸泡效率,本文研究了超声和碳酸氢钠作用下绿豆的吸水动力学、水分分布、水分迁移、硬度、种皮结构以及总酚和植酸含量的变化。超声对绿豆吸水特性、硬度和营养成分含量的影响与绿豆表皮结构变化有关。400 W超声使绿豆表皮形成微孔通道,提高绿豆的吸水速率以及自由水和结合水的含量,降低硬度,总酚和植酸含量也显著降低（P<0.05）。1.5%碳酸氢钠对绿豆浸泡特性的影响可能是通过改变浸泡液的酸碱性发挥作用。碳酸氢钠会提高浸泡液pH,从而减缓吸水速率,降低总酚含量,抑制植酸含量降低,但对绿豆硬度的降低作用不明显,并且碳酸氢钠组的自由水和结合水含量与对照组有一定差异。若以最低硬度为评价指标,则对照组和1.5%碳酸氢钠组的最佳浸泡时间为7 h,而400 W超声组最佳浸泡时间为4 h。本文探明了超声和碳酸氢钠处理对绿豆浸泡特性的影响机制,可为超声波技术以及碳酸氢钠预处理技术在杂粮食品开发中的应用提供理论指导。     

Content of antinutritional factors and HCl-extractability of minerals from white bean (Phaseolus vulgaris) cultivars: Influence of soaking and/or cooking

White bean seeds were subjected to soaking in distilled water for 1, 2 and 3 days. In order to perform complete processing, the seeds were cooked until soft. Effects of soaking and/or cooking of white bean seeds on antinutritional factors, mineral contents and HCl-extractability were studied. Phytic acid and polyphenol contents of all cultivars were reduced. Soaking alone and soaking, followed by cooking, reduced mineral contents of the cultivars, but HCl-extractability was significantly (P ? 0.01) improved to varying extents, depending on cultivar type. Soaking and/or cooking treatment was thus found to be an effective technique and caused further improvement in the availability of both major and trace minerals in white bean.     

The impact of processing on phytic acid,in vitro soluble iron and Phy/Fe molar ratio of faba bean (Vicia faba L.)

BACKGROUND: Faba bean is one of the important legumes in Asian countries. It is also a major source of micronutrients in many rural areas. Unfortunately, the bioavailability of iron from faba bean is low because it is present as an insoluble complex with food components such as phytic acid. The influence of soaking, germination and fermentation with the expectation of increasing the bioavailability of iron was investigated. RESULTS: Fermentation treatments were most effective in decreasing phytic acid (48–84%), followed by soaking at 10 °C after preheating (36–51%). Steeping faba beans for 24 h at 25 °C had the least effect on the removal of phytic acid (9–24%). With increased germination time at 30 °C, phytic acid progressively decreased from 9 to 69%. Most wet processing procedures, except soaking after wet preheating, caused losses of dry matter and iron (8–15%). In vitro iron solubility, as a percentage of total iron in soaked faba bean after dry preheating, was significantly higher than in raw faba bean (P < 0.05). Fermentation and germination did not have significant effects on the solubility of iron. CONCLUSION: The expected improvement of iron bioavailability levels due to lower phytic acid was not confirmed by increasing levels of in vitro soluble iron. Soaking, germination and fermentation can decrease phytic acid in faba bean. However, results from in vitro solubility measurement of iron showed little improvement of iron bioavailability in fermented and germinated faba beans over untreated raw faba beans (P < 0.05). It seems that componets of dietary fibre other than phytic acid are more important in binding iron. Probably, a complex association between dietary fibre and iron is the reason for the poor bioavailability of iron in faba bean. Copyright © 2009 Society of Chemical Industry     

Effect of pre-dehulling treatments on some nutritional and physical properties of navy and pinto beans (Phaseolus vulgaris L.)

The effect of pre-dehulling treatments using low and high temperatures on some nutritional and physical properties of navy and pinto beans was investigated. Beans were exposed to water (14%, 28% and soaking 1:5, w/v for 6 h, 16 and 16 h, respectively) to facilitate seed coat detachment prior to freeze drying (FD) for 48 h or heat drying (HT) for 20 or 60 min. Exposure to the highest moisture levels produced the largest seed coat yields (17.38-20.91%) and was independent of the drying conditions. The total phenolic content was positively correlated to the 1,1-diphenyl-2-picrylhydrazyl (DPPH) antioxidant activity and increased as the exposure time to HT increased, but it was unaffected by the FD. The nutritional properties of the bean varieties differed significantly, phytic acid was unaffected, and the highest antioxidant activity was observed on the seed coats of HT pinto beans (69.24-84.46% of DPPH discoloration). Significant physical changes were observed for the HT seeds, with the highest yellowness and the lowest peak viscosity detected in the soaked and HT (60 min) beans.     

Effect of soaking and hydrothermal processing methods on the levels of antinutrients and in vitro protein digestibility of Bauhinia purpurea L. seeds

The effects of various domestic processing methods such as soaking, cooking and autoclaving on the levels of certain antinutritional factors and in vitro protein digestibility of seeds of Bauhinia purpurea L., an underutilised legume collected from South India, were investigated. The raw seeds were found to contain antinutritional factors like total free phenolics (2.75 g/100 g), tannins (2.35 g/100 g), phytic acid (692 mg/100 g) and flatulence factors, raffinose (0.54 g/100 g), stachyose (1.17 g/100 g) and verbascose (0.95 g/100 g). Soaking the seeds in distilled water caused maximum reduction in the phytic acid content (37%), whereas soaking in NaHCO₃ solution reduced significant levels of phenolics and tannins (72% and 78%, respectively). A reduction in the levels of oligosaccharides (raffinose by 63%, stachyose by 42% and verbascose by 79%) was observed during cooking. Of the attempted treatments, autoclaving appeared to be most effective in reducing levels of all the investigated antinutrients, except phytic acid, and also improved the in vitro protein digestibility of B. purpurea seeds.     

浸泡处理对红芸豆的物理性质及蒸煮品质的影响

以红芸豆为原料,探讨不同浸泡温度(25、45、65℃)对芸豆物理性质及蒸煮品质的影响。结果表明:芸豆在浸泡过程中,随着浸泡温度升高与时间延长,其吸水率、体积膨胀率、固形物溶出率等均呈增加的趋势,平衡吸水率常数则呈下降趋势;浸泡温度的提高有利于达到浸泡平衡及缩短浸泡时间。在加工性能方面,45℃下浸泡可显著缩短煮豆时间并提高煮熟红芸豆的品质。     

Variation among physical,chemical and technological properties in three Sicilian cultivars of Chickpea (Cicer arietinum L.)

Three Sicilian chickpea cultivars (‘Calia’, ‘Etna’ and ‘Principe’) were evaluated for physical, chemical and technological properties. Whereas no substantial differences were ascertained on seeds chemical composition, the cultivars greatly differed in terms of seed size, specific surface area (SSA) and seed coat incidence. These last two properties affected the technological properties of the seeds. In particular, a high SSA (‘Calia’) contributed to a faster softening, whilst a great coat thickness (‘Etna’) delayed both hydration and softening rate. The time required to obtain an acceptable firmness (cooking time) was greatly reduced by presoaking the seeds in salt solution (0.5% NaCl or NHCO₃). ‘Calia’ required the lowest cooking time when soaked in distilled water or in 0.5% NaCl. Presoaking seed in NaHCO₃ allowed halving the cooking time in all cultivars.     

Short communication: Effect of pre-soaking on the rate of thermal softening of soybeans

Whole soybeans and dehulled soybean cotyledons were soaked in water at ambient temperature for 0, 8 and 12h then cooked in boiling water at atmospheric pressure for up to 6h. In every case there was an initial rapid rate of softening followed by progressively slower softening until, after about 3h, there was little change in firmness. The kinetics of softening of every sample was consistent with the two substrate theory of thermal softening. The firmness ranking in descending order after 15 min cooking was no soak, whole beans > 12h, soak cotyledons > no soak, cotyledons > 8h soak, whole beans > 12h soak, whole beans. This ranking was maintained for the entire cooking period. For whole beans the soaked samples were less firm than the unsoaked samples while for the cotyledons the soaked samples were more firm than the unsoaked. This reversal in behaviour may be caused by the seed coat (skin) retarding the imbibition of water in the whole beans thus delaying the onset of enzyme activity in the bean tissue.     

Hard-to-Cook Phenomenon in Beans: Effects of Accelerated Storage on Water Absorption and Cooking Time

Black beans stored for 7–14 days at 41°C, 100% RH, required more cooking time than fresh beans and thus paralleled cooking time for beans stored forr more than 1 yr at room temperature. With corrections for solids lost during soaking, water absorption did not differ between fresh and stored beans. The rate of electrolyte leakage was greater from stored beans than from fresh samples, indicating that the cotyledon deteriorated during aging. Bean moisture content was found to be related to cooking time. In general, the higher the moisture content after soaking, the shorter the cooking time. However differences in cooking times between fresh and aged samples persisted regardless of bean moisture content.