Effect of soaking,dehulling, and cooking methods on certain antinutrients and in vitro protein digestibility of bitter and sweet lupin seeds

Effect of several physical treatments (soaking, dehulling, ordinary cooking, microwave cooking, and autoclaving) on the level of antinutrients and in vitro protein digestibility of bitter and sweet lupin seeds were investigated. The raw bitter and sweet lupin seeds were found to contain phytic acid, tannins, trypsin inhibitor activity, and lectin activity, but α-amylase inhibitor was absent. Dehulling significantly increased the levels of phytic acid (PA), trypsin inhibitor activity (TIA), and tannins, but lectin activity was not changed. Also soaking in bitter (for 96 hr) and sweet (for 24 hr) seeds caused a significant increase in these factors except lectin activity. Cooking methods differently affected the levels of the antinutrients. Thus, PA increased but tannins were not changed, on the other hand TI and lectin activities were inactivated; ordinary cooking and autoclaving were the most effective in both seeds. For combination effect, soaking following cooking treatments significantly decreased PA, tannins, and lectin activity, but increased TIA in both seeds. Moreover, dehulling following soaking and cooking methods resulted in a significant increase of PA, TIA, and tannins. In vitro protein digestibility (IVPD) of raw bitter and sweet lupin seeds were 78.55 and 79.46%, respectively and it was improved by all processing methods; soakingdehulling after autoclaving was the most effective in both seeds. Although some treatments increased the level of antinutrients, they improved IVPD. Therefore, the studied antinutrients are not the only responsible factor for lowering IVPD.     

Effect of domestic processing and cooking on the antinutrients of black gram

Domestic processing and cooking methods including soaking, ordinary and pressure cooking of soaked and unsoaked seeds, and sprouting significantly lowered phytic acid, saponin and polyphenol contents of black gram (Vigna mungo) seeds. Soaking for 18 h removed 28% of the phytic acid; extents of removal were higher with longer periods of soaking. Saporins andpolyphenols were relatively less affected. Loss of the antinutrients was greater when soaked instead of unsoaked seeds were cooked. Pressure cooking had a greater effect than ordinary cooking. Antinutrient concentrations declined following sprouting; the longer the period of germination the greater was the reduction. Phytic acid was reduced to a greater extent than polyphenols or saponins.     

不同预处理对发酵酸豆乳品质及抗营养因子含量的影响

本文以大豆为研究对象,在浸泡温度为25℃、豆水比为1:4、浸泡时间16h的条件下,采用不同介质(水、0.45%柠檬酸溶液、0.45%碳酸氢钠溶液)浸泡及萌发等预处理后制备发酵酸豆乳,考察对酸豆乳抗营养因子变化及营养品质的影响。结果如下：以干豆榨取的豆乳作为对照组,酸豆乳中胰蛋白酶抑制剂的还原作用依次为发芽>碳酸氢钠>水>柠檬酸；植酸含量依次为发芽>柠檬酸>水>碳酸氢钠；单宁含量的降低作用依次是发芽>碳酸氢钠>柠檬酸>水。浸泡处理可有效降低酸豆乳中抗营养因子的含量,碳酸氢钠浸泡组去除抗营养因子效率最高,质量最好。此外,高温处理将胰蛋白酶抑制剂含量降低70%,植酸和单宁属于热不敏感因子,高温处理效果不够显著。因此,本研究最终确定的预处理条件为发芽,碳酸氢钠浸泡。     

Effect of soaking process on nutritional quality and protein solubility of some legume seeds

Legume seeds (soy bean, lupin and bean seeds) were soaked in 0.5% sodium bicarbonate in attempt to evaluate their nutritional quality and protein solubility index. Soaking process led to an increase in the hydration coefficient, seed weight, total protein, ash, fat, fiber, while non protein nitrogen, total carbohydrates, starch, stachyose, raffinose, reducing sugars, and minerals (except Na) were decreased. All antinutritional factors such as phytic acid, tannin, trypsin inhibitor and hemagglutinin activity were decreased during soaking in 0.5% sodium bicarbonate; it was the same for the protein solubility in different solutions, while the in-vitro protein digestibility and available lysine were increased.     

Oligosaccharides, Antinutritional Factors, and Protein Digestibility of Dry Beans as Affected by Processing

Dry beans (Phaseolus vulgaris) were subjected to soaking, cooking or a combination of both prior to fermentation, and then assessed for oligosaccharides, antinutritional factors and in-vitro protein digestibility. Results showed an important decrease in raffinose oligosaccharides and antinutritional factors. However, an increase of trypsin inhibitor and tannin contents occurred respectively in cooked or soaked-cooked fermented beans and in raw or soaked fermented beans. Appreciable improvement in in-vitro protein digestibility was only observed in cooked or soaked-cooked beans. After fermentation, the largest decreases were observed in soaked-cooked beans (92.75%) for raffinose, in cooked beans (31.57%) for phytic acid, in soaked beans (90.86%) for stachyose, and in raw beans for trypsin inhibitor (38.77%). The highest increase due to fermentation was observed in raw beans for in-vitro protein digestibility (1.73%).     

常见加工方式对杂豆品质的影响与调控

杂豆富含蛋白质、膳食纤维和维生素等多种营养成分，但也含有植酸、胰蛋白酶抑制剂、植物凝集素等抗营养因子，这大大降低了其生物利用率。采用不同的加工方法可以降低或去除抗营养因子，从而改善杂豆的营养品质、风味品质和感官特性，提升杂豆适用性。常见加工方式主要包括浸泡、脱壳、煮制、微波处理、高压处理、挤压膨化、烘烤、发酵和发芽等。本文总结不同加工方式对杂豆品质的影响，以期为精准调控杂豆品质和发展新型杂豆加工技术提供理论参考和新的研究方向。     

Effect of soaking,germination, cooking and fermentation on antinutritional factors in cowpeas

The present work deals with the study of efficacy of some treatments, namely soaking (in water and bicarbonate solution( ordinary and pressure cooking, germination and fermentation in reducing or removal of antinutritional factors usually present in cowpeas (protease inhibitors, tannins, phytic acid and flatus‐producing oligosaccharides (raffinose and stachyose). The results showed that long‐time soaking (16 h) in bicarbonate solution caused remarkable reduction in the antinutritional factors. Pressure cooking was more effective than ordinary. Cooking pregerminated cowpeas was most effective. Fermentation completely removed trypsin inhibitor, oligosaccharides and reduced remarkably phytic acid. However, tannins noticeably increased.     

Effect of soaking,germination, cooking and fermentation on antinutritional factors in cowpeas

The present work deals with the study of efficacy of some treatments, namely soaking (in water and bicarbonate solution), ordinary and pressure cooking, germination and fermentation in reducing or removal of antinutritional factors usually present in cowpeas (protease inhibitors, tannins, phytic acid and flatus-producing oligosaccharides (raffinose and stachyose). The results showed that long-time soaking (16 h) in bicarbonate solution caused remarkable reduction in the antinutritional factors. Pressure cooking was more effective than ordinary. Cooking pregerminated cowpeas was most effective. Fermentation completely removed trypsin inhibitor, oligosaccharides and reduced remarkably phytic acid. However, tannins noticeably increased.     

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.     

EFFECT OF PROCESSING TREATMENTS ON NUTRITIONAL AND ANTINUTRITIONAL CONTENTS OF GREEN GRAM

High‐yielding varieties of green gram (Vigna radiata L.), namely Asha and MH1K‐25 contained a significant amount of antinutrients. Various processing and cooking methods, namely soaking, dehulling, ordinary cooking, pressure cooking and sprouting, decreased the level of antinutrients and improved in vitro digestibility of protein and in vitro availability of calcium, iron and zinc observed. The beneficial effect was more pronounced with pressure‐cooked and soaked seeds followed by ordinary cooking, sprouting (24 h), dehulling and soaking in both cultivars. A significant increase in in vitro protein digestibility (34–35%), in vitro availability of Ca (59–61%), Fe (52–56%) and Zn (62–67%) may be ascribed to the reduced content of phytic acid (35–39%), polyphenols (41–42%) and trypsin inhibitor activity (69–70%). Pressure cooking was the most effective treatment in improving the nutritional quality of green gram.     

Phytic acid content of chickpea (Cicer arietinum) and black gram (Vigna mungo): varietal differences and effect of domestic processing and cooking methods

Phytic acid content of various cultivars showed a narrow variation: 7.48-8.00 g kg^?1 and 6.47-6.68 g kg^?1 for chickpea (Cicer arietinum L) and black gram (Vigna mungo L), respectively. Phytic acid was lowered significantly by the common methods of domestic processing and cooking including soaking, cooking, autoclaving and sprouting of the legume grains. Sprouting had the most marked phytic acid lowering effect followed by autoclaving and soaking. Cooking of soaked seeds lowered phytic acid by 20-26% in chickpea and 35-40% in black gram grains whereas the loss was 7-11% and 6-9% in these pulses, respectively, when unsoaked seeds were cooked.     

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     

Nutritional composition and antinutritional factors of mung bean seeds (Phaseolus aureus) as affected by some home traditional processes

The effects of some domestic traditional processes, such as dehulling, soaking, germination, boiling, autoclaving and microwave cooking, on the nutritional composition and antinutritional factors of mung bean seeds were studied. Germination and cooking processes caused significant (p<0.05) decreases in fat, carbohydrate fractions, antinutritional factors and total ash contents. All processes decreased the concentrations of lysine, tryptophan, threonine and sulfur-containing amino acids. However, all treatments were higher in total aromatic amino acids, leucine, isoleucine and valine contents than the FAO/WHO reference. Dehulling, soaking and germination processes were less effective than cooking processes in reducing trypsin inhibitor, tannins and hemagglutinin activity contents. Also, germination was more effective in reducing phytic acid, stachyose and raffinose. Germination resulted in a greater retention of all minerals compared to other processes. In vitro protein digestibility and protein efficiency ratio were improved by all processes. The chemical score and limiting amino acids of mung bean subjected to the various processes varied considerably, depending on the type of process.     

Effect of gamma irradiation on physicochemical properties,proximate composition,vitamins and antinutritional factors of the tribal pulse Vigna unguiculata subsp. unguiculata

Effect of gamma irradiation on Vigna unguiculata subsp. unguiculata seeds (maroon‐coloured seed coat) at various doses (2, 5, 10, 15 and 25 kGy) on the physicochemical properties, proximate composition, vitamins (niacin and ascorbic acid) and antinutritional factors were analysed. No significant changes were recorded in the physicochemical properties of irradiated seeds. Gamma irradiation resulted in a significant increase in crude protein, while the crude lipid, crude fibre and ash contents resulted in a dose‐dependent decrease. Gamma‐irradiated seeds presented a significant decrease in the ascorbic acid and niacin content. Irradiation processing significantly reduced the level of L‐DOPA, phytic acid, hydrogen cyanide, trypsin inhibitor activity, oligosaccharides and lectins. The total free phenolics, tannins and in vitro protein digestibility on irradiation showed a significant dose‐dependent increase. Gamma irradiation seems to be a good procedure to improve the quality of legume seeds from the nutritional point of view.     

Effect of oil treatments on the levels of antinutritional factors in Callosobruchus chinensis (L.) infested stored pulses

Coconut, groundnut and mustard oil treated whole red gram, green gram and bengal gram were infested with Callosobruchus chinensis (L.), stored for 6 months, and observed at monthly intervals for antinutritional factors (phytic acid, trypsin inhibitor activity (TIA) and saponins). The values of phytic acid and TIA of treated and untreated pulses were similar at month one. The saponin content of green gram and Bengal gram were, however, higher in control than the oil treated pulses at month one. From month two to six the untreated controls had progressively more antinutrients than their oil treated counterparts. In mustard and groundnut oil treated pulses, the antinutrients remained static for 6 months, however, coconut oil treated pulse had increased antinutrients from end of month four onwards. The storage period was associated with the level of insect infestation which in turn influenced the antinutrient contents of pulses.     

大豆中植酸和胰蛋白酶抑制剂的抗营养和抗癌效应

大豆是重要的油料作物和植物蛋白来源,富含植物化学物质,如植酸和胰蛋白酶抑制荆等。传统营养理论认为这些植物化学物质是抗营养因子,然而近来研究显示这些化学成分具有天然抗癌作用。以植酸和STI为例主要介绍了它们的结构、分布、生理活性、抗营养效应及抗癌效应。     

The effect of popping,soaking, boiling and roasting processes on antinutritional factors in chickpeas and red kidney beans

This study was conducted to determine the effect that a popping head (like a rice cake machine), a low-shear and low-water processing technology, has on the concentration of antinutritional factors in chickpeas and red kidney beans. Seeds were popped under several parameters (popping time, sample format and equipment type) and analysed against soaking (1:5 w/v in reverse osmosis water for 24 h), roasting (100 g at 180 °C for 20 min) and boiling (1:5 w/v in reverse osmosis water at 100 ± 1 °C for 1 h) processes. Popping and roasting significantly reduced phytic acid content in chickpeas (6%–22%) and red kidney beans (16%–39%). In contrast, phytic acid content after soaking and boiling was not significantly different to raw seeds. Condensed tannins were significantly reduced in red kidney beans after soaking (74%), boiling (100%) and 4 s popping (28%–42%) treatments and increased in both pulses after roasting (137%) and 8 s popping (21%–47%). Further analysis showed that the soluble phenolic content increased with popping, but total and bound phenolic content was reduced. These results demonstrate that the high temperatures and pressures applied during the popping process effectively reduce antinutritional factors in pulses, compared to conventional processing methods.     

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.     

Amino Acid Composition and Some Antinutritional Factors of Cooked Faba Beans (Medammis): Effects of Cooking Temperature and Time

Easy-and hard-to-cook bean seeds were cooked by different heat treatments (100–125°C for 1–12 hr). Amino acid composition, tannins, phytic acid and trypsin inhibitor activity were determined. Almost all essential amino acids declined after cooking. Less than 10% of total tannins were decomposed during cooking, while up to 50% were leached to the cooking liquor. Retention of phytic acid in cooked beans was significantly lower than in cooked bean-liquor mixtures. Loss of phytic acid due to leaching was much higher for easy-to-cook beans than for hard-to-cook ones. Apparent retention of trypsin inhibitor activity amounted to about 50%. Optimum heat treatments were 125°C at 1 hr for easy and 120°C at 2 hr for hard-to-cook beans.     

大豆预处理方式对豆浆品质的影响

为了最大程度地降低抗营养因子含量,同时保证其品质优良,试验探究不同预处理方式及浸泡介质对豆浆中抗营养因子及其营养品质的影响。结果表明,在降低胰蛋白酶抑制因子活性方面,高温处理﹥萌发处理﹥浸泡处理,高温处理下的胰蛋白酶抑制因子活性仅为(3.12±0.70)TIU/mg,相对于未处理组降低了95.35%;3种处理方式下单宁含量均显著增高(P<0.05),萌发处理﹥高温处理﹥浸泡处理;在降低植酸方面,萌发处理﹥浸泡处理﹥高温处理,最低含量仅为(3.66±0.19)mg/mL;品质方面,浸泡方法为最优方法,保证了豆浆的高蛋白含量和低沉淀率。浸泡介质中,NaHCO3在某些条件下降低胰蛋白酶抑制因子的效果较好,同时较好地保持了豆浆品质;而柠檬酸在降低植酸含量上表现出色,但品质方面表现较差。综上,对豆浆进行预处理宜选择浸泡处理,在保持豆浆品质的同时,可以最大限度降低豆浆中抗营养因子含量。