大豆异黄酮甙元对结肠癌HT-29细胞增殖和凋亡的影响

大豆异黄酮通过促进肿瘤细胞凋亡可抑制多种肿瘤细胞的增殖.从大豆提取大豆异黄酮糖甙,再将其部分水解成其甙元,研究大豆异黄酮甙元抑制结肠癌细胞的增殖和促进其凋亡的作用.采用MTT比色法观察大豆异黄酮甙元对结肠癌HT-29细胞增殖的影响,采用TUNEL染色法检测其对HT-29细胞凋亡的影响,采用免疫细胞化学法检测凋亡相关蛋白bax、bcl-2和p53的表达.结果表明:大豆异黄酮甙元可在20～80 mg·L-1范围内时间和浓度依赖性地抑制结肠癌HT-29细胞增殖和诱导细胞凋亡.用40 mg·L-1大豆异黄酮甙元作用结肠癌HT-29细胞72 h时,细胞生长抑制率为(57.1±4.9)%,其对肿瘤细胞凋亡率为(20.9±2.1)%.免疫组化结果还显示,大豆异黄酮甙元可显著性增加HT-29细胞凋亡相关基因bax蛋白表达和降低bcl-2表达.提示,大豆异黄酮甙元可通过诱导结肠癌细胞凋亡发挥抗结肠癌作用.     

Phenolic Profile and Antioxidant Capacity of Chickpeas (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) as Affected by a Dehydration Process

This study presents the effects of soaking, cooking and industrial dehydration on the phenolic profile, and antioxidant capacity in two chickpea varieties (Sinaloa and Castellano). Chromatographic analysis identified a total of 24 phenolic components, being isoflavones the main phenolics in raw and processed Sinaloa and Castellano flours. The impact of the industrial dehydration was different depending on the chickpea variety. Although Castellano chickpea exhibited the highest levels of phenolic compounds (103.1 μg/g), significant reductions were observed during processing; in contrast, the dehydration did not cause any further effects in Sinaloa flours. Interestingly, Sinaloa variety showed high thermal stability of isoflavones during processing. As expected, the levels of antioxidant capacity were in accordance with the behavior of phenolic compounds exhibiting noticeable reductions in Castellano chickpea and not relevant changes in Sinaloa chickpea. Thus, the significant occurrence of bioactive phenolic compounds along with the relevant antioxidant capacities of dehydrated chickpea flours make them to be considered functional ingredients for their beneficial health effects, especially in case of Sinaloa.     

Phytic Acid Level in Wheat Flours

The phytic acid content of refined (hand-made and factory-made) and whole (factory-made) wheat flours, much consumed in the Canary Islands, have been determined in this study. A total of 200 samples of flours from different types (100 refined and 100 whole) were analysed. The method proposed by Garcı́a-Villanova et al. (1982) was used for determination of phytic acid content in wheat flours. Most of the phytic acid concentrations are within the range 2–4 mg/g for the refined flours and 6–10 mg/g for the whole ones. The arithmetic mean obtained from all the samples studied is 3·77 mg/g for hand-made, refined flours, 2·96 mg/g for factory-made refined flours and 8·50 mg/g for the whole ones. On analysing the phytic acid content in all the flour samples, significant differences were observed for the different types of flour. Refined flours had a content lower than whole ones.     

Isoflavone Contents in Germinated Soybean Seeds

The effect of germination on isoflavone contents in two soybean varieties (Hutcheson and Caviness) was investigated. Soybean seeds were soaked at 25 ^∘C for 12 h, germinated at 40 ^∘C, and freeze-dried. The isoflavone contents of dry, soaked, germinated (hypocotyl length at 0.5, 2.5, and 6.5 mm), and nongerminated seeds were determined by high performance liquid chromatography. The maximum amount of total isoflavone, genistein, and daidzein with their β-glucoside conjugates was obtained when hypocotyl length of the germinated-seed from var. Hutcheson was 0.5 mm (2.491, 1.500, and 0.671 mg/g), and from var. Caviness was 2.5 mm (2.78, 1.523, and 0.905 mg/g). A dramatic increase in malonylgenistin and malonyldaidzin (1.305 mg/g and 0.476 mg/g in Hutcheson, and 1.308 mg/g and 0.677 mg/g in Caviness, respectively) was observed at these hypocotyl lengths. A decrease was observed after this stage. Genistein and daidzein contents were highest just after soaking. Glycitein and its β-glucoside conjugates remained almost the same during germination. Controlled germination can be used to enhance isoflavone content in soybean seed.     

Comparison of chickpea and soy protein isolate and whole flour as biodegradable plastics

The objective of the present work is to compare some different crop products such as protein isolates and defatted whole flours from legumes, as chickpea and soy bean, involved in the molded compression processing to obtain plastics. The present work analysed the possibility of forming new plastic materials with products of chickpea, and soy bean seeds typically from the North West of Argentina, conditioned as chickpea isolate (CI), chickpea whole flour (CWF) in relation with soy protein isolate (SI) and soy whole flour (SWF). The blends containing isolates or defatted whole flour of chickpea, with the addition of glucopolysaccharide, glycerol and water as plasticizers were compression molded at 120°C, at 20 MPa, for 7 min. The glucopolysaccharide employed from this vegetals presented a ratio of amylose to amylopectin structure 95/5. The molded specimens were calculated for their tensile strength, percent elongation at break and water absorption. The chickpea isolate would be important in the production of plastic materials because of the best mechanical properties and the smallest water absorption. The chickpea whole flour product gave better material than soy whole flour product, even if the mechanical properties of both are lower than chickpea and soy isolates, respectively. Addition of boric acid in the blend induced a fall in water absorption in the case of soy plastics, but was not important in chickpea plastics. The effect of irradiation was to decrease water absorption in soy plastics and chickpea whole flour, while the effect on mechanical properties was not important.     

吉林省普通大豆品种(系)异黄酮含量分析

利用超声波法对吉林省26份普通大豆品种(系)大豆异黄酮含量进行HPLC测定.建立了一种HPLC测定大豆籽粒中异黄酮含量的方法.结果表明:异黄酮各异构体在50～1000μmol·L~(-1)范围内线性系数良好,相关系数为0.9998～0.9999;检出限为1.09～2.06 mg·L~(-1),定量限为3.25～6.46 mg·L~(-1);异黄酮各异构体同收率为97.11%～103.31%;相对标准偏差(RSD,n=7)分别为2.03%～4.32%.该方法线性范围广,线性关系好,灵敏度和准确度高,适合于大豆及大豆制品中异黄酮含量的测定.测得吉林省261份普通大豆品种(系)中的异黄酮含量范围1.46～4.97 mg·g~(-1),超过4 mg·g~(-1)的品种(系)有23个,占测定品种(系)总数的8.81%.     

东北地区栽培大豆品种籽粒异黄酮含量分析及不同测定方法优化比较

利用超声波技术,以大豆异黄酮主要组分染料木素为对照,根据单因素试验和正交试验结果建立三波长比色法和紫外分光光度法,确定大豆异黄酮最佳提取工艺:乙醇浓度70％,料液比1:25,提取温度50℃,提取时间5h,提取2次.比较新建立方法与之前建立HPLC法的精密度和准确度,结果依次为:高效液相色谱法＞三波长比色法＞紫外分光光度...     

大豆异黄酮甙元抗脂质过氧化作用的研究

从大豆提取大豆异黄酮糖甙,再将其部分水解成其甙元,研究其体外抗氧化能力.用T-AOC方法测定化学模拟体系中的总抗氧化能力,用八木变法测定过氧化脂质(LOOH)含量,用硫代巴比妥酸(TBA)法测定丙二醛(MDA)含量,用分光光度法测定红细胞溶血和肝线粒体膨胀程度.结果表明:大豆异黄酮甙元的体外总抗氧化能力较强,可抑制血浆及肝组织脂质过氧化,减少红细胞溶血和减轻肝线粒体膨胀程度.说明大豆异黄酮甙元具有抗脂质过氧化作用.     

Maillard Reaction Evaluation by Furosine Determination During Infant Cereal Processing

The furosine content of infant cereals has been used to evaluate the thermal damage caused to those foods during their manufacture (toasting, amylolysis and drying steps). The mean furosine contents of raw and toasted flours were 13·7 and 13·8 mg/100 g of protein, respectively. The furosine content increased to 47·3 mg/100 g of protein after hydrolysis usingalpha-amylase. The amylolysis process raised the reducing sugar content from 0·5% for raw samples to 12·7%. The furosine content of infant cereals rose to average levels of 500 mg/100 g of protein after roller-drying. The infant cereals with the highest levels of reducing sugars, with or without soy flour, exhibited the highest furosine contents. Furosine is a useful indicator to evaluate the progress of the Maillard reaction during the amylolysis and roller-drying stages of infant cereals manufacture.     

Physico-chemical properties and acceptability of yam flour substituted with soy flour

Yam flour was substituted 10, 20 and 40% with defatted and full fat soy flour. The effect of the substitution on the proximate composition, swelling power, solubility, water binding capacity and Brabender visco amylograph cooking properties of the yam flour and acceptability of the cooked paste (amala), were evaluated. Protein contents of the mixtures were 23.0 and 25.5% on substituting 40% full-and defated soy flours for yam flour; ash and crude fibre contents increased while carbohydrate content, swelling power, Brabender paste viscosities decreased with increase in soy flour substitution of yam flour. Colour, texture, taste and overall acceptability of pastes (amala) from the mixed flours were rated lower than that of yam flour. Up to 10% defated and 20% full fat soy flour substitution for yam flour was acceptable for amala.     

The influence of milling on the nutritive value of flour from cereal grains. 2. Wheat

Wheat was milled into flours having extraction rates between 100 and 66%. The nutritive value of the various fractions was studied by chemical analyses and in balance trials with rats. The concentration of essential nutrients decreased when the extraction rate was lowered. The lysine content (g/16 g N) e.g. was 2.52 in whole wheat, but only 2.18 in the 66% extraction flour; however, only a slight reduction in biological value was found. The content of minerals was reduced to 30% of that in whole wheat, and the apparent zinc absorption and retention expressed in absolute values, were significantly higher from the flours of high extraction than from the more refined flours, in spite of a much higher phytate content in whole wheat and lightly milled flours. It could be concluded that milling of wheat into highly refined flours not only preclude considerable amounts of nutrients from human consumption, but the remaining flours have a much poorer nutritive value than flour made from whole wheat.     

Effect of shading on accumulation of soybean isoflavonoid under maize-soybean strip intercropping systems

Maize-soybean strip intercropping system is an important ecological planting system; the wide development of intercropped soybean has contributed to the soybean industry in China. Soybean growth and seed production were affected by the shading from maize. Previous studies confirmed that relay strip intercropping shading facilitates the accumulation of isoflavone glucosides but does not take advantage of the accumulation of isoflavone aglycone. However, the regulation of isoflavones accumulation under strip intercropping system was unknown; in which soybean and maize were sown at the same time, and soybean was mainly shaded in the reproductive stage. In order to reveal the effects of intercropping shading on the isoflavones accumulation in soybean seed, two independent field experiments were conducted in eastern China. We compared the isoflavones profiles of soybean seeds, which were grown under various maize-soybean intercropping systems with different shade levels. The results showed that the intercropping shading was not benefited to the accumulation of soy-isoflavones, including aglycones and isoflavones glycosides and various forms of isoflavones were decreased with the decline of photosynthetic active radiation. Multivariate statistical analysis and significance analysis showed that acylated isoflavones may be more susceptible to intercropping shading.

Abbreviations: HCA: Hierarchical cluster analysis; PAR: photosynthetically active radiation; PCA: Principal component analysis; LC-MS: Liquid chromatography mass spectrometer.     

The USDA trypsin inhibitor study. I. Background,objectives, and procedural details

Short-term feeding studies have shown that raw soy flour and purified trypsin inhibitors (TI) cause pancreatic hypertrophy and hyperplasia in certain monogastric animals. Prolonged exposure to high levels of TI in raw soy ultimately leads to pancreatic nodular hyperplasia and acinar cell adenoma in rats exposed to low levels of pancreatic carcinogens. Such change has been observed even in the absence of any exposure to known carcinogens. These results emphasized the need for chronic (2 yr) feeding trials which would clearly reveal dose response relationships of alterations in pancreatic pathology to dietary TI and possible interactions with dietary protein and fat.Here we report on the objectives and designs of the first phase of the USDA TI Study, including composition of diets, preparation, and analyses of test substances. To provide the requisite TI and protein levels, raw and heated defatted soy flours, soy protein isolates, and lactic casein were used. The interrelationship of dietary level of TI (93–1270 mg/100 g diet) and that of protein (10%, 20%, and 30%) to pancreatic function and pathology will be reported in the following three papers. Both serial and chronic sacrifice regimes, respectively, were employed with 26 diets and 40 weaning male Wistar rats per dietary group.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

The influence of milling on the nutritive value of flour from cereal grains. 1. Rye

Rye was milled into flours having extraction rates between 100 and 65%. The nutritive value of the various fractions was studied by chemical analyses and in balance trials with rats. The concentration of essential nutrients decreased when the extraction rate was lowered. The lysine content (g/16 g N) was 4.23 in whole rye, but only 3.76 in the 65% extraction flour, and a corresponding reduction in biological value was found. A reduction of 50% or more was observed for several minerals with zinc and phosphorus being most affected. The apparent zinc absorption and retention expressed in absolute values, were significantly higher from the flours of high extraction than from the more refined flours, in spite of a much higher phytate content in whole rye and lightly milled flours. It could be concluded that milling of rye into highly refined flours not only preclude considerable amounts of nutrients from human consumption, but the remaining flours have a much poorer nutritive value than flour made from whole rye.     

The USDA trypsin inhibitor study. IV. The chronic effects of soy flour and soy protein isolate on the pancreas in rats after two years

In two year feeding trials, histologic changes in the pancreas of the Wistar rat were evaluated after chronic dietary exposure to raw and heated, dehulled, defatted soy flour and soy protein isolates which provided a range of trypsin inhibitor (TI) concentrations from 93 to 1271 mg/100 g diet. Also investigated was the nutritional interaction of level of dietary protein with the development of pancreatic pathology. Graded levels of TI were achieved from mixtures of raw and heated soy flour or protein isolate. Dietary protein levels were 10%, 20%, and 30%; the two higher levels obtained in some diets through casein supplementation. A total of 26 diets, including casein controls, were fed to groups of 40 male rats. Growth rates with these diets were commensurate with protein quality and level. Mortality rates tended to be slightly greater in the higher protein diets, and rats fed only raw soy as a source of protein survived well.Two lesions, nodular hyperplasia (NH) and acinar adenoma (AA) constituted the major pathological findings in the pancreas, and the incidence rates of both were positively associated with the concentration of dietary TI. The incidences of pancreatic NH and AA compared to those of the corresponding casein control were significantly elevated in rats fed heated soy flour supplying 10% protein and the lowest level of TI investigated (93 mg/100 g diet). At low levels of TI (215 mg/100 g diet), supplementation by casein to raise the concentration of protein from 10% to 20% and 30% reduced the frequency of NH and AA. When the dose-response data for NH and AA was linearized by plotting the probit of percent incidence against log of TI concentration per gram of dietary protein, the response to soy flour and soy protein isolate was not significantly different. Numerous lesions commonly found in the aging rat were diagnosed, and modulation of their rate of occurrence by nutritional factors associated with the diets was apparent in some instances.Reference to a company and/or product named by the Department is only for purposes of information and does not imply approval or recommendation of the product to the exclusion of others which may also be suitable.     

IFS转基因大豆的鉴定及高异黄酮植株的筛选

大豆异黄酮是一种广泛应用的保健性活性物质,近年来已成为衡量大豆品质的重要指标之一。异黄酮合酶是大豆异黄酮合成途径中的关键酶基因之一,其在植物中的表达效率直接影响异黄酮含量。为进一步验证该基因的功能并获得高异黄酮稳定遗传转基因植株,本试验基于已有的IFS转基因材料开展研究。将其扩繁至T2代,考种分析植株农艺性状,发现转基因植株的性状指标未发生明显变化,PCR鉴定IFS转基因后代的结果显示:在125株转基因植株中,60株为阳性,占比48%,说明IFS在后代中可稳定遗传。选取IFS转基因吉林35、Willimas 82品种T2代的41株,利用改良后的三波长法测定籽粒中大豆异黄酮的含量,结果显示:IFS转基因植株的平均异黄酮含量为1.2 mg·g~(-1);其中15株的异黄酮含量高于非转基因植株,占比达到36.6%,说明从转入IFS基因转基因大豆能够筛选出高异黄酮植株。本研究获得了稳定遗传的高异黄酮植株,为大豆遗传育种提供优异的种质资源;改良后的三波长法较原有方法更为精准、快速。     

大豆异黄酮含量与主要农艺性状相关性及通径分析

利用高效液相色谱法检测了中豆27(♀)×九农20(♂)重组自交系的异黄酮含量.结果显示重组自交系间异黄酮含量差异显著.分析了异黄酮含量同主要农艺性状和化学品质性状的相关性,结果表明:总异黄酮含量与蛋白含量、脂肪含量、蛋白脂肪总合量、分枝数、单株产量、总荚数、主茎荚数和分枝荚数呈现负相关,其中与蛋白含量和蛋白脂肪总合量相关都分别达到显著和极显著水平;同株高、主茎节数和百粒重呈正相关趋势,并进一步估算了各异黄酮的含量与主要农艺性状的通径系数.     

响应面优化超声辅助提取大豆异黄酮联产分离蛋白和低聚糖

设计了一条绿色高效地提取纯化大豆异黄酮,并联产制备大豆分离蛋白和低聚糖的工艺。首先通过单因素实验和响应面(RSM)优化,确定了超声辅助提取大豆异黄酮的工艺条件:超声功率250 W,70%乙醇,提取温度70℃,提取时间120 min,大豆异黄酮提取量为2 104.25μg.g-1,提取率85.34%;并通过三步简单的分离纯化从豆粉中得到1 838.00μg.g-1、纯度为62.09%的异黄酮,最终收率74.54%;最后以提取异黄酮后的剩余豆渣为原料,联产制备了大豆分离蛋白(216.25 mg.g-1)和低聚糖(73.75 mg.g-1),全过程无废液废渣排出。     

Flowability,moisture sorption and thermal properties of tef [Eragrostis tef (Zucc.) Trotter] grain flours

Recently tef is attracting the attention of the modern food industry since it is a gluten-free grain encompassing highly appreciated nutritional advaxntages. As a relatively new raw material, little information on its handling and processing properties is available. Flowability, water sorption characteristics and thermal properties of flours from three Ethiopian tef varieties were studied. Wheat (whole and refined) and rice flours were included as references. Tef flours were less flowable than the reference flours and their flow properties were more sensitive to water activity changes. Tef flours led to sigmoidal sorption isotherms with estimated monolayer water content of 0.053 (BET model) and 0.057 (GAB model) g water/g dry solids. No significant differences among the three tef varieties were observed on their gelatinization enthalpies that were higher than that of wheat and similar to rice. The amylopectin recrystallization extent after 7 days of storage at 4 °C was significantly higher in tef than in wheat flour.     

Evaluation of Particle Size Influence on Proximate Composition,Physicochemical, Techno-Functional and Physio-Functional Properties of Flours Obtained from Persimmon (<Emphasis Type="Italic">Diospyros kaki</Emphasis> Trumb.) Coproducts

The aim of the work was to study the influence of particle size in the composition, physicochemical, techno-functional and physio-functional properties of two flours obtained from persimmon (Diospyros kaki Trumb. cvs. ‘Rojo Brillante’ (RBF) and ‘Triump’ (THF) coproducts. The cultivar (RBF and THF) and particle size significantly affected all parameters under study, although depending on the evaluated property, only one of these effects predominated. Carbohydrates (38.07–46.98 g/100 g) and total dietary fiber (32.07–43.57 g/100 g) were the main components in both flours (RBF and THF). Furthermore, insoluble dietary fiber represented more than 68% of total dietary fiber content. All color properties studied were influenced by cultivar and particle size. For both cultivars, the lower particle size, the higher lightness and hue values. RBF flours showed high values for emulsifying activity (69.33–74.00 mL/mL), while THF presented high values for water holding capacity (WHC: 9.47–12.19 g water/g sample). The bile holding capacity (BHC) and fat/oil binding values were, in general, higher in RBF (19.61–12.19 g bile/g sample and 11.98–9.07, respectively) than THF (16.12–12.40 g bile/g sample and 9.78–7.96, respectively). The effect of particle size was really evident in both WHC and BHC. Due to their dietary fiber content, techno-functional and physio-functional properties, persimmon flours seem to have a good profile to be used as potential functional ingredient.