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1.
The aim of the present work was to explore the suitability of two kinds of bean with typical protein quality and different starch structure to produce moulded specimens by compression. In this work we analysed the possibility of forming new plastic materials from two kinds of bean preparations; with different protein content, in the presence or absence of inherent cellulose material and other biopolymer such as starch. Significant differences were determined in the fine structure of glucopolysaccharides isolated from the different types of bean. Complete moulding of the specimens took place at 20 MPa at a temperature not higher than 140°C, for 7 min. The mechanical properties of the moulded plastics based on soluble protein black bean (BP) were superior in elongation, tensile strength and low water absorption than the soluble protein white bean (WP) variety. However, the addition of boric acid 3% (w/w, in total batch basis) to white bean plastic materials was effective in improving slightly the mechanical properties in the case of their whole flours products (WWF). The gamma radiation was effective to reduce water absorption only in plastics materials with cellulose–starch content (BWF, WWF) and improved their mechanical properties. The gelatinization process of the moulded material was influenced by the predominant lineal structure of the carbohydrate content.  相似文献   

2.
The proximate composition and functional properties of fullfat and defatted beniseed (Sesamum indicum L.) flour were evaluated. Functional properties studied were foam capacity and stability, water and oil absorption, bulk density, emulsion capacity and nitrogen solubility. Defatting increased the crude protein, ash, crude fiber, carbohydrate and mineral contents. Defatted flour showed comparatively better foam capacity and stability, water absorption and emulsion capacities but diminished bulk density and oil absorption capacity. Nitrogen solubility was pH dependent with a minimum at pH 4 and maximum at pH 8. Maximum nitrogen solubility (95%) was recorded for defatted flour while that for the fullfat flour was 60%. The proximate composition and functional properties of the samples suggest that beniseed flour would have useful application in fabricated foods.  相似文献   

3.
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.  相似文献   

4.
Experimental weaning foods were prepared from alfalfa leaves, peanut oil, and mung bean, chickpea or soy flour. The weaning foods were analyzed to determine their yield, proximate composition and amino acid content. Yields from starting materials ranged from 29 to 99%. Highest yields were obtained when 20% legume or oilseed flour was incorporated into leaf protein-peanut oil gels. The moisture content of the weaning foods ranged from 42 to 65%, protein from 3.4 to 6.5%, fat from 23 to 48%, and carbohydrate from 3 to 13%. Proteins in the experimental weaning foods were found to be deficient in the sulfur amino acids. Amino acid scores for weaning foods containing 20% legume or oilseed flour ranged from 50 for mung bean to 62 for soy. It was estimated that a four-ounce daily serving of one of the soy weaning foods would supply 40% of the energy and 35% of the protein needs of a one-year-old infant.  相似文献   

5.
In this study, partial substitution of wheat flour with chickpea flour at the levels of 10, 20 and 30% was carried out to study their rheological and baking performance. Chickpea flour addition increased the water absorption and dough development time (p < 0.05), while, the extensibility of dough and the resistance to deformation were reduced. Regarding dough stability, it appears that 10% chickpea exhibited higher stability and resistance to mechanical mixing values than the control, while it decreased as the substitute level increases from 20% to 30%. The dough surface of the wheat dough and the blend with 10% was classified as “normal”, however the blend with 20% and 30% produced “sticky” dough surface. The presence of chickpea flour in dough affected bread quality in terms of volume, internal structure and texture. The color of crust and crumb got progressively darker as the level of chickpea flour substitution increased. While the substitution of wheat flour with 10% chickpea flour gave loaves as similar as control.  相似文献   

6.
Pea (Pisum sativum), faba bean (Vicia faba) and soybean (Glycine max) seeds were characterized, and protein isolates were prepared following an isoelectric point precipitation procedure. Soybean seeds showed the highest protein content (36.7%) and carbohydrate was the major constituent in the pea (59.4%) and the faba bean seeds (52.1%). Protein contents were higher than 80% in all the protein isolates. The amino acid contents in the protein isolates were, in general, higher than those in their own starting seeds. The antinutritional factor contents were reduced after the protein isolate preparation. The highest reductions achieved for tannins were 95% in the faba bean protein isolate, and for phytates (45%) and trypsin inhibitor activity (46%) in the pea protein isolate. Haemagglutinating activity was not detected in any of the protein isolates. Minimum solubility values were observed at a pH range between 4.0 and 6.0, and maximal solubilities were obtained at basic pH values. The faba bean protein isolate showed the highest water and oil absorption capacities, and the best gelling properties. The soybean protein isolate had the best foam expansion capacity. Thus, the protein isolates had an improvement in some of the characteristics compared to their original seeds with lower contents in tannins, phytates and haemagglutinating activity, but had weak functional properties.  相似文献   

7.
The physical properties of extruded products from three Mexican common bean cultivars were investigated. Common bean cultivars Flor de Mayo, Pinto Villa and Bayo Victoria from the same harvesting season (2006) were used in this work. Beans were milled and the flour was hydrated to 24, 26 and 28 g of water/100 g of dry weight. Two temperatures, 130 degrees C and 165 degrees C at the end of the extruder barrel without die, were experimented. Common bean flour extrudates were evaluated for water absorption index (WAI), water absorption capacity (WAC), oil absorption capacity (OAC), and emulsifying capacity (EC). Flor de Mayo extrudates showed the highest WAC and WAI values. Thus starch from Flor de Mayo beans showed minor restricted water availability. In all cases, the OAC of extruded products was lower than the crude bean flour. The EC for Bayo Victoria flour increased as a consequence of the extrusion process. The EC for Flor de Mayo was higher at lower temperature and lower moisture content than Pinto Villa and Bayo Victoria beans. EC behavior of Pinto Villa was similar to Bayo cultivar. These results indicate that it is possible to produce new extruded products with good physical properties from these common bean cultivars.  相似文献   

8.
Mixtures of sweet potato flour and soy flour were made in a pilot mixer. They were moisturized with 18, 25, and 30% water and extruded in a single screw extruder at 80 rpm, using a die of 6mm. Extrusion temperature was maintained at 100 +/- 3 degrees C. Effects of adding soy flour into sweet potato flour, as well as variation in feed moisture on the composition and some functional properties of the extrudates were investigated. Increase in sweet potato content increased carbohydrate values. Protein increased with increase in soy flour. Feed moisture did not significantly (p < or = 0.05) affect extrudate composition. Increase in sweet potato content and feed moisture increased expansion ratio. Bulk density decreased with decrease in feed moisture, but increased with increase in soy flour. Starch content increased as sweet potato content increased. Degree of gelatinization increased with sweet potato content. Lower feed moisture enhanced gelatinization. Water absorption index (WAI) increased as sweet potato content increased. Feed moisture had a slight effect on WAI and water solubility index (WSI). Amylose increased with increase in sweet potato content. Increase in soy flour led to an increase in yellowness (b*) of extrudates.  相似文献   

9.
The knowledge of the contents and profile of isoflavones present in soy protein ingredients, as well as the effect of industrial processing, is important for the development of functional foods rich in these compounds. The results obtained here showed that the total isoflavone content varied significantly among products. For defatted and whole soy flours the total isoflavone content ranged from 120 to 340 mg/100 g, for soy protein isolates from 88 to 164 mg/100 g, and for commercial textured soy proteins, from 66 to 183 mg/100 g (wet basis, expressed as aglycones). The highest isoflavone content was found for soy hypocotyl flours, from 542 to 851 mg/100 g. Compared to hypocotyl and whole and defatted flours, soy ingredients presented a decrease of malonylglycosides and deesterified β-glycosides with a significant increase in the percentage of aglycones, mainly for soy fibers (65–76%). While defatting was shown to cause isoflavone concentration without altering conjugation, extrusion process caused destruction of isoflavones and a significant increase in the amount of acetylglycosides, but this effect was less intense for the concentrates. From the results obtained it can be concluded that differences in isoflavone concentration and profile may be related to oscillations in the isoflavone content present in the raw material and to the type of processing.  相似文献   

10.
Mixtures of sweet potato flour and soy flour were made in a pilot mixer. They were moisturized with 18, 25, and 30% water and extruded in a single screw extruder at 80 rpm, using a die of 6mm. Extrusion temperature was maintained at 100 ± 3°C. Effects of adding soy flour into sweet potato flour, as well as variation in feed moisture on the composition and some functional properties of the extrudates were investigated. Increase in sweet potato content increased carbohydrate values. Protein increased with increase in soy flour. Feed moisture did not significantly ( p 0.05) affect extrudate composition. Increase in sweet potato content and feed moisture increased expansion ratio. Bulk density decreased with decrease in feed moisture, but increased with increase in soy flour. Starch content increased as sweet potato content increased. Degree of gelatinization increased with sweet potato content. Lower feed moisture enhanced gelatinization. Water absorption index (WAI) increased as sweet potato content increased. Feed moisture had a slight effect on WAI and water solubility index (WSI). Amylose increased with increase in sweet potato content. Increase in soy flour led to an increase in yellowness (b*) of extrudates.  相似文献   

11.
Natural fiber composite replaces the conventional and synthetic materials in many fields especially in light weight applications. The randomly oriented short snake grass fiber reinforced isophthallic polyester composites are prepared by hand lay-up technique and finally compression molded. The various length and weight fraction of fiber are used in composite fabrication. The mechanical properties and water absorption under various climatic conditions are examined according to the prescribed standard. SEM image revealing the fiber pullout and breakage of the tensile and impact fractured composite specimens has been analysed and compared with control through scanning electron microscope. The result shows that the mechanical properties increase with increase in fiber length and weight fraction of the composites. The rate of water absorption increases with increase in temperature and time. Obtained experimental tensile strength of the composite is compared with various theoretical models such as Series, Hirsch’s, Halpin-Tsai, Modified Halpin-Tsai and Modified Bowyer & Brader’s and the obtained inferences are discussed.  相似文献   

12.
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.  相似文献   

13.
Mixtures of defatted soy flour and sweet potatoes wereextruded at 0:100, 25:75, 50:50, 75:25 and 100:0ratios in an Insta-Pro 600 single screw extruderoperated at 180, 200, 220 rpm.Oil (3–5%) was added into the mix before extrusion.A 5×32 fractional factorial central compositeresponse surface design was adopted forinvestigating the variables: feed composition, % oil,and screw rotation speed (RPM). Percent oil andscrew speed were randomly investigated at threelevels, while feed composition was randomlyinvestigated at five levels. Effect of extrusioncooking on functional properties: bulk density,expansion ratio, water absorption and solubilityindices and trypsin inhibitor were assessed.Results showed that feed composition and screw speedhad strong influences on the process. The effect ofadding oil, into defatted soybean significantly(p<0.05) affected only trypsin inhibitor content.High extrusion temperature (>130 °C), andaccompanying high shear, were the result of thenon-pasting nature of the extrudate. Therefore theproducts may have limited uses.  相似文献   

14.
Protein isolates from pea flour were prepared by extraction of protein at pH 7.0 or 9.0 which was followed by precipitation as isoelectric isolates or as proteinates. After spray-drying, chemical composition, water retention capacities, thickening properties, and flow behaviours were determined and compared to those of a soybean protein isolate (Supro 620).  相似文献   

15.
戊二醛改性提高大豆胶粘剂耐水性能   总被引:1,自引:1,他引:0  
以脱脂大豆粉(SF)为原料,选用十二烷基硫酸钠(SDS)和戊二醛(GA)作为改性试剂,制备出具有较好耐水性能的木材用胶粘剂,并应用于杨木胶合板,分别研究了pH值、戊二醛用量、反应时间以及最终改性胶粘剂贮存时间对耐水胶合性能及表观粘度的影响,并采用十二烷基硫酸钠.聚丙烯酰胺凝胶电泳(SDS-PAGE)和傅屯叶变换红外光谱(FT-IR)分析手段探讨了改性胶粘剂耐水性能增强机理.结果表明:较佳合成工艺为:pH值为12.0,GA添加量0.80wt%(基于脱脂豆粉质量),反应时间1.0 h,反应温度30.0℃.按照GB/T 9846-2004胶合板中Ⅱ类板标准检测,耐水胶合强度可达0.68MPa.SDS-PAGE谱图说明蛋白质分子间形成化学键交联,FT-IR分析表明有环状吡啶结构生成,这些可能是改性胶粘剂耐水性能提高的原因.  相似文献   

16.
Protein isolates from L. campestris and soybean seeds were prepared using isoelectric precipitation (PI) and micellization (MI) procedures. The amount of protein recovered was considerably higher with the isoelectric precipitation than with the micellization procedure (60% and 30%, respectively). Protein contents were higher than 90% in protein isolates. Antinutritional factors content (alkaloids, lectins, and tannins) were reduced to innocuous levels after protein isolate preparation. Minimum protein solubility for the precipitated lupin protein isolate (LPI) was at pH 4.0, and between pH 4 and 6 for the micellized lupin protein isolate (LMI), increasing at both extremes of the pH scale. Water absorption for the LMI was 1.3 ml/g of protein and its oil absorption 2.2 ml/g of protein. The LPI had 1.7 ml/g of protein in both water and oil absorption. Foaming capacity and stability was pH-dependent. Foaming capacity was higher at pH 2 and lower near the protein isoelectric points. Minimum protein concentration for gelation in LMI was 8% w/v at pH 4, while for LPI was 6% at pH 4 and 6. Amino acid composition in L. campestris flour and protein isolates was high in lysine and low in methionine. Most of the essential amino acids in lupin protein isolates were at acceptable levels compared to a reference pattern for infants and adults. The electrophoretic pattern of both protein isolates showed three bands with different mobilities, suggesting that the protein fractions belong to alpha-conglutin (11S-like protein), beta-conglutin (7S-like protein) and gamma-conglutin. It is proven that some of the functional properties of L. campestris protein isolates are similar to those soybean protein isolates recovered under equal conditions.  相似文献   

17.
This study has shown that the protein in bread may be quantitatively increased significantly by addition of full-fat or defatted cocoa powder to white flour. The recipe in which white flour is incorporated with up to 10 percent defatted cocoa powder gives bread that is nearly as well accepted as white bread, but with a significantly higher protein content than the latter. However, organoleptic acceptability drops with increasing percentage of cocoa supplementation. The bitter taste of theobromine, which is normally present in high amounts in cocoa bean, is thought to be responsible for this problem of poor acceptability of high cocoa breads. This problem will have to be addressed in order to enhance the scope of increasing bread protein by cocoa supplementation.  相似文献   

18.
The objective of this work was to study the characteristics of four gluten-free bread formulations and the possibility of substituting soya protein with other legume proteins. Four bread recipes were prepared with chickpea flour, pea isolate, carob germ flour or soya flour. Carob germ flour batter structure was thicker compared with the other batters, probably due to the different protein behaviour and the residual gums present in carob germ flour. However, carob germ flour bread obtained the lowest specific volume values (2.51 cm3/g), while chickpea bread obtained the highest (3.26 cm3/g). Chickpea bread also showed the softest crumb. Confocal scanning-laser microscopy results showed a more compact microstructure in carob germ flour bread compared with soya and chickpea formulations. Chickpea bread exhibited the best physico-chemical characteristics and, in general, good sensory behaviour, indicating that it could be a promising alternative to soya protein.  相似文献   

19.
Flour samples were prepared from fermented and unfermentedAfrican oil bean (Pentaclethra macrophylla) seeds (AOBS). The flour samples were evaluated for proximate composition and certain functional properties. The influenceof defatting on these properties was also determined. Fermentation significantly increased (p<0.05) the proteinand decreased the crude fiber, ash, fat and carbohydrate contents of the AOBS flours. The nitrogen solubility of both fermented and unfermented flours was pH dependent withminimum and maximum solubility at pH 4.0 and pH 8.0, respectively, and with increased nitrogen solubility in the fermented sample. The fermented and unfermented flour sampleshad least gelation concentrations of 14 and 16% (w/v), respectively. The water absorption capacity and foam capacitiesof the fermented flour were 36 and 34%, respectively, over the unfermented seed flour. On the other hand, fermentation decreased the fat absorption capacity, emulsion activity and emulsion and foam stabilities. Fermentation decreased (p<0.05) the bulk density of AOBS flour by 15%. Defattingimproved all the functional properties evaluated except emulsion activity. These results indicate potential food usesof fermented and unfermented AOBS flour samples as protein supplements in diets and as functional ingredients in formulated foods.  相似文献   

20.
甲基丙烯酸缩水甘油酯对大豆分离蛋白塑料性能的影响   总被引:1,自引:0,他引:1  
用模压的方法制备了甲基丙烯酸缩水甘油酯(GMA)改性大豆分离蛋白质(SPI)塑料,探讨了GMA含量对SPI塑料的力学性能和耐水性的影响,并采用TG、SEM对SPI塑料和GMA改性SPI塑料进行了表征。结果表明:少量GMA可以对SPI塑料起到增强、增韧作用,并可提高其耐水性;加入少量的GMA可以提高SPI塑料的热稳定性;少量GMA改性SPI塑料能形成性能良好的柔性链结构,这种结构能明显提高SPI塑料的断裂伸长率。  相似文献   

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