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1.
Rodríguez-Ambriz SL Martínez-Ayala AL Millán F Dávila-Ortíz G 《Plant foods for human nutrition (Dordrecht, Netherlands)》2005,60(3):99-107
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
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Evangelos S. Lazos 《Plant foods for human nutrition (Dordrecht, Netherlands)》1992,42(3):257-273
Defatted pumpkin (C. pepo andC. maxima) seed flour has potential food uses because of its high protein content, 61.4±2.56%. The functional and electrophoretic properties of the defatted flour were investigated. Polyacrylamide gel electrophoresis and electrofocusing indicated 14 bands of water-soluble protein subunits with isoelectric points between 3.81–8.08 and apparent molecular weights between 19,200 and 97,000 daltons. Minimum nitrogen solubility was observed at pH values between 3.0–7.0 and exceeded 90% at pH above 9.0. Solubility was a function of ionic strength. It appeared that, even at the pH of minimum solubility, the pumpkin seed proteins could be dissolved up to high concentrations by increasing NaCl molarity. The viscosity of flour-water dispersion was affected by flour and salt concentrations, and temperature. The least gelation concentration was 8% (w/v) and the water and oil absorption 24.8±2.03 and 84.4±4.05 g/100 g respectively. Sorption isotherms, BET monolayer moisture and binding energy of sorption were also calculated. Both foam capacity and stability were pH dependent. 相似文献
3.
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
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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
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本研究以新鲜槟榔为实验材料,研究了常温贮藏条件下,负载茶树精油(0%、0.1%、0.3%和0.5%)的辣木籽渣蛋白乳液涂膜液对新鲜槟榔保鲜效果的影响。结果表明,负载0.1%、0.3%和0.5%茶树精油的辣木籽渣蛋白乳液对抑制槟榔的腐烂具有较好的效果,且随着浓度的增加(0%~0.3%),抑制越显著,但高至0.5%时效果减弱,其中0.3%茶树精油涂膜可有效减少新鲜槟榔贮藏期内水分的蒸发,进而减缓质量损失,同时还能有效维持较高的硬度,减缓组织软化,可有效减缓槟榔表皮转黄,保持较好色泽形态,常温贮藏期达到11 d,且抑菌试验表明,负载0.3%茶树精油–辣木籽渣蛋白乳液对大肠杆菌(Escherichia coli)的抑菌直径为(11.33±0.81) mm,对金黄色葡萄球菌(Staphylococcus aureus)的抑菌直径为(13.38±0.88) mm。综上所述,负载0.3%茶树精油–辣木籽渣蛋白乳液涂膜效果最好,既能达到抑菌效果,同时也能最大程度保持槟榔外观品质和营养品质,可作为延长槟榔保鲜时间和贮藏品质的适宜处理条件。 相似文献
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Silva-Sánchez C González-Castañeda J de León-Rodríguez A Barba de la Rosa AP 《Plant foods for human nutrition (Dordrecht, Netherlands)》2004,59(4):169-174
The functional and rheological properties of amaranth albumins isolates extracted from two new Mexican varieties were determined. Functional properties tested were protein solubility, foaming, water and oil absorption capacities, emulsifying activity, and emulsion stability. The maximum solubility values for both amaranth albumins were found above pH 6 and values were compared to the solubility of egg albumins. Albumins from amaranth showed excellent foaming capacity and foaming stability at pH 5, suggesting that this protein could be used as whipping agents as egg albumins, also the water and oil absorption capacities reached their maximum values at acidic pH, suggesting that amaranth albumins could be appropriate in preparation of acidic foods. The rheological test based on farinograms and alveograms showed that wheat flour supplemented with 1% amaranth albumins improves the dough properties due to higher mixing stability and the bread had better crumb characteristics. In addition of the known high nutritional values of amaranth albumins, our results indicate the high potential for use of these proteins as an ingredient in food preparations. 相似文献
7.
The inhibition by bisulfite of the oxidation of tyrosine in the enzymatic blackening reaction was pH dependent. At a pH of 5.0 or lower, bisulfite was a very effective enzyme inhibitor. A pH higher than 5.0 resulted in much less enzyme inhibition. At a pH of 4.0, the pH alone was a very effective enzyme inhibitor while a pH of 5.0 or above did not inhibit tyrosine oxidation very much. Thus, when bisulfite was present at a pH above 5.0, the main factor inhibiting enzymatic blackening was the bisulfite. Below pH 5.0 the inhibition of the polyphenol oxidase by both bisulfite and pH was important. The inactivation of polyphenol oxidase by bisulfite was a function of time and was pH dependent. Rapid inactivation occurred at pH 4.0 while inactivation occurred much more slowly at pH 5.0, 6.0 and 7.0. The residual enzyme activities were higher at pH 5.0 or above than at pH 4.0. Reactivation of the polyphenol oxidase did not occur over a 7 day period. 相似文献
8.
Osman MA 《Plant foods for human nutrition (Dordrecht, Netherlands)》2004,59(1):29-33
The baobab seed and pulp were analyzed for proximate composition, mineral content, and amino acid composition. The seed oil and protein were evaluated for their fatty acid profile and protein solubility. The seed was found to be a good source of energy, protein, and fat. Both the kernel and the pulp contain substantial quantities of calcium, potassium, and magnesium. Amino acid analyses revealed high glutamic and aspartic acid contents and the sulfur-containing amino acids as being the most limited amino acid. The fatty acid profile showed that oleic and linoleic were the major unsaturated fatty acids, whereas palmitic was the major saturated acid. Of the several solvents tested to solubilize the seed protein, 0.1 M NaOH was found to be the most effective. The protein was more soluble at alkaline than acidic pH, with the lowest solubility at pH 4.0. 相似文献
9.
Marcone MR Kakuda Y Jahaniaval F Yada RY Montevirgen LS 《Plant foods for human nutrition (Dordrecht, Netherlands)》2002,57(2):107-120
The storage proteins of the pili nut (Canarium ovatum, Engl.), quantitatively extracted using the modified Osborne protein fractionationscheme, revealed that the salt-soluble globulin was the main storage proteinwithin the kernel (i.e., >>60.3%). Further physicochemicalcharacterization of this aqueous soluble globulin revealed that it existed in an11S like form and was composed of two main subunits of 22,600 and31,600 Da. These subunits were found to be disulfide-linked (in a 1:1ratio) forming intermediary subunits (i.e., dimers) with a molecular weightof approximately 52,600 Da. The overall molecular weight of the 11Sglobulin was determined to be approximately 300,000 Da suggesting thatthe globulin possessed a dodecameric-like structure of 6 dimers for a totalof 12 subunits. Using differential scanning microcalorimetry, thedenaturation temperature of the globulin was shown to occur at89.3 °C. Overall, the pili nut 11S globulin was found to possessmany similar physicochemical properties to those of other 11S oilseedglobulins. 相似文献
10.
Nantaprapa Nantiyakul Samuel Furse Ian D. Fisk Gregory Tucker David A. Gray 《Journal of Cereal Science》2013
In this paper, we demonstrate a novel and environmentally-conscious approach to the isolation of oil bodies (OBs) from the bran arising from the milling of Oryza sativa (Basmati rice). We have used several physical techniques to determine the effect of the steps of the process on the OBs, and describe an isolation process that is scalable to an industrial level. The physical techniques [microscopy, particle size determination (diameter 1.9–5.8 μm), ζ-potential (−40 mV at pH 8.0, 0 mV at pH 4.0, 17 mV at pH 2.0), and relative turbidity measurements (pH 3.0–5.0 unstable, pH 6.0–8.0 stable)] and chemical analyses (lipid 83.7%, protein 11.5% dry basis) also give us an insight into the physical properties of OBs in general. This understanding has implications for the use of OBs in food manufacturing, and on the isolation of OBs from a variety of cereal crops. 相似文献
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Compositional,functional and storage properties of flours from raw and heat processed African breadfruit (Treculia africana Decne) seeds 总被引:1,自引:0,他引:1
Giami SY Adindu MN Akusu MO Emelike JN 《Plant foods for human nutrition (Dordrecht, Netherlands)》2000,55(4):357-368
African breadfruit (Treculia africana Decne) seeds were either boiled or roasted and then milled into flour. Chemical composition, functional properties and storage characteristics of raw and treated flours and the effect of partial proteolysis on selected functional properties of the raw flour were determined. Raw flour contained 20.1% crude protein, 2.5% total ash and 13.7% fat. Heat processing significantly (p<0.05) improved in vitro protein digestibility, and water and fat absorption capacities but decreased bulk density, nitrogen solubility, emulsion and foaming properties, trypsin inhibitor, and phytic acid and polyphenol contents of the samples. Boiling proved more effective than roasting for improving protein digestibility, emulsion capacity and foam stability and reducing antinutritional factor levels. Partial proteolysis increased nitrogen solubility, bulk density and water and fat absorption capacities but decreased foam capacity at hydrolysis levels greater than 35%. Fatty acid and peroxide values of the samples increased during storage. Compared to raw samples, heat processed samples had significantly (p<0.05) lower and more acceptable peroxide values and free fatty acid contents and higher and more stable water (3.0 g/g sample) and fat (2.4 g/g sample) absorption capacities. 相似文献
14.
本研究以前期制备的澳洲坚果蛋白为原料,经复合酶(木瓜蛋白酶和中性蛋白酶)酶解制备澳洲坚果蛋白肽,采用水解度为指标,利用单因素试验与正交试验考察各酶解因素对澳洲坚果蛋白水解度的影响,同时通过不同分子量(3、10、30 kDa)的超滤离心管对制备的蛋白肽进行初步的分离,并基于DPPH自由基清除能力对不同分子量的澳洲坚果蛋白肽的抗氧化活性进行评价。结果表明:各酶解因素对复合酶酶解制备澳洲坚果蛋白水解度的影响依次为酶解初始pH>复合酶配比>酶添加量>酶解时间;最佳复合酶酶解条件为复合酶配比1∶5、酶添加量12 000 U/g、酶解液初始pH 9.0、酶解时间360 min,在此条件下澳洲坚果蛋白的水解度为21.88%;同时,通过分析不同分子量的澳洲坚果蛋白肽组分发现,不同分子量的澳洲坚果蛋白肽均具有抗氧化活性,分子量在3~10 kDa的肽段组分具有较强的抗氧化能力,其DPPH自由基清除能力达到80.97%,且随着蛋白肽组分浓度的增加,其抗氧化能力也逐渐增强。 相似文献
15.
Fagbemi TN 《Plant foods for human nutrition (Dordrecht, Netherlands)》1999,54(3):261-269
Flours were prepared from raw and blanched samples of and ripe mature plantain Musa aab and examined for theirproximate composition, physical characteristics and functionalproperties. The plantain flours contained 3.5 g crude protein,2.5–3.5 g crude fat, 5.7–7.1 g moisture, 1.33–2.0 g crudefiber, 1.66–2.0 g ash, and 82.25–86.07 g carbohydrate per 100 gsample. The flours had bulk densities between 0.42–0.72 g/ml,emulsion capacities of 4.7–14.7%, water absorption capacitiesof 250–338%, oil absorption capacities of 214–371%,foaming capacities of 1.90–5.79%, least gelation concentrationsof 6–8%, and viscosities of 23.7–46.7 CP at 2% slurry concentration. Foaming capacity increased with increasing flourconcentration. Blanching considerably reduced the emulsion capacity and viscosity, while bulk density, water and oilabsorption capacities were increased by blanching. Ripening wasfound to have a negative effect on all the functional propertiesexamined except the bulk density, and gelation property. Unripe plantain could be used as an emulsifier and thickener in a foodsystem. 相似文献
16.
Composition and functional properties of protein isolates obtained from commercial legumes grown in northern Spain 总被引:1,自引:0,他引:1
Fernández-Quintela A. Macarulla M. T. del Barrio A. S. Martínez J. A. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1997,51(4):331-341
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
17.
Jacques Gueguen Jacques Lefebvre 《Plant foods for human nutrition (Dordrecht, Netherlands)》1983,33(2-3):201-208
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
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Nugdallah Gaafar A. El Tinay Abdullahi H. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1997,51(3):277-282
Nine cowpea cultivars obtained from Wad Medani Research Station were used in this study. The variation in protein fraction was: albumins 4.0–12.0, globulins 65.6–79.7, prolamins 1.4–2.2, G1-glutelins 0.9–3.0, G2-glutelins 1.4–2.9. G3-glutenins 9.1–14.0 and insoluble protein 0.5–3.0%. Two cowpea cultivars, H8-14 and CB-46, selected for their high albumin content, were cooked in 150 ml of boiling distilled water under reflux for 45 minutes. The protein fractions in the cooked seeds were determined. Results indicated that albumin and globulin fractions decreased significantly (p0.05) for both cultivars after cooking. This decrease was accompanied by a significant increase in G3-glutelin fractions. 相似文献
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Ndjouenkeu R. Akingbala J. O. Oguntimein G. B. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1997,51(3):245-255
This study investigated the emulsifying properties of okra (Hibiscus esculentus), dika nut (Irvingia gabonensis) and khan (Belschmiedia sp.), three African food hydrocolloids used to thicken and flavor soups. Results showed that khan has an emulsion potential approximately 20 and 100 times higher than the second and the first, respectively. A kinetic study indicated that the mechanism involved formation of thick and strong interfacial gum films around the oil globules, in addition to a high Water Absorption Capacity and weak gelling behavior of khan gum in solution. These results indicated that, when used in soups, which are typical oil/water emulsions, khan contribute both to thickening and stabilizing of the emulsion, whereas okra and dika nut functioned more as thickeners than as emulsion stabilizers. 相似文献