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1.
The albumins and globulins extracted from Lupinus luteus var. Aurea/Weico and Lupinus albus var. Multolupa defatted flour samples were analyzed by polyacrilamide gel electrophoresis. The purpose was to determine the percentage distribution of pattern in the electrophoretograms and the relative mobility values of protein. The L. luteus albumins densitogram showed six fractions, two of them, No. 2 and No. 4, represented 58.1% of the total. On the other hand, the globulins densitogram revealed five fractions, numbers 1, 2 and 3 representing 90.7%. The densitogram of peak I from Sephadex G-100 globulins filtration indicated two fractions similar to those number 1 and 2 of the total globulins, showing low relative mobility values (from 0.26 to 0.39). The L. albus albumins resolved in four fractions, with No. 2 being the most prevalent (54.3%). In regard to the L. albus globulins, these showed five fractions identical in distribution with those of peak I, fraction 2 appearing as the most important (48.2%). It was found that Sephadex G-100 did not perform a good separation. As to the relative mobility values of globulins, fractions 2 and 3 were the most prominent (relative mobility of 0.35 and 0.48, respectively). It may be concluded that L. luteus albumins presented more components but with lower relative mobility values than those of L. albus. As for the globulins from both lupine flour samples, the gel separated fractions were classified in two groups of components, those of high and of low relative mobility.  相似文献   

2.
Samples of Lupinus luteus, var. Aurea/Weico and Lupinus albus var. Multolupa flours were analyzed. The flour proteins were extracted and fractionated by gel filtration, and the per cent pattern for both globulins and albumins was then determined. The dehulled seeds, previously analyzed for composition, were ground, defatted and consecutively extracted with distilled water (pH 5.0) and phosphate buffer (0.05 M, pH 8.5). The extracted protein content was measured by the Lowry simplified method. Globulins (pH 8.5 fraction) from both species were filtered through Sephadex G-100; besides, Lupinus albus globulins were filtered through Sephadex G-150, and absorbance of the collected fractions was measured at 280 nm. The dehulled seed (DS) of L. luteus and L. albus revealed a good protein content (58.2 and 41.0%, respectively). The protein extracted from L. luteus was constituted by 17% albumins and 58.4% globulins. In contrast, L. albus presented a higher albumin content (55.6%) than globulins (31.5%). The elution pattern for the Sephadex G-200 gel filtration showed for both lupine species analyzed a preponderant peak I corresponding in L. luteus to 55.0% and in L. albus to 84.1% of the total globulins content. From these results, it may be concluded that the dehulled seed protein content is 42.0% higher for the L. luteus sample than for the L. albus. The applied methodology indicated a predominant content of globulins above albumins in L. luteus, while in the case of L. albus, the albumin content was the highest.  相似文献   

3.
The effects of opaque-2 corn and the complementation with lupin flour on the sensory quality and nutritive value of "humitas" were evaluated. Moreover, the nutritional and quality changes which occur during the retorting of the product canned in two can sizes, were studied. Hybrid and opaque-2 corn were replaced with 6%, 8%, 10% and 12% lupin flour, being 8% the complementation level with the best sensory and nutritional quality. Heat penetration studies of the product canned in N2 and N6 tin cans, were carried out. Total process time at 121 degrees C was 73 min and 147 min, respectively. "Humitas" prepared with hybrid and opaque-2 corn, with and without 8% lupin flour, prior and after sterilization, were subjected to proximate analysis, pH, titratible acidity and available lysine determinations. Biological evaluation of the protein by the net protein ratio (NPR) and digestibility, as well as organoleptic quality and acceptability analyses were also determined. It was concluded that the complementation with 8% lupin flour improves significantly the nutritional value of hybrid corn "humitas", but not that of opaque-2 corn. The canning process affected lysine availability and was directly related to the amino acid concentration, and to the retorting duration. On the other hand, the thermal processing adversely affected the biological quality of protein and some sensory attributes. The 8% lupin complementation was also detrimental for the organoleptic quality of the product.  相似文献   

4.
Two protein mixtures, A and B, based on sweet lupine, wheat flour and dried skim milk powder were formulated, bearing in mind the chemical and nutritional standards set by the National System of Health Services for protein mixtures used through the National Program of Complementary Feeding (PNAC) for preschool children. Both formulas contained 12% of sweet lupine flour, but they differed in their skim milk content, which was 15% in mixture A, and 10% in mixture B. Taking as reference value a content of 2% moisture, formula A contains 17.6% protein and mixture B, 16.4%, with a caloric content of 420 kcal/100 g for both of them. The amino acid score was 0.80 for both mixtures. The biological quality of the proteins of A and B, measured as protein efficiency ratio (PER), was 2.2 and 2.1, respectively. These values are not statistically different, although they are lower than the value of 2.5 obtained for casein (p less than 0.01).  相似文献   

5.
The purpose of this study was to determine the effect of incorporating sweet lupine flour (SLF) to bread, upon the organoleptic characteristics and acceptability of the product. The substitution levels were 3, 6, 9 and 12%. The sensory evaluation test was done by 25 trained judges using the hedonic scaling method (9 to 1 scoring). Internal and external characteristics of appearance, color, aroma, texture, bitterness and flavor, as well as general acceptability, were measured. Sensory evaluation results of the external characteristics were significant at the 9 and 12% SLF levels for color (p less than 0.05) while the other parameters did not show significant differences. In regard to the internal characteristics, a significant difference for color was found at the 3% level of SLF (p less than 0.05); and at 6, 9 and 12% SLF levels, for appearance (p less than 0.05). The general acceptability was good at all the levels tested, with no significant differences among them. An acceptability study at the consumer level for 9% lupine flour bread was carried out in a group of 90 girls, aged 10-12 years, during a 10-day period. The results showed a very good acceptability of the product (p less than 0.01). The results of this study indicate that the incorporation of 6% SLF to the bread, did not affect adversely its sensory properties. Moreover, the acceptability of bread containing up to 12% SLF was excellent.  相似文献   

6.
Quinolizidine alkaloid contents of leaves and seeds ofLupinus argenteus (Fabaceae) collected from seven different localities near Gothic, Colorado were determined by capillary GLC. Differences in alkaloid levels between sites are substantial and alkaloid quantity decreases as elevation increases. Leaves at the lowest elevation, for example, contain six times the alkaloid levels of leaves at the highest elevation. Seeds from plants of low-and high-elevation sites were grown under identical conditions in the green-house. Alkaloid levels of leaves of seedlings were significantly higher in those seedlings derived from populations of low elevations than those of high elevations, indicating that the observed differences in the field are at least partly genetic and not environmental. To determine whether predation rates were responsible for these genetic differences, data on seed predation rates and observations on herbivory were collected.  相似文献   

7.
The feasibility of adding chick-pea flour substituting part of wheat flour in yeast-leavened bread-making in order to increase the protein value, was studied. A 70% extraction chick-pea flour of commercial granulometry (150 mu) was prepared. Wheat flours of 74% and 78% extraction were then blended with 5%, 10% and 15% of chick-pea flour. Every flour and blend were subsequently analyzed to determine protein, ash, fiber, fat and maltose content, as well as sedimentation, farinogram and bread-making. Addition of chick-pea flour increased protein, fiber, ash and fat content in the blends, not causing a severe effect on quality, even at the 15% level of substitution. Blends showed an increase in maltose content, W value and bread specific volume. Furthermore, breads prepared were of good quality even without the use of maturing agents.  相似文献   

8.
利用显微照相和DNA提取等技术,研究了外源紫杉醇作用于服浮培养南方红豆杉细胞(Taxus chinensis var.Mairei)的凋亡和对紫杉醇(taxol)的耐受性。利用荧光显微照相技术观察到,外源紫杉醇作用下,随培养时间延长,南方红豆杉细胞发生明显核分化,应用DNA电泳观察到细胞DNA断裂形成典型的180bp及其整数倍梯形条带(DNA.ladders) ,应用TUNEL检测发现DNA的3'-OH断端可被特异性标记,证实了加入紫杉醇后南方红豆杉细胞发生了凋亡。研究结果说明南方红豆杉细胞对紫杉醇的耐受性是有限度。并证明了植物细胞有类似于动物细胞的凋亡特征,也表明该体系可以作为研究植物细胞凋亡的实验模型。  相似文献   

9.
Experimental bread made of wheat flour complemented with 5, 10 and 15% chick-pea flour was studied, using wheat bread as control. Samples were analyzed for their proximal chemical composition and amino acids content. Crude fiber and protein increased from 0.36% to 0.55%, and from 14% to 17.6%, respectively, when 15% chick-pea flour was added. The lysine content increased as the level of supplementation was raised. Biological quality of proteins was measured in rats as protein efficiency ratio (PER) as well as apparent digestibility resulting in an increase of PER values from 0.90 to 1.34 and small variations in bread protein digestibility. Bread nutritive value was significantly improved by adding chick-pea flour.  相似文献   

10.
The effects of wood flour content (60–80%) and m-TMI-g-PP content (0–14%) on the properties of wood flour/polypropylene composites (WF/PP) were investigated by means of mechanical properties, thermal analysis, dynamic rheological analysis, and scanning electron microscopy (SEM). The results demonstrated that WF significantly increased the mechanical properties, char yield, heat deflection temperature (HDT), vicat softening temperature (VST), T c, G′, G″, and η ?. However, WF above 70% led to decreased mechanical properties, so for the comprehensive consideration of the cost and environmental issues, 70% WF is the best. With the addition of m-TMI-g-PP, the mechanical properties, thermal stability, HDT, VST, △H m, and T m of composites were all got improvement, which was attributed to the strong interfacial interaction of m-TMI-g-PP on composites. However, when it exceeded 10%, the mechanical properties of the composites declined, it probably formed a separate phase in the PP matrix. Therefore, the 10% m-TMI-g-PP was chosen in WF/PP. In addition, the results were all further confirmed by SEM analysis.  相似文献   

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Spring and fall adults of the white pine weevil,Pissodes strobi (Peck), were exposed in no-choice and two-choice tests to bark from water-stressed and non-water-stressed white pine (Pinus strobus L.), which had also been exposed or not exposed to weevil attack. This experiment demonstrated that the weevils could discriminate between bark from water-stressed white pine and preferred bark from the nonstressed plants. The weevils also preferred bark from nonstressed plants that were previously exposed to weevil damage. Spring and fall adults displayed the same feeding preferences. No sex differences were found in feeding preferences. Less nitrogen, phosphorus, and potassium were found in bark from the nonstressed plants, and the potassium level was higher in damaged plants. We expect that the biological performance of the weevil should be favored by vigorously growing plants rather than by stressed plants.  相似文献   

13.
This study pursued the isolation and partial characterization of the enzyme polyphenoloxidase from apple (Malus domestica Anna variety), grown in the Hermosillo Coast (State of Sonora, Mexico). The effects of pH and temperature as well as its specificity towards substrates, and its behavior under conditions of hydrophobic chromatography, were studied. The enzyme was isolated from a residual powder obtained from ripe apples homogenized with cold acetone. The extract thus prepared was used to characterize the enzyme, and it showed an optimum pH of 5.36 and an optimum temperature of 35 degrees C. The substrate specificity proved to decrease from 4-methyl catechol, chlorogenic acid, catechol, and caffeic acid, to 3,4-dihydroxiphenyl alanine (DOPA). The enzyme resulted to be more thermostable (temperature range: 35 degrees C to 60 degrees C) than the rest of oxidases of plant origin. When the extract was eluted under conditions of hydrophobic chromatography separation, it appeared as a single peak resulting in a 300 fold purification. The phenolase activity characteristics found in the present study were similar to those observed in other apples from temperate climates; however, this particular polyphenoloxidase is more thermostable under natural conditions. This explains why apples of the Anna variety, at the high harvesting temperature, show a very fast formation of brown spots even when there is a minor damage. The content of compounds with phenolic group was high (1.16 g/100 g fresh weight). Further increase of the velocity of fruit enzymatic browning was due to this reason.  相似文献   

14.
In laboratory assays, we investigated responses of female plum curculios (PCs),Conotrachelus nenuphar (Herbst), to host and nonhost fruit or leaf odor when PCs were crawling on experimental tree branchlets or twigs. In choice tests where test specimens were hung from the ends of a wooden crosspiece, PCs made significantly more visits to host plum fruit than to plum leaves, nonhost tomato fruit, wax models of plum fruit, or blanks (wire). In similar tests, PCs made significantly more visits to plum leaves compared to nonhost maple leaves or to blanks. PCs in test chambers that contained host or nonhost odor were significantly more prone to feed on wax plum models in the presence of odor from host fruit or host leaves compared to odor from nonhost fruit or leaves or a water blank. In choice tests offering alternating cluster types on an apple branchlet, PCs visited leaf clusters bearing a host apple fruit more than leaf clusters without a fruit. In tests to assay the distance at which PCs can detect an individual host fruit, PCs crawled from the central stem of an apple branchlet onto a side stem significantly more often when an apple fruit on a side stem was hung 2 cm from the central stem compared to 4 or 8 cm away. Our combined results suggest that PCs use host fruit odor to locate host fruit at close range.  相似文献   

15.
Recent decades have seen an increase in groundwater pollution thought to be a consequence of increasing intensity of land use, primarily through greater use of high N analysis materials as fertilizers. A two-season lysimeter experiment was carried out in a wetland in central Zimbabwe in order to determine the effect of cattle manure quality on (1) NO3–N concentration in leachate and nitrate leaching (2) dry matter accumulation and uptake of N by tomato and rape crops grown in wetland conditions. Two cattle manure quality types based on N content were used in the experiment. The manure collected from a kraal of the smallholder wetland community was classified as high quality manure (high N, 1.36 % N) while that collected from the adjacent commercial farming area was classified as low quality manure (low N, 0.51 % N). The two manure types were applied in rates of 0, 15, 30 Mg ha?1. The treatments were arranged in a randomized complete block design with four replicates. When 15 and 30 Mg high and low N manure ha?1 were applied, the concentration of NO3–N in leachate exceeded the recommended 10 mg L?1 concentration in portable water by 15–104 and 53–174 % respectively. The substitution of 15 and 30 Mg of high N manure with 15 and 30 Mg ha?1 of low N manure reduced total N lost through leaching by 10–43 and 22–69 % respectively. Ground water contamination by nitrate overload can be considerably reduced by application of low N manure to vegetable crops.  相似文献   

16.
The objective of this investigation was to study the functional properties of Pigeon pea (Cajanus cajan (L.) Millsp) flour and protein concentrate. The solubility of both samples were superior than 70% at pH above 6.7 and below 3.5. The water and oil absorption were 1.2 and 1.07 ml/g of sample and 0.87 and 1.73 ml/g of flour and protein concentrate samples, respectively. The minimum concentration of flour and protein concentrate needed for gelation was 20% and 12%, respectively. The emulsifying capacity of flour and concentrate was 129.35 g and 191.66 g oil/g of protein and the emulsion stability 87.50 and 97.97%, respectively, after 780 minutes. The foam capacity and stability of flour foam were 36.0% and 18.61, while of the concentrate were 44.70% and 78.97% after 90 minutes. These properties indicate that the flour as well as the concentrate could have application in various food systems.  相似文献   

17.
The proximate composition as well as vitamin and mineral contents of a sample of chiga (Campsiandra comosa Benth) flour was analyzed, having determined that it was essentially a carbohydrate source. The product was evaluated as source of energy, substituting 33, 67 and 100% of the corn starch of isoproteic and isocaloric feeds for growing Sprague-Dawley rats. In an experimental period of 15 days, results indicated that the substitution of one-third of the carbohydrate with chiga flour did not reduce the weight gain, food consumption, metabolizable energy or utilization of the food energy by the rats. Higher levels of the product in the diet originated a decrement in these variable values. The apparent nitrogen and energy digestibility of the diets was progressively reduced as the concentration range of chiga flour utilized was increased. The metabolizable energy value of chiga flour was 3.15 kcal/g, which indicated that approximately 78% of its gross energy (4.01 kcal/g) was metabolized.  相似文献   

18.
The prevalence of insulin resistance and risk factors for chronic diseases is not known in Colombia. The purpose of the study was of determine the association of insulin resistance and risk of chronic diseases in young, apparently healthy adults. By convenience, 97 subjects, mean age of 24 years were studied. Family and personal history, anthropometrics, lipid profile, and a short insulin tolerance test was done to each subject to identify prevalence of insulin resistance and its association with risk factors. Plasma lipids and anthropometrics were within acceptable range. Insulin sensitivity was categorized as high, border high, border low and low. Out of 97 subjects 47 had altered sensitivity. Most women (68%) were classified as border low, and most men (60%) as low. There was a difference between these two categories in waist circumference and weight. Border low and low cases had not less than 3 risk factors but the total number of factors was not different within the 4 groups. More than 50% of cases had family history of chronic diseases, sedentary life and low C-HDL. There was a negative association between insulin sensitivity and fasting Glycaemia and positive with fasting triglycerides, BMI, Waist hip ratio and weight. Results suggest a surprisingly high prevalence of risk factors in a young group associated with altered insulin sensitivity. It may be possible to identify early indicators of risk and develop appropriate strategies for prevention.  相似文献   

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