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1.
The effects of the commonly used processing techniques of soaking (at different pH values) and cooking on the digestive and nutritive utilization of calcium, phosphorus, and magnesium from common beans (Phaseolus vulgaris L.) were studied. Before the cooking step, the beans were soaked in solutions of acid (2.6 and 5.3) or basic (8.4) pH. Chemical and biological methods were used to determine nutritional parameters in growing rats, and the fiber content of the beans was established. As the pH of the soaking solution increased, so did mineral absorption and the apparent digestibility coefficient, which reached suitable values for growing rats, due to the reduced losses of soluble minerals and the increased food intake. Metabolic utilization also improved with increased pH of the soaking solution, although the values were, in general, low as a result of urinary losses under the experimental conditions. For the experimental period of 10 days, the femur and the muscle seem to be good metabolic indicators for calcium, but not for phosphorus or magnesium. The increased amount of cellulose in the soaked seed did not have a negative effect on the digestive utilization of minerals.  相似文献   

2.
The effect of mild hydrothermal treatment and the addition of phytase under optimal conditions (pH 5.5, 37 degrees C) on the nutritive utilization of the protein of pea (Pisum sativum L.) flour was studied in growing rats by examining the chemical and biological balance. Mild hydrothermal treatment produced reductions of 83, 78, and 72%, respectively, in the levels of alpha-galactosides, phytic acid, and trypsin inhibitors and also produced a significant increase in the digestive utilization of protein. The additional fall in the levels of phytic acid caused by the addition of phytase did not lead to a subsequent improvement in the digestive utilization of protein. The mild hydrothermal treatment of pea flour produced a significant increase in the metabolic utilization of protein and carbohydrates, which was reflected in the protein efficiency ratio and food transformation growth indices. These effects were not observed in the phytase-supplemented pea diet.  相似文献   

3.
There has been considerable debate regarding the nutritional benefits of pollen and the propolis produced by bees, although most contributions have lacked scientific soundness. This paper describes the possible beneficial effect of their use in pharmacological products in cases of anemic syndrome. We studied the effect of these two natural products on the digestive utilization of iron, calcium, phosphorus, and magnesium, using control rats and rats with nutritional ferropenic anemia. The addition of these products to the diet produced a positive effect on weight gain; this fact could constitute a scientific basis for the application of pollen and propolis as fortifiers. They improve the digestive utilization of iron and the regeneration efficiency of hemoglobin, especially during recovery from an anemic syndrome. They also have a positive effect on phosphocalcic metabolism and maintain an appropiate level of magnesium metabolism. Furthermore, in iron-deficient rats, these natural products palliate, to a large extent, the adverse effects of iron deficiency on calcium and magnesium metabolism as a result of the improvement in the digestive utilization of these minerals.  相似文献   

4.
Tortillas are made by cooking maize in a lime solution during variable times and temperatures, steeping the grain for up to 12 h, washing and grinding it to a fine dough, and cooking portions as flat cakes for up to 6 min. The effects of the main processing steps on the chemical composition, nutritive value, and functional and physicochemical characteristics have been areas of research. The present work evaluates the effect of lime concentration (0, 1.2, 2.4, and 3.6%) and cooking times (45, 60, and 75 min) on phytic acid retention of whole maize, its endosperm, and germ, as well as on the content of calcium, iron, and zinc on the same samples. The effects of steeping time and temperature and steeping medium on the phytic acid of lime-cooked maize were also studied. Finally, phytic acid changes from raw maize to tortilla were also measured. The results indicated that lime concentration and cooking time reduce phytic acid content in whole grain (17.4%), in endosperm (45.8%), and in germ (17.0%). Statistical analyses suggested higher phytic acid loss with 1.2% lime and 75 min of cooking. Cooking with the lime solution is more effective in reducing phytic acid than cooking with water. Steeping maize in lime solution at 50 degrees C during 8 h reduced phytic acid an additional 8%. The total loss of phytic acid from maize to tortilla was 22%. Calcium content increased in whole maize, endosperm, and germ with lime concentration and cooking and steeping times. The increase was higher in the germ than in the endosperm. The level, however, can be controlled if steeping of the cooked grain is conducted in water. Iron and zinc contents were not affected by nixtamalization processing variables but were affected in steeping.  相似文献   

5.
A novel approach for determination of phytic acid in cereals has been applied in 2 traditional methods. In the first, phytic acid in a sample extract is first separated and concentrated by ion-exchange chromatography. The phytic acid concentrate is then quantitatively determined as phosphorus by inductively coupled plasma atomic emission spectrometry (ICP-AES). In the second method, extracted phytic acid is first precipitated by FeCl3 solution. The complexed iron is converted to ferric hydroxide by adding NaOH, thus releasing phytic acid as soluble sodium phytate. Phytate is then quantitatively determined as phosphorus by ICP-AES. In these methods, both the difficult acid digestion and the spectrometric determination of phosphorus found in traditional methods are eliminated by using ICP-AES. This results in a method that is simpler, faster, and more accurate than earlier procedures.  相似文献   

6.
The objective of this study was to document the effects of phytic acid, tannic acid, and zinc on iron uptake in an in vitro digestion/Caco-2 cell culture model. The effects of phytic acid and tannic acid on iron uptake were measured at increasing molar ratios of FeCl3 to phytic acid or tannic acid. Maximal inhibition of iron uptake by phytic acid occurred at a 1:10 ratio of Fe to phytic acid. Dialyzable Fe decreased with a low Fe to phytic acid ratio but increased with Fe:phytic acid ratios greater than 1:3 indicating that more iron was soluble at higher phytic acid levels but less available. As in human studies, heme iron was less inhibited by phytic acid than nonheme iron. Tannic acid was a more potent inhibitor of nonheme iron uptake, as maximal inhibition (97.5%) of iron uptake occurred at a ratio of 1:1 or less. The addition of ZnCl2 to the digest at ratios of 1:0.5 and 1:1 decreased iron uptake by 57 and 80%, respectively. Overall, the results agree qualitatively with studies in humans and demonstrate the relative effects of these compounds on iron uptake in this model system. This study provides key information for determining iron availability under more complex meal conditions.  相似文献   

7.
研究了植酸对霍山石斛类原球茎悬浮培养细胞生长、多糖合成和培养基中主要营养成分消耗的影响,并分析了细胞中可溶性还原糖、可溶性蛋白质、丙二醛含量以及过氧化物酶和多酚氧化酶的活性。结果表明,植酸能抑制过氧化物酶和多酚氧化酶的活性,提高细胞活力,从而促进细胞生长和多糖合成,以2.5g/L浓度的植酸效果最好,培养36d时,类原球茎干重为29.4g/L,多糖产量为2.06g/L。动力学分析表明,添加2.5g/L的植酸还有利于碳、氮、磷等营养物质的吸收。  相似文献   

8.
A high-performance anion exchange chromatographic method was adapted for the quantitative determination of phytic acid and inositol pentakisphosphate isomers (excluding enantiomers) in foods. Because of the cost and limited availability of inositol phosphate standards, a phytic acid sodium salt standard was used for the calculation of an average relative response factor for the quantification of inositol pentakisphosphate isomers, and the purity of phytic acid sodium salt standard was also accurately established. The detection limits (S/N = 3) for phytic acid and inositol pentakisphosphates were in the range of 1.5-3.4 microM (0.1-0.2 microg/100 microL). This method has been successfully applied to the determination of phytic acid and inositol pentakisphosphates in a variety of beans and nuts after extraction with 0.5 M HCl and cleanup with solid phase extraction cartridges. The results demonstrated that there was a strong correlation between either the phytic acid content or the total content of phytic acid together with inositol pentakisphosphates and the total dietary fiber content in the group of all raw dry beans and in the group of raw dry black beans but not in the group of raw dry red kidney beans, which was probably due to the insufficient number of the raw dry red kidney bean samples.  相似文献   

9.
水稻低植酸突变基因和外源铁蛋白基因的聚合   总被引:3,自引:2,他引:1  
对所获得的2份低植酸突变系和2份铁蛋白(Fer)转基因富铁系稻米进行了无机磷、种子GUS、叶片PCR、稻米矿质元素含量检测和简单的遗传分析,表明这些材料作为低植酸突变种质和Fer富铁种质具有良好的实用价值。对所配杂种F1进行了花药培养,并对愈伤组织诱导、分化、生根和花培苗倍数性、成活率、结实性等性状进行考察,认为低植酸基因和铁蛋白外源基因对花培过程影响不明显。在大量的花培后代中筛选到31份低植酸基因和外源铁蛋白基因双重表达的花培纯系,经检测,该批材料富铁效果极为显著,是难得的低植酸富铁转基因优良新种质。  相似文献   

10.
Previous studies describe the suitability of a new type of phosphorus (P) fertilizer, called “rhizosphere‐controlled fertilizer” (RCF), to supply available P to plants while reducing soil phosphorus fixation. In order to explore the involvement of organic acid root exudation in P uptake from RCF, we investigated the relationship between shoot and root P concentrations, and the concentration of the main polycarboxylic organic acids in roots, shoots, and plant exudates. Plant species with different P‐acquisition efficiency (low: maize; medium: chickpea; high: lupin) were grown in hydroponics with three different P fertilizers: The water‐insoluble P fraction of RCF (RCF); Phospal, a slow‐release source of phosphate composed of calcium and aluminum phosphates (PH); monopotassiumphosphate (KP), and a control treatment without P (P–). RCF was as efficient as KP in supplying P to plants in the case of chickpea and lupin, and slightly less efficient than KP in maize. However, P from PH was not available for maize and less available compared to KP and RCF in chickpea and lupin. This variation reflects the different efficiencies in P acquisition for the three plant species. Except in the case of maize, plants receiving KP presented the lowest concentration of organic acids in roots and exudates, while those plants suffering severe P deficiency (P– and PH) showed the highest organic acid concentration. However, RCF had a high concentration of organic acids in roots and exudates, as well as a high P concentration in the shoot indicating that P uptake from RCF is enhanced due to root release and action of specific organic acids.  相似文献   

11.
A method is described for the extraction and analysis of various nitrogen‐, phosphorus‐ and carbon‐containing fractions from plant material. Lipids were extracted with chloroform/methanol and chloroform/methanol/water. Soluble nitrogen (nitrate, ammonia, and amino acid), phosphorus (inorganic and sugar phosphate) and carbon (sugar and tannin) fractions were extracted with cold trichloracetic acid. Hot soluble nitrogen and phosphorus (nucleic acid) and carbon (starch and tannin) fractions were extracted with hot trichloracetic acid. Protein remained in the residue. A detailed automated scheme is described for the analysis of each of the above fractions. Also included are methods for analyzing triglyceride, hydrolyzable ester phosphate and phytic acid.  相似文献   

12.
Common bean effects on health have been related to its dietary fiber content and other active compounds. This study assessed the content of flavonoids, coumestrol, phenolic acids, galactooligosaccharides, and phytic acid in wild and cultivated Mexican common bean seeds (raw and cooked) and that of flavonoids, coumestrol, and phenolic acids in germinated bean seeds. The presence of isoflavones in raw bean seeds was not confirmed by the UV spectra. Quercetin, kaempferol, p-coumaric acid, ferulic acid, p-hydroxybenzoic acid, and vanillic acid mean contents were 10.9, 52.3, 10.1, 9.6, 5.4, and 18.2 microg/g, respectively; raffinose, stachyose, verbascose, and phytic acid mean contents were 8.5, 56.3, 5.5, and 11.5 mg/g, respectively, in raw seeds. All compounds were affected by autoclaving, and germination resulted in a de novo synthesis of flavonols, phytoestrogens, and phenolic acids. The impact on health of common bean seed is affected by dietary burden, specific compounds content, and processing. On the other hand, germinated bean seed or beans sprouts may be sources of antioxidants and phytoestrogens.  相似文献   

13.
The nutritional value of breadmaking cereal spelt (Triticum aestivum ssp. spelta) is said to be higher than that of common wheat (Triticum aestivum ssp. vulgare), but this traditional view is not substantiated by scientific evidence. In an attempt to clarify this issue, wholemeal and milling fractions (sieved flour, fine bran, and coarse bran) from nine dehulled spelt and five soft winter wheat samples were compared with regard to their lipid, fatty acid, and mineral contents. In addition, tocopherol (a biochemical marker of germ) was measured in all wholemeals, whereas phytic acid and phosphorus levels were determined in fine bran and coarse bran samples after 1 month of storage. Results showed that, on average, spelt wholemeals and milling fractions were higher in lipids and unsaturated fatty acids as compared to wheat, whereas tocopherol content was lower in spelt, suggesting that the higher lipid content of spelt may not be related to a higher germ proportion. Although milling fractionation produced similar proportions of flour and brans in spelt and wheat, it was found that ash, copper, iron, zinc, magnesium, and phosphorus contents were higher in spelt samples, especially in aleurone-rich fine bran and in coarse bran. Even though phosphorus content was higher in spelt than in wheat brans, phytic acid content showed the opposite trend and was 40% lower in spelt versus wheat fine bran, which may suggest that spelt has either a higher endogenous phytase activity or a lower phytic acid content than wheat. The results of this study give important indications on the real nutritional value of spelt compared to wheat. Moreover, they show that the Ca/Fe ratio, combined with that of oleate/palmitate, provides a highly discriminating tool to authenticate spelt from wheat flours and to face the growing issue of spelt flour adulteration. Finally, they suggest that aleurone differences, the nature of which still needs to be investigated, may account for the differential nutrient composition of spelt and wheat.  相似文献   

14.
菜籽粕植酸提取和分离蛋白的制备   总被引:2,自引:1,他引:1  
植酸和蛋白是菜籽粕中2种极具经济价值的成份。为提高菜籽粕的综合利用效果,该文以双低冷榨菜籽粕为原料,采用醋酸溶液提取植酸,在膜分离精制植酸粗提液过程中同时回收蛋白;再对植酸提取后的残余物进行蛋白分离,超滤纯化后获得高纯度的蛋白成品。响应面优化的植酸最适提取条件为:醋酸质量分数0.7%,提取温度48℃,液料比10 mL/g,提取时间1.6 h,该条件下植酸得率为1.865%。植酸粗提液中回收出的蛋白和损失植酸分别占菜籽粕的3.63%和0.395%。超滤精制的分离蛋白可达到70%~90%不同纯度的要求,蛋白中多酚含量显著减少,且植酸与硫苷未检出。  相似文献   

15.
Phytic acid would form soluble and insoluble complexes with proteins. Our objective was to determine if phytic acid forms insoluble complexes with major peanut allergens, and if such reaction results in a peanut extract with a lower level of soluble allergens and allergenic property. Extracts from raw and roasted peanuts were treated with and without phytic acid at various pH values and then analyzed by SDS-PAGE and a competitive inhibition ELISA (ciELISA). The ciELISA measured IgE binding using a pooled serum from peanut-allergic individuals. Results showed that phytic acid formed complexes with the major peanut allergens (Ara h 1 and Ara h 2), which were insoluble in acidic and neutral conditions. Succinylation of the allergens inhibited complex formation, indicating that lysine residues were involved. A 6-fold reduction in IgE binding or allergenic potency of the extract was observed after treatment with phytic acid. It was concluded that phytic acid formed insoluble complexes with the major peanut allergens, and resulted in a peanut extract with reduced allergenic potency. Application of phytic acid to a peanut butter slurry presented a similar result, indicating that phytic acid may find use in the development of hypoallergenic peanut-based products.  相似文献   

16.
The effects of soaking, cooking, and industrial dehydration treatments on soluble carbohydrates, including raffinose family oligosaccharides (RFOs), and also on total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble (SDF) dietary fiber fractions were studied in legumes (lentil and chickpea). Ciceritol and stachyose were the main alpha-galactosides for chickpea and lentil, respectively. The processing involved a drastic reduction of soluble carbohydrates of these legumes, 85% in the case of lentil and 57% in the case of chickpea. The processed legume flours presented low residual levels of alpha-galactosides, which are advisable for people with digestive problems. Processing of legumes involved changes in dietary fiber fractions. A general increase of IDF (27-36%) due to the increase of glucose and Klason lignin was observed. However, a different behavior of SDF was exhibited during thermal dehydration, this fraction increasing in the case of chickpea (32%) and decreasing in the case of lentil (27%). This is probably caused by the different structures and compositions of the cell wall networks of the legumes.  相似文献   

17.
Phytic acid, myo‐inositol 1,2,3,4,5,6 hexakisphosphate. the major storage form of phosphorus (P) in seeds, comprises 60 to 90% of total seed P. Phytic acid has also been observed in other vegetative and reproductive tissue including roots although no studies to date have unequivocally demonstrated that phytic acid is indeed present in roots. Three methods (ferric precipitation, ion‐exchange chromatography, and high voltage paper electrophoresis) were used to demonstrate that phytic acid is a P‐containing compound within the root and crown tissue of alfalfa (Medicago sativa L.). Phytic acid P was found to represent from 10 to 15% of total root and crown P.  相似文献   

18.
Five strains of lactic bacteria have been isolated from sour doughs and examined for their ability to degrade phytic acid. In white flour medium in which phytic acid was the only source of phosphorus, the disappearance of phytate and an elevation of inorganic phosphate were observed after only 2 h of incubation in all strains tested (-30 and +60%, respectively). Both phenomena correspond to phytate breakdown. No difference was observed in the levels of phytic acid hydrolysis among strains, suggesting that phytase enzymes are similar among these bacteria. Using whole wheat flour medium naturally rich in phytic acid in the presence of Leuconostoc mesenteroides strain 38, a 9 h fermentation established that the degradation of PA and the production of lactic acid lead to greater Ca and Mg solubility than in control medium.  相似文献   

19.
The Phosphorus Dynamics of Soft Raw Phosphate and Soil Investigation Problems In long term trials with a brown earth, pH 6.2 and a pseudogley, pH 4.9 and 6.0 when limed, yield and phosphorus uptake were compared with available phosphorus, as estimated by different methods, including Chang and Jackson's phosphorus fractionation. The evaluation of soil investigations depends very much on the dynamics of the site, especially when soft raw phospates are being examined. The rate of availability to plants of apatite rock phosphates depends on pH, the biological activity of the soil and on its transformation power. Soft raw phosphates lead to increased levels of calcium phosphates in soils of higher pH. Available phosphorus is often over estimated in soils where P transformation is in fact low due to the ready extractability of calcium phosphates inherent in some methods. This especially applies to the lactate (Egner-Riehm) and the lactate-acetate (Egner-Riehm-Domingo) methods. Soil testing methods must be verified against plant trials. Soil type and nutrient dynamics must be considered to give accurate evaluation; Chang and Jackson's phosphorus fractionation is helpful.  相似文献   

20.
Phytic acid consists of 65-80% of the total phosphorus (P) in cereal grains. Its salts are concentrated in the germ and aleurone layers, which are typically removed during milling. We hypothesize that concentrations of different types of P and minerals in milled products will be greatly altered in low phytic acid (lpa) barleys. Seeds of cv. Harrington (control) and four lpa isolines-lpa1-1, lpa2-1, lpa3-1, and M955-were abraded by a laboratory method into five surface layer and four remaining kernel fractions. Results show that phytic acid in the four lpa lines ranged from 75% to 5% of the control. The decrease in phytic acid P concentration was matched almost equally by an increase in inorganic P, so that the rest of P (the sum of all P-containing compounds other than phytic acid P and inorganic P) and total P levels remained relatively unchanged among the five genotypes. These trends were also observed for the processed fractions. The major mineral elements in barley seeds were P, K, Mg, S, and Ca, while minor ones were Fe, Zn, Mn, Cu, and Ba. All types of P and other minerals measured were generally concentrated in the outer layers of the grain. Although there were substantial differences in mineral contents of bran fractions among genotypes, the level of phytic acid P had little effect on mineral contents in whole or abraded kernels. One major exception was Fe, which had the highest level in all tissues of M955 genotype. The above findings were all confirmed by analyzing another set of barley samples grown in a different environment. Thus, in general, breeding lpa barleys does not lead to reduced mineral contents in whole grains or elevated mineral levels in milled products.  相似文献   

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