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Fish oil replacement in aquaculture feeds results in major modifications to the fatty acid makeup of cultured fish. Therefore, in vivo fatty acid biosynthesis has been a topic of considerable research interest. Evidence suggests that pyridoxine (vitamin B(6)) plays a role in fatty acid metabolism, and in particular, the biosynthesis of LC-PUFA has been demonstrated in mammals. However, there is little information on the effects of dietary pyridoxine availability in fish fed diets lacking LC-PUFA. This study demonstrates a relationship between dietary pyridoxine supplementation and fatty acid metabolism in rainbow trout. In particular, the dietary pyridoxine level was shown to modulate and positively stimulate the activity of the fatty acid elongase and Δ-6 and Δ-5 desaturase enzymes, deduced by the whole-body fatty acid balance method. This activity was insufficient to compensate for a diet lacking in LC-PUFA but does highlight potential strategies to maximize this activity in cultured fish, especially when fish oil is replaced with vegetable oils.  相似文献   

3.
The effects of dietary alpha-tocopheryl acetate (alpha-TA) doses (75, 150, and 225 mg/kg) and the duration of this supplementation (0, 10, 21, 32, and 43 days prior to slaughter) on fatty acid composition, alpha-tocopherol content, and oxidative status were studied either in raw or in cooked dark chicken meat with its skin. With regard to fatty acid composition, raw meat was affected by both dietary factors. Various polyunsaturated fatty acids decreased as a result of higher alpha-TA doses, whereas these fatty acids increased with longer supplementation periods. Cooked meat showed similar trends for the duration of alpha-TA supplementation. On the other hand, alpha-tocopherol content in raw and cooked meat increased as a result of the dose and duration of alpha-TA supplementation. Formation of lipid hydroperoxides and thiobarbituric acid values of these meats were also influenced by these two dietary factors, and the dietary combination of 150 mg/kg of alpha-TA during the last 32 days was optimal in terms of supplementation costs and meat oxidative stability.  相似文献   

4.
Berry fruit supplementation and the aging brain   总被引:1,自引:0,他引:1  
The onset of age-related neurodegenerative diseases such as Alzheimer's or Parkinson's disease, superimposed on a declining nervous system, could exacerbate the motor and cognitive behavioral deficits that normally occur in senescence. In cases of severe deficits in memory or motor function, hospitalization and/or custodial care would be a likely outcome. This means that unless some way is found to reduce these age-related decrements in neuronal function, health-care costs will continue to rise exponentially. Thus, it is extremely important to explore methods to retard or reverse age-related neuronal deficits, as well as their subsequent behavioral manifestations, to increase healthy aging. In this regard, consumption of diets rich in antioxidants and anti-inflammatory polyphenolics, such as those found in fruits and vegetables, may lower the risk of developing age-related neurodegenerative diseases. Research suggests that the polyphenolic compounds found in berry fruits, such as blueberries and strawberries, may exert their beneficial effects either through their ability to lower oxidative stress and inflammation or directly by altering the signaling involved in neuronal communication, calcium buffering ability, neuroprotective stress shock proteins, plasticity, and stress signaling pathways. These interventions, in turn, may exert protection against age-related deficits in cognitive and motor function. The purpose of this paper is to discuss the benefits of these interventions in rodent models and to describe the putative molecular mechanisms involved in their benefits.  相似文献   

5.
Bread flour was spiked with folic acid (1.40 mg/lb or 3.08 μg/g of flour) and processed into bread by the sponge and dough method. Changes that occurred to added folic acid and endogenous folate contents through different processing stages, including sponge formation, proofing, and baking, were assessed by reversed‐phase ion‐pair HPLC combined with UV and fluorometric detection. Sample extraction required α‐amylase and rat plasma deconjugase digestion, and sample preparation required purification by solid‐phase extraction. Added folic acid was measured by monitoring UV absorption at 280 nm. Four selected forms of endogenous folates including tetrahydrofolate (THF), 5‐formyl‐THF, 10‐formylfolate, and 5‐methyl‐THF were identified and quantified throughout the bread processing using a fluorescence excitation wavelength of 290 nm and emission wavelength of 350 or 450 nm. Data indicate a relatively good stability of added folic acid and native folates to the baking process, and increased endogenous folate contents in dough and bread as compared with the flour from which they were made.  相似文献   

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HPLC法测定谷子籽粒叶酸含量及种质资源评价   总被引:1,自引:0,他引:1  
侯思宇  宋敏  闫陆飞  孙朝霞  韩渊怀  李红英 《土壤》2018,50(6):1235-1240
谷子籽粒中富含叶酸,作为一种功能性食品深受北方人民的喜爱,而作物籽粒,如小米叶酸测定方法及含量分析存在较大差异,为小米品质鉴定及高叶酸谷子种质筛选造成了一定困难。本研究通过"三酶法"提取小米中的叶酸,建立了一种基于高效液相色谱技术(HPLC)高效化、规模化且稳定适用于测定谷子籽粒叶酸含量的方法,对2016年和2017年种植的45个谷子种质进行叶酸含量测定和分类评价。结果表明:叶酸标准品梯度曲线呈线性方程相关,相关系数为0.99;小米样品叶酸测定过程中精密度、稳定性和重复性的相对标准偏差(RSD)分别为0.81%、1.19%和1.65%,各项指标符合精密测定标准,准确度高,重复性好;45个谷子种质籽粒叶酸含量分布范围为0.26~2.56μg/g(2016年度)和0.53~2.86μg/g(2017年度),含量均值分别为1.19和1.84μg/g,标准差0.47和0.51μg/g,变异系数39.5%和27.7%;对上述种质进行正态分布曲线分析,发现叶酸含量整体呈现偏度分布;从中筛选出9个高叶酸(含量≥1.91μg/g)和3个低叶酸(含量≤1.15μg/g)的谷子种质。上述结论为小米叶酸含量提供了测定标准和评价体系,也为高叶酸谷子种质创新与利用奠定了基础。  相似文献   

8.
Degradation of added folic acid and native folates in micronutrient‐fortified corn masa and tortillas was evaluated using masa prepared from either nixtamalized corn flour or fresh nixtamal. Variations in masa pH, masa holding time at an elevated temperature, and iron source failed to show significant differences in folate loss in corn flour masa prepared in the laboratory. Masa was subsequently prepared from fresh nixtamal in a commercial mill in Mexico, and fortified with one of two different micronutrient premixes containing iron, zinc, B‐vitamins, and either unencapsulated or lipid‐encapsulated folic acid. Folate loss in commercial masa increased significantly with prebake masa holding time for both premixes. Unencapsulated folic acid showed a 73% loss after 4 hr of holding, compared to 60% loss for encapsulated. The difference was statistically significant, indicating a protective effect from the lipid coating. No significant differences in folate levels were found between prebake masa and baked tortillas. Holding baked tortillas for up to 12 hr also had no effect on folate levels. Native folate showed no significant losses throughout the process. Results from the commercial tortilla mill indicate that most of the loss in added folic acid occurs during prebake holding of masa, possibly from microbial degradation.  相似文献   

9.
In 2002, Brazil issued a regulation requiring that corn and wheat flours be fortified by the addition of folic acid and iron. The aim of the present work was to evaluate the levels of folic acid, iron, and zinc in macaroni, pizza, and bread prepared with fortified flour. The methodologies used for the mineral (FAAS) and vitamin (HPLC) determinations were validated and considered adequate. For macaroni, the folic acid content range was 50.0–182.4 μg/100 g. The iron and zinc levels were 1.6–5.4 mg/100 g and 0.7–1.0 mg/100 g, respectively. The pizza and bread samples contained 14.8–271.3 μg/100 g and 47.4–481.4 μg/100 g of folic acid, respectively. The iron and zinc levels were 2.6–7.3 mg/100 g and 0.4–0.9 mg/100 g, respectively, for pizza, and 3.0–12.4 mg/100 g and 0.4–0.8 mg/100 g for bread. The results indicated that the distribution of folic acid and iron in the majority of the samples tested was heterogeneous. This study could be of use to governmental authorities in their food fortification evaluation programs. Moreover, the average iron contents observed in the products could result in problems with zinc absorption, and it is important to consider that iron can induce oxidative stress in cells.  相似文献   

10.
Upon B removal from the nutrient solution, several response reactions of root cells can be measured within minutes. These include: reduction of cell wall elasticity modulus ε, increase of hydraulic conductivity, reduced activity of plasmalemma-bound inducible (NADH) reductase, (smaller) changes of the membrane potential, and liberation of Ca2+ (apoplastic and membrane-bound). The B most demanding (root) tissues are epidermal and outer cortical cells of the extension zone, xylem vessels, and root hair tips. Deprivation of B leads to morphological changes which can be noticed within hours to days, including browning of tissues, growth inhibition, death of apical meristems, and lack of root hairs. How the primary response reaction(s) lead to the expression of visible symptoms, however, is not yet clear. The present review summarizes rapid responses to B deprivation and shows several possibilities how primary might be linked to secondary reactions, including cytoskeleton-mediated responses.  相似文献   

11.
Many Mexican women are deficient in folic acid. Fortification of the corn tortilla could be an effective way to help increase the folic acid levels among the Mexican population. Previous studies have shown significant folic acid losses in the masa dough as it is held before baking. This loss in folic acid could be owing to utilization by lactic acid bacteria naturally present in the masa. The objective of this study was to determine the effect of bacteria native to corn masa on the folic acid content in masa. Bacteria in dough samples from six mills in Guadalajara, Mexico, were isolated and identified. Bacterial isolates were inoculated into sterile fortified corn masa flour, which was converted to masa and held at 56°C for 0, 3, and 6 h, replicating the conditions of freshly milled masa as held before baking. All samples, including the control, showed losses of folic acid between 66 and 79% w/w in the first 3 h of incubation. Because folic acid degradation in the sterile control sample was not different than the inoculated sample results, the decline in folic acid was not owing to bacteria (mainly Streptococcus spp.) present in the masa flour but appeared to be a chemical degradation related to time and temperature.  相似文献   

12.
Effects of selenium supplementation on four agricultural crops   总被引:3,自引:0,他引:3  
Agricultural crops can be used either to remediate selenium-contaminated soils or to increase the daily selenium intake of consumers after soil supplementation using inorganic or organic selenium sources. In this study, four agricultural crops were examined for potential selenium enhancement. Soils containing tomato, strawberry, radish, and lettuce plants were supplemented with either an inorganic or an organic form of selenium. Two different soils, i.e., low Se and high Se containing, were also used. Statistically significant differences in appearance, fruit production, and fresh weights of the fruit produced were studied. Next, the amount of selenium retained in the edible fruits, nonedible plant, and soil for each was analyzed by acid digestion followed by hydride generation atomic absorption analysis. Finally, inhibition effects on the seeds of the agricultural plants were studied. The results show that supplementation with an inorganic form of selenium led to higher retention in the plants, with a maximum of 97.5% retained in the edible portion of lettuce plants.  相似文献   

13.
Dietary supplementation of a high-gamma-linolenic acid canola oil (HGCO) containing approximately 36% (w/w) of gamma-linolenic acid (GLA, 18:3n-6) from the seeds of a genetically transformed canola strain, was assessed for its long-term biological effects. Growing Sprague-Dawley rats (n = 30) were fed a purified AIN93G diet containing 5, 10, or 15% (w/w) of HGCO as the fat source. For comparison, a separate group of rats (n = 10) was given the diet containing 15% (w/w) of borage oil (BO), which contained 22% (w/w) of GLA. After 12 weeks of feeding, the growth, relative organ weights, hematology, and serum biochemistry were found to be similar among rats fed the 5, 10, and 15% HGCO diets. The GLA levels in plasma and liver phospholipids (PL) were also similar. However, the levels of GLA in peripheral tissues (muscle PL and adipose triacylglycerols) were significantly higher in rats fed the 10 and 15% HGCO diets than those fed the 5% HGCO diet. When the above biologic parameters were compared between the 15% HGCO and 15% BO dietary groups, there were no significant differences except for lower final body weights and higher tissue levels of GLA, dihomo-gamma-linolenic acid (20:3n-6) and arachidonic acid (20:4n-6) in the 15% HGCO dietary group as compared with the 15% BO dietary group. This is due to a higher GLA content and possibly a more favorable stereospecific distribution of GLA in HGCO. Overall, long-term (12-week) feeding with diets containing up to 15% HGCO resulted in no adverse effects on growth, organ weight, hematology and serum biochemistry as compared to the diet containing 15% BO, suggesting that HGCO may be a safe alternative source of GLA.  相似文献   

14.
《Cereal Chemistry》2017,94(6):917-921
Neural tube defects occur at higher rates in Hispanic populations in the United States. Such populations would benefit from folic acid fortification of corn masa flour (CMF). This study evaluated folate stability in fortified CMFs and tortillas and tortilla chips made therefrom. There was no significant loss of folate during the six‐month shelf life of fortified tortilla CMF and tortilla chip CMF. There was a 13% loss (P < 0.05) of folate during tortilla baking and no loss during tortilla chip frying. Both tortillas and tortilla chips showed significant folate losses over the two‐month shelf life for these products, with a 17% loss in fortified tortillas and a 9% loss in tortilla chips. Folate in fortified CMFs, tortillas, and tortilla chips is relatively stable and comparable to the stability of folate in wheat flour and breads.  相似文献   

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16.
A plant stress is related both to deficiency of a particular nutrient and to inadequate relationships between nutrients. The objective of the study was to assess the sugar beet nutritional status in response to sodium chloride (NaCl) application. Plant sampling was conducted at two early stages of beet growth (7-leaf – BBCH 17, and well-developed rosette – BBCH 43). The white sugar yield (WSY) was used as an evaluation criterion. The data used in this study originate from a set of 20 field experiments, conducted in years with a significant shortage of precipitation. Each trial was consisted of control (NPK) and a plot with 50 kg Na ha?1 (NPK+Na). The nutrient concentration approach and the Compositional Nutrient Diagnosis, based on centered log ratios (CND-clr), were used to evaluate sugar beet nutritional status. The effect of sodium (Na) was evaluated within two subsets of fields: NR – without, and R – with a significant increase in WSYs. The CND-clr indices for Na increased, but for K, Ca and Mg decreased along with Na application, irrespective of the growth stage and subset of fields. However, Na application improved relation between nutrients in fields responding to sodium application, especially at BBCH 43.  相似文献   

17.
Abstract

The aim of this work was to evaluate manganese (Mn) sources and levels effects in irrigated rice production in central Brasil (tropical lowlands of Tocantins state). The experiment was conducted in a 5x5?+?1 factorial scheme, five Mn sources and five levels (0.5; 1.0; 1.5; 2.0; and 2.5?kg ha?1), applied in induction of tillering of rice plants, plus a control without treatment, and Mn content in leaves (mg kg?1), number of panicles per area (m2), hundred grains weight (g), intact grains (%), and grain yield (kg ha?1) were analyzed. Treatments with Mn-carbonate source got the best results and this source at the level of 1.5?kg ha?1 provided the highest yield: 7,375?kg ha?1. Higher values were obtained with the application of 1.0 to 1.5?kg ha?1 of Mn, except for the intact grains where the best means were obtained at 2.5?kg ha?1.  相似文献   

18.
有机铬制剂对生长肥育猪生产性能和胴体品质的影响   总被引:7,自引:0,他引:7  
选择平均体重约15kg的杜长大三元杂交断奶仔猪60头,随机分成对照组(Ⅲ组)、试验I组和试验Ⅱ组,进行为期110d(前期60d,后期50d)的试验。研究有机铬制剂(蛋白质和肽类络合铬)对生长肥育猪的生产性能、血清生化指标及胴体品质的影响。试验饲粮处理为:对照组前、后两期均不添加铬制剂(含铬0μg/kg),试验I组全期添加有机铬制剂(含铬200μg/kg),试验Ⅱ组前期不添加有机铬制剂(含铬0μg/kg),后期添加有机铬制剂(含铬200μg/kg)。结果表明:全期饲粮中添加有机铬制剂,一定程度上可改善生长肥育猪的生产性能,提高日增重和饲料利用率;而对猪血清生化指标似无显著影响。全期添加或仅后期添加有机铬制剂均可增加胴体瘦肉率、降低体脂肪而改善胴体品质,且以后期添加效果更好。  相似文献   

19.
Hydroponically grown maize (Zea mays L.) plants were deprived of the external source of sulfate following an initial period of 13 d during which the sulfur (S) supply was sufficient. The amounts of dry mass (DM), water, sulfate, sulfur, nitrate, ammonium, nitrogen, phosphorus, potassium, magnesium, calcium, boron, iron, copper, zinc, and manganese were monitored in the shoots and the roots for 10 d. The deprivation altered the nutritional balance between them, causing a 70% decrease of sulfate in shoots and roots after 2 d. At 10 d, 95% of sulfate had vanished in both shoots and roots. Total S remained rather constant in shoots or was slightly decreased in roots after 4 d. This coincided with a decrease of Fe in shoots after 4 d. The calculated decreases of S and Fe in –S shoots, up to 6 d were linearly correlated. Kinetic analysis of the changes revealed a sequence in their onset, and we distinguished early and late changes. Among the early changes, we highlight the following ones: (1) an increased amount of Cu in both shoots and roots at 2 d; Fe was 40% decreased in both shoots and roots at 2 d; (2) a decrease in transpiration rate by 35% after 2 d; (3) alterations in boron allocation; in –S shoots the % changes in S were linearly correlated with the corresponding % changes in B; (4) calcium content was not affected by the S deprivation in –S shoots, whilst it increased in –S root after d 2; (5) Mn and Mg decreased from the beginning and in a uniform fashion in both –S shoots and roots. Day 6 may be considered as the boundary between the early and late changes. The root fraction of DM increased progressively after 4 d. Changes in DM seemed to be similar to those of P. Changes of Zn also took place rather late. In –S shoots and for the time interval between 6 d and 10 d, linear correlations were found between the corresponding % changes of the pairs DM–S, DM–P, DM–N, DM–water, S–N, S–P, and N–P.  相似文献   

20.
To determine the effects of chromium (Cr) supplementations on oxidative stress of type 2 diabetes and euglycemic (EU) subjects, adult having HbA(1C) values of <6.0% (EU), 6.8-8.5% (mildly hyperglycemic, MH), and >8.5% (severely hyperglycemic, SH) were supplemented for 6 months with 1000 microg/day of Cr (as Cr yeast) or with a placebo. In the beginning, the levels of the plasma Cr in the MH and SH groups were 25-30% lower than those of the EU subjects. The values of thiobarbituric acid reactive substances (TBARS) and total antioxidative status (TAS) of the MH and SH groups were significantly higher than those of the EU ones. Following supplementations, the levels of plasma TBARS in the Cr groups of MH and SH groups were significantly decreased (the inverse was found in the EU) and showed no significant changes in the placebo group. The levels of plasma TAS in the Cr groups of EU and MH were significantly decreased (the inverse was found in the SH) and showed no significant changes in the placebo group. No significant difference was found in the antioxidant enzyme (superoxide dismutase, glutathione peroxidase, catalase) activities during supplementations. These data suggest that Cr supplementation was an effective treatment strategy to minimize increased oxidative stress in type 2 diabetes mellitus patients whose HbA(1C) level was >8.5%, and the Cr in EU groups might act as a prooxidant.  相似文献   

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