阳离子微粒氢氧化镁铝的合成及其微粒助留作用

混合二元金属氢氧化物是自然界中唯一带有正电荷的粘土矿物,可望与阴离子聚丙烯酰胺组成阳离子微粒助留体系.本文采用共沉淀法合成了以Cl-为层间阴离子、以不同摩尔比的镁、铝为金属阳离子的混合二元金属氢氧化物一氢氧化镁铝胶体,并对其化学结构式、粒度、Zeta电位等进行了分析,研究了氢氧化镁铝对苇浆的微粒助留作用.结果表明,氢氧化镁铝在从酸性到碱性的抄纸pH值范围内均带有正电荷,其带电情况和粒度随镁铝摩尔比而变化.各镁铝摩尔比不同的氢氧化镁铝与阴离子聚丙烯酰胺均可组成有效的阳离腚子微粒助留体系,且阳离子氢氧化镁铝的粒度越小,其微粒助留作用越好.     

不同类型镁肥对腾冲火山灰酸性植烟土壤的改良效果

为了寻求改善腾冲烟区火山灰土壤母质条件下的植烟土壤酸化严重、镁含量不足的方法,通过大田试验研究了不同类型镁肥对土壤pH、养分、土壤微生物、土壤酶活性的影响。结果表明,施用白云石粉为土壤补充镁元素(土壤有效镁含量提高13.07~20.36 mg/kg)的同时能够改善土壤的酸化程度,并且该肥料在腾冲当地可以大量开采,成本廉价。因此,在腾冲烟区水田环境中,建议施用白云石粉作为补充镁素、改善土壤酸化的肥料。而不再施用硫酸镁以及生石灰来补充镁肥以及改善土壤pH。     

The results of application of magnesium-bearing medications and different load doses of vitamins B1 and B2 in volunteers

Presently is no consensus of opinion of the size of human optimal daily allowance as for thiamine and riboflavin, so for magnesium, what their content in polyvitamin and mineral preparations testify to. The study was conducted in 60 volunteers, who once took oral dosing of magnesium -bearing preparation "Magnerot" (500 mg of magnesium orotat converting to Mg2+ 32,8 Mg) and "Centrum" (100 mg of magnesium oxide converting to Mg2+ - 60,3 Vg) or vitamins B1 and B2 in 10, 20 and 30 mg doses. The received data testify that during the application of both of these preparations, equal concentration of this element takes place, though in case of magnesium oxide it happens later. As for the used vitamin B1 and B2 doses, it is determined that 10 mg is the optimal dose for treating their hypoavitaminosis.     

Änderung des Gehaltes an Phosphor,Calcium und Magnesium in Kartoffelstärke durch verschiedene Düngungsbedingungen

Change of Contents of Phosphorus, Calcium and Magnesium by Various Conditions of Fertilization. Quality of potato starch is affected by the presence of phosphorus, calcium and magnesium. Thus, determination of their contents in the starch is useful. As amounts of these elements seem to be influenced by conditions of fertilization three years of field tests were evaluated. Towards the end of the vegetation period the phosphorus content increased in the starch. Doses of Ca and Mg reduced the phosphorus content during maturity phase. The substantial differences between fertilization varieties observed in the earlier vegetation phases will decrease during maturity. Changes in calcium content in the starch were caused by different conditions of fertilization. Towards the end of vegetation calcium content decreases. In the maturity phase a lower average magnesium content than during full bloom was observed. Compared to the fading phase an increase of magnesium content was observed with simultaneous adding of Ca and Mg. The effect of Ca- and Mg-doses was in close relationship to the amount of N-, P-, K-doses and to the vegetation phase.     

浅论镁离子对啤酒发酵的影响

讨论了麦汁中镁离子含量对啤酒酵母发酵的影响。镁离子是酵母代谢过程中许多酶的重要辅助因子,它的浓度直接影响啤酒的发酵。提高镁离子的含量,均会提高初始发酵率,提高酵母活性,促进酵母对麦芽三糖及麦芽糖的吸收,增加酒精生成率和生成量,从而提高啤酒发酵度。     

Effects of potassium and magnesium nutrition on the quality components of different types of tea

In field experiments, the effects of potassium and magnesium nutrition on the quality components of different types of tea, including black tea, oolong tea and green tea, were studied. The results show that K and Mg fertilizer application increased the contents of free amino acids and caffeine of the various tea types with the maximum increase found in the treatment including both nutrients. The content of polyphenols in tea leaves was also increased by K application. The effect of Mg on polyphenol content was inconsistent. In general, Mg apparently decreased the content of polyphenols and only in case the soils were depleted of plant available K and Mg, a slight increase could be observed. The contents of theaflavins and thearubigins, important quality components of brewed black tea, were also increased by K application. Flavour compounds in brewed oolong tea were considerably improved by K and Mg application. © 1999 Society of Chemical Industry     

Effect of Magnesium Fertilizers on Total Glycoalkaloids and Nitrate-N in Katahdin Tubers

The effect of two sources of magnesium fertilization (56 kg/ha, MgO). ensom salt and dolomite. on total alvcoalkaloid (TGA) and nitrate-nitrogen (N0₃-N) content of Katahdin potatoes was examined. Both magnesium fertilizers increased the TGA and NOJ-N content of tubers. Tubers grown in soils receiving epsom salt had significantly (p < 0.05) higher TGA content than the tubers receiving dolomite immediately following harvest, but after 5 mo storage, no significant differences were observed between the two Mg sources. The NO₃-N levels in tubers from plants receiving Mg fertilization were higher than the controls. Those receiving epsom salt were higher than those receiving dolomite. The N03-N levels decreased in all tubers after 5 mo storage. Cortex tissue was significantly (p < 0.05) higher in N03-N than the pith.     

Effect of Four Drying Methods on the Quality of Intermediate Moisture Lowbush Blueberries

Lowbush blueberries have been processed by freeze dry, forced air, vacuum oven, and micro-convection methods to a moisture content of 16-25%. The drying effect on the product quality was evaluated. There were no significant differences in vitamin A and niacin retention except freeze dried berries had higher vitamin C retention. No significant differences occurred in retention of mineral content except higher sodium and lower magnesium were found in the micro-convection and freeze dry methods, respectively. Freeze dried and vacuum dried blueberries had higher soluble solids retention and were darker and redder than forced air or micro-convection dried berries. Freeze dried berries were found to have highest rehydration ratio and lowest bulk density.     

Evaluation of zinc and magnesium bioavailability from pea (Pisum sativum, L.) sprouts. Effect of illumination and different germination periods

The effect of sprouting pea seeds (Pisum sativum, L) for 2, 4 and 6 days, with and without light, on the content of zinc (Zn) and magnesium (Mg) and their nutritive utilisation by growing rats was studied. Soaking of pea seeds prior to germination caused a 49% reduction in Zn content followed by minor losses during germination. The content of Mg decreased by 6% as a result of the soaking process, and by 20–28% during germination. Sprouting for 2 and 4 days improved the bioavailability of Zn and Mg from pea seeds (from 32.2 to 88.6–108.0 μg retained Zn per day, and from 1.64 to 2.97–4.79 mg retained Mg per day in raw and sprouted pea flour diets, respectively), outweighing the reductions in Zn and Mg content because of seed soaking. The presence or absence of light during the germination process did not affect the results. We conclude that sprouting of peas for 4 days was the most effective treatment to improve the bioavailability of Zn and Mg in pea seeds.     

Ration digestibility and mineral balance in lactating cows fed rations containing dried whey.

Including dried whey in rations of nonruminants usually increases digestibilities and mineral retention, presumably because of the lactose in the whey. A trial with total collection had five lactating cows per treatment to determine the effects of 5% dried whey product in the concentrate on digestibility of the ration and on absorption and retention of calcium, magnesium, and phosphorus. Rations included corn silage ad libitum, 3 kg alfalfa hay, and either control or dried whey product in concentrate ration at 1 kg/3 kg milk produced. Rations were balanced for content of nitrogen, calcium, magnesium, and phosphorus. Digestibilities of dry matter, nitrogen, and energy were not increased with dried whey product in the ration. Apparent absorption of calcium, magnesium, and phosphorus was not affected significantly by inclusion of whey in the ration. Productive (milk plus retained) calcium and magnesium were not increased when dried whey product was in the ration although productive phosphorus was slightly higher with the dried whey product. Adding small amounts of dried whey to a ruminant's ration will not increase mineral absorption and retention probably because tthe lactose in dried whey is fermented in the rumen and unavailabe for aiding absorption from the small intestine.     

INFLUENCE OF VARIOUS SALTS IN THE COOKING WATER ON PECTIN LOSSES AND COOKED TEXTURE OF COWPEAS (VIGNA UNGUICULATA)

The effects of processing with solutions of calcium chloride, magnesium chloride, sodium bicarbonate and a local tenderizer known as ‘Kanwa’ (sodium sesquicarbonate) on pectin losses and cooked texture of cowpea seeds were investigated. For comparison, the cowpeas were processed in double distilled water and a local tap water. Analysis included total pectin, calcium and magnesium content, leached solids, texture and water absorption. The results show that CaCl₂, MgCl₂ and the local tap water increased firmness, Ca and Mg content in the cooked beans compared to distilled water; however, water absorption, leached solids and pectin solubilization were decreased by these salts. Kanwa and NaHCO₃ increased water absorption, leached solids and softness in the cooked beans and also increased pectin solubilization but decreased Ca and Mg when compared to distilled water or the other salts. These changes are discussed with respect to the effects of divalent and monovalent cations on the texture of the bean tissue.     

Manufacture of magnesium-fortified Chihuahua cheese

The aim of this study was to manufacture magnesium-fortified Chihuahua cheese and to evaluate the effect of magnesium fortification on quality parameters. Addition of magnesium chloride to milk during pasteurization (5.44, 10.80, 16.40, 22.00, and 25.20 g of MgCl₂·6H₂O/L of milk) resulted in cheese with increased magnesium content, proportional to the amount of magnesium added (up to 2,957.13 mg of Mg/kg of cheese). As magnesium content increased, coagulation time and moisture content also increased, whereas calcium content decreased. Higher levels of magnesium fortification (16.40 g of MgCl₂·6H₂O/L of milk or more) induced the development of bitter-acid flavors and softer texture. Addition of 10.80 g of MgCl₂·6H₂O/L to milk resulted in Chihuahua cheese that meets regulatory standards and possesses physicochemical and sensory characteristics similar to those of nonfortified Chihuahua cheese. Under this milk fortification level, the manufactured cheese is able to provide 148.4 mg of magnesium per day (35% of the recommended daily intake of magnesium for adult males and 46% for adult females) assuming 3 portions (28 g each) are consumed.     

Bioavailability of calcium,magnesium and phosphorus in rats fed probiotic,prebiotic and synbiotic powder follow‐up infant formulas and their effect on physiological and nutritional parameters

The effect of infant formulas supplemented with functional ingredients on calcium (Ca), magnesium (Mg) and phosphorus (P) bioavailability was investigated in rats. Seven follow‐up infant formulas containing probiotics (Bifidobacterium bifidum and Bifidobacterium longum), prebiotics (galactooligosaccharides at 12, 50 and 100 g kg^?1) or synbiotics (bifidobacteria and galactooligosacccharides) were administered to weanling rats for 30 days. A 3 day mineral balance was performed over three periods (8–10, 18–20 and 28–30 days) to monitor mineral apparent absorption and retention ratios and physiological and nutritional parameters. Feeding rats on infant formula‐based diets showed high feed efficiency (≥0.46). It was found that infant formulas supplemented with probiotics and/or prebiotics for 30 days increased Ca, Mg and P bioavailability in rats. Mineral apparent absorption and retention ratios were higher than 90% for Ca and P and 80% for Mg during the first balance period regardless of the infant formula used, but they decreased during the next two balance periods. Although it was not possible to select one infant formula as the best to improve mineral absorption, the 100 g kg^?1 prebiotic and 50 and 100 g kg^?1 synbiotic infant formulas were the most efficient at increasing Ca, Mg and P bioavailability compared with the control group. Copyright © 2006 Society of Chemical Industry     

水热法制备碱式硫酸镁晶须

文章以MgSO4和NaOH为原料 ,考察了常温合成 -水热反应方式制备碱式硫酸镁晶须的可行性 ,着重讨论了水热溶液组成对产物形貌、结构及组成的影响 ,初步确立了制备碱式硫酸镁晶须的工艺条件     

Nutritional Evaluation with an Animal Model of Cottage Cheese Fortified with Calcium and Guar Gum

Apparent absorption of calcium by rats from cottage cheese was very efficient under the conditions tested. However, overall calcium retention and, to a lesser extent, bone calcium content increased with each increment in dietary calcium. Despite sensitivity of the model to variation in calcium intake, no effect of guar gum on calcium utilization was noted. Increasing the calcium added to cottage cheese increased phosphorus retention, did not antagonize utilization of magnesium and zinc, and only slightly decreased iron utilization in rats.     

PEO与合成硅酸镁铝凝胶二元体系的助留助滤性能

研究了PEO-合成硅酸镁铝凝胶系统以及不同PEO用量对系统留着率的影响,并将PEO-合成硅酸镁铝凝胶体系与PEO-凹凸棒土、PEO-膨润土系统的助留助滤效果进行了比较。对PEO-合成硅酸镁铝系统改善滤水性能,提高填料留着率及成纸白度方面的影响进行了探讨。结果表明：PEO-合成硅酸镁铝凝胶系统在PEO用量为0.16kg/t,合成硅酸镁铝凝胶为10kg/t时,细小纤维留着率在73%以上,填料留着率在45%以上,同时打浆度能够下降20°SR。综合比较,PEO-合成硅酸镁铝凝胶二元助留体系的助留助滤效果优于PEO-凹凸棒土二元体系和PEO-膨润土二元体系。     

3A分子筛氯化镁脱水试验研究

在常压下,利用分子筛吸附氯化镁乙醇溶液中的水分,研究了氯化镁浓度、温度、时间、分子筛加入量对脱水量的影响。根据试验结果,得出结论:(1)分子筛最佳停留时间为6 h;(2)浓度越低,溶液中的最终含水量越小,但浓度越高,吸附量越高;(3)温度升高,吸附速率提高,但升高到一定温度,吸附率不再明显提高,最佳温度为26℃。(4)氯化镁乙醇溶液,每100 g溶液加入120 g分子筛,吸附量最大,吸附率可达76.5%。     

超细氢氧化镁复合表面改性对过滤性能和洗涤效果的影响

采用硬脂酸钠与水溶性钛酸脂对超细氢氧化镁进行湿式复合改性,在改善超细氢氧化镁的表面性能的同时提高过滤性能,并考察表面改性对氢氧化镁料浆洗涤效果的影响。实验结果表明:采用固含率为15%(w/v)的超细氢氧化镁悬浮液为原料,当硬脂酸钠与水溶性钛酸脂的加入量均为1.0 g/100 g Mg(OH)2,可以明显降低滤饼比阻、提高洗涤氯离子的效果,同时吸油值仍可降至42 mL/100 g Mg(OH)2。     

Effects of dietary vitamin D(3), vitamin E, and magnesium supplementation on pork quality

Meat quality traits and palatability characteristics were evaluated on 240 barrows and gilts subjected to one of eight dietary regimens: (1) control (no supplement), (2) vitamin D(3)(D(3)), (3) vitamin E (E), (4) magnesium (Mg), (5) vitamins D(3) and E (D(3)/E), (6) vitamin D(3) and magnesium (D(3)/Mg), (7) vitamin E and magnesium (E/Mg), and (8) vitamins D(3) and E, and magnesium (D(3)/E/Mg). Barrows supplemented with D(3)/E/Mg had the highest (P>0.05) ultimate pH. Those supplemented with E had a higher ultimate pH than those supplemented with D(3)/Mg or the control. Gilts supplemented with Mg had the highest ultimate pH of all of the gilts while those supplemented with D(3) had the lowest. Barrows supplemented with Mg or E had more marbling than those supplemented with D(3) or D/E. Gilts supplemented with Mg had the most marbling when compared to other gilts. At 48 h postmortem, no differences due to dietary treatment were observed in L (?), a (?) or b (?) value, drip loss or purge loss. At 14 days postmortem, no differences due to diet existed in sensory characteristics. Results suggest that supplementation of swine diets with some dietary supplement combinations of containing Mg may have some potential benefit for increasing ultimate pH.     

Nutrition and magnesium absorption: a review.

This paper reviews the evidence that certain dietary components can affect intestinal absorption of magnesium. Increased intakes of protein and fructose improve apparent magnesium absorption (magnesium intake minus fecal excretion) in humans, whereas a lowering effect occurs with consumption of cellulose and phytate. Although dietary concentrations of lactose, fat, calcium and phosphate have clear effects on magnesium absorption in experiments with rats, the impact of these nutrients on magnesium absorption in humans remains unsettled. Mechanisms underlying the effects of dietary components on magnesium absorption in humans are generally poorly understood. A change in magnesium absorption not necessarily results in a change in magnesium retention. When consuming practical diets, the fall of apparent magnesium absorption caused by phytate and cellulose is generally compensated by increased magnesium intake due to high magnesium concentrations in phytate- and cellulose-rich products. Furthermore, to maintain homeostasis, urinary magnesium excretion will be raised after stimulation of apparent magnesium absorption and it will be lowered after impairment of apparent magnesium absorption. Thus, the effects of dietary components on magnesium absorption probably are critically important only at low intakes of magnesium. At low magnesium intakes, differences in magnesium absorption may be expected to influence magnesium retention and thus can either induce or abolish magnesium deficiency.