Supplementation with Magnesium Salts—A Strategy to Increase Nutraceutical Value of Pleurotus djamor Fruiting Bodies

The use of substrates supplemented with minerals is a promising strategy for increasing the nutraceutical value of Pleurotus spp. The current research was performed to analyze the effect of substrate supplementation with magnesium (Mg) salts on the Mg content, biomass, and chemical composition of pink oyster mushroom (Pleurotus djamor) fruiting bodies. Before inoculation, substrate was supplemented with MgCl₂ × 6 H₂O and MgSO₄, both salts were applied at three concentrations: 210, 420, and 4200 mg of Mg per 2 kg of substrate. The harvest period included three flushes. Substrate supplementation with 4200 mg of Mg caused the most significant decrease in mushroom productivity, of about 28% for both Mg salts. The dry matter content in fruiting bodies was significantly lower in the treatment in which 210 mg of Mg was applied as MgSO₄ in comparison to the control. Supplementation effectively increased the Mg content in fruiting bodies of P. djamor by 19–85% depending on the treatment, and significantly affected the level of remaining bioelements and anions. One hundred grams of pink oyster fruiting bodies, supplemented with Mg salts, provides more than 20% of the Mg dietary value recommended by the Food and Drug Administration (FDA); thus, supplementation can be an effective technique for producing mushrooms that are rich in dietary Mg. Although P. djamor grown in supplemented substrate showed lower productivity, this was evident only in the fresh weight because the differences in dry weight were negligible. Mg supplementation increased the antioxidant activity of the fruiting bodies, phenolic compounds, and some amino acids, including L-tryptophan, and vitamins (thiamine and l-ascorbic acid).     

Simultaneous sample preparation for high-performance liquid chromatographic determination of Vitamin A and β-carotene in emulsified nutritional supplements after solid-phase extraction

Determination of small amounts of the fat-soluble species Vitamin A (VA) (2.5 μg/g) and β-carotene (9 μg/g) from emulsified nutritional supplements containing 50 kinds of co-existing compounds and a fat content between 2000 and 8000 times higher was performed by solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) with fluorescence detection set at ex. 350 nm and em. 480 nm, and visible detection at 450 nm using an Inertsil ODS 80A (5 μm) analytical column. Mobile phases of methanol-ethanol (50:50) and acetonitrile-ethanol (70:30) were used for the both vitamins. A Bond Elut C₁₈ cartridge was chosen for SPE after comparison with eight other types of SPE cartridge. Retention time of VA and β-carotene was 7 and 8 min, respectively, giving a limit of detection of ca. 0.1 ng per injection at a signal-to-noise ratio 3:1. Recoveries of VA and β-carotene were over 90% by the standard addition method. Relative standard deviation of VA and β-carotene were ca. 2.9 (n=5) and 2.3% (n=5), respectively.     

Current mass spectrometry strategies for selenium speciation in dietary sources of high-selenium

This document reviews the most relevant mass spectrometry approaches to selenium (Se) speciation in high-Se food supplements in terms of qualitative and quantitative Se speciation and Se-containing species identification, with special reference to high-Se yeast, garlic, onions and Brazil nuts. Important topics such as complexity of Se speciation in these materials and the importance of combining Se-specific detection and molecule-specific determination of the particular species of this element in parallel with chromatography, to understand their nutritional role and cancer preventive properties are critically discussed throughout. The versatility and potential of mass spectrometric detection in this field are clearly demonstrated. Although great advances have been achieved, further developments are required, especially if speciatedcertified reference materials (CRMs) are to be produced for validation of measurements of target Se-containing species in Se-food supplements.     

小毛足鼠(Phodopus roborovskii)食性和食量的研究

小毛足鼠饲喂试验结果以及颊囊食物统计结果表明,该鼠在饲喂条件下食物资源利用谱相对较宽,但在野外条件下食物资源的利用主要以植物种子为主;并结合具体情况探讨了造成野外条件下该鼠食物资源利用范围趋于特化的原因．估算了小毛足鼠的采食效率为０．０７６％～０．１４％．在以上研究基础上,对小毛足鼠的危害与防治问题作了初步分析与说明     

On line trace enrichment for isolation of vitamin B2 in food samples

Summary Vitamin B₂ was enriched by liquid-solid extraction from large volumes of aqueous samples on a short precolumn. The enriched compounds were transferred onto an analytical reversed-phase column and separated by ion-pair chromatography. The equipment used provides the possibility of automation for routine analysis.Dedicated to Professor J. F. K. Huber on the occasion of the 60th birthday.     

Determination of triclosan in foodstuffs

A reverse-phase high-performance liquid chromatographic (RP-HPLC) method coupled with an ultraviolet detector was developed to determine triclosan which had migrated into foodstuffs from packaging materials. The method includes extraction with hexane, followed by evaporation to dryness and residue re-dissolution in ACN 90%. Chromatographic separation was performed with a Kromasil 100 C18 column (15 cm x 0.4 cm ID, 5 microm particle size) at 30 degrees C and using ACN and water as mobile phases. Regarding recoveries, good results (higher than 83% and lower than 112%) were obtained for the three representative food matrixes selected (orange juice, chicken breast meat, and Gouda cheese).     

富锌排铅咀嚼片安全性毒理学评价

对富锌排铅咀嚼片(RZLR)进行了急性毒性试验、Ames试验、骨髓微核试验、精子畸形试验和30 d喂养试验。结果表明,小鼠急性毒性LD50(BW)>21 500 mg/kg,属无毒级;Ames试验、小鼠骨髓微核试验、精子畸形试验和30 d喂养试验结果均为阴性;30 d喂养试验也未显示明显毒性。本研究证实RZLR是一种安全、无毒副作用的保健食品。     

Thermal analysis,state transitions and food quality

Thermal properties of food systems are important in understanding relationships between food properties and changes in food quality. Concentrated food systems (low-moisture and frozen foods) are seldom in an equilibrium state and they tend to form amorphous, non-crystalline structures. Several glass transition-related changes in such foods affect stability, e.g., stickiness and caking of powders, crispness of snack foods and breakfast cereals, crystallisation of amorphous sugars, recrystallisation of gelatinised starch, ice formation and recrystallisation in frozen foods and rates of non-enzymatic browning and enzymatic reactions. Relationships between glass transition, water plasticisation and relaxation times can be shown in state diagrams. State diagrams are useful as stability or quality maps and in the control of rates of changes in food processing and storage.This revised version was published online in November 2005 with corrections to the Cover Date.     

Do proficiency tests always verify laboratories’ performance? The case of FAPAS PT 0270

In this paper, the case of FAPAS PT 0270 “Doramectin and Oxfendazole in Sheep Liver” is discussed. During evaluation of the data received from participants (determination of total, oxidised oxfendazole residue and calculation of the sum of oxfendazole and oxfendazole sulfone residues), significant differences were observed between the results obtained by use of two analytical approaches. This phenomenon can be explained by the route of oxfendazole metabolism, which results in the presence of fenbendazole in the sample. This was not predicted by the provider; consequently, not all the necessary tests on the material were conducted. Due to the high uncertainty of the z-scores in this test, the results of the PT cannot be used for purposes of evaluation, and the benefits of participation in PT 0270 are questionable.     

固体超强酸SO_4~(2-)/SiO_2-TiO_2催化合成异维生素C钠

在异维生素C钠(D-VcNa)的合成过程中,以SO42-/S iO2-TiO2复合固体超强酸作为酯化反应催化剂,2-酮基-D-葡萄糖酸(2-KGA)和甲醇为原料,采用精馏脱水酯化工艺,不断除去酯化过程中产生的水。催化剂的最佳焙烧温度为550℃,催化剂用量为2.5%;反应时间3~4 h,产品收率为88.6%,催化剂的重复使用性较好,催化体系优于硫酸法。