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1.
Summary The use of fat soluble and water soluble food dyes in food technology requires reliable proofs and precise identification of these substances in foodstuffs. This problematic has been studied more detailed in our Institute. During these studies some suitable procedures for thin layer chromatographic separation of these substances have been developed.For the separation of fat soluble food dyes the chromatography on thin layers of aluminium oxide and the chromatography on thin layers of starch with reversed phases were used. In the first case good separation was achieved with a solvent system containing petroleum ether and carbon tetrachlorid and their mixtures. In the second case the starch plates were impregnated with paraffin or vegetable oil, and as mobile phases a solvent system containing methanol-water-acetic adic (16 : 3 : 1) and others solvent mixtures currently used in paper chromatography were used.Water soluble food dyes were separated on thin layers of polyamide powder, which was used also for their quantitative isolation from foodstuffs. The best results were achieved with basic solvent system, for example, with a mixture containing ammonia-methanol water (5 : 15 : 80).The developed analytical procedures are suitable for the proof and the separation of fat soluble and water soluble food dyes in all foodstuffs.
Zusammenfassung Die Verwendung von wasser- und fettlöslichen Lebensmittelfarben erfordert verläßlichen Nachweis und genaue Identifikation dieser Stoffe in den Lebensmitteln. Wir haben diese Problematik in unserem Institut eingehend studiert und einige Verfahren der chromatographischen Trennung dieser Stoffe mittels DC erarbeitet.Zur Trennung der fettlöslichen Farbstoffe verwendeten wir einerseits DC-Platten mit Aluminiumoxid, andererseits führten wir die Trennung dieser Stoffe auf einer dünnen Stärkeschicht mit umgekehrter Phase durch. Im ersten Falle wurde eine gute Trennung mit Laufmitteln erreicht, die Petroläther und Tetrachlormethan und deren Gemische enthalten. Im zweiten Falle wurde als stationäre Phase Paraffinöl, als mobile Phase eine Gemisch von Methanol, Wasser und Essigsäure im Verhältnis 16 : 3 : 1 und andere Gemische in gleichen Verhältnissen verwendet, die sich bei der Papier-Verteilungschromatographie bewährt haben.Wasserlösliche Farbstoffe wurden auf einer dünnen Schicht von Polyamidpulver getrennt, das auch zu deren quantitativer Isolation aus den Lebensmitteln verwendet wurde. Die besten Ergebnisse wurden mit alkalischen Laufmitteln erzielt, z.B. mit dem Gemisch von Ammoniak, Methanol und Wasser im Verhältnis 5 : 15 : 80.Die erarbeiteten analytischen Verfahren für Nachweis und Trennung fett- und wasserlöslicher Lebensmittelfarben bewährten sich für alle Lebensmitteltypen.

Résumé L'utilisation des colorants alimentaires solubles dans l'eau et dans la graisse exige des preuves sûres et l'identification exacte de ces substances dans les aliments. Nous avons étudié ces problèmes en détail à notre institut et élaboré quelques procédés de séparation chromatographique de ces substances par chromatographie sur couche mince.A la séparation des colorants solubles dans la graisse, nous avons utilisé d'une part des couches versées sur l'alumine, d'autre part la séparation de ces substances sur une couche mince de fécule à phase inverse. Au premier cas une bonne séparation fut atteinte aux systèmes comprenant l'éther de pétrole et le tétrachlore carbonique, ou leurs mélanges. A l'autre cas on applique, comme une phase ancrée, de l'huile paraffinique, comme une phase mobile, du mélange de méthanol, d'eau et d'acide acétique en proportion 16 : 3 : 1 et d'autres en mêmes proportions qui avaient fait leurs preuves à la chromatographie de séparation sur le papier.Les colorants solubles dans l'eau furent séparés sur une couche mince de poudre polyamidé qui avait été de même appliqué à leur isolement quantitatif de l'aliment. Les meilleurs résultats furent atteints avec les systèmes alcalins p.e. avec le mélange de méthanol, d'ammoniac et d'eau en proportions 5 : 15 : 80.Les procédés analytiques élaborés pour des preuves et les séparations des colorants solubles dans la graisse et dans l'eau prouvèrent leur attestation avec tous les types de matières alimentaires.
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2.
干旱高纬度环境对大豆蛋白质和脂肪含量的影响   总被引:1,自引:0,他引:1  
对干旱高纬度环境下大豆蛋白质和脂肪含量的研究结果表明,干旱高纬度环境对大豆蛋白质含量的影响较大,而对脂肪含量的影响较小。  相似文献   

3.
Saccharomyces cerevisiae and Lactobacillusplantarum ATCC 10776 were used as starters toferment various composite blends of cereals and legumes produced through malting and toasting of two varieties of maize – Zea mays (DMR-LSR white & DMR-ESR yellow),sorghum – Sorghum bicolor (Dawa white & Dawared) and one variety of soybeans (Glycine max). Compared to the untoasted and unmaltedfermented blends, a relatively lower pH (3.6),highly sour product was obtained with 12 h offermentation. Results also showed that cereal and soybeantoasting brought about a better reconstitution indices(B25, 84 ml; B45, 87 ml), water holding capacities(B25, 0.68 ml/g; B45, 0.62 ml/g), bulk densities (C15,11.6; C35, 10.8) and gross energy (B15, 501.5Kcal/100g; B45, 508.5 kcal/100g) at the end offermentation. Furthermore, reductions in totalpolyphenol and tannin contents were observedwith fermentation of toasted and malted cereal blendssupplemented with toasted and malted soybeans whileporridges from the same blends displayed desirablestarch stability and consistent gelling tendency,although B15 (a ferment of malted, toasted white maizesupplemented with toasted and malted soybean) fellwithin acceptable limits. In all, the physicalcharacteristics were affected by varieties of cerealand soybeans.  相似文献   

4.
Soil slaking is an environment-friendly technique that is gaining importance in restoring saline soils. The objective of this article is to evaluate the effect of initial water content (IWC) on saturated hydraulic conductivity (K s) in desalinization with slaking and drying. Accordingly, a slaking test was carried out during February, 2009 for evaluating the effects of slaking and drying on K s, sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) under various IWC. We prepared natural and air-dried soils of paddy field in Kojima Bay Polder, Japan to give different pre-drying, air-dried, and not dried (natural). The air-dried soils were resaturated. Each soil was well mixed, then dried to different initial moisture contents (60, 50, 40, 30, 20, and 10% by weight). The specimens were immersed into water in the pot for 24 h. The K s was measured, and cations in slaked and unslaked soils were analyzed. The K s was high under the water content below 30% in both the natural and the air-dried soils. But the effects were more pronounced in the natural soil. The air-dried soil showed far smaller K s than the natural soil. In outer solution, the highest SAR was noted at 30% in the natural and 30 and 20% in the air-dried soils. Significant decrease in ESP of the soils (slaked + unslaked) was also observed at the same water content. Lower water content was more effective in decreasing the soil ESP after desalinization from saline soil. The natural soil showed lower ESP and higher porosity, which was considered as a reason for higher K s of natural soil than that of air-dried soils. The results indicated that lower water content (10–30%) had no hazardous effect on K s by slaking and drying of soil.  相似文献   

5.
中蓖杂1号以雌性系油5~88414为母本,恢复系9404为父本配组选育而成。该杂交种抗旱、耐盐碱、耐瘠薄、抗枯萎病能力强,种子含油率达50.87%。品种鉴定平均产量3640.5kg/hm^2,比对照油蓖5号增产33.3%。生产示范平均产量3874.5kg/hm^2,比对照油蓖5号增产43.5%。适宜华中地区春播种植。  相似文献   

6.
高产高油抗病油葵杂交种晋葵5号的选育   总被引:4,自引:0,他引:4  
晋葵5号是以雄性不育系76202-3A为母本,恢复系902-11R为父本组配选育而成,该杂交种抗旱、耐盐碱、耐瘠薄、耐菌核病能力强,含油率达51.44%,品种鉴定平均产量3823.5kg/hm^2,比对照品种汾葵杂3号增产13.9%,生产示范平均产量2056.5kg/hm^2,比对照品种晋葵2号增产17.0%,适宜高寒山区春播及麦茬复播。  相似文献   

7.
The study of starch digestion in cereal-based products is essential since the extent and rate of hydrolysis affects the glycemic index associated with several food-related diseases. Besides, a unique matrix is usually studied and many variations of in vitro techniques (e.g. enzymes, pH, food:enzymes ratio) are selected, then comparison of results became difficult. The recently published INFOGEST in vitro static method with international consensus (Minekus et al., 2014) was applied to several cereal-based products to address whether it is suitable for analysis of starch hydrolysis kinetics. Bread, pasta and cookies were selected taking into account the analysis of different cereal matrixes, including gluten-free products. White bread presented the highest in vitro starch hydrolysis (87%) showing significant differences compared to gluten-free bread (76.5%). Refined flour sheeted pasta (72.6%), whole-wheat extruded pasta (92.0%) and gluten-free pasta (54.3%) showed differences in the extent and rate of hydrolysis. Cookie samples presented the lowest starch hydrolysis (∼45%). The starch availability was estimated by the dializability method, which measures the maltose equivalents dialyzed after simulating digestion. Starch dializability was 35%, 25% and 15% on average for bread, pasta and cookie samples respectively, with positive correlation with rapidly digested starch. The tested in vitro method allowed discriminating the effect of different processing techniques, product types and formulation of the three most common cereal-food matrixes in starch digestion.  相似文献   

8.
由国家农业部批准设立的“高脂肪、高蛋白大豆生产技术体系试验示范”项目,以3个高脂肪品种(品系)和2个高蛋白品种(品系)为核心良种,以优质品种的繁育与保优,壮根、壮苗的土壤耕作,经济有效平衡施肥、精量播种、生育调控、病虫防治、节本增效和优质品种质量监控等8项内容组装,形成优质、高产与高效的配套技术,目前项目已在黑龙江、吉林两省顺利实施。  相似文献   

9.
Wheat (Triticum aestivum L) and barley (Hordeum vulgare L) are two important cereals cultivated worldwide. The effect of aleurone cell wall structure on water diffusion and distribution within wheat and barley grains was evaluated at different relative humidity levels. Time domain nuclear magnetic resonance was used to measure the transverse relaxation time T2 of grains. Two water states were distinguished within grains, namely W1 (lower mobility) and W2 (higher mobility). Grains with thicker aleurone layer cell walls had a higher W2. The water-absorption and desorption rates were mainly determined by the thickness of the aleurone cell walls and decreased with increasing cell wall thickness. The higher W2 values observed in grains with thicker aleurone cell walls with the a water content of 2.0% (w/w) and 12.1% (w/w) were probably related to a higher water motion within the grains, in response to higher porosity. Arabinoxylan and (1,3)(1,4)-β-glucan alternating multilayer films were prepared, each film had 20 layers, one layer was approximately 1 μm thick. The film was used as a model to simulate the aleurone layers. These results show that cell walls of the aleurone layer regulate the diffusion and distribution of water within grains.  相似文献   

10.
播种期补灌对土壤含水量和小麦籽粒产量的影响   总被引:1,自引:0,他引:1  
林祥  王东  谷淑波 《麦类作物学报》2015,35(12):1700-1711
为明确播种期0~200 cm土体贮水量及其纵向分布对小麦出苗、群体发育和籽粒产量的调节作用,于2013-2014年度小麦生长季,在土壤容重、田间持水量和肥力条件一致,而小麦播前土壤贮水量不同的A、B两个地块,在播种期设置不同的计划湿润层深度和目标土壤含水量进行补灌。结果表明,在地块A和地块B 0~100 cm土层土壤贮水量分别为201.5和266.3 mm、0~200 cm土层土壤贮水量分别为554.2和586.4 mm的条件下,播种期补灌,土壤水分平衡后,灌溉水在地块B下渗的深度较大,但主要集中在60 cm以上土层,其中0~10和0~20 cm土层土壤含水量提高的幅度最大;小麦出苗率主要受播种期0~10 cm土层土壤含水量的影响,而群体发育、干物质积累和产量形成则受播前土壤贮水量和播种期补灌水平的共同影响。播种期上部土层土壤含水量过低不利于幼苗发育,显著减少越冬至拔节期间的单位面积茎数。播种前0~100 cm土层土壤贮水量过低,即使播种期在一定范围内增加补灌水量,并于拔节期和开花期再补灌,仍会制约小麦生育中后期的生长,导致成穗数和干物质积累量减少,产量降低。在同一底墒条件下,小麦总耗水量和籽粒产量均随播种期补灌目标土壤相对含水量的提高呈增加趋势,但补灌水量过多,籽粒产量不再增加,水分利用效率降低。  相似文献   

11.
The fungi most frequently isolated (of 20–100% incidence) from fresh okra, pepper fruits and melon seeds areBotryodiplodia theobromae, Rhizopus stolonifer, Trichoderma harzianum, Mucor mucedo andFusarium oxysporum. The major mycoflora of the fruits which had been sun-dried for twenty days are comprised ofAspergillus spp andPenicillium spp which initially had formed the minor components (of less than 20% incidence) of the colonising population. The effect of sun-drying on the fruits was a statistically significant (P=0.05) decrease in the riboflavin content and a generally small and non-significant decrease in the concentrations of thiamine, niacin, biotin and ascorbic acid. The effect of mouldiness during sun-drying was to further decrease the concentration of the vitamins.  相似文献   

12.
13.
This study evaluated the effects of cultivar and region on the composition of alkylresorcinols (ARs) of 24 wheat bran samples from 6 cultivars grown in four locations (Bath, Nairn, Palmerstone and Ridgetown) in Ontario (ON), Canada, using gas chromatography/mass spectrometry (GC/MS). Total phenolic content (TPC) of wheat bran extracts was determined by the Folin–Ciocalteau method and the antioxidant activity of wheat bran extracts was measured by 2, 2-Dipheny-1-picryhydrazyl radical (DPPH) scavenging activity and oxygen radical absorbance capacity (ORAC). The highest ARs content (μg/g) was found in cultivars Emmit (1522), Harvard (1305), Warthog (1170), and Superior (853), grown in Ridgetown. The relative saturated and unsaturated ARs (%) were 89 and 11, respectively. Total ARs content, their composition, TPC and antioxidant activity of wheat bran extracts were significantly (P < 0.05) affected by location and cultivar and their interaction. TPC, %DPPHdis, and ORAC values for different wheat bran sample extracts ranged from 3 to 58 (mg FAE/g), 5 to 68 (%), and 6 to 94 (μmol TE/g), respectively. Our work provides a detailed examination of region and cultivar effects on potential of ARs in wheat bran and the results can be used for screening and breeding purposes.  相似文献   

14.
种子脂肪含量是花生的重要经济性状。本研究旨在通过分析花生脂肪含量遗传的直接效应和母体效应,为高脂肪含量新品种选育、分子标记开发及基因组选择策略的确定提供依据。选用不同脂肪含量的中间型花生品种豫花9326及潍花6号,龙生型农家品种永城小麻壳,珍珠豆型品种湛油62及泉花6号,配置完全双列杂交组合,索氏残渣法分析5个亲本、20个杂交组合的F1和F2等3个世代种子的脂肪含量,利用广义遗传模型分析脂肪含量遗传的种子胚基因直接效应、母体效应及其遗传力。研究结果表明,双亲之一具有较高脂肪含量,另一亲本具有中等以上脂肪含量,则F1的脂肪含量较高;双亲脂肪含量中等,或者亲本之一脂肪含量较低,则后代脂肪含量较低。种子直接加性效应方差最大,其次为母体加性效应,母体显性效应的方差较小,种子脂肪含量无细胞质效应。种子直接效应的遗传力大于母体效应。高脂肪含量亲本的直接加性效应正值较大,低脂肪含量亲本的直接加性效应的负值较大,中间脂肪含量亲本的直接加性效应数值基本居中,方向有正有负。本研究表明脂肪含量的遗传主要受种子自身基因型的加性效应控制,其次是母体加性效应,无细胞质效应。高脂肪含量花生品种豫花9326和永城小麻壳是优良的高脂肪含量供体亲本。挖掘种子脂肪含量关键调控基因应该兼顾荚果皮中表达基因对种子脂肪含量的调控作用。杂交后代选择及分子标记开发应注重基因的累加效应和优良单倍型的选择。  相似文献   

15.
16.
对福州市部分超市销售的皮蛋、精装香肠、散装香肠、普通榨菜和儿童榨菜进行抽检及3个月的跟踪调查,通过分光光度法,测定食品中亚硝酸盐的含量。结果表明,不同食品中亚硝酸盐含量存在一定差异,但均符合国家标准。  相似文献   

17.
The effects of ultrasound-assisted freezing on the freezing time and water migration of dough, and the structural characteristics of gluten components were investigated. The effects of ultrasound-assisted freezing in the whole immersion freezing process (UWF) on the freezing time were better than those of ultrasound-assisted freezing in the maximum ice crystal generation zone. The shortest freezing time was obtained at 80 W/L, and was 577 s shorter than that with traditional immersion freezing. The UWF treatment at 80 W/L significantly (p < 0.05) affected the absorption enthalpy, freezable water content and water migration of frozen dough. In UWF compared with traditional immersion freezing, the SH content of gluten, glutenin and gliadin was significantly (p < 0.05) higher, by 12.06%, 27.55% and 21.65%, respectively. The surface hydrophobicity of gluten, glutenin and gliadin in UWF treated samples significantly (p < 0.05) decreased, by 19.67%, 13.21% and 9.17%, respectively. The secondary structure of gluten components was also significantly changed by UWF. The network of gluten, the chain structure of glutenin and the gliadin particles were all changed by UWF treatment. These findings indicated that UWF is an effective method to improve the moisture distribution in dough and reduce the damage to protein molecular structure caused by freezing.  相似文献   

18.
A wheat×maize induced doubled haploid population that segregates at the Awned locus for awned and awnless phenotypes were studied at two field sites using a genetic linkage map. Interval QTL analysis indicated that significant QTLs for wheat flour water absorption and protein content were located on a linkage group associated with the morphological marker, awns. The QTL peak for flour water absorption was located at the Awned locus (B1, 5AL), whilst the QTL peak for protein content was located nearby, 10.1 cm away from the Awned locus. The locations of those QTL were confirmed by analysing data from two independent field trials conducted under different environment conditions. The QTL identified for water absorption controlled 12% and 11% of the observed variance at the two field trials, whilst for flour protein content the QTL explained 7% and 19% of the variance respectively. Variance component analysis indicated that the QTL for water absorption controlled approximately 14.8–25.0% and 13.6–23% of the genetic variance at the two sites studied (Roma and Jimbour) whilst the QTL for protein content explained between 12.8% and 30.4% of the genetic variance at Roma and 34.7–82.6% at Jimbour. Cross-site analysis with composite interval mapping approach resulted in significant LOD values of 6.12 and 9.94 for water absorption and protein content, respectively. The QTL for water absorption was independent from the hardness locus.  相似文献   

19.
As titanium oxide is a well-known photocatalyst, we investigated the effects of silver content and nanostructural morphology on the photocatalytic degradation of two dyes, methylene blue and rhodamine B. Two nano-formulations were utilized, including nanofibers and nanoparticles. Silver-grafted titanium oxide nanofibers were synthesized using the electrospinning of silver nitrate/titanium isopropoxide/poly(vinyl acetate) sol-gel. The nanoparticulate form was obtained by calcination of a ground powder prepared from the same electrospun sol-gel. The results affirmed the advantage of the silver-grafted titanium oxide nanostructures over the silver-free ones. Increasing the silver content in the nanofibers led to increases in their surface area, which is an important parameter in heterogeneous catalytic chemical reactions. Therefore, the results strongly suggest the use of silver-grafted titanium oxide in a nanofibrous form. These results further support utilizing Agloaded titanium oxide nanofibers as a photocatalyst.  相似文献   

20.
Summary Significant differences were found in sugar content and invertase activity of tubers of 8 Indian cultivars stored at 3–5°C. Freshly harvested tubers of all the cultivars had low amounts of sugars, which increased during storage, and little or no basal invertase activity but both basal and total invertase activities in all the cultivars increased during storage. There were significant correlations between the reducing sugar content and basal and total invertase activities. Publication no. 116, Central Potato Research Institute, Shimla.  相似文献   

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