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1.
Whole seeds were digested in sulfuric acid with catalyst in conical beakers on a hot plate and the digest was analyzed for nitrogen. The nitrogen analysis of the digest can be performed by distillation-titration or colorimetrically, using manual or automatic procedures, linear regression analyses of 8 samples of 16 soybeans each gave values that agreed within 2% of those obtained by the standard Kjeldahl procedure. Precision of the method is 1.8 relative standard deviation compared with 1.4 relative standard deviation for the standard method. The whole seed procedure gives results that are independent of seed size and has been applied to samples of both oilseeds and cereal grains.  相似文献   

2.
In the crop year 1979, freshly harvested dent corn was coUected at maturity in 57 sets of 2 equivalent samples/set. One set was dried the day of collection in Georgia and the other set was shipped to Peoria in corrugated cardboard boxes before drying, The set that was not dried in Georgia was shelled and dried as soon as possible after arrival in Peoria to prevent further aflatoxin formation. Both sets of samples were analyzed randomly at the Northern Regional Research Center, Peoria. In 22 Peoria-dried samples, aflatoxin was detected in levels ranging from 2 to 449 ng/g total toxin but was not detected in the matching samples dried die same day of collection in Georgia. It took an average of 7 days to ship samples from Georgia. Of the 57 samples dried in Georgia, 63% were negative for aflatoxin; aflatoxin was below violative levels (>20 ng/g) in 82%; the average aflatoxin level in all samples was 36 ng/g. In the matching 57 samples dried in Peoria after shipment, aflatoxin was detected in all but 37%; aflatoxin was below violative levels in 70% of the samples; the average aflatoxin level in all samples that had been dried later was 78 ng/g. There was a significant increase in aflatoxin-positive samples associated with shipment prior to drying. These results indicate that aflatoxin formed during shipment of the 1979 freshly harvested corn samples from Georgia.  相似文献   

3.
Effect of seeds on the formation of sol-gel mullite   总被引:3,自引:0,他引:3  
Mullite precursor gels have been prepared from a mixture of particulate boehmite sol and tetraethoxysilane at a pH of 4. The sol has been seeded with submicron size -Al2O3, γ-Al2O3 and mullite limited to two percent by weight of the mullite phase. These gels have been invesitgated with respect to phase formation, densification and microstructural development. Dilatometric studies on the seeded precursor gels indicate marked shrinkage in their profiles. Of the different seed nuclei, fine mullite particles have shown excellent influence in the early ceramic phase formation as well as densification. Further they induce complete transformation of the precursor gel to the high temperature phase as well as a uniform fine-grained microstructure.  相似文献   

4.
‘Forrest’ soybeans were stored for two yearsand the extracted lipids were assayed for hydroperoxide content. The crude lipid was separated by high- performance liquid chromatography (HPLC), and three hydroperoxide peaks plus the triglyceride peak were measured every two months. There was a lag in hydroperoxide production for the first nine months followed by a steady increase for the remaining twenty- two months. This method of measuring changes in lipid oxidation should be useful for monitoring seed changes in germination and vigor during storage. Published with the approval of the director of the Arkansas Agricultural Experiment Station.  相似文献   

5.
Kinetics of the lipolysis ofNigella sativa oil catalyzed by native lipase in crushed seed were studied between 20 and 90°C. Data fitted the pseudo first-order rate equation at 20, 30 and 40°C; and the pseudo second-order equation at 50, 60 and 70°C, but neither equation fit at 80 and 90°C. Lipolysis approximated first-order with respect to water.  相似文献   

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9.
Aflatoxin assays were conducted on seeds from cotton bolls inoculated withAspergillus flavus in commercial fields in Arizona. Inoculations were at sutures at the initiation of boll opening either in the morning or evening in August over a three-year period. One morning inoculation was followed by a water treatment that simulated rain. Fully fluffed bolls were harvested after two or four weeks, and lint and seed linters were examined for bright-green-yellow-fluorescence (BGYF). Ginned seed were assayed for aflatoxin. While BGYF of lint was detected, no seed linters exhibited BGYF and no seeds from the 140 bolls examined contained aflatoxin. Results imply that boll infection byA. flavus occurs before the initiation of boll opening, an observation that is in agreement with recent reports ofA. flavus infection but contrary to conclusions made in earlier reports.  相似文献   

10.
Summary Excised Lincoln soybean stems bearing pods and leaves were supplied with C14 labeled-sucrose for brief periods, and the subsequent appearance of radio-activity in the different fatty acids was observed up to 18 days. The individual fatty acids were separated as their 2,4-dinitrobenzenesulfenyl chloride derivatives and the specific activity of the different fractions were determined. Radioactivity appeared in the fatty acids in the following order: oleic, saturated, linoleic, linolenic. Consistent presence of highest specific activity in the oleic acid fraction indicated that oleic may be converted to the other acids, at least to some extent. Journal Paper No. 719 of the Purdue Agricultural Experiment Station, Layfayette, Ind.  相似文献   

11.
Globally, there is an increasing demand for sources of plant-based protein. While Brassica napus L. is an important oilseed crop worldwide, there is also interest in improving its ability to serve as a valuable source of plant-based protein. Cruciferin, a seed storage protein that makes up 60% of the protein found in mature seeds of B. napus, is of interest for human consumption as a source of protein and as an ingredient in food products due to its functional properties. Existing methods for quantification of cruciferin protein are often time consuming and destroy the seed. This study explored the potential for the measurement of cruciferin protein content in whole seeds of B. napus by near-infrared spectroscopy (NIRS), to allow for efficient and non-destructive screening of breeding material. An enzyme-linked immunosorbent assay (ELISA)-based reference method was utilized to assess cruciferin content in a diverse population of B. napus. Scanning of whole seed samples produced spectra that were used to develop NIRS calibration equations. Statistical analysis of the calibration results indicated that the NIRS equations developed are poorly suited for prediction of cruciferin content.  相似文献   

12.
超临界CO2萃取八角茴香油及其化学成分研究   总被引:2,自引:0,他引:2  
朱凯  朱新宝 《现代化工》2006,26(Z2):178-180
用超临界CO2萃取(SFE-CO2)技术,在压力16 MPa、温度35℃、反应时间2 h及CO2流量30L/h的条件下,对八角茴香的果实进行了萃取,得到八角茴香萃取物,并用水蒸气蒸馏法提取八角茴香精油.对不同提取工艺得到的八角茴香产品的得率及质量进行了分析比较,结果显示SFE-CO2法产品得率高,为10.5%,而水蒸气蒸馏法仅为7.5%.用GC-MS分别对SFE-CO2萃取物和水蒸气蒸馏精油的化学成分及相对含量进行了测定,共鉴定出40种化合物超临界CO2萃取物有39个,其中大茴香脑质量分数为78.91%;水蒸气蒸馏精油有37个,大茴香脑质量分数为83.8%.  相似文献   

13.
High-resolution13C and1H magic angle sample spinning nuclear magnetic resonance (NMR) spectra have been obtained and used to define the relative unsaturated acyl distribution of triacylglycerols in whole oil seeds. Inverse gated proton decoupled13C and1H NMR spectra permit the quantitative analysis of seeds containing simple oils,e.g., sunflower seeds containing oleyl and linoleyl unsaturates only. More sensitive13C NMR techniques are necessary for the analysis of specific seed classes. One such class is the rapeseed, which is especially difficult due to its low oil content (≈ 2 mg oil/seed) and complex unsaturated acyl profile of oleyl, linoleyl, linolenyl, erucyl, and eicosenoyl. The Distortionless Enhancement by Polarization Transfer technique significantly improves sensitivity to the extent that single rapeseeds can be examined within an hour of acquisition time. Furthermore, some positional (1,3- or 2-glycerol attachment) groups can be identified leading to a partial estimation of the 1,3-, 2-acyl distribution.  相似文献   

14.
Enzymology and Molecular Biology of Aflatoxin Biosynthesis   总被引:2,自引:0,他引:2  
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15.
The aflatoxin contamination potential in pecans has been clearly demonstrated in the literature. No definitive study has been published indicating the extent of aflatoxin contamination in pecans. Good manufacturing practices can be maintained in culture, drying, sizing, storing, and processing which should reduce the possibility of mold growth or aflatoxin production. Sampling of pecans for aflatoxin analysis would be costly due to the great number of pecan sizes and grades as well as to the high cost of pecans. Surveillance costs could be minimized by incorporating chopping with subsampling.  相似文献   

16.
浅谈三种茴香油及工业生产方法   总被引:6,自引:0,他引:6  
徐善述  杨洪珍 《天津化工》2003,17(4):32-33,36
文章主要介绍了三种茴香油(即大茴香油、茴香油、小茴香油)的性质和用途,深加工产品情况及工业生产方法。并详细阐述了工业生产上在常压下用水蒸气蒸馏法来制取大茴香油的工艺过程、主要设备和生产步骤。文章最后对该产品的经济效益和发展前景进行了分析。  相似文献   

17.
The seeds of 8 plant species of Mimosaceae were studied for their fat and protein contents and fatty acid and mineral compositions. The oil fromEntada phaseoloides contained 14 newly identified acids in addition to 8 previously reported. Six seed oils were rich in oleic and linoleic acid as the sum of 18:1 and 18:2 ranged from 64.4–78.5%.  相似文献   

18.
Studies on crude safflower oils have established that three phosphatides extracted with the oil from the kernel of the seed are responsible for color formation. The phosphatides have been isolated and identified as phosphatidylethanolamine (PE), phosphatidylmyoinositol (PI) and phosphatidylcholine (PC). Phosphatidylethanolamine was the most potent contributor to color formation, followed by phosphatidylinositol and phosphatidylcholine. The color-forming compounds were separated from the crude oil by precipitation with water and obtained in pure form by column chromatography on DEAE cellulose. The components were identified by comparison of Rf values of intact and deacylated phosphatides with those of known reference compounds, by determination of molar ratios of ester, glycerol, choline, inositol, nitrogen and phosphorus, and by qualitative and quantitative gas chromatographic analysis of the fatty acid residues. Presented at the AOCS Spring Meeting, San Francisco, April 1969. W. Utiliz. Res. Dev. Div., ARS, USDA.  相似文献   

19.
TheMoringa peregrina kernel contains 1.8% moisture, 54.3% oil, 22.1% protein, 3.6% fiber, 15.3% carbohydrate and 2.5% ash. The composition and characteristics of the extracted oil were determined. Gas liquid chromatography of methyl esters of the fatty acids shows the presence of 14.7% saturated fatty acids and 84.7% unsaturated fatty acids. The fatty acid composition is as follows: palmitic 9.3%, palmitoleic 2.4%, stearic 3.5%, oleic 78.0%, linoleic 0.6%, linolenic 1.6%, arachidic 1.8% and behenic 2.6%.  相似文献   

20.
韩振亚  潘振朝  张燕  刘辉  陈磊 《广东化工》2016,(12):129-130
黄曲霉毒素是由黄曲霉菌产生的一种次级代谢产物,对人和动物都有很大的伤害。黄曲霉毒素会通过被污染的谷物、粮食、饲料等以及通过用污染的饲料喂养动物而进入人体,从而对人畜产生致癌、致畸等危害,因此,准确地检测食品中的黄曲霉毒素含量具有重要的意义。本文论述了黄曲霉毒素的酶学检测方法,并就其应用进行讨论。  相似文献   

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