scholarly journals Determination of the cohesion, powder flow speed dependency and caking tendency of cocoa powders

2019 ◽  
Vol 2 (3) ◽  
pp. 483-491
Author(s):  
Mahmut Dogan ◽  
Duygu Aslan Türker
Keyword(s):  
Flow Characteristics ◽  
Fat Content ◽  
Flow Speed ◽  
Solid Particles ◽  
Powder Flow ◽  
Food Powders ◽  
Three Samples ◽  
Powder Flowability ◽  
The Mean

Cocoa is one of the most popular foodstuffs known for centuries and cocoa powders are particularly exposed to caking, a phenomenon of agglomeration of solid particles that disrupt powder functionality. This study aimed to identify the main powder flow characteristics such as caking, cohesion and powder flow speed dependency of cocoa powders, according to their fat content. The loose and tapped bulk density, as well as Carr ratio of cocoa powders, was determined as bulking properties for comparing and interpreting the flowability. The caking was observed in all three samples. With increasing fat content, a decrease in the powder flowability was detected. The mean cake strength of the low fat, reduced fat and full-fat cocoa powders was recorded as 110.42±1.71; 164.175±1.75 and 207.96±0.93, respectively. These results suggest that the fat contents of the food powders may be a useful parameter to describe the powder flowability.

Analysis of Fat-Soluble Vitamins. XX. Determination of Vitamin D in Multivitamin Preparations. Second Collaborative Study

1978 ◽  
Vol 61 (3) ◽  
pp. 735-745
Author(s):  
Ellen J De Vries ◽  
Frits J Mulder ◽  
Ben Borsje
Keyword(s):  
Vitamin D ◽  
Vitamin A ◽  
Test Data ◽  
Vitamin D3 ◽  
Collaborative Study ◽  
Three Samples ◽  
The Mean ◽  
Fat Soluble Vitamins

Abstract The official first action method for determining vitamin D in multivitamin preparations was modified. The method was collaboratively studied by 7 laboratories, using 6 preparations in oil. The preparations consisted of vitamin D at various levels and at various ratios (in w/w) to vitamin A. Three samples contained cholecalciferol and 3 samples contained vitamin D3 from vitamin D3 resin. After outliers were eliminated by the Dixon test, data were analyzed and averages were compared with amounts of vitamin D known to be in each sample. For samples with vitamin D: vitamin A ratios of 1:0.5, 1:5, and 1:10, the mean vitamin D recoveries were 98.8, 94.6, and 90.7%, respectively. The method has been adopted as official final action.

A simple spectroturbidimetric method for the determination of the fat content of homogenized ice-cream mixes

1962 ◽  
Vol 29 (1) ◽  
pp. 47-53 ◽  
Author(s):  
J. D. S. Goulden ◽  
P. Sherman
Keyword(s):  
Standard Deviation ◽  
Ice Cream ◽  
Fat Content ◽  
Fat Globule ◽  
The Mean ◽  
Simple Filter

SummaryA rapid spectroturbidimetric method for the determination of the fat content of homogenized ice-cream mixes using a simple filter absorptiometer has been devised. Turbidities are measured at two different wavelengths to allow for changes in the degree of homogenization. The standard deviation of the differences from the values obtained by the Werner-Schmid method was found to be 2·5% of the mean fat content value. The method also enables the mean fat globule diameter to be determined.

Compression characteristics of agglomerated food powders: Effect of agglomerate size and water activity Características de la compresión de alimentos en polvo: Efecto del tamaño del aglomerado y del contenido de humedad

1997 ◽  
Vol 3 (5) ◽  
pp. 351-359 ◽  
Author(s):  
H. Yan ◽  
G.V. Barbosa-Cánovas
Keyword(s):  
Particle Size ◽  
Water Activity ◽  
Flow Characteristics ◽  
Exponential Model ◽  
Compression Tests ◽  
Food Powders ◽  
Powder Flowability ◽  
Compression Data ◽  
The Stability ◽  
Compression Characteristics

The stability of food agglomerates is very important for keeping optimal instant properties as well as flow characteristics. Compression tests have been proven not only to be useful tools in char acterizing attrition, but also excellent descriptors for powder flowability. The purpose of this work was to study the effects of particle size and water activity ( a w) on the compression characteristics of selected agglomerated food powders, and then to identify suitable mathematical models by using a non-linear regression program for predicting the compression characteristics of food agglomerates when partial attrition takes place. Three agglomerated food powders - non-fat milk, low fat milk and instant coffee - were classified by size into five or six fractions with a set of RX-29 sieve screens. Each fraction was conditioned at three aw levels, placed in a cylindrical compression cell, and compressed with a piston attached to the crosshead of a TA-XT2 texture analyser. The crosshead speed was 1 mm/s in all tests and the maximum force applied was 245 N. Particle size was found to play a significant role in compression tests in that the greater the particle size, the greater the volume reduction. It was easier to compress the low aw samples, but in all tests changing aw did not significantly affect compression characteristics. Sone's two- parameter model accurately described the combination of compaction and attrition when compres sion pressure did not exceed a certain level, while Peleg's double-exponential model with four parameters best fitted the compression data.

scholarly journals Occurrence of aflatoxins in peanuts and peanut products determined by liquid chromatography with fluorescence detection

2013 ◽  
pp. 27-35 ◽  
Author(s):  
Biljana Stojanovska-Dimzoska ◽  
Zehra Hajrulai-Musliu ◽  
Elizabeta Dimitrieska-Stojkovic ◽  
Risto Uzunov ◽  
Pavle Sekulovski
Keyword(s):  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Limit Of Detection ◽  
Total Content ◽  
Immunoaffinity Column ◽  
Limit Of Quantification ◽  
Three Samples ◽  
The Mean ◽  
Positive Results

Liquid chromatography with fluorescence detection using immunoaffinity column clean-up was a method described for determination of aflatoxins (AFB1, AFB2, AFG1 and AFG2) in peanuts and peanut based products. The validation of the procedure was performed. Good coefficient of correlation was found for all aflatoxins in the range of 0.9993-0.9999. Limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.003-0.005 mg/kg and 0.009-0.023 mg/kg, respectively, which was acceptable. The mean recovery for total aflatoxins was 88.21%. The method also showed acceptable precision values in the range of 0.171-2.626% at proposed concentration levels for all four aflatoxins. RSDR values (within laboratory reproducibility) calculated from the results showed good correlation between two analysts for all aflatoxins and they ranged from 4.93-11.87%. The developed method was applied for the determination of aflatoxins in 27 samples of peanuts and peanut based products. The results showed that 21 peanut samples (77.7%) were below LOD of the method. Three samples had positive results over the MRL. There was one extreme value recorded for the total aflatoxins in peanut (289.2 mg/kg) and two peanut based products, peanut snack and peanut, with total content of aflatoxins being 16.3 mg/kg and 8.0 mg/kg, respectively. The obtained results demonstrated that the procedure was suitable for the de?termination of aflatoxins in peanuts and peanut based products and it could be implemented for the routine analysis.

Analysis of Fat-Soluble Vitamins. XX. Determination of Vitamin D in Multivitamin Preparations. Second Collaborative Study

1978 ◽  
Vol 61 (3) ◽  
pp. 731-734
Author(s):  
Ellen J De Vries ◽  
Frits J Mulder ◽  
Ben Borsje
Keyword(s):  
Vitamin D ◽  
Vitamin A ◽  
Test Data ◽  
Vitamin D3 ◽  
Collaborative Study ◽  
Three Samples ◽  
The Mean ◽  
Fat Soluble Vitamins

Abstract The official first action method for determining vitamin D in multivitamin preparations was modified. The method was collaboratively studied by 7 laboratories, using 6 preparations in oil. The preparations consisted of vitamin D at various levels and at various ratios (in w/w) to vitamin A. Three samples contained cholecalciferol and 3 samples contained vitamin D3 from vitamin D3 resin. After outliers were eliminated by the Dixon test, data were analyzed and averages were compared with amounts of vitamin D known to be in each sample. For samples with vitamin D: vitamin A ratios of 1:0.5, 1:5, and 1:10, the mean vitamin D recoveries were 98.8, 94.6, and 90.7%, respectively. The method has been adopted as official final action.

Flow Characteristics of Planted Soil Filters

1994 ◽  
Vol 29 (4) ◽  
pp. 37-44 ◽  
Author(s):  
R. Netter
Keyword(s):  
Residence Time ◽  
Tritiated Water ◽  
Flow Characteristics ◽  
Stagnant Water ◽  
Soil Material ◽  
Hydraulic Load ◽  
Investigation Period ◽  
The Mean ◽  
Stable Anion

Various water tracers were used for the determination of flow characteristics such as residence time, velocity of flow, and dispersion phenomena especially under the aspect of stagnant water regions. The tracers applied were bromide, uranin, eosin, lithium salt, and in one case tritiated water as a reference. Bromide as a chemically very stable anion with no detectable retardation proved under these conditions as very reliable. Uranin and eosin showed low retardation but were subject to losses by sorption, degradation, and photolysis in uncovered regions. Lithium can not be recommended for such applications. The results showed that the mean residence time in the filter was between 6 and 40 days with respect to hydraulic load, evapotranspiration, soil material and the hydraulic gradient. The determined conductivity of the filters was approximately 10−4 to 10−5 m/s and did not vary during the investigation period.

How Reliable are Reported Plasma Clozapine Levels?

2001 ◽  
Vol 35 (4) ◽  
pp. 468-473 ◽  
Author(s):  
Ron Bell ◽  
Ron Bell ◽  
Andrew Mclaren ◽  
David Copolov
Keyword(s):  
New Zealand ◽  
Human Plasma ◽  
Phase Ii ◽  
Phase Iii ◽  
Three Samples ◽  
Freeze Dried ◽  
Maximum Coefficient ◽  
The Mean ◽  
High Level

Objective: Many practitioners use plasma levels to determine the optimum dosage of clozapine. The aim of this study was to determine the intra- and interlaboratory accuracy in assaying samples of clozapine dissolved in human plasma. Method: Three samples were sent to one laboratory to obtain an initial determination of accuracy (phase I). Then samples of clozapine dissolved in human plasma were prepared at concentrations of 140, 310 and 580 ng/mL and despatched on dry ice to 10 assaying centres in Australia and New Zealand. The results of the survey were analysed and posted to each centre (phase II). The programme was repeated using concentrations of 160, 380 and 640 ng/mL (phase III). Samples prepared in purified water and freeze-dried samples were also despatched. Results: In phase II there were two centres with results significantly different from the mean. In phase III all the centres returned concordant results. There was a high level of consistency in the measurement of samples with a maximum coefficient of variation of 0.16. The concentrations determined by the centres, however, were significantly lower than the nominal concentrations of the prepared solutions. Conclusions: Clinicians in Australia and New Zealand who wish to know their patients' plasma-clozapine levels can be confident that the result of the assay is unlikely to vary with the choice of centre or the operator who performs the assay.

scholarly journals Chromatographic Method for the Determination of Aflatoxin M1 in Cheese, Yogurt, and Dairy Beverages

2011 ◽  
Vol 94 (5) ◽  
pp. 1513-1518 ◽  
Author(s):  
Maria Helena Iha ◽  
Cynara Baltazar Barbosa ◽  
Rosa Maria Duarte Favaro ◽  
Mary W Trucksess
Keyword(s):  
Fluorescence Detection ◽  
Chromatographic Method ◽  
Fat Content ◽  
Aflatoxin M1 ◽  
Immunoaffinity Column ◽  
Aqueous Methanol ◽  
Methanol Extraction ◽  
The Mean ◽  
Dairy Beverages

Abstract The aim of this work was to develop and validate a method to determine aflatoxin M1 (AFM1) in cheese, yogurt, and dairy beverages. The method consisted of aqueous methanol extraction, immunoaffinity column purification and isolation, RPLC separation, and fluorescence detection. The four types of cheese samples were classified according to moisture and fat content. The mean recoveries were 71% for cheese at spiked levels from 100 to 517 ng/kg, and 76% for yogurt and dairy beverages spiked at levels from 66 to 260 ng/kg. The mean RSDs were 5.9% for cheese, and 10% for yogurt and dairy beverages. The LOD was 3 ng/kg and the LOQ was 10 ng/kg for all test commodities. To test the applicability of the developed method, a small survey of the presence of AFM1 in cheese, yogurt, and dairy beverages purchased in Ribeirão Preto-SP, Brazil, was conducted. AFM1 was detected (>3 ng/kg) in all samples. Twenty cheese samples (83%) were contaminated with AFM1 in the range of 13–304 ng/kg. In yogurt and dairy beverages, the contamination was lower (13–22 ng/kg) in five samples (42%). The results indicated that the method is adequate for the determination of AFM1 in these four types of cheese, as well as in yogurt and dairy beverages.

Determination of Polyolefins Powder Flow Characteristics in a Purge Column during Product Transitions

2007 ◽  
Vol 46 (24) ◽  
pp. 8120-8129
Author(s):  
Alberto Buchelli ◽  
Jeffrey R. Golden ◽  
Debra L. Beran
Keyword(s):  
Flow Characteristics ◽  
Powder Flow

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

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