342. A note on the density of full-cream milk solids

1946 ◽  
Vol 14 (3) ◽  
pp. 400-402 ◽  
Author(s):  
C. H. Lea ◽  
R. Gane
Keyword(s):  
Milk Powder ◽  
The Other ◽  
Displacement Method ◽  
Method Error ◽  
Headspace Gas ◽  
Entrapped Air ◽  
Liquid Displacement ◽  
Milk Solids ◽  
Spray Dried

A knowledge of the density of air-free milk solids is required for calculation of the quantity of oxygen originally enclosed in sealed cans containing milk powder, and for conversion of percentages of oxygen obtained by analysis of the headspace gas to absolute units. Determination of this figure is a matter of some difficulty owing to the presence of entrapped ‘air’ in the spray-dried product. In the liquid displacement method there is also a danger of error due to incomplete ‘wetting’ of the particles, or to solution of one or other constituent of the powder, while in the gas-displacement method error may be introduced by solution or adsorption of the gas by the powder. Lea, Moran & Smith(1) obtained values of 1·29 by a pyknometer method with ethylene glycol, and 1·31–1·32 by a nitrogen displacement method for full-cream solids containing 27% of fat. Muers & Anderson(2), on the other hand, reported values of 1·26–1·28 by a liquid-displacement method using propylalcohol. Further determinations have therefore been made by various modifications of all these methods.

404. Determination of the solubility of roller-dried milk powder

1949 ◽  
Vol 16 (3) ◽  
pp. 377-378 ◽  
Author(s):  
A. T. Parsons
Keyword(s):  
Milk Powder ◽  
Comparative Assessment ◽  
Index Test ◽  
Dry Milk ◽  
The Government ◽  
Government Chemist ◽  
Spray Dried

This note gives particulars of a method of determining the solubility of roller-dried milk powders which has been in use in the Department of the Government Chemist for some years. The figures obtained are empirical but are found to be a valuable aid in the comparative assessment of quality. The method is not claimed to be highly original, but appears to have aroused sufficient interest to justify publication. It is used in the Department for roller-dried milks only. For spray-dried powders a method is employed which measures the volume of deposit given on centrifuging similar to the Solubility Index test of the American Dry Milk Institute.

A technique for evaluating reconstitution properties of milk powders

1973 ◽  
Vol 40 (2) ◽  
pp. 135-147
Author(s):  
T. C. Wyeth ◽  
G. C. Cheeseman
Keyword(s):  
Quantitative Data ◽  
Milk Powder ◽  
Skim Milk ◽  
The Other ◽  
Reproducible Technique ◽  
Freeze Dried ◽  
The Ideal

SummaryAn accurate and reproducible technique involving a continuous aqueous elution from a bed of dried-milk powder was developed to evaluate reconstitution characteristics. Quantitative data for the determination of reconstitution behaviour were obtained by analysis of the eluate for protein, lactose and Ca constituents. A reconstitution coefficient (P) was derived from the formula (W1+ΣWi)/T, where W1 was the amount reconstituted in the first eluate fraction, ΣWi the total amount reconstituted in 8 fractions, and T the time taken for 1/3 of the constituent to be reconstituted. Values obtained for P were thus related to the reconstitution properties and could be used to grade the powders. A freeze-dried skim-milk gave the ideal reconstitution behaviour with W1 values in the range 42·0–44·2, ΣWi values in the range 93·6–101·3, T values in the range 3·0–3·3 and reconstitution coefficients in the range 41·1–46·3 for the 3 constituents. All the other preparations tested gave lower values for W1 and P, although some gave ΣWi values in the same range, whilst all T values were higher than those for the freeze-dried sample.

Determination of Orotic Acid by Liquid Chromatography as a Criterion for Calculating Nonfat Milk Solids in Milk Bread

1989 ◽  
Vol 72 (4) ◽  
pp. 627-631
Author(s):  
Lap V Bui
Keyword(s):  
Orotic Acid ◽  
Chromatographic Method ◽  
Colorimetric Method ◽  
Milk Powder ◽  
Skim Milk ◽  
Nonfat Milk ◽  
Liquid Chromatographic Method ◽  
Milk Solids ◽  
Liquid Chromatographic

Abstract A sensitive and reproducible isocratic liquid chromatographic method is described for the determination of orotic acid levels in skim milk powder and milk bread. The results are used to calculate the nonfat milk solids content in milk bread. Sample preparation is simple and rapid and produces an extract which, after passing through an on-line cleanup system, has a minimum adverse effect on the performance and life of the analytical column. Mean recoveries of 96-105% were obtained with coefficients of variation in the range 1.0-8.5% and a detection limit of 5 mg/kg. The liquid chromatographic method was more sensitive than the standard colorimetric method, while results obtained by both methods agreed closely.

scholarly journals Gas chromatographic determination of some carboxylic acids: comparison between solution and headspace analysis

Chemija ◽  
2019 ◽  
Vol 30 (4) ◽  
Author(s):  
Birutė Bugelytė ◽  
Karolina Ilonina ◽  
Vilius Poškus ◽  
Vida Vičkačkaitė
Keyword(s):  
Gas Chromatography ◽  
Carboxylic Acids ◽  
Chromatographic Analysis ◽  
Headspace Analysis ◽  
Chromatographic Determination ◽  
The Other ◽  
Headspace Gas Chromatography ◽  
Solid Samples ◽  
Headspace Gas

Direct and headspace gas chromatographic analysis is compared for the determination of lactic, oxalic, succinic, malic and citric acids. For better chromatographic behaviour, prior to GC analysis carboxylic acids were derivatized using BSTFA as a silylation reagent. Three solvents – acetone, diethyl ether and dimethylformamide – were tested as a derivatization medium and DMF was considered as the best. Derivatization conditions were optimized and analytical characteristics of the direct gas chromatographic determination of analytes in solutions were determined. The method was applied for the determination of citric acid in food. For the analytes dissolved in DMF, the headspace gas chromatographic determination was not sensitive enough. Concentrations of the derivates in the headspace were very low, thus the limits of detection were high and the method was not of practical use. On the other hand, headspace gas chromatography can be applied for identifying of carboxylic acids in solid samples.

341. The effect of the pre-heating temperature on the bacterial count and storage life of whole milk powder spray-dried by the Krause process

1946 ◽  
Vol 14 (3) ◽  
pp. 378-399 ◽  
Author(s):  
J. D. Findlay ◽  
Constance Higginbottom ◽  
J. A. B. Smith
Keyword(s):  
Room Temperature ◽  
Heating Temperature ◽  
Milk Powder ◽  
Bacterial Count ◽  
Strong Reaction ◽  
Whole Milk ◽  
Whole Milk Powder ◽  
And Storage ◽  
Spray Dried

1. Storage tests on spray-dried full-cream milk powders prepared from milk preheated at 160,170,180, 190 and 200° F. for approximately 20 sec. and dried by the Krause process have been carried out at 47, 37 and 15° C. or room temperature. The storage tests were carried out independently at two different research stations. At the Hannah Institute the powders were packed in plain tin-plate containers as received from the factory. At Cambridge grease-free plain tin-plate and lacquered tin-plate containers were used. Deterioration was followed at both stations by a tasting panel and by determination of the amount of oxygen absorbed by the powder and of the accumulation of peroxide in the fat.2. When fresh the powder pre-heated at 180° F. had the best flavour, followed in order of preference by those pre-heated at 190 and 200° F., which had a definite but quite pleasant ‘boiled’ or ‘cooked’ flavour, and by those pre-heated at 160 and 170° F. which had an incipient tallowy flavour, but were nevertheless still acceptable. The 200 and 190° F. powders gave a strong reaction for volatile sulphur, the 180° F. powder a much weaker but quite definite reaction, and the 170 and 160° F. powders a negative reaction. The copper content of the 180° F. powder which, with the 170° F. sample, was the highest of the group, may have been partly responsible for the weakness of the reaction for volatile sulphur given by this sample. The solubility of the 180, 190 and 200° F. powders was not adversely affected by the high pre-heating temperatures, and the moisture contents of all the powders were sufficiently low to prevent any obvious loss of solubility, which remained very good indeed throughout the storage tests.

Determination of the pore sizes of permeable metallic materials by the liquid displacement method

1987 ◽  
Vol 26 (9) ◽  
pp. 721-724 ◽  
Author(s):  
L. E. Lunin ◽  
A. G. Kostornov ◽  
A. S. Glushchenko ◽  
G. A. Kolesnichenko
Keyword(s):  
Metallic Materials ◽  
Displacement Method ◽  
Pore Sizes ◽  
Liquid Displacement

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

Determination of the Burgers vector of a dislocation in a Fe-Mn alloy by weak-beam image in HVEM

1978 ◽  
Vol 36 (1) ◽  
pp. 330-331
Author(s):  
Y. Ishida ◽  
H. Ishida ◽  
K. Kohra ◽  
H. Ichinose
Keyword(s):  
High Order ◽  
Simulation Technique ◽  
The Other ◽  
Image Simulation ◽  
Diffraction Vector ◽  
Burgers Vector ◽  
Weak Beam ◽  
Beam Image ◽  
Edge Component

IntroductionA simple and accurate technique to determine the Burgers vector of a dislocation has become feasible with the advent of HVEM. The conventional image vanishing technique(1) using Bragg conditions with the diffraction vector perpendicular to the Burgers vector suffers from various drawbacks; The dislocation image appears even when the g.b = 0 criterion is satisfied, if the edge component of the dislocation is large. On the other hand, the image disappears for certain high order diffractions even when g.b ≠ 0. Furthermore, the determination of the magnitude of the Burgers vector is not easy with the criterion. Recent image simulation technique is free from the ambiguities but require too many parameters for the computation. The weak-beam “fringe counting” technique investigated in the present study is immune from the problems. Even the magnitude of the Burgers vector is determined from the number of the terminating thickness fringes at the exit of the dislocation in wedge shaped foil surfaces.

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