Effect of Yeast Extracts Containing Propionic Acid on Bread Dough Fermentation and Bread Properties

Excess molar volumes of binary liquid mixtures of (acetic or propionic acid = hexane) at 25 and 35°C, and (acetic or propionic acid + heptane or octane) and (acetic acid + dodecane) at 25°C, measured with a tilting dilution dilatometer, are reported. The excess volumes are positive over the entire concentration range for all mixtures and increase with increasing length of an alkane molecule, decrease with increasing of the alkyl chain in a molecule of carboxylic acid, and increase with increasing temperature.

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Vapour-liquid equilibrium in the ternary system cyclohexane-acetic acid-propionic acid

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19892840 ◽

1989 ◽

Vol 54 (11) ◽

pp. 2840-2847 ◽

Cited By ~ 1

Author(s):

Ivona Malijevská ◽

Alena Maštalková ◽

Marie Sýsová

Keyword(s):

Acetic Acid ◽

Ternary System ◽

Propionic Acid ◽

Activity Coefficients ◽

Error Propagation ◽

Analytical Techniques ◽

Liquid Equilibrium ◽

Consistency Test ◽

Propagation Law ◽

Equilibrium Data

Isobaric equilibrium data (P = 101.3 kPa) for the system cyclohexane-acetic acid-propionic acid have been measured by two different analytical techniques. Activity coefficients calculated by simultaneous solving of equations for the chemical and phase equilibria were subjected to a consistency test based on inaccuracies determined from the error propagation law, and were correlated by Wilson’s equation. The activity coefficients measured were compared with those calculated from binary vapour-liquid equilibrium data and with values predicted by the UNIFAC method.

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XXI.—The Synthesis of Some Methyl- and Dimethylfluoranthenes

Proceedings of the Royal Society of Edinburgh Section A Mathematical and Physical Sciences ◽

10.1017/s0080454100008773 ◽

1972 ◽

Vol 69 (4) ◽

pp. 281-286

Author(s):

H. F. Andrew ◽

Neil Campbell ◽

E. M. Swan ◽

N. H. Wilson

Keyword(s):

Benzene Ring ◽

Propionic Acid ◽

Hydrofluoric Acid ◽

Phenyl Ring ◽

Ring Closure ◽

Methyl Group ◽

Image Position

3-Methylfluorene-9-propionic acid (1) with hydrofluoric acid undergoes ring-closure on the substituted ring to give 1,2,3,10b-tetrahydro-5-methylfluoranthen-3-one (II).Wolff-Kishner reduction of the ketone yielded l,2,3,10b-tetrahydro-5-methylfluoranthene which on dehydrogenation gave 2-methylfluoranthene (III, R=H) identical with a sample prepared according to the method of Tucker (1952) and differing from 8-methylfluoranthene. This proved that ring-closure of (I) had occurred as expected on the methyl-bearing benzene ring. In this instance ring-closure occurs in the position meta to the methyl group and is reminiscent of the similar ring-closure of 2-phenyl-2-p-tolylpropionic acid to give 6-methyl-3-phenylindanone (Pfeiffer and Roos 1941). It thus provided a further example of the limitations of von Braun's statement that Friedel-Crafts ring-closure occurs much less readily at the position meta to a methyl group than on a phenyl ring (von Braun, Manz and Reinsch 1928).

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