1,4-Di-tert-butylbenzene (DTBB) was crystd. from several org. solvents to study the effect of solvents and crystn. conditions on its habit. The length to width ratio of DTBB crystals varies from 1.2 to 20 being correlated directly to the max. attainable supersatn. Some effect of elongation was detected caused by addn. of impurities to the crystg. soln. A special crystal habit modification of acicular outgrowths was noted in crystals grown from tert-butyl-alc. The appearance of outgrowths is ascribed to solvent-solute alignment induced by structural compatibility of the DTBB mol. and tert-butyl-alc. dimers. [on SciFinder(R)]

Several food emulsifiers serve as crystal structure modifiers for stearic acid [57-11-4] crystd. from various org. solvents. Stearic acid that usually ppts. under appropriate crystn. conditions as the B-form is converted into the C-form when 1-5% of sorbitan esters or ethoxylated sorbitan esters of fatty acids are present in the soln. Other emulsifiers such as polyglycerol esters, substituted monoglycerides and sucrose esters of fatty acids consisting of bulky hydrophilic groups, are also effective emulsifiers in preserving the C-form of the crystd. stearic acid. The active emulsifiers modify the external crystal habit of stearic acid. Mass spectrograph anal. indicates that sorbitan monostearate (Span 60) is pptd. with the stearic acid. [on SciFinder(R)]

Polyglycerol esters of fatty acids were analyzed by high-performance liq. chromatog. with a 25 cm × 4.6 mm column packed with 10 $μ$m LiChrosorb Diol. The isomers were eluted by gradient with a hexane-iso-PrOH mixt. within 60 min, and the components monitored by UV absorption at 220 nm. Monoglycerol and polyglycerol monoesters, as well as polyglycerol polyesters of oleic acid, were sepd. and evaluated. [on SciFinder(R)]

Four of 17 polyglycerol fatty acid esters, added to flour at the 0.5% level, affected bread quality by raising the loaf vol. significantly over that of the control. These were decaglycerol decaoleate [11094-60-3], decaglycerol tetrastearate [79665-91-1], octaglycerol monooleate [75719-56-1], and decaglycerol monolaurate [34406-66-1]. Decaglycerol monolaurate and octaglycerol monooleate markedly improved the dough mixing characteristics and increased the dough development time from 1.5 to 4.5 min. With the addn. of decaglycerol tetrastearate or decaglycerol monolaurate, the dough becomes more resistant to extension in comparison with the control (490 and 570 Brabender units, resp., compared to 310 for the control). [on SciFinder(R)]

Free oleic acid is emulsified in water and oxidized using potassium permanganate, to azelaic and pelargonic acids, together with dihydroxy-, ketohydroxy- and diketo-stearic acids at neutral pH. The yield and the products distribution are controlled by: the type of emulsifier and its concn.; the oleic acid concn. in the emulsion; and the oleic acid-oxidant ratio. [on SciFinder(R)]

A new method for rapid evaluation of emulsion stability was developed. The technique is based on elec. cond. measurements during non-destructive short heating-cooling-heating cycles carried out on cosmetic viscous emulsions. The cond. curve obtained during the second heating cycle is lower and almost parallel to the first curve. The bigger the cond. difference between the two heating curves, the lower is the stability of the emulsion. A relative stability index, $Δ$/h, indicating relative change in cond. between two cycles was elaborated allowing easy comparison of emulsion stabilities having different initial cond. The method was compared to std. stability tests with good correlation. [on SciFinder(R)]

Mimic (artificial) urine soln. of 10-3M Ca2+ concn. was mixed with equimolar Na oxalate soln. and the Ca2+ concn. (activity) was measured. The Ca2+ concn. rapidly decreased as a result of Ca oxalate pptn., reaching a plateau after 30 min. Addn. of polyglutamate or polyaspartate retarded the drop in the Ca2+ concn. Glutamate or aspartate (monomer) and glutamylglutamic acid (dimer) had no retardation effect. Three other polymers with free carboxylic or sulfonic groups (PAS, PAA, CMC) inhibited Ca2+ pptn. in a similar way to polyglutamate, whereas albumins and polyethyleneglycol had no effect. Addn. of 5-10% normal urine retarded Ca2+ pptn., whereas 10% pathol. urine had no effect. [on SciFinder(R)]

Mono-, di-, tri-, and polyesters of sucrose prepd. by transesterification with Me stearate or palmitate and tallow fat were sepd. by high-performance liq. chromatog. with UV and refractive index detectors using MeOH-iso-PrOH and aq. MeOH as eluents. [on SciFinder(R)]

Ease of formation and stability of oil (D-limonene) in water emulsions were studied and detd. by measuring the spectral adsorption of dild. emulsions at 2 wavelengths (800 nm and 400 nm). Stability indexes were derived from measurements carried out 24 h after prepn. at room temp. and after an addnl. 8 h of incubation at 75°. Various factors affecting emulsion stability, such as type of emulsifier and required HLB, oil concn., and amt. of emulsifier and the method of prepn. were tested by using this method. [on SciFinder(R)]

The soly. curves of 1,4-di-tert-butylbenzene in a series of solvents were detd. The attainable undercooling was measured at cooling of 6-60°/h in those solvents. The correlation between the soly. power of each solvent and the attainable undercooling for an org. compd. may allow prediction of undercooling for that compd. at a specified cooling rate, when the soly. in that solvent is known. [on SciFinder(R)]

Polymorphic transformations of stearic acid in their crystn. solns. were studied. When stearic acid crystals were left in the ethanolic satd. mother liquor, the B-form modification was obtained throughout the whole process. In hexane and benzene during the first 2-3 h, the C-polymorph was the predominant form and later transformed progressively into the B-form so that towards the end of the expt. the whole ppt. was in the B-form. The proposed explanation is that the transformation is due to dissoln. caused by thermal fluctuation in the bath, and subsequent pptn. The dissoln. and repptn. was followed up by micro photographs. In the presence of Span 60, only the C form was obtained in all solvents. [on SciFinder(R)]

A std. bakers' grade wheat flour contg. 11.5% protein was mixed with various concns. of Na stearoyl-2-lactylate (SSL) [25383-99-7], Ca stearoyl-2-lactylate [5793-94-2], isostearoyl-2-lactylate [76021-79-9], SSL-Span 60 [1338-41-6] (3-7:7-3), SSL-Polysorbate 60 [9005-67-8] (1-3:1), or a mixt. of monoglyceride stearate [31566-31-1] and diglyceride stearate [1323-83-7], and farinog., extensog., and baking quality measurements were made. Best overall results were obtained with 0.5% SSL, Ca stearoyl-2-lactylate, or SSL-Span 60 (7:3), which induced a 10-15% increase in loaf vol. as compared to controls without emulsifiers. Flour with 0.5% mono- and diglyceride stearate added produced a relatively poor quality product. [on SciFinder(R)]

Stearic acid was crystd. from various org. solvents (acetone, benzene, EtOH, and hexane) under different conditions. The structural modifications (A, B, and C) of the fatty acid are correlated to the solvent properties and depend on the interplay between the crystn. conditions and the solvent-solute interactions. [on SciFinder(R)]

The crystal size and the length to width ratio of nitrofurantoin (I) [67-20-9] can be controlled using an appropriate mixt. of solvents and suitable crystn. conditions. DMF formed undesirable complexes with I while with HCO2H [64-18-6] no crystal structure modification or complexation was detected. The length (y) to width (x) ratio of I varies from 2.5 to 1.5 when crystd. from pure HCO2H or in a mixt. with H2O or EtOH [64-17-5]. The y/x values corresponded to the solvent interactions and supersatn. The crystal growth regularity is ascribed to the solvent power and thus when more regular crystals will ppt. bioavailability and solubilization of the drug will increase. Best results were obtained when a mixt. of HCO2H-EtOH (2:1) soln. was used as the crystn. media yielding large tabular crystals. [on SciFinder(R)]