Analysis of soaps with hydrogen bromide in glacial acetic acid

Alkali metal carboxylic acid salts of long-chain fatty acids and of α-sulfo fatty acids are determined by titration with hydrogen bromide in glacial acetic acid medium. Crystal violet is used as indicator. A laboratory of the E. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

氯碱产品滴定分析误差的研究

对固体氢氧化钠和工业盐酸2种氯碱产品的滴定分析方法和过程进行初步的研究,探讨了分析结果的主要误差来源,并估算了误差的大小。     

Silicates in soaps

Journal of the American Oil Chemists' Society -     

Melting-point determination of fat products

A variety of methods exist for the determination of the melting point (mp) of fats. These include the Wiley mp (AOCS Method Cc 2–38), open capillary slip point, softening point and Mettler dropping point. The conditions under which the tests are performed influence the values obtained. Several of these methods were compared using a variety of fats, including margarine and soft margarine oils, lard, butter and hydrogenated Canola oils. The Mettler dropping-point values were found to coincide with the extrapolated solid fat curves obtained using wide-line NMR for all fats except butterfat. The reproducibilities of the Mettler dropping point and softening point were excellent; that of the slip point was poor. Presented at the 73rd AOCS annual meeting, Toronto, 1982.     

A distillation method for water in soaps

Conclusion The use of anhydrous barium chloride for an anti-foaming agent in the distillation method for determining the amount of water in soap, is superior to sodium acetate in respect to speed, ease of handling the test, and finally in respect to leaving more cleanable apparatus. It offers another advantage in that anhydrous BaCl₂ is more easily prepared than is anhydrous sodium acetate.     

Biomarkers for intake of dairy fat and dairy products

The aim of this study was to correlate the fatty acids characteristic of dairy fat (14:0, 14:1, 15:0, 17:0 and 17:1) in adipose tissue, serum lipid fractions and the estimated intake of dairy fat, and to investigate whether they can be used as biomarkers for dairy fat/product intake. The highest correlations were observed between 14:0 in adipose tissue and the estimated intakes of 14:0 (r = 0.60) and dairy fat (r = 0.50), and between 15:0 in adipose tissue and the estimated intakes of 15:0 (r = 0.55) and dairy fat (r = 0.55). Among the fatty acids in serum lipid fractions, 15:0 in cholesteryl esters (CE) and triacylglycerols showed the highest correlation to both 15:0 in adipose tissue, intakes of 15:0, dairy fat and dairy products. The results from our study suggest that the contents of fatty acids characteristic of dairy fat (14:0, 14:1, 15:0, 17:0, 17:1) in adipose tissue might be used as markers not only for the intake of dairy fat, but also of dairy products (times/day). When adipose tissue specimens are not available, 15:0 in serum CE appears to be the best marker for dairy fat intake. It was also observed that fatty acids from dairy fat are incorporated differently into serum lipid fractions and adipose tissue.     

Potassium silicates in soaps

Summary Properties of potassium silicates of interest in regard to their use as a detergent with soaps have been studied. A 40% potassium coconut oil soap can be mixed in all proportions with the comercial 3.3 ratio potassium silicate containing 39.6% solids. The pH's of the silicate solutions vary from 9.6 to 11 at concentrations of most practical interest. The 3.3 ratio silicate increases the pH of a potassium coconut oil soap solution. More suds form when the soap is dissolved in a 0.031% K₂O·3.3SiO₂ solution than in the same molality of a potassium carbonate solution or in pure water. Quantitative measurements of their suspending action on ilmenite shows that at their optimum concentrations both silicates are more effective than potassium carbonate and almost as good as soap. The maximum effect of soap occurs at a higher concentration than that for the silicates. A mixture of soap and K₂O·3.3SiO₂ prevents the deposition of ferric oxide pigment on cotton cloth about equally as well as soap alone; this mixture is more effective than soap alone for preventing the deposition of raw umber. Both silicates prevented the deposition of raw umber more effectively than soap alone or soap-alkali mixtures below 0.1% and are not much less effective above this concentration. Soil removal experiments with a cottonseed oil-Oil-dag soil showed that a mixture of K₂O·3.3SiO₂ and potassium coconut oil soap was about equally as efficient in distilled water and more efficient in 300 p.p.m. hard water than soap alone.     

Viscoelastic properties of plastic fat products

An instrument is described for the creep analysis of plastic fat products. The instrument records the deformation of a sample under constant force. Deformation is sensed by a displacement transducer. Instantaneous elasticity, retarded elasticity and plastic flow can be calculated. The extent of instantaneous elasticity of plastic fat products was found to be dependent on loading time. At longer loading times, the instantaneous elasticity as a percentage of total deformation decreased, with a corresponding increase in permanent deformation. The effects of temperature, magnitude of force and work softening were investigated. The results are discussed in relation to the nature of the crystal network structure in plastic fat products.     

自动电位滴定法测量牙齿美白产品中过氧化物含量

建立了电位滴定法自动测定牙齿美白产品中过氧化物的方法.该方法以铂金复合电极为指示电极,硫代硫酸钠为滴定剂,滴定曲线一级微商极值判定终点.该方法避免了传统手动滴定中颜色判定的人为误差,并且提高了测试结果的准确度.该方法操作简单,滴定终点清晰,准确可靠,重复性好,能满足日常检测的需求.     

Permeability of some fat products to moisture

Summary Films of cocoa butter, highly hydrogenated cottonseed oil, mixtures of highly hydrogenated cottonseed oil and cottonseed oil, chocolate liquor, and sweet milk chocolate were prepared; and their permeability to water vapor was determined by the cup method. The permeability constant was calculated in terms of grams of water diffusing through a centimeter cube in one second under a vapor pressure gradient of one millimeter of mercury across the cube. Under the test conditions employed, the permeability constant for cocoa butter at room temperature was found to vary from 5.8×10⁻¹² to 81.6×10⁻¹². The permeability constants for the highly hydrogenated cottonseed oil and the cocoa butter, under comparable conditions at room temperature, was found to be approximately 1.3×10⁻¹² and 33×10⁻¹², respectively. From data obtained with cocoa butter it was concluded that the permeability constant increased with moderate increases in film thickness. Polymorphism was found to have a large effect on permeability, an approximately 15-fold difference was found between quickly chilled and tempered films of cocoa butter at 3°C. (37.4°F.). The percentage of liquid component in the fat was found to have a large effect on permeability. The increasing of the percentage of liquid cottonseed oil in highly hydrogenated cottonseed oil from 0 to 40% increased the permeability constant from 1.3×10⁻¹² to about 420×10⁻¹². The permeability of chocolate liquor and sweet milk chocolate at room temperature was increased greatly when the relative humidity on the wet side of the films was increased to 100%. The nonfat components absorbed enough moisture to impair the structure of the film. Presented at the 32nd Fall Meeting of the American Oil Chemists' Society, Chicago, Ill., October 20–22, 1958. Fellow, National Confectioners' Association. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

A novel sample preparation for chloride analysis in bar soaps

A simple and rapid sample preparation technique is described for the potentiometric determination of chloride in bar soaps. Usual preparation of soap for potentiometric chloride analysis involves time-consuming dissolution of the sample in water or heating to affect dissolution, followed by a cooling step. Also, when performing potentiometric titrations for chloride under the usual acid conditions, aqueous solutions of soap bars (unlike combination soap/detergent bars) will form insoluble semisolid fatty acids that can occlude some chloride and make clean-up difficult. This paper describes a simple dissolution of bar soap sample in dilute H₂SO₄/methanol at ambient temperature that simultaneously acidifies the sample solution and produces noninterfering methyl esters from the soap fatty acids; water is then added, and the chloride is determined potentiometrically with standardized AgNO₃. This procedure has been shown to work well with automatic titrators.     

Kinetics of fat migration within chocolate products. Part III: fat bloom

Nougat filled milk chocolates were stored at different temperatures to registrate the changes of their qualities. As a consequence of fat migration, triglyceride composition, melting properties, and solid fat contents of coating and filling were changed. After long-term storage fat bloom was developed on the chocolate surfaces. In parts I and II of the publication the influences of storage temperature on kinetics of lipid migration have been reported. Now, part III demonstrates the influence of storage temperature on bloom formation. Fat bloom on filled chocolates is started by fat migration and influenced by the crystallization tendency within the chocolate coating. The results are useful to improve shelf-life of filled chocolates and chocolate-coated bakery.