Sucrose esters structure

Emulsifiers. The chemical structures of emulsifiers, or surfactants, enable these materials to reduce the surface tension at the interface of two immiscible surfaces, thus allowing the surfaces to mix and form an emulsion. An emulsifier consists of a polar group, which is attracted to aqueous substances, and a hydrocarbon chain, which is attracted to lipids. Emulsifiers include mono- and diglycerides, lecithin, propylene glycol esters, luctylated esters, sorbttan and sorbitol esters, polysorbate.x, and sucrose esters. 

T. Kawaguchi, T. Hamanaka, Y. Kito, and H. Machida, Structural studies of a homologous series of alkyl sucrose ester micelle by X-ray scattering,. / Phys. Chem., 95 (1991) 3837-3846. 

The use of surfactants in the food industry has been known for centuries. Naturally occurring surfactants such as lecithin from egg yolk or soybean and various proteins from milk are used for the preparation of many food products, such as mayonnaise, salad creams, dressing, and desserts. Polar lipids such as monoglycerides have been introduced as emulsifiers for food products. More recently, synthetic surfactants such as sorbitan esters (Spans) and their ethoxylates (Tweens), sucrose esters, have been used in food emulsions. It should be mentioned that the structures of many food emulsions is complex, and in... 

Thevenin, M. A., Grossiord, J. L., and Poelman, M. C. (1996), Sucrose esters cosurfactant microemulsion systems for transdermal delivery—assessment of bicontinuous structures,/. I. Pharm., 137(2), 177-186. 

Figure 8. Structure of the pure sucrose ester from tobacco TI 165. The C position has an acetate R=3-methylvalerate.

In the early researches on 0. europaea, [35], Panizzi demonstrated that oleuropeic acid 31, the 4-( 1. hydroxyisopropyl> 1 -cycloexene-1 -carboxylic acid, occurs in the root bark of (). europaea, mainly as a sucrose ester, i.e. the 6-O-oleuropeil saccharose 32 (see Figure 14). The structure of 31 was determined by comparison with an authentic sample [36-38]. The demonstration of the position of ester linkage in oleuropeil saccharose 32 was achieved with a combination of enzymatic and chemical reactions [39]. 

P-methylvaleric) during the smoking process, led many years later to a series of studies aimed at determining the structure of the sucrose esters in tobacco. Despite the numerous studies, seldom was the precise structure of a sucrose ester defined. The various studies included those of Rivers (3185) in the early 1980s and of Severson et al. (3606), Schlotzhauer et al. (3473), Wahlberg et al. (4102), and Danehower (896) in the mid- to late 1980s. 

M. A. Thevenin, J. L. Gros.siord. M. C. Poelman. Sucrose esters/cosurfaciant micro-emulsion systems for transdermal delivery assessment of bicontinuous structures, int. J. Pharm. 137 177-186, 1996. 

Figure 11 shows the g(r) for two emulsion samples. The emulsion samples had the same composition, except one had sucrose ester (0.1 wt%) as the watersoluble siufactant and the other had sucrose oleate (0.1 wt%). The fat content was 40 wt%, the protein (sodium caseinate) was 4 wt%, and the water content was 56 wt%. The RDF shows that the corresponding effective pair potential of interaction between fat particles is also oscillatory. The periodicity of the curve is nearly the size of the particles. The structure factor S((t) for these samples is shown in Fig. 12. The first peak height of the structure factor of the sucrose oleate sample is higher, indicating that the addition of sucrose oleate facilitates the fat-particle structure formation. Thus, the fat-particle structure in the sucrose oleate sample is much...

TI165 and TI 1396 produce duvane diterpenes and/or labdane diterpenes and/or sucrose esters (See Figures 1 and 2 for structures and References 5,7 and 8 for capillary gas chromatograms). The tobacco introductions with simple trichomes, TI 1112,1-35, and those with nonsecreting glandular trichomes, TI 1024 and TI 1406, produce low levels of diterpenes and sucrose esters. The cuticular extracts of all N, tabacum plants studied, independent of trichome type, contained a series of aliphatic hydrocarbons... 

In modifying sucrose for the preparation of sucrose esters, great attention must be focused on the structure, the conformation of sucrose in solution, the reaction conditions (solvent, electrophilic reagent, catalysis, temperature, etc.) and the purification procedures of the reaction product. 

Nearly always the sucrose esters, at D.E. s of 5 or better seem to have a unique behavior, even at comparable iodine values. It seemed that they peroxidiz-ed and gained weight with minimal decomposition, compared to most natural oils. Whether this was a condition entirely due to the greater purity of this ester compared to natural oils, or whether some features of structural chemistry were involved in it, must be left to future investigators. 

Table S.l Examples for the occurrence of sucrose esters in the Solanaceae and the basis for the structural diversity of such metabolites... 

Several surfactants have been synthesized starting from mono- or oligosaccharides by reaction with the multifunctional hydroxyl groups. The technical problem is one of joining a hydrophobic group to the multihydroxyl structure. Several surfactants have been made, e.g. esterification of sucrose with fatty acids or fatty glycerides to produce sucrose esters (1.11). 

The final part deals with applications in the food industry. Food colloids are complex multiphase systems that are mostly stabilized by naturally occurring surfactants such as lipids or proteins. Some synthetic surfactants such as sorbitan esters and their ethoxylates as well as sucrose esters are used in food emulsions. The particles or droplets in food colloids may remain as individual units suspended in the medium, but in most cases aggregation of these particles or droplets takes place forming three-dimensional structures, referred to as gels . These aggregation structures are determined by the interaction forces between the particles or droplets that are controlled by the relative magnitudes of attractive (van der Waals forces) and repulsive forces. The... 

The earlier of these studies concentrated on the behavior of water in a model sucrose ester-based water-in-oil (w/o) microemulsion [95]. The behavior of water in w/o microemulsions is of particular importance to the behavior of solutes in the aqueous compartments. The ratio of bulk to free water was examined in microemulsions of this type, comprising sucrose esters and butanol, with linear alkanes as the oil component. Subzero dilferential scanning calorimetry (DSC) was used to show that the hydroxyl groups of the surfactant are the principal determinant of the maximal level of bound or interfacial water and that it is essentially independent of the oil used. Butanol occupies the interface and thereby also influences the water binding capacity. Variation in the chain length of the surfactant induced substantial dilferences in the dilutability of the microemulsions with water, possibly indicating a change in the structure of the microemulsions. 

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